[AVAILABLE] TTSH V4 Build Thread

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musicorchard
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Re: [AVAILABLE] TTSH V4 Build Thread

Post by musicorchard » Wed Jan 29, 2020 9:49 pm

I just received my TTSH kit today and I'm stoked. Now I just have to find the time to build it! :sb:

Silly question that I can't seem to find the info on: I'm looking to add the midimplant to the TTSH. Is this something that comes with the kit or is purchasing it separately necessary? I saw in the guide there is a synthcube version, but it looks sold out at the moment. Is the version on midimplant.com the most recent version that has the gate amplitude fixed at +5v as per the build guide?

Thanks for any help!

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by thomaskobrick » Thu Jan 30, 2020 7:12 am

spacecadet, amazing! Thank you so much!!!

Also, I can't believe I spelled it "resister" hahaha.

Here's where I am as of last night. Working through the capaciters. (jokes! :hihi: )
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Re: [AVAILABLE] TTSH V4 Build Thread

Post by fuzzbass » Thu Jan 30, 2020 7:28 am

musicorchard wrote:
Wed Jan 29, 2020 9:49 pm
I just received my TTSH kit today and I'm stoked. Now I just have to find the time to build it! :sb:

Silly question that I can't seem to find the info on: I'm looking to add the midimplant to the TTSH. Is this something that comes with the kit or is purchasing it separately necessary? I saw in the guide there is a synthcube version, but it looks sold out at the moment. Is the version on midimplant.com the most recent version that has the gate amplitude fixed at +5v as per the build guide?

Thanks for any help!
Scroll back a bit and you will find a link to my build guide, which discusses MIDImplant installation. So long as you also use a gate booster, it does not matter which Implant version you have.
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Re: [AVAILABLE] TTSH V4 Build Thread

Post by musicorchard » Thu Jan 30, 2020 8:40 am

fuzzbass wrote:
Thu Jan 30, 2020 7:28 am
musicorchard wrote:
Wed Jan 29, 2020 9:49 pm
I just received my TTSH kit today and I'm stoked. Now I just have to find the time to build it! :sb:

Silly question that I can't seem to find the info on: I'm looking to add the midimplant to the TTSH. Is this something that comes with the kit or is purchasing it separately necessary? I saw in the guide there is a synthcube version, but it looks sold out at the moment. Is the version on midimplant.com the most recent version that has the gate amplitude fixed at +5v as per the build guide?

Thanks for any help!
Scroll back a bit and you will find a link to my build guide, which discusses MIDImplant installation. So long as you also use a gate booster, it does not matter which Implant version you have.

Gotcha. Thanks!

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by synthcube » Thu Jan 30, 2020 10:04 am

very exciting to see the build examples and stories coming to life!!

please keep them coming--

just FYI, fully assembled pre-orders are within a short time of final assembly, calibration testing et al and will be shipped via the order queue.

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by spacecadet » Thu Jan 30, 2020 11:12 am

thomaskobrick wrote:
Thu Jan 30, 2020 7:12 am
spacecadet, amazing! Thank you so much!!!

Also, I can't believe I spelled it "resister" hahaha.

Here's where I am as of last night. Working through the capaciters. (jokes! :hihi: )
Just don’t mix up impedance and impotence :hihi:

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by minimamoralia » Fri Jan 31, 2020 10:08 am

fuzzbass wrote:
Wed Jan 29, 2020 7:35 pm
minimamoralia wrote:
Tue Jan 28, 2020 3:34 pm
Hey everyone, long time reader, very rare poster. This is my first build of this size and complexity, I'm pretty good at following instructions but not super well versed in electricity. Of course, thanks so much to all the users posting here about their experience and especially Fuzzbass for all the time put in to the build guides and answering questions here.

I finished all soldering and began checking my power supply, (synthcube kit) checking power gets distributed to the board, trimmed both V+ and V- to 15V without a problem, my led's all lit up, and one speaker began to hiss (nothing crazy, seemed like a reasonable amount, but it was only the right speaker). After a little while, the 10 ohm resistor in the Amp section right below the R speaker output connector let the smoke out.

