MUFF WIGGLER Forum Index
 FAQ & Terms of UseFAQ & Terms Of Use   Wiggler RadioMW Radio   Muff Wiggler TwitterTwitter   Support the site @ PatreonPatreon 
 SearchSearch   RegisterSign up   Log inLog in 
WIGGLING 'LITE' IN GUEST MODE

[BUILD] God's Box 'Humpback' - 8hp Eurorack Multimode VCF
MUFF WIGGLER Forum Index -> Music Tech DIY  
Author [BUILD] God's Box 'Humpback' - 8hp Eurorack Multimode VCF
Monobass
A full DIY kit for a 2-pole multimode filter reminiscent of the classic ‘SEM’ style state variable VCF.
Special features include a hot rodded resonance circuit and increased frequency range.

http://www.thonk.co.uk/shop/humpback/

BUILD DOC AND SCHEMATICS– http://thonk.co.uk/documents/gbox/humpback/





Monobass
...
talfred
Well, this sounds like a very good filter. Might just juild this one and sell my koma svf. Any more demos somewhere?
Monobass
More demos coming this week, it sound great but we've been totally focussing on getting the kits ready! More soon.
Monobass
Build document now online - http://thonk.co.uk/documents/gbox/humpback/

LowOver
that sounds good , always wanted a sem style filter in my rack....and diy , great...will order if the full turing machine kids are avaiable again applause
Monobass
Yep they will be this week Guinness ftw!
Monobass
I sold 50 kits and have an empty build thread, must be good news? smile
(touch wood)
Monobass
nice vid on the Humpback from DivKid

oberkorn
built it yesterday, sounds delightfully creamy good, even without calibration w00t

only issue, one of the IC sockets was bad, wouldn't allow one leg of the chip to go in,
only noticed this once it was soldered in, had to desolder it luckily without damaging the pads,
replaced it and one 220r resistor I damaged in the process with parts from the spares bin and everything was happy smile

you can get the most wonderful phaser-like effects by mixing the filter outputs, will try to do a demo over the weekend
Monobass
oh sorry about the socket! I think that's the first report I've ever had like that on an ic socket. Next time you place an order let me know and i'll replenish you smile

yeah I really like the phaser-like notch output, so much more interesting than a lot of notches out there I think!
Biotron345
How do I calibrate this little beast? It's peanut butter jelly time!
Monobass
One of the main goals of the Humpback was for a filter which required as little trimming as possible, to this end the tracking trimmer makes such a subtle change that we have actually considered removing it in the next revision.

Or the short answer is I haven't actually trimmed the last two I built and haven't found it necessary.
starmandeluxe
I just built this and its sound is amazing! I love it. Maybe best DIY I've done. The only questionable thing is when I turn the resonance almost all the way up, it starts doing some strange things such as the signal cuts out almost completely and goes all crackly, and turning it past that the resonance gets SUPER loud, so it's almost unusable at the extremes. I know there's a jumper that can change this behavior but I haven't tried it yet. I do like the heavily distorted sound but I wish the level was consistent instead of jumping into armageddon-mode hihi

Hear it in action here! (Sequenced by my Turing Machine with Expanders!)

[s]https://soundcloud.com/starmandeluxe/noisering-modulation-volca-sam ple[/s]
Monobass
Sounds great.

The module does allow you to keep increasing the resonance level until it vastly dwarfs the input signal and starts clipping the module internally, the answer is just backing off on the dial smile

But do you have the jumper on or off at the moment?
starmandeluxe
Monobass wrote:
Sounds great.

The module does allow you to keep increasing the resonance level until it vastly dwarfs the input signal and starts clipping the module internally, the answer is just backing off on the dial smile

But do you have the jumper on or off at the moment?


The jumper was on. I actually tried taking it off yesterday just to see what the alternative is like, and I decided to put it back on cool

Thanks for a wonderful filter!
megaohm
Schematic missing from build doc.
Is this posted anywhere?
mpTRONIX
Schematic = i Need too. seriously, i just don't get it hmmm..... help help help help help help help help help help help help help help help help help help help help help cry
thorncore
any plans for a PCB only option?
lowacid
megaohm wrote:
Schematic missing from build doc.
Is this posted anywhere?


i'd like it too. i find it a little too harsh with resonance (even with jumper off) on the second i have made.

i'd like to recalibrate it a little less "savage" héhé. At least in sem classic mode.
johyde
I've just finished this kit - enjoyable build!

I have unfortunately got some problems with it. The high pass and band pass outputs sound exactly as I'd expect, but the low pass and notch produce some strange results - the response as I sweep the cutoff knob is completely non-linear, with reasonably expected sound in places, no sound in some others, and distortion/clicks in others. This varies when I tweak the input and resonance, but always exhibits this behaviour.

The only mistake I made is that when I first tried it I took the patch cables going through another filter and just swapped them in on this one. Unfortunately I did them the wrong way round, so the output was connected to the input and vice versa. So I had a triangle-wave from a Make Noise DPO plugged into the LP out. I know this isn't a good idea, but I'm sure I will have made similar mistakes before and it's not caused me to blow anything. Can anyone tell me if this is a likely cause. Otherwise I'll just keep looking for any mistakes I might have made.

Love the filter anyway. the BP and HP sound lovely, and I actually got some quite nice stuff out of the funky LP, which sounds kinda cool even if not what I expected.

I have tried with the jumper on and off, and I've also fiddled with the trimpot , which didn't seem to make much difference. What does that do anyway?
LektroiD
thorncore wrote:
any plans for a PCB only option?


Or PCB/Panel. Seems a lot of extra money to spend on jellybean parts.
johyde
Hmm.. still having a few issues. I swapped out the TL072s as I had some knocking around, and that seems to have somehow sorted that intermittent problem. However, now I'm finding the resonance way too strong - this seems to strike a chord with what lowacid said. Even with the resonance knob turned right down, the lower half of a sweep sounds quite nice (though with definite pronounced resonance), but in the higher frequencies it goes completely into self oscillation. Removing the jumper seems to make a small amount of difference, but not much. Again, I'm getting some useable sounds out of it, but it would be more versatile if I could have a bit more control over that resonance..
seank
just finished mine and it's self oscillating even with the res turned all the way down and the jumper removed. i can barely hear the input passing through. any tips?
lowacid
seank wrote:
just finished mine and it's self oscillating even with the res turned all the way down and the jumper removed. i can barely hear the input passing through. any tips?


