[BUILD] Manhattan Analog Discrete Transistor Amplifier (DTA)

From circuitbending to homebrew stompboxes & synths, keep the DIY spirit alive!

Moderators: Kent, Joe., luketeaford, lisa

User avatar
negativspace
Manhattan Analog
Posts: 6577
Joined: Tue Apr 13, 2010 2:50 am
Location: Manhattan, KS, USA
Contact:

[BUILD] Manhattan Analog Discrete Transistor Amplifier (DTA)

Post by negativspace » Tue Sep 25, 2018 3:56 pm

It's been brought to my attention recently that I've neglected to post build notes for this one... my bad! Let's fix that.

BOM

Resistors
[2] 8.2R R12,R25
[1] 62R R11
[2] 100R R3,R4
[3] 120R R7,R8,R10
[1] 150R R9
[2] 330R R5,R6
[1] 470R R17
[1] 510R R21
[2] 680R R13,R14
[1] 820R R2
[2] 1k R15,R16
[1] 3.3k R23
[1] 6.8k R20
[1] 33k R24
[1] 47k* R1
[1] 68k R18
[1] 150k R22
[1] 270k R19

Capacitors
[2] 100nF C3,C4 - Ceramic
[2] 10uF C1,C2 - Electrolytic
[1] 10uF C7 - Electrolytic (audio path)
[1] 4.7uF NO DESIGNATOR - Electrolytic. Near "+v" & "out" wire pads.
[2] 220uF C6,C8 - Electrolytic
[1] 1uF C5 - Film **Silkscreen on v1.0 PCBs is incorrect, 1nF will not work.

Transistors/Diodes/etc.
[2] Ferrite Bead (you can sub a ~10R resistor or wire link)
[2] 1N4001 (D1,D2)
[2] PTC Resettable Fuse (Mouser #652-MF-R005-0)
[2] 2N458/1N914/1N4148/etc (D3,D4)
[1] LM78L05 (incorrectly marked Q3 - Next to C6)
[3] 2N3906 or similar (Q7,Q8,Q9)
[6] 2N3904 or similar (Q1,Q2,Q4,Q5,Q6, and the correctly marked Q3 next to Q4)

Trim/Pots
[1] 20R Trimpot (Bourns 3362 or similar) T1
[1] 100R Trimpot (same) T2
[1] A50k (Alpha 9mm or similar)
[2] B50k (same)

Notes

1) The CV and VOL jacks need to have a 5V signal applied to the N/C connection. That's what the +5V output pad is for. I simply run a resistor clipping between the two jacks' normal lugs and then connect that to the PCB.

2) Calibration - the two trimpots are for minimizing CV