Going back to the isolated PSU, I now no longer have any output. 12V comes in, goes through the Muratas, gets to the resistors and capacitors, and then i lose it. I found a reversed 47u electrolytic on the -15V side, replaced that, and began testing again, but I get the same result. Does it seem likely that I fried the LDO regulators? There's no voltage anywhere on those, or the 2x Bourns trimmers.

Thanks for any insight! Sorry for the newb question (and mistakes!)
Not sure about your PSU I have not broken one yet. Both the LDOs and the Muratas are designed to tolerate some abuse. I have smoked one of the amps just like you did, and it did not take out the PSU.

But if you smoked a resistor in the the amps section, you have either: 1 miswired the headphone/jack/speakers; 2. Plugged a TR cable in there, which is a no-no, or 3. you have a reversed diode in the amps section.
thank you fuzzbass! i did plug in a TS cable trying to test the headphone out! :bang: i found one other reversed electrolytic in the EG section, but all my diodes were correct. off to read more schematics and figure this out... much appreciated.

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by thecivildefense » Fri Jan 31, 2020 3:11 pm

I have a couple quick questions for things I'm thinking of playing around with down the road after I finish the immediate plans of adding sync (put off just to make sure all else works right first and because I want to drill new holes for switches and want to figure out where I really want it):

1)The "stereo" nature of the reverb:

From how I understand it from the manual, the stereo split for the reverb is just that the phase is reversed on one side to provide a pseudostereo effect. I'm sure it's just personal taste or from being a mix engineer but pulling up the verbs and having the center image and tone go out is totally disorienting and bothers me...to the extent where I was sure I messed something up when I was first working with it. I realize that's how the 2600 was designed (and from I assume just based on using them other synths like the synthi use phase tricks to enhance the spatialization) and that some people might be into it.
Is the in-phase signal the right side?
And I've seen discussion of mods to build a second reverb return (duplicating the output circuit). For those who took the time to do that, were you satisfied with the results? Is there enough variation from tank to tank to just have a second tank for the new output channel or should tank size really be changed for the second one? I'm considering doing this, but it's a couple steps down the road.

2) Speaker tests:

I'm using the crappier kit-supplied speakers, but was thinking about trying the "hi-fi" ones (https://www.parts-express.com/peerless- ... --264-1056) since they're cheap and deciding what I prefer. Generally I like having the shittier speaker option on stuff like this (love the speaker sounds on Synthis, magnecorder tape machine preamps, etc). I couldn't find that much discussion on them online but maybe I should just get both or others and experiment. I like it as-is but it's a bit "nicer" and closer actual sound than I expected (like it's too middle ground and maybe I want it either a little more oddball or w/ a bit better low-end response like I'd imagine the above hifi ones to have). I'll play around but if anyone's tried both and has impressions or even tried others I'd love to hear them.

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by fuzzbass » Sat Feb 01, 2020 10:11 am

thecivildefense wrote:
Fri Jan 31, 2020 3:11 pm
I have a couple quick questions for things I'm thinking of playing around with down the road after I finish the immediate plans of adding sync (put off just to make sure all else works right first and because I want to drill new holes for switches and want to figure out where I really want it):

1)The "stereo" nature of the reverb:

From how I understand it from the manual, the stereo split for the reverb is just that the phase is reversed on one side to provide a pseudostereo effect. I'm sure it's just personal taste or from being a mix engineer but pulling up the verbs and having the center image and tone go out is totally disorienting and bothers me...to the extent where I was sure I messed something up when I was first working with it. I realize that's how the 2600 was designed (and from I assume just based on using them other synths like the synthi use phase tricks to enhance the spatialization) and that some people might be into it.
Is the in-phase signal the right side?
And I've seen discussion of mods to build a second reverb return (duplicating the output circuit). For those who took the time to do that, were you satisfied with the results? Is there enough variation from tank to tank to just have a second tank for the new output channel or should tank size really be changed for the second one? I'm considering doing this, but it's a couple steps down the road.