Could you make some pictures of your builds ? that would be helpfull to help
lowacid
johyde wrote:
Hmm.. still having a few issues. I swapped out the TL072s as I had some knocking around, and that seems to have somehow sorted that intermittent problem

thumbs up

About the jumper, it makes a noticeable difference for sure.
The tracking trimmer is more subtile though... but i find it usefull to get a perfect tracking.
johyde
lowacid wrote:

About the jumper, it makes a noticeable difference for sure.
The tracking trimmer is more subtile though... but i find it usefull to get a perfect tracking.


Yeah, the trimmer is I guess working perfectly in fact - it changes the pitch of the filter frequency across around and octave range (that's just a guess).

The jumper does make a bit of difference. Without the jumper is probably what I would have expected with it in place. With it is even more extreme!
Monobass
edit: sorry, responding to the wrong issue there
Monobass
johyde wrote:
I've just finished this kit - enjoyable build!

I have unfortunately got some problems with it. The high pass and band pass outputs sound exactly as I'd expect, but the low pass and notch produce some strange results - the response as I sweep the cutoff knob is completely non-linear, with reasonably expected sound in places, no sound in some others, and distortion/clicks in others. This varies when I tweak the input and resonance, but always exhibits this behaviour.


Hey Jo, a recording would help here so we can work out if it's simply the filters nature or if it's a problem with your module. These sorts of things are so subjective.
johyde
Monobass wrote:
Hey Jo, a recording would help here so we can work out if it's simply the filters nature or if it's a problem with your module. These sorts of things are so subjective.


Thanks Steve. I'm away for a few days but will post a recording when I'm back. It's certainly extremely different to what I hear in the demo video. It seems to be essentially doing what it should, except that the Resonance control goes from 'lots of resonance' to 'bonkers amounts of resonance' instead of from none or little to lots or bonkers, if that makes sense!
Monobass
Hi Jo, you can literally not have resonance even with the pot fully counter-clockwise? it sounds to me like you maybe swapped over some caps or resistors accidentally to me.
johyde
Yeah, that's right. I always have resonance, even with the resonance pot fully counter-clockwise (and even without the jumper). I was quite careful with the components I thought, and there were only a few cap values involved, but it does seem a bit like that - the module's basically working but the resonance seems in the wrong range. I definitely did check the pots themselves as an obvious error, and they were correct. I'll check through the rest later this week when I get home. Thanks!
Monobass
Could be a short or a bad connection between the boards too.
I had a problem one time where I'd lazily not screwed the boards together and the resonance locked on full due to an intermittent connection between the boards.
johyde
Ah yes, that could be possible. To be honest, whilst I did screw the boards together to start with, whilst I've been tinkering with it I haven't had them screwed together either.
seank
does it matter if you have the male/female pin headers swapped? like male on board a and female on board b instead of the other way around. they line up just fine but i'm still having the same problem with the resonance. it's full self oscillating all the time.
Monobass
Hi Sean, no it makes no difference.. you may want to do a continuity check with your multimeter on each connection though to make sure you have a good solid mating. Will need to see photos of your build to progress further now I think.
johyde
Well I'm pretty sure I've found my problem, anyway Dead Banana

Basically, where there's a 10 pf capacitor that isn't used (very clearly stated in the instructions...). It's next to a 10 nf capacitor, and I soldered the 10nf capacitor into the 10pf position (leaving the 10nf position empty). Doh!

Unfortunately I couldn't get the little cap out without breaking it, so I'm just awaiting a new one. But it seems pretty clear that was the issue!

It seems a quite obvious mistake (he says, somewhat defensively..), so I wonder if anyone else with OTT resonance did the same thing?
Monobass
seank did exactly this.. although replacing the 10nf didn't solve the issue.. curious.

s
seank
gonna post a couple photos of my pcb's today and you guys can all yell at me for making an obvious, dumb mistake. deal?
Monobass
it's safe! The Agonizer!
johyde
Didn't get a chance to do it before.. but correcting the error with the 10pf / 10 nf capacitors did work for me - yay! All good now, and loving the filter!
Monobass
Ah great news smile
RecycleYourPets
anyone know the power consumption for this?
stikygum
Wow, this filter sounds great. Will have to order this if I get ambitious enough to build it.
Biotron345
Built this a few weeks ago. Loving that notch filter! Guinness ftw!
atte
RecycleYourPets wrote:
anyone know the power consumption for this?


Anyone?
RecycleYourPets
atte wrote:
RecycleYourPets wrote:
anyone know the power consumption for this?


Anyone?


I got in touch with Thonk and they are looking into getting the info. God's Box is on vacation so they said it might take a minute to get in touch with them
Emalot
Hi, i'm just discovering this project, but it's only full kit?
It's not possible to buy PCB?
bloke_zero
Will it work in a 15V system?

Thanks!
wavefold
Just finished my build and, damn, this filter sounds good! Very neat kit, simple build, epic price and sound!
As I turn fully CW the resonance pot it behaves strangely: the self oscillation gets very slow at some point towards the end of the turn, is that normal?
Monobass
Is that with the jumper on or off?
wavefold
Monobass wrote:
Is that with the jumper on or off?

With rhe jumper on it's way more accentuated and starts earlier
Monobass
ok it might be good to post photos of your build then, that would suggest perhaps that you've got some resistor or cap values swapped.. or perhaps the pot values swapped?
wavefold
Monobass wrote:
ok it might be good to post photos of your build then, that would suggest perhaps that you've got some resistor or cap values swapped.. or perhaps the pot values swapped?



here they are




Monobass
will have a look in the morning, how about the pots?
wavefold
Monobass wrote:
will have a look in the morning, how about the pots?


checked and they're alright
wavefold
Monobass wrote:
ok it might be good to post photos of your build then, that would suggest perhaps that you've got some resistor or cap values swapped.. or perhaps the pot values swapped?


tested again today w/o jumper and it seems to work fine now hmmm.....
j_p_higgins
Built this today, lovely filter. With the jumper on the back the upper resonance just goes absolutely mental, its great.
drip.feed
I had a couple of oddities building this bad boy (though it's all good now).