2) Speaker tests:

I'm using the crappier kit-supplied speakers, but was thinking about trying the "hi-fi" ones (https://www.parts-express.com/peerless- ... --264-1056) since they're cheap and deciding what I prefer. Generally I like having the shittier speaker option on stuff like this (love the speaker sounds on Synthis, magnecorder tape machine preamps, etc). I couldn't find that much discussion on them online but maybe I should just get both or others and experiment. I like it as-is but it's a bit "nicer" and closer actual sound than I expected (like it's too middle ground and maybe I want it either a little more oddball or w/ a bit better low-end response like I'd imagine the above hifi ones to have). I'll play around but if anyone's tried both and has impressions or even tried others I'd love to hear them.
A brick wall you might run into is that there is not proper stereo imaging of the L/R outputs, and stereo effect is simulated with reverb phase - best using headphones. It would seem like you have to solve that problem too.

If you are going to all that trouble with the reverb, why not build an outboard stereo reverb unit instead, and use if from the mixing console. You could greatly improve upon the driver and return amps, and put three pans in, mix and match them with a rotary switch. You could greatly improve on noise reduction and sound isolation of the springs. You could add a vactrol based voltage control for mix, like on the MTM Spring module. You could add a vactrol based tremelo circuit. I'd buy that kit from you and build one!

Speakers.... its all a matter of taste. But having heard both types, I can say the more expensive ones are not going to knock your socks off either.
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Re: [AVAILABLE] TTSH V4 Build Thread

Post by fuzzbass » Sat Feb 01, 2020 10:24 am

minimamoralia wrote:
Fri Jan 31, 2020 10:08 am
fuzzbass wrote:
Wed Jan 29, 2020 7:35 pm
minimamoralia wrote:
Tue Jan 28, 2020 3:34 pm
Hey everyone, long time reader, very rare poster. This is my first build of this size and complexity, I'm pretty good at following instructions but not super well versed in electricity. Of course, thanks so much to all the users posting here about their experience and especially Fuzzbass for all the time put in to the build guides and answering questions here.

I finished all soldering and began checking my power supply, (synthcube kit) checking power gets distributed to the board, trimmed both V+ and V- to 15V without a problem, my led's all lit up, and one speaker began to hiss (nothing crazy, seemed like a reasonable amount, but it was only the right speaker). After a little while, the 10 ohm resistor in the Amp section right below the R speaker output connector let the smoke out.

Going back to the isolated PSU, I now no longer have any output. 12V comes in, goes through the Muratas, gets to the resistors and capacitors, and then i lose it. I found a reversed 47u electrolytic on the -15V side, replaced that, and began testing again, but I get the same result. Does it seem likely that I fried the LDO regulators? There's no voltage anywhere on those, or the 2x Bourns trimmers.

Thanks for any insight! Sorry for the newb question (and mistakes!)
Not sure about your PSU I have not broken one yet. Both the LDOs and the Muratas are designed to tolerate some abuse. I have smoked one of the amps just like you did, and it did not take out the PSU.

But if you smoked a resistor in the the amps section, you have either: 1 miswired the headphone/jack/speakers; 2. Plugged a TR cable in there, which is a no-no, or 3. you have a reversed diode in the amps section.
thank you fuzzbass! i did plug in a TS cable trying to test the headphone out! :bang: i found one other reversed electrolytic in the EG section, but all my diodes were correct. off to read more schematics and figure this out... much appreciated.
Um yes I meant TS. About one in ten builders experience this when they hit upon the idea of running a guitar lead from the headphone jack out to a Tube Screamer. You can still use it as an output, but you need one of those TRS splitter (insert) cables and choose either left(tip) or right (ring). You can run these to a mixer and pan them. In these applications you need to keep their levels way down low.
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Re: [AVAILABLE] TTSH V4 Build Thread

Post by fuzzbass » Sat Feb 01, 2020 10:26 am

sorry - double post.
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Re: [AVAILABLE] TTSH V4 Build Thread

Post by minimamoralia » Sat Feb 01, 2020 10:59 am

Thanks for the guidance folks. My speakers aren't working yet, but it's alive! And it sounds so good.



Turned out the PSU problem was just a bad connection at the input, so that's all fine now. 4012 filter works great, VCOs, Ring Mod and Noise works, S&H, Voltage processors, VCF and VCA mixers are all good, Reverb works (that out of phase stereo effect is pretty crazy), CV in works, I've got the VCOs and Filter tracking V/Oct, GateBooster seems to be good. Need to test the preamp in and the enevelope follower.

Slowly getting a handle on how the Amplifier schematic applies to the actual circuit. I currently have a constant tone (DC i guess?) in the right speaker whenever I plug it in, and there's no resistance across its terminals. The left speaker does measure ~44 ohms (just below the speaker's 45), but I have no sound from it. The main outputs at the top are working just fine though.

:sb:
Last edited by minimamoralia on Sat Feb 01, 2020 1:13 pm, edited 1 time in total.

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by thecivildefense » Sat Feb 01, 2020 12:55 pm

minimamoralia wrote:
Sat Feb 01, 2020 10:59 am

Slowly getting a handle on how the Amplifier schematic applies to the actual circuit. I currently have a constant tone (DC i guess?) in the right speaker whenever I plug it in, and there's no resistance across its terminals. The left speaker does measure ~44 ohms (just below the speaker's 45), but I have no sound from it. The main outputs at the top are working just fine though.

:sb:
What does the headphone output sound like? Assuming it's also not right, it seems like there might be a wiring mixup between the amp outs/hp jack/speakers. I know I had to make sure i was double or triple checking there that I wasn't mixing things up. If you didn't already I'd double check the paths there if you haven't already.

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by minimamoralia » Sat Feb 01, 2020 1:22 pm

thecivildefense wrote:
Sat Feb 01, 2020 12:55 pm
minimamoralia wrote:
Sat Feb 01, 2020 10:59 am

Slowly getting a handle on how the Amplifier schematic applies to the actual circuit. I currently have a constant tone (DC i guess?) in the right speaker whenever I plug it in, and there's no resistance across its terminals. The left speaker does measure ~44 ohms (just below the speaker's 45), but I have no sound from it. The main outputs at the top are working just fine though.

:sb:
What does the headphone output sound like? Assuming it's also not right, it seems like there might be a wiring mixup between the amp outs/hp jack/speakers. I know I had to make sure i was double or triple checking there that I wasn't mixing things up. If you didn't already I'd double check the paths there if you haven't already.
thank you. i will listen through headphones when i get home, i suspect they will also have noise on the right and nothing on the left. i have quintuple checked the headphone wiring guide in the Fuzzbass build guide against what I did, and i swear i have it right! i'm pretty sure it's a bad component or two on the PCB, having already fried the circuit once, but i could be wrong. i replaced the obviously burnt resistor but there must be something else bad. i'm uh... very close to understanding how to locate it. haha

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by thecivildefense » Sat Feb 01, 2020 3:01 pm

minimamoralia wrote:
Sat Feb 01, 2020 1:22 pm

thank you. i will listen through headphones when i get home, i suspect they will also have noise on the right and nothing on the left. i have quintuple checked the headphone wiring guide in the Fuzzbass build guide against what I did, and i swear i have it right! i'm pretty sure it's a bad component or two on the PCB, having already fried the circuit once, but i could be wrong. i replaced the obviously burnt resistor but there must be something else bad. i'm uh... very close to understanding how to locate it. haha
Ah right. I forgot you were the one who had the smoke after a TS cable. I'd have to look at the circuit there but lots of times on other gear when you smoke resistors they're not the only things to go...ICs and transistors in that section get damaged or fail too (thinking of my console, where this happens occasionally on the monitor amps). Luckily that section is super simple. Like one IC and a couple transistors. The ICs are the same as everywhere so just swap from some other unused section to test. If you desolder the transistors if you don't have a transistor tester you should be able to test them with a multimeter to see if they failed (if you haven't done this before it's like this: You have to do something else for jfets though so check what types are there even though the 172/182 and 2n5172 are all pnp/npn I think). If you have spares I'd change the transistors and 2 ics and do another visual to see if you have more damaged resistors as well.

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by Jfettig » Sat Feb 01, 2020 4:20 pm

spacecadet wrote:
Tue Jan 21, 2020 2:46 pm
Jfettig wrote:
Tue Jan 21, 2020 12:45 am
fuzzbass wrote:
Sun Jan 19, 2020 12:51 pm
Jfettig wrote:
Sat Jan 18, 2020 3:14 pm
I was hoping not to be back so soon with another question, but alas..

after pluging in my PSU board for the first time my readings are not quite perfect. 0v to -15v reads correctly at -15.75 v, but 0v to +15v reads 18.14v. whats perhaps more interesting is that neither of my trimmers seem to change either reading no matter how much I move them.