1. Solder seemed really reluctant to stick to pads or 'wet' through the double-sided PCB to the other side. I really had to fight to get the power header installed. I've never had that with any other PCB that I can remember. It didn't make much difference if I cleaned it beforehand with IPA. Weird, but I got there in the end. It just took forever.

2. Grounding. I always test modules with an external bench power supply and hook them up to my main modular to get CV and audio etc. But with Mr Humpback I couldn't get rid of a distinct mains hum and some head-scratching behaviour with the resonance. I had the bright idea that I should test it in-situ in my rack instead of on the bench because my rack and bench PSUs don't share a common ground. Hey presto all the weirdness went away, no more hum and the filter works perfectly in my rack. So, just in case anyone else is pulling their hair out, try testing it in your modular.
gdm
I just built the Humpback with a lot of fun (was my first DIY module), BUT, I also have this issue with the nonlinear behavior of the filter... Any findings about this issue? (I just checked and the 10pf is in its right place...)
gdm
Here are the pictures of the PCBs, hopefully it helps...


[/img]
stikygum
Anyone have any more audio clips of this? Anyone looking to sell one? Mr. Green
Staticcharge
I bought the kit the other day and have had nothing but problems with it. I've built lots of kits before from Turing machines mk1 mk2, rampage, peg and RYO kits. This kit came with only one tl072 which I put on the filter board. With changes happening from time to time I thought nothing of it.
Plugged it in and powered it up. I've got nothing from it, with a square wave in the input I only get a tone out of the HP socket, with the input knob have a volume effect. Nothing else works.
Contacted thonk regarding ICs, replacement TLs in post....what about the CA3080 ICs could these be damaged?
......help.
Monobass
Hi staticcharge

Yeah sorry for sending you TL071s instead of 72s, our mistake. You won't have damaged anything as the +v rail on the TL072 would lead to an unused pin on the TL071, the -v rail is the same on both.

If the rest of the build is ok it'll just work when you pop the new chips in

Steve
Staticcharge
Arrived today, very prompt.
Popped them in and I'm getting more than I had. Freq has nothing after the 12 o'clock position and with res at Max I get a clicking...any ideas?
Just gone thought the both boards with a magnifying glass looking for shorts and have found non, components all correct including the 1nf, made that mistake initially.
Staticcharge
Once I replaced the CA ICs that were damaged by being supplied with the wrong TLs the module came alive.
Getting some cool sounds from it now.
Hezza11
Does anyone know how this compares to Doepfers A-106-5 SEM 12db module?

Are they similar enough to not bother having both? Just looking for some DIY VCF's and this looks interesting, though I already have the Doepfer...
Outtatune
Hezza11 wrote:
Does anyone know how this compares to Doepfers A-106-5 SEM 12db module?

Are they similar enough to not bother having both? Just looking for some DIY VCF's and this looks interesting, though I already have the Doepfer...


I have both. I built the Humpback first, and purchased the A-106-5 later. They are very similar, but if I was forced to keep only one I'd keep the Humpback. It seems to have a slightly richer sound to me.
Hezza11
Outtatune wrote:

I have both. I built the Humpback first, and purchased the A-106-5 later. They are very similar, but if I was forced to keep only one I'd keep the Humpback. It seems to have a slightly richer sound to me.


Thanks Outtatune, I'll probably hold off on it for now and look for something further from what I've already got. Think I was getting carried away with the name and panel art smile
MAXTHEDOG
Hi Monobass,

I've just bought and finished putting together your Humpback filter, and it sounds great except for the BP output. There's virtually none. Because it's all working except for this I've not dismantled it to do any checks. Have you any ideas of where I should start? I'm pretty much happy with it without the BP so it's no great deal, but it'd be nice to get my first kit 100%

Regards,
MTD
MAXTHEDOG
Hi again,

Just had it apart after all, did some tests with the multimeter - continuity, visual etc. Put it back together and all is now fine.

Fantastic filter, capable of ripping ones head clean off!
AndrewM
My kit (via Thonk) arrived earlier this week and I was excited to have time to build it this weekend.

The build went smoothly - took me just shy of 2 hours from sitting down and opening up the build docs to having it installed in the rack and doing some listening tests. Great documentation, nicely packaged so everything was easy to find.

First impressions (I didn't bother tuning it, and left the jumper on): somewhere around 3:30 / 4:00 on the Resonance pot is where the oscillation goes crazy, which is about the same point as my Frequency Central Vogue VCLPF. It'll be easier to remember that way. Seems like most of my sonic range is covered by half of the range of the Cutoff pot.

A few notes about the build process:

  • nice, generously-sized solder pads on the PCB made it easy to work with
  • build docs v0.9; page 6, item 15: mentions "7x 47R resistor", but there's only 1 included. Thankfully there weren't markings on the PCB for the other 6 ;-)
  • the 10nF caps shipped with the kit had 5mm lead spacing instead of 2.5mm, which required some leg-straightening in order to get them to fit
  • page 9, step 25: mentions "The cap is marked 334, NOT the brighter red 'MKS 4' part. Well, there's only one 0.33uF cap in there, and it's also a WIMA MKS 4, and it's marked 0.33.
  • Thanks for including matched transistors! I had to match my own for my TH 555 VCO, and while it worked out great, it was somewhat time-consuming. Very nice to have those included.
  • Also good to see some good quality Nichicon and WIMA caps in there as well.


All told, very happy with the quality of the filter, and the ease of construction.

The BP output volume definitely sounds quieter than the other outputs, but I'm guessing that's just due to the narrow band of frequencies that it's passing.
Daisuk
I finished building this from kit today, everything went smoothly really, except for soldering the power header. Solder didn't flow so well around the pads, so I ended up soldering a few pins together. Took me quite a bit to de-solder them. It looks allright now, none of the pins are flowing together, but there is some slight debris around each pin, and very hard to tell if anything is touching between the pins.