I tried reflowing everything, and checked the polarity on all my caps. I compared my board visually to photos of others to make sure my trimmers weren't backwards. What next?

Additional useful information might be that my DC Voltage reading between 0 and V- is -14.24, but between 0 and V+ is 0. This obviously doesn't seem right.

Thanks again,

Jeff
It sounds like there is an issue with the divider used to feed the ADJ pin on the Murata, positive side. This is the 240R, 2K4 and 500R trimmer +15V side. Look for a cold joint, bridge. or bad trimmer.
OK,

So I did find that I had a 2.7k resistor where the 27k resistor needed to be. whoops. I fixed that and was able to get the proper 15.74v at the +15 pin. The V+ pin still reads 0v. I tried swapping the trimmers, and pulled both the 240 and 2k4 resistors, and measured them within tolerance. still no dice.

is it possible I fried something with having the wrong value resistor in the 24k spot?

What else to try?

Thanks,

Jeff

The murata trim resistor equation is as follows from the murata datasheet :-

R-trim = 25000 / ( desired V out - 15 ) - 5110

27K resistor gives you the desired 15.75v . 2.7K gives you over 18v - so your measurements with the incorrect resistor fit . In fact I am surprised the murata didn't shut down when that voltage was requested.

Please go and get a copy of the TTSH v3 schematics from the human comparator website and you should see what I mean. It is on page 14. The lower circuit is the murata circuit that generates 15.75v. The upper circuit on that page are for the two ldo's that generate +/- 15.0v

This 15.75v feeds the 15v ldo regulator that generates the 15.0v - the TL1963A.

http://www.ti.com/lit/ds/symlink/tl1963a.pdf

Fortunately 18v looks like its within the absolute maximum rating of this part so I doubt you have damaged it that way. These parts are ESD sensitive though - are you taking ESD precaution building your TTSH?

Anyway - the circuit for this is simple. All that is needed is an input voltage, the shutdown pin to be in the correct state and the output trimmed using a resistor divider on the ADJ pin.

As this is a SMT part - first check you have not shorted SHDN pin to ground. Then check for having got the 240ohm and the 2K4 resistors the right way around. I strongly suspect you should double check your soldering for this part as its a pain if you are not used to hand soldering SMT.
Use your ohmmeter to buzz out the connectivity of all the pins on this part to ensure it matches with the schematic.

If the LDO is getting 15.75 on its VIN from the murata , and the SHDN pin is in the correct state and the ADJ pin is clamped to 1.21v then there is not much that can go wrong. Note that the 2K4+ 500ohm trimmer and 240ohm resistor form a divider. For the regulator to output 15V, the resistor divider needs to generate 1.21v when the output is 15v. This should be achieved when the trimmer is at around 336ohm, using the following calculation Vout = Vin x 240ohm / (2400ohm + 240ohm + 336ohm )

EDIT: I just noticed you wrote "is it possible I fried something with having the wrong value resistor in the 24k spot?"

We know you got it wrong in the 27K spot, so was this a typo, or did you also put the wrong resistor in the 2K4 spot as well?

Note that if you have somehow messed things up so that the ADJ pin gets a voltage from somewhere even when the regulator output is at 0v, then the regulator will never startup. So this would occur if you shorted ADJ with VIN, for example. If you managed to get more than +/- 7v on ADJ (clearly, from a source other than this regulators output), then you have stressed the regulator beyond its absolute maximum ratings and you will likely need to replace it.

This is unlikely to occur at the soldering of the part itself as ADJ and VIN are not adjacent.

VOUT and GND ARE adjacent though - please check that very carefully under magnification.

Thank you for this thoughtful response. Im doing my best to understand.

sorry for the typo, it was just the 27k resistor that I got wrong.

I think I've figured out that the issue is with the muRata on the Positive side, but wanted a second opinion because SynthCube wants $60 for a new one. (mouser has what seems to be the same model for $32 but not in stock).

The +Vout (pin 3) measures 15.74V which seems correct, but the Output trim (pin 4) measures only 2.095V. On the Negative side, the trim measures -13.64 and works properly. This seems like a significant discrepancy.

Is it something else that dictates the output of the Trim out, or would this be an internal issue with the muRata?

Thanks Again,

Jeff

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by fuzzbass » Sat Feb 01, 2020 6:05 pm

Ok just spent the afternoon troubleshooting a unique issue where the first LED in a string was frying. The rest of the string keeps going because the LED fails closed, with ~1K of resistance. Turn the synth on everything is fine. But if you press down lightly on the panel near the slider in question, bzzt, puff of smoke and dead LED.

Root cause: a signal trace in the LED string is passing under one of the (grounded) support legs of 3.5mm jack. The trace is covered in solder mask, but light pressure was enough to bring the ground of the jack's shroud into contract with the trace. This would isolate one of the slider LEDs between +15.75V and ground, with no current limiter, so it was going supernova.

It's a bad practice to route signal traces along paths where they can be shorted by components occupying those spaces. Get this: there are 19 jack positions on the TTSH violating this rule. I'm pretty sure this part of the design has been in place since V2. I have built sixteen V2 or higher, and first time I encountered this. But I have heard others report similar issues: press on the panel here and there is a power glitch.

The particular LED in this case was the right reverb control, and the jack that was shorting was directly above, Right Input. The fix in this case was to relieve or remove portions of the jack shroud that might short to the trace in question.
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Re: [AVAILABLE] TTSH V4 Build Thread

Post by spacecadet » Sat Feb 01, 2020 6:47 pm

Jfettig wrote:
Sat Feb 01, 2020 4:20 pm
spacecadet wrote:
Tue Jan 21, 2020 2:46 pm
Jfettig wrote:
Tue Jan 21, 2020 12:45 am
fuzzbass wrote:
Sun Jan 19, 2020 12:51 pm
Jfettig wrote:
Sat Jan 18, 2020 3:14 pm
I was hoping not to be back so soon with another question, but alas..

after pluging in my PSU board for the first time my readings are not quite perfect. 0v to -15v reads correctly at -15.75 v, but 0v to +15v reads 18.14v. whats perhaps more interesting is that neither of my trimmers seem to change either reading no matter how much I move them.

I tried reflowing everything, and checked the polarity on all my caps. I compared my board visually to photos of others to make sure my trimmers weren't backwards. What next?

Additional useful information might be that my DC Voltage reading between 0 and V- is -14.24, but between 0 and V+ is 0. This obviously doesn't seem right.

Thanks again,

Jeff
It sounds like there is an issue with the divider used to feed the ADJ pin on the Murata, positive side. This is the 240R, 2K4 and 500R trimmer +15V side. Look for a cold joint, bridge. or bad trimmer.
OK,

So I did find that I had a 2.7k resistor where the 27k resistor needed to be. whoops. I fixed that and was able to get the proper 15.74v at the +15 pin. The V+ pin still reads 0v. I tried swapping the trimmers, and pulled both the 240 and 2k4 resistors, and measured them within tolerance. still no dice.

is it possible I fried something with having the wrong value resistor in the 24k spot?

What else to try?

Thanks,

Jeff

The murata trim resistor equation is as follows from the murata datasheet :-

R-trim = 25000 / ( desired V out - 15 ) - 5110

27K resistor gives you the desired 15.75v . 2.7K gives you over 18v - so your measurements with the incorrect resistor fit . In fact I am surprised the murata didn't shut down when that voltage was requested.

Please go and get a copy of the TTSH v3 schematics from the human comparator website and you should see what I mean. It is on page 14. The lower circuit is the murata circuit that generates 15.75v. The upper circuit on that page are for the two ldo's that generate +/- 15.0v

This 15.75v feeds the 15v ldo regulator that generates the 15.0v - the TL1963A.

http://www.ti.com/lit/ds/symlink/tl1963a.pdf

Fortunately 18v looks like its within the absolute maximum rating of this part so I doubt you have damaged it that way. These parts are ESD sensitive though - are you taking ESD precaution building your TTSH?

Anyway - the circuit for this is simple. All that is needed is an input voltage, the shutdown pin to be in the correct state and the output trimmed using a resistor divider on the ADJ pin.