Should I clean it with some alcohol (what type is recommended?) perhaps? I'm just assuming that it will short if two of the pins connect, but not sure if that is the case, so any light shedding on this would be ace. Don't want to plug in the module just yet, in case I short it. hmmm.....
Hezza11
You can clean it with isopropyl alcohol and a stiff brush. Depending on what flux your solder has in it, it might come off easily enough. There's various youtube videos of people showing different techniques.

If you have a multimeter (and if you plan to build modules you really should get one!) then do a continuity test between the +12v, -12v and GND pins. You should do that before connecting any DIY modules to your system really.

Good luck!
Daisuk
Hezza11 wrote:
You can clean it with isopropyl alcohol and a stiff brush. Depending on what flux your solder has in it, it might come off easily enough. There's various youtube videos of people showing different techniques.

If you have a multimeter (and if you plan to build modules you really should get one!) then do a continuity test between the +12v, -12v and GND pins. You should do that before connecting any DIY modules to your system really.

Good luck!


Thanks a lot! I got a multimeter last week to calibrate another module, so now to look into how to do continuity. Many thanks for the tips. smile
Hezza11
Daisuk wrote:

Thanks a lot! I got a multimeter last week to calibrate another module, so now to look into how to do continuity. Many thanks for the tips. smile


Most multimeters have a mode where if you touch the two probes it will bleep showing you there's a short.

So you want to touch one probe to the +12v pins, then with the other work your way around the 6 middle pins which are GND, and then over onto the -12v pins on the other side, there should be no beeps. Then check there's no beeps between the -12v and the GND pins, and you should be good to go.

There could be other issues which could cause a short when powered up, but the above is a good basic check to do before plugging in any DIY module.
MAXTHEDOG
+1 to what Hezza said.
I do that as a matter of course, then check the actual resistance between all the power pins, because there's a resistance level above which the meter won't beep but could still cause problems. Any thing in the Megohms and you're good to go.
BTW keep plugging away, the filter is worth it. I've just been doing battle with a Shakmat Modular Knights Gallop that only one of two channels working. After several sessions with DMMset to 'beep' I found two dodgy solders on the op and chip. Redid them and now it's doing its thing. So it's worth the time. You also get to learn something about the circuits for the future.
Regards,
MTD.
Hezza11
MAXTHEDOG wrote:
then check the actual resistance between all the power pins, because there's a resistance level above which the meter won't beep but could still cause problems. Any thing in the Megohms and you're good to go.
MTD.


Cheers, didn't know that but makes complete sense.

Still fairly new to all of this myself and only found out about the continuity testing after a brown pants moments connecting up a diy Befaco Rampage, blew my powersupplies internal fuse. Before that never had any issues and think I was pretty lucky to not have damaged some modules. Now really careful before connecting stuff up and check everything I can It's peanut butter jelly time!
MAXTHEDOG
Hi Hezza,
Actually it should beep very briefly but you might miss it especially if you're not looking at the display that instant you touch the probes. It's always better to know there's a high resistance between thes pins.
Regards,
MTD.
Daisuk
Hezza11 wrote:
Daisuk wrote:

Thanks a lot! I got a multimeter last week to calibrate another module, so now to look into how to do continuity. Many thanks for the tips. smile


Most multimeters have a mode where if you touch the two probes it will bleep showing you there's a short.

So you want to touch one probe to the +12v pins, then with the other work your way around the 6 middle pins which are GND, and then over onto the -12v pins on the other side, there should be no beeps. Then check there's no beeps between the -12v and the GND pins, and you should be good to go.

There could be other issues which could cause a short when powered up, but the above is a good basic check to do before plugging in any DIY module.


Thanks for this! So, touching the pins where they stand up, where you connect the power cable, yeah? Not where you've soldered? Does it matter which of the probes are connected where?

Thanks, MTD! I'll try that out as well, see if I can hook up my Multimeter like that. I've only used it to measure volts so far, so not sure which settings to use, but that should be clear enough by reading the manual. I'll try it out tonight.

Thanks a lot for chipping in. smile
AgentOrange
Hi,
No it doesn't matter which way round the leads go.

AO.
Daisuk
AgentOrange wrote:
Hi,
No it doesn't matter which way round the leads go.

AO.


Thanks. smile Just to be sure, if I have one lead on one +12 pin and put the other on a +12 pin, it's normal that it beeps, right? Same thing happens with -12 pins. I'm pretty sure it's supposed to behave like that, but just asking in case. smile
Hezza11
Daisuk wrote:


Thanks. smile Just to be sure, if I have one lead on one +12 pin and put the other on a +12 pin, it's normal that it beeps, right? Same thing happens with -12 pins. I'm pretty sure it's supposed to behave like that, but just asking in case. smile


Yep, you are essentially just touching the two probes together if they're both on the +12v rail. Doing this you can trace round a circuit and figure out where you have a short, or where you don't have connection when you should.
Daisuk
Hezza11 wrote:
Daisuk wrote:


Thanks. smile Just to be sure, if I have one lead on one +12 pin and put the other on a +12 pin, it's normal that it beeps, right? Same thing happens with -12 pins. I'm pretty sure it's supposed to behave like that, but just asking in case. smile


Yep, you are essentially just touching the two probes together if they're both on the +12v rail. Doing this you can trace round a circuit and figure out where you have a short, or where you don't have connection when you should.


Thanks! smile Finally plugged it in now, and it seems to be working nicely! Love the sound of it. applause
Hezza11
Daisuk wrote:

Thanks! smile Finally plugged it in now, and it seems to be working nicely! Love the sound of it. applause


Glad it worked out! I'm still tempted by the Humpback but have a Serge VCFQ to build first.
Daisuk
Hezza11 wrote:
Daisuk wrote:

Thanks! smile Finally plugged it in now, and it seems to be working nicely! Love the sound of it. applause


Glad it worked out! I'm still tempted by the Humpback but have a Serge VCFQ to build first.


On my list too! smile The Humpback is fantastic, sounds just gorgeous. Really my type of filter. I'd go as far as saying it's probably the sweetest creamiest sort of filter I've ever heard. Looove it. Will need a second. Mr. Green w00t applause
Negorod
Hi.
I whant to order God’s Box ‘Humpback’ Filter but it's Insufficient stock in thonk.co.uk. When it backs to stock? Or may be I could order it in another shop?
templar
I'm pretty sure Thonk is the only place that sells it

add your name to the waitlist - it should come back in stock at some point
atte
There's no waiting list Dead Banana
echox
Since I'm also waiting for several months I also wonder if it will be back in stock or if there are no planed reruns waah waah waah
Also missing the "join waitlist" button smile
JAO
echox wrote:
Since I'm also waiting for several months I also wonder if it will be back in stock or if there are no planed reruns waah waah waah
Also missing the "join waitlist" button smile


Since these shift faster than hot pies, I would presume the order for parts is being filled as we type. No rare stuff either, that I am aware of. Hang in there!

Edit: Just received a 1 month estimate for refill.
Sammus
JAO wrote:
echox wrote:
Since I'm also waiting for several months I also wonder if it will be back in stock or if there are no planed reruns waah waah waah
Also missing the "join waitlist" button smile


Since these shift faster than hot pies, I would presume the order for parts is being filled as we type. No rare stuff either, that I am aware of. Hang in there!

Edit: Just received a 1 month estimate for refill.


Fingers crossed for this to be true smile Been hanging out for one of these for a while, waiting for that notification email from Thonk!
Monobass
Sorry they'll be a couple of weeks longer, one part has been really slow to source this time.
FrJK
Hi DIY wigglers, I built one yesterday and sadly it is not working properly.
LP and BP no any output, HP and N have output (just the clean signal), but only the input pot does work. Cut off and resonance just nothing...so no any filter function...

Anywhere to find a schematic? Or anyone have an idea where I can look for the problem?
I replaced all ICs, checked again solder joints and for shorts...

Any help is much welcome.. Thanks, Frank.
Monobass
Hi Frank,

problems like that can sometimes be due to a poor connection between front and back board

schematics here - https://thonk.co.uk/documents/gbox/humpback/
diode_destroyer
Are more kits coming into Thonk in the future? Only found these now and I want one!
Monobass
Yeah well have more soon, an annoying delay one one part.
FrJK
Monobass wrote:
Hi Frank,

problems like that can sometimes be due to a poor connection between front and back board

schematics here - https://thonk.co.uk/documents/gbox/humpback/


Thanks again Steve, but still no success..
I checked the board connections (4 and 10 pin) by multimeter, also checked the 4 transistors, again checked solder joints by microscope ... nothing.

Then I build up the 2nd kit I got and the bad news is it behaves absolutely same as the first one ...

Any more ideas how I can find out what is wrong here?

Thanks,
Frank.
DenisOvan
Hey Frank, Post up some hi res pictures of your build, both sides of the boards. It's the best way to help Wigglers help you get to the bottom of your probs
FrJK
DenisOvan wrote:
Hey Frank, Post up some hi res pictures of your build, both sides of the boards. It's the best way to help Wigglers help you get to the bottom of your probs

Hi Denis, thanks for helping. Here are the pictures:


FrJK
[quote="FrJK"]
DenisOvan wrote:
Hey Frank, Post up some hi res pictures of your build, both sides of the boards. It's the best way to help Wigglers help you get to the bottom of your probs

Hi Denis, thanks for helping. Here are the pictures:


... based on my very low knowledge, I now think it is the 100R trimmer that is missing..

The build manual does mention it, but it was not in the kit, in this thread here I read that it was supposed to be removed, plus I do not find the trimmer in the schematic .... However, I will try with a trimmer ...
ethnotronics
diode_destroyer wrote:
Are more kits coming into Thonk in the future? Only found these now and I want one!

Me too!
FrJK
[quote="FrJK"]
FrJK wrote:
DenisOvan wrote:
Hey Frank, Post up some hi res pictures of your build, both sides of the boards. It's the best way to help Wigglers help you get to the bottom of your probs

Hi Denis, thanks for helping. Here are the pictures:


... based on my very low knowledge, I now think it is the 100R trimmer that is missing..

The build manual does mention it, but it was not in the kit, in this thread here I read that it was supposed to be removed, plus I do not find the trimmer in the schematic .... However, I will try with a trimmer ...


Fixed!
Luckily had 2 100R trimmers on hand at work, dropped them in and now they do.
Staticcharge
I'm looking to build another one of these with the PCB panel but there doesn't seem to be a BOP and there is no info on the C1 & C2 blue 220pF caps. Anyone have any idea what type they are or if a standard disc type will be ok. I've had a look on the schematic and both just go to ground but other than the value there's no more info on there either. I'm assuming it's a polyester film type?
templar
220pf caps should be either Silver Mica or polystyrene
strewya
Hi peeps,

I'd love to build this filter but at the moment there are no full kits at thonk.

I don't mind sourcing part but can't see BOM anywhere ? Could anyone point me in the right direction please.

Many thanks cool
Staticcharge
strewya wrote:
Hi peeps,

I'd love to build this filter but at the moment there are no full kits at thonk.

I don't mind sourcing part but can't see BOM anywhere ? Could anyone point me in the right direction please.

Many thanks cool

Steve has put the BOM with the other documents.
I've got everything else but the 220pF silver mica caps are hard to find and there still isn't a voltage rating.
Anyone have any ideas where I can get them in the UK?
Staticcharge
templar wrote:
220pf caps should be either Silver Mica or polystyrene


Will these be ok?
Axial Polystyrene HSQ220PF2160V 220PF 160V 2%.
Also can I use polybox caps for 0.15uf and 0.33uf?
templar
Those styrene caps should be fine

Looks like those other values are specified as polybox anyway
Staticcharge
templar wrote:
Those styrene caps should be fine

Looks like those other values are specified as polybox anyway


Thanks for your help.
Staticcharge
Those caps worked fine Templar. Bought some naff CA3080 ICs though so waiting for replacements. Tested against the Ti ICs I've got in my other Humpback I've got no cutoff after say 1/4 turn.
My plan is to build a twin Humpback based on the BF-22 but looking like this:


Saint and sinner switches ar for the hotrod res jumper on the back of each module. Link is output of left to input of right and the knob below is for link type ie LP.BP.HP.N but I've got to get the indicator to line up with the letters before deciding where they need to go. Work in progress
Ms304671
Hi all,

Struggling to find CA3080e ICs here in the UK and im reluctant to purchase on ebay for fear of fakes. Can anyone reccomend a good place to purchase or perhaps have any they would be willing to sell?