As this is a SMT part - first check you have not shorted SHDN pin to ground. Then check for having got the 240ohm and the 2K4 resistors the right way around. I strongly suspect you should double check your soldering for this part as its a pain if you are not used to hand soldering SMT.
Use your ohmmeter to buzz out the connectivity of all the pins on this part to ensure it matches with the schematic.

If the LDO is getting 15.75 on its VIN from the murata , and the SHDN pin is in the correct state and the ADJ pin is clamped to 1.21v then there is not much that can go wrong. Note that the 2K4+ 500ohm trimmer and 240ohm resistor form a divider. For the regulator to output 15V, the resistor divider needs to generate 1.21v when the output is 15v. This should be achieved when the trimmer is at around 336ohm, using the following calculation Vout = Vin x 240ohm / (2400ohm + 240ohm + 336ohm )

EDIT: I just noticed you wrote "is it possible I fried something with having the wrong value resistor in the 24k spot?"

We know you got it wrong in the 27K spot, so was this a typo, or did you also put the wrong resistor in the 2K4 spot as well?

Note that if you have somehow messed things up so that the ADJ pin gets a voltage from somewhere even when the regulator output is at 0v, then the regulator will never startup. So this would occur if you shorted ADJ with VIN, for example. If you managed to get more than +/- 7v on ADJ (clearly, from a source other than this regulators output), then you have stressed the regulator beyond its absolute maximum ratings and you will likely need to replace it.

This is unlikely to occur at the soldering of the part itself as ADJ and VIN are not adjacent.

VOUT and GND ARE adjacent though - please check that very carefully under magnification.

Thank you for this thoughtful response. Im doing my best to understand.

sorry for the typo, it was just the 27k resistor that I got wrong.

I think I've figured out that the issue is with the muRata on the Positive side, but wanted a second opinion because SynthCube wants $60 for a new one. (mouser has what seems to be the same model for $32 but not in stock).

The +Vout (pin 3) measures 15.74V which seems correct, but the Output trim (pin 4) measures only 2.095V. On the Negative side, the trim measures -13.64 and works properly. This seems like a significant discrepancy.

Is it something else that dictates the output of the Trim out, or would this be an internal issue with the muRata?

Thanks Again,

Jeff

You really don’t need to worry about what the voltage is at the trim pin. So long as you are getting +/- 15.75v on the respective outputs, you are good. In any case those measurements are what I would expect. Vtrim is about 2v higher wrt to the -ve pin . That is 0v for the positive murata, and -v for the negative Murata. I think everything is working ok.

minimamoralia
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Re: [AVAILABLE] TTSH V4 Build Thread

Post by minimamoralia » Sat Feb 01, 2020 7:51 pm

thecivildefense wrote:
Sat Feb 01, 2020 3:01 pm
minimamoralia wrote:
Sat Feb 01, 2020 1:22 pm

thank you. i will listen through headphones when i get home, i suspect they will also have noise on the right and nothing on the left. i have quintuple checked the headphone wiring guide in the Fuzzbass build guide against what I did, and i swear i have it right! i'm pretty sure it's a bad component or two on the PCB, having already fried the circuit once, but i could be wrong. i replaced the obviously burnt resistor but there must be something else bad. i'm uh... very close to understanding how to locate it. haha
Ah right. I forgot you were the one who had the smoke after a TS cable. I'd have to look at the circuit there but lots of times on other gear when you smoke resistors they're not the only things to go...ICs and transistors in that section get damaged or fail too (thinking of my console, where this happens occasionally on the monitor amps). Luckily that section is super simple. Like one IC and a couple transistors. The ICs are the same as everywhere so just swap from some other unused section to test. If you desolder the transistors if you don't have a transistor tester you should be able to test them with a multimeter to see if they failed (if you haven't done this before it's like this: You have to do something else for jfets though so check what types are there even though the 172/182 and 2n5172 are all pnp/npn I think). If you have spares I'd change the transistors and 2 ics and do another visual to see if you have more damaged resistors as well.
much appreciated, thecivildefense. i started checking the LM301s and they seem ok. i dont have any spare 172 or 182s but i suspect they are the culprit. thanks for that video link.

spacecadet
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Fruit of my Labour

Post by spacecadet » Sun Feb 02, 2020 3:08 pm

Here is where I have got to for my efforts - setup to play seagulls

It’s making my dogs go nuts :lol:
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thomaskobrick
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Re: [AVAILABLE] TTSH V4 Build Thread

Post by thomaskobrick » Mon Feb 03, 2020 8:10 am

Congratulations, spacecadet! It's looks beautiful and I'm sure sounds as good as it looks!