Thanks in advance!

help
templar
edit: see below
MAXTHEDOG
Hi,
Try Cricklewood Electronics -£4.50+VAT.

Regards,
MtD.
Ms304671
MAXTHEDOG wrote:
Hi,
Try Cricklewood Electronics -£4.50+VAT.

Regards,
MtD.


Thanks mate thumbs up
MAXTHEDOG
No probs.
I did the Humpback from the full kit. Nice easy build and sounds great. Goes manic with the jumper switched over.....
MTD.
Staticcharge
I've ordered 10 Harris ca3080 Ics. Although from ebay, if they are fake your covered by using PayPal. Though the LM13700 is a dual 3080 but you'll have to build an interface for the larger IC. Worth looking into, word on the street is the 3080 die was lost in a fire at Ti, not sure how true that is.
hirada
Hello,

a question about the BOM. Except the panasonic ECQ-V1J334JM, which seems to be available only in the US and only if you buy for more than $200, I have most stuff together. Kits haven't been available, so I went just for PCB and panel.

Any recommendation for an alternative to the panasonic? Are those somewhat relevant as the mica silvers are supposed to be?

Another uncertainty is the shunt. What are you taking for this one? Usually I know a shunt as a precision very low resistance device, but of course I have no data about this one.

Finally the Hex Spacer, how long are those supposed to be?

Thanks for any help. Still new to DIY.
MAXTHEDOG
Hi Hirada,

Don't know where you are but try these-

Capacitor:
http://uk.farnell.com/w/c/passive-components/capacitors/film-capacitor s/general-purpose-dc-film-capacitors?capacitance=0.33uf&voltage-rating -v-dc=63v&capacitance-tolerance=posneg-5pc
Farnells have the Panasonic one but say it's no longer manufactured.

Shunt/Jumper:
http://uk.farnell.com/w/c/connectors/connector-tools-accessories/jumpe rs-shunts/prl/results?st=Jumpers

I did mine from the full kit so never saw a BOM. IIRC the hex spacers are the same height as the PCB connectors so I would guess about 12.7mm.
Get the PCB's and fit the board connectors temporarily together you'll soon see how long the hex spacers need to be.

Hope this helps,
MtD.
infovore
Just a quick note for those of you building your own from PCB/panel - it's been designed around 5mmx7mm aluminium caps; if your caps that you've got kicking around your parts box are taller than 7mm, you will have problems a) sandwiching the two boards and b) getting the panel on. You need stumpy caps.

This advice brought to you by: me, who discovered this the hard way. The BOM has the details.
hirada
Thanks for your help, MTD and sorry for the late reply, been completely away from anything modular. Also thanks for the heads up with the alu caps.


So far I've found the Panasoncic ECQ-E2334JF as replacement, they are slighty thicker, about 1mm, but should fit according to the doc, and for the shunt I've should have read the build doc more thoroughly, it's just an ordinary jumper.

The panasonics are General Film Capacitors as opposed to Stacked Film Capacitors from the original choice, whatever that may mean. Not sure wehter they actually are sound relevant.

Kemet hast stacked film capacitors, but only in 5mm spacing, not 7.5.


However, is it possible the something completely unimportant as the ssm2220 IC is missing in the BOM? Will be the next adventure organizing this. Anyone by chance ordered from goodtronic in china maybe?
butter
Another pcb/panel build here, have managed to find pretty much everything I need, but would appreciate if someone could help out with the last two bits... Feel a bit silly asking, but this is my first move beyond full kits, still feeling my my around what is likely obvious!

- what is the size/height of the hex spacer? My mated headers seem to be about 11mm, not sure if that means standard spacers are 10,11 or 12mm? (or in light of the "less than 7mm height caps" post, any merit in going a bit bigger here?) I'll likely be getting a few extra, but suspect I've already picked up enough "stock" of parts that are just out of normal range haha.

- the 10uF caps I have seem unlikely to fit - could anyone point me in the direction of the "stumpy" caps? Keep feeling I'm ending up finding the wrong "family" when I search based on size...

Thanks!
echox
infovore wrote:
Just a quick note for those of you building your own from PCB/panel - it's been designed around 5mmx7mm aluminium caps; if your caps that you've got kicking around your parts box are taller than 7mm, you will have problems a) sandwiching the two boards and b) getting the panel on. You need stumpy caps.

This advice brought to you by: me, who discovered this the hard way. The BOM has the details.

Yep...

I managed to work around this by bending them 90 degrees. So they lay flat on the board which works for the most places ;-)
echox
Since the kit is unavailable for a long time I bought the Panel + PCB option.

The filter is fully populated but I can't get it to work... confused

Error description:
BP: I have to match exactly the signal with the cutoff, otherwise nothing can be heard.
LP: nothing

Input amplification seems to work and resonance seems to work if I match exactly the frequency.

Other things: There is exactly one sweet spot where the filter 'self-oscillates' but sounds like a square wave.

Things I checked:
Measured the resistors twice.
Double checked the solder joints and reheated most of them (just to be sure).
Sandwich board connection (measured the individual connection pins from both sides)
Orientation of the components (caps, ICs)
Any shorts...

Here is a picture of the components:

Btw.: The bended caps look a little bit strange but I tripple checked if there are any shorts or something like this, so they should be fine.

Any help is appreciated.

diode_destroyer
I just wanted to report that I did the pcb+panel from Thonk, and first built it up with wima caps for the 220pf ones, then just recently changed out the 220pf caps for Silver Micas, and honestly can't tell a difference in sound...sounds the same to me.
diode_destroyer
Also, looks like the full kits are back in stock at Thonk now...
JAO
diode_destroyer wrote:
Also, looks like the full kits are back in stock at Thonk now...


Indeed. CA3080AE back in production, also being sold by thonk separately.
AntonWoldhek
So i ordered the pcb/panel option and the rare part (the CA3060 and the silver mica caps). Unfortunatly the pcb/panel option didnt link up to the matched transistor's which are also required.

If i didnt use matched 2N3906's, what problems would i likely get?
keninverse
It looks like these are just used in the control input so it just won't track 1v/oct very well. Just buy a tape of transistors and you will probably be ok if the transistors are next to each other on the tape. Or you can use a fritz transistor matcher and match them yourself or you can pick up a ssm2220
AntonWoldhek
Thanks Ken!

Anybody got a suggestion for equivalent of the 2N3819? I normally buy from TME.eu or Tayda but it seems only mouser has this mosfet.
https://nl.mouser.com/productdetail/central-semiconductor/2n3819?qs=sG AEpiMZZMvDjfggS9kWsemihYCU8ViWI4XW6jNH1TQ%3D
JAO
AntonWoldhek wrote:
Anybody got a suggestion for equivalent of the 2N3819?


That one is conveniently available on ebay.
Or see here for suitable replacements.
AntonWoldhek
Thanks JAO!
mantid
Hi,

I built this today and so far so good.

Would anyone be able to clarify: CV1 and CV2 are multiple inputs (each with their own attenuators) to adjust the same thing (cutoff)?

I would love a "user manual" if there is one. I watched the divkid video and the module is largely self-explanatory, but if there is a doc I am overlooking, would love to know about it.

Thanks!
AntonWoldhek
Dont have it at hand but i was under the impression CV2 was for Resonance.

[edit] looking at the schematic I think you are correct.
Ms304671
Hi all,

Firstly my apologies for the incoming noob question.

The buid doc asks for 1 x 1nF 102k and 12 x 10nF 103. I know these have 10% tolerances. My question is can i substitute these for the capacitors i have available in my parts box which are 102J & 103J (5%)?

I think/ hope the answer is yes, would save me another mouser order, just looking for some clarification from a more experienced builder.

Thanks in advance!

help
autodafe
I built one from PCB+Panel

I ended up creating a short between -12 and GND on the power header pins...

I think I shorted for just a couple of seconds, nothing was powering uo so I quickly turned it off...

The filter now does nothing. Only some cracking noise when resonance is full open.

Could the 2 second short have fired the ICs? or other components I will need to replace?

Also, is the value of the trimmer really important? I had another trimmer lying around and I used this...
zorglub76
Anyone knows what are RX1, RX2, second RX2, RX3 and second RX3? These are empty pads (test points?) on the board.

I've built my second Humpback. The first one works great, but I'm having problems with the second one and don't really know how to debug it.

At RX1 I measure -11.34V on both modules
At RX2 (close to RX1) I measure -0.062V on good, and +4.865 on bad one
At second RX2 and RX3 that are close one to the other, I measure 0V on both modules
At the second RX3 (at the bottom of the board) I measure 0.266V on the good and 10.79V on the bad one.

I've turned all the pots on the module to 0 (counter clockwise) and disconnected all patch cables when measuring the voltages.
JAO
A question about the old panasonic 0.33uF lacquer coated metal film capacitor.

Can this be substituted with the potted box type?

I've done mods before where the old style were integral to the sound, but I'm finding them difficult to source.
infovore
mantid wrote:
Hi,

I built this today and so far so good.

Would anyone be able to clarify: CV1 and CV2 are multiple inputs (each with their own attenuators) to adjust the same thing (cutoff)?

I would love a "user manual" if there is one. I watched the divkid video and the module is largely self-explanatory, but if there is a doc I am overlooking, would love to know about it.

Thanks!


Correct. CV1 and CV2 are two attenuated CV inputs for cutoff (there's no CV for resonance). If you put the attenuator full to the right, the CV signal will be applied in full, and added to the position of the main cutoff knob. It allows you to mix two different CV signals at different quantities.

I'm not quite sure what else you'd need a manual for. Input goes into input, level is attenuated by the INPUT knob before it hits the filter; CV1+CV2 have attenuators and add to the CUTOFF knob; RESONANCE is RESONANCE. All four outputs along the bottom operate simultaneously: Lowpass, Hipass, Bandpass, Notch. There's a jumper on the back to determine how much the resonance scale goes up to; it's possibly to put some seriously heavy distortion on in the higher setting.

And... that is it. It's a filter. It's a fun one.
mantid
I just like more info than less. I've figured out all the apparent function via trial and error at this point and do love this filter. The two CV inputs for Cutoff is a fun approach, although I wouldn't have minded one for resonance.
JAO
JAO wrote:
A question about the old panasonic 0.33uF lacquer coated metal film capacitor.

Can this be substituted with the potted box type?

I've done mods before where the old style were integral to the sound, but I'm finding them difficult to source.


Does anyone use generic green in place of old red panasonic?
infovore
mantid wrote:
I just like more info than less. I've figured out all the apparent function via trial and error at this point and do love this filter. The two CV inputs for Cutoff is a fun approach, although I wouldn't have minded one for resonance.


One for resonance is more complex - or rather, it requires adding a VCA to the circuit, not just wiring a jack and a pot together. The resonance pot is basically just an attenuator how much feedback gets fed back into the filter. So to control that with voltage you need a VCA.

(This is one of the things in the circuit design of MI Ripples - the VCA chip ends up serving two purposes - one VCA is used to allow for CV control of Resonance, and the other becomes the output-VCA on the LP4>VCA output, controlled by GAIN. I always wonder which need for the VCA came first).
ScientificDreamz
Would this be suitable as a first build? smile
Catflap
ScientificDreamz wrote:
Would this be suitable as a first build? smile


Yes, It was my first build. Nothing in the build that is overly complicated. Just take your time and try not to rush when the finish line is in sight.
magnesi
Hi, I'm getting a lot of hiss from my Humpback especially in low pass mode. Is this normal or does anyone think I need to replace something?

I love the sound of the filter otherwise.

Solved: So...I'm new to this whole modular stuff and was using the filter at the end of my chain (after microbrute or Monologue). This I realise now is recipe for noise especially on vintage design filters.