This is my update: Got through all capacitors, non-matched transistors, and sanity checked my resistors, thanks to spacecadet's kind sharing of his pictures. The only casualty was my poor lone 12p capacitor that got soldered into a 20p spot (evidenced by the fact that I had a 20p capacitor left over and nothing to put in the 12p spot), which did not survive the repair. So while I wait for his replacement, I'll be doing my transistor matching tonight, which I have saved to the end.

Also got caught by the 10K resistor short, but that's an easy fix. It did motivate me to do a thorough resistor-reading-practice session with my board, which caused me to be much quicker at it by the end. :)

My only worry right now is the language in the build guide, that states: "Note that in the first batch of V4 (Synthcube) boards, the footprint of the 2N3954 in the VCO2 section has pins 5 and 6 reversed. If you are building this main board, be sure to form those pins on the 2N3954 to fix that bug." I believe I have one of these, since I was down a 10K resistor, but I can't tell from the included picture if I am supposed to reverse the 5 and 6 pin, and what is the best way to go about it - just bend the wires around each other? Are you guys using insulation on one of them or anything?

The mounting/header pin situation also has me a bit nervous since I don't quite understand how it should look when done (correctly). If anyone has a model citizen they would be willing to share to show how these mounting pins get connected I would be very grateful.
IMG_8083.jpg
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thecivildefense
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Re: [AVAILABLE] TTSH V4 Build Thread

Post by thecivildefense » Mon Feb 03, 2020 10:01 am

thomaskobrick wrote:
Mon Feb 03, 2020 8:10 am


My only worry right now is the language in the build guide, that states: "Note that in the first batch of V4 (Synthcube) boards, the footprint of the 2N3954 in the VCO2 section has pins 5 and 6 reversed. If you are building this main board, be sure to form those pins on the 2N3954 to fix that bug." I believe I have one of these, since I was down a 10K resistor, but I can't tell from the included picture if I am supposed to reverse the 5 and 6 pin, and what is the best way to go about it - just bend the wires around each other? Are you guys using insulation on one of them or anything?

The mounting/header pin situation also has me a bit nervous since I don't quite understand how it should look when done (correctly). If anyone has a model citizen they would be willing to share to show how these mounting pins get connected I would be very grateful.

IMG_8083.jpg
You should insulate one of the pins so you don't have a chance to short them. Just put a little piece of shrink tubing on one of the legs you bend...don't even have to shrink it. Always good practice to do this at least when you have to bend pins or use radial caps instead of axial esp on unmasked boards etc.

thecivildefense
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Re: [AVAILABLE] TTSH V4 Build Thread

Post by thecivildefense » Mon Feb 03, 2020 10:06 am

thomaskobrick wrote:
Mon Feb 03, 2020 8:10 am

The mounting/header pin situation also has me a bit nervous since I don't quite understand how it should look when done (correctly). If anyone has a model citizen they would be willing to share to show how these mounting pins get connected I would be very grateful.

IMG_8083.jpg
Hope this helps with the headers if you zoom in.

Image
Image

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synthcube
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Re: [AVAILABLE] TTSH V4 Build Thread

Post by synthcube » Mon Feb 03, 2020 10:49 am

Update on led slider caps--- we are making great progress, taking the time to make sure these are really solid for you. We are making a very very slight mod to the tooling in order to tighten up the cap on the slider. Based on the prototypes we have seen and held, these will be a very nice addition to TTSH (or any module/synth that uses the Bourns sliders)

Questions, please don't hesitate to ask!

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paperCUT
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Re: [AVAILABLE] TTSH V4 Build Thread

Post by paperCUT » Mon Feb 03, 2020 1:49 pm

Has anybody found a replacement for the C56206L2X switches? They are 8 euros each from mouser! :confused:

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