Since then I've built my rack uo to a full basic modular synth i.e. Oscillators, filter, LFO, EG and VCA. The noise has completely disappeared now. One good reason I guess to have the VCA at the end of the chain?

Yep!... I'm still learning
mantid
Thanks for the follow-up!

I'm still really loving this filter - and such a fun, simple build.
danfastlikeflan
Anyone know what the trim pot does? I haven’t seen any word on what it does
Thanks
magnesi
danfastlikeflan wrote:
Anyone know what the trim pot does? I haven’t seen any word on what it does
Thanks


I'd like to know the answer too. I can't seem to hear it making any difference on my one.
Monobass
Basically the trimmer adds a very small offset to the centre frequency, in reality it probably should have been designed out of the final board as it's not very useful, it turned out the tolerances of the final BOM kind of made it not necessary. So essentially, don't worry about it.
magnesi
Monobass wrote:
Basically the trimmer adds a very small offset to the centre frequency, in reality it probably should have been designed out of the final board as it's not very useful, it turned out the tolerances of the final BOM kind of made it not necessary. So essentially, don't worry about it.


Thanks Monobass. So if I've turned it in several directions (mine doesn't seem to have a stop point in either direction) should I need to recalibrate anything? I've twisted it quite a few turns. Not quite sure what you mean by "centre frequency".
Monobass
It doesn't matter what position it's set in, just leave it. Centre Frequency is basically cutoff frequency.
danfastlikeflan
Could I replace it with a resistor? I would love to have a switch on the front for the resonance overload header on the back.
jakokrull@gmail.com
Help - the filter does not function. LP and BP outputs have only noise coming out and HP and N produce a clean output signal with no filtering applied. Any suggestions? I have checked all the solder points and they seem solid.
templar
jakokrull@gmail.com

maybe post some pictures of your build?
JP8
As a replacement for the Nichocon Gold caps I can only find 16v in small size instead of the suggested 25v. I’d guess that the maximum power on the caps would be 12v, but I’m not sure. Is this difference significant? Can I use the 16v capacitors?
jstck
I'm about to buy a kit for one of these and was just making sure I had all the parts required, and got a bit confused by the potentiometers. More specifically, the two "tall trimmer" pots. In the BOM, they are listed as B50K pots (CV1 and CV2), but from what I can gather from the schematic they correspond to R24 and R35 which are listed there as B10K. There are no 50k pots to be found anywhere in the schematic, and no other 10K pots in the BOM other than R25 (cutoff frequency knob).

Which one should I use? They're both just voltage dividers for incoming CV signal (and are mixed, together with R25 signal, via 100K input resistors) so I guess either should work in some fashion, but what is the reason for the disparity?
rosch
10k will draw more current but will be less affected by noise. you could even use 100k for voltage divider. that's just generally speaking, haven't looked at the particular schematics
jstck
These are the schematics I could find, the cutoff frequency input section is in the top left:

https://thonk.co.uk/documents/gbox/humpback/schematic_humpback_topboar d.png

The value of those potentiometers will of course determine the input impedance, where both 10K and 50K are within reason (though I would prefer higher for these as I would probably use one for "note tracking"). I'm guessing though that the input would be have more nonlinearity to it if the potentiometer value gets close to that of the mixer input resistor.

There are other discrepancies though between the schematic and the BOM; The schematic has a 1K pot/trimmer, R32, after the cutoff frequency mixer op amp, which is not mentioned or visible anywhere else. And if the BOM matches what's currently being sold, I guess the schematic is just a bit off. Does anyone know of a more accurate schematic somewhere?
JP8
I finished my build. First it didn’t work. I only got a soft sound passing through without any filter action. So I took it apart, resoldered all joints and double checked the headers as suggested in this thread. I also replaced all the ICs. I put it back together but still no change. The frequency knob seems to act like a volume pot...

Any help would be appreciated. Picture of the build enclosed.

Cheers,
Ricardo
boork
hi folks,

I just finished a build of humpback using a new thonk kit, and everything on it more or less works - lowpass is lowpass, highpass is highpass, CV works, etc., sound comes out of it filtered, and sounds very good... the weird thing is it just isn't very resonant. Definitely won't self oscillate, and that is even with the jumper on (there's practically no resonance at all when off).

I also notice when I try basic sweeps, I get no change from closed to about 1o'clock, then from 1 to full clockwise I get a nice sweep (true of both the highpass and low, and I assume of the notch and band although I haven't checked w scope).

So I'm guessing I swapped some thing(s) in the build, but I don't know where to look. Tried making sense of the schematics, but they're over my head right now, sad to say. Anyway, was wondering / hoping someone might have some hints on where to focus my troubleshooting / start looking, before I sorta just go over the entire thing (?)

(Right now it sounds really nice, and I don't mind it, but I'd love to get that howl out of it if I can)

Thanks much!
honeyb
Just ordered two kits for this, but ran into a snag-- Mouser doesn't stock the 2n3819 transistors. "silicon N-Channel JFET designed for RF amplifier and mixer applications" Unless you order in batches of 5000 ....

Anyone have a good substitute which worked in their builds?
Pav
You could try banzai music in Germany ..their website is showing stock and will be able to order tiny quantities albeit delivery can be slow at times.
JAO
honeyb wrote:
Mouser doesn't stock the 2n3819 transistors.


Just grab them on ebay. Plenty available.
honeyb
Working on the build right now. The board has several points which say "RX2 (see manual)"

But of course there is no manual...

Any idea what these connections are for?
Trashcan
HI, does anyone have the Mouser part no. for the trimmer, I misread something somewhere that lead me to think that it was not required... very frustrating
workingklass0
Hello all!

I am trying to compile a Mouser project list for this filter. However, I am a little bit confused about which TL071 and TL072 chips I should add. Any recommendations or suggestions? Thanks.
mutate
Finished my build and noticed the cutoff does not completely filter out all sound when turned fully counter clockwise (LP out). Wondering if anyone else noticed this on theirs?
MUFF WIGGLER Forum Index -> Music Tech DIY  
Page 1 of 7
Powered by phpBB © phpBB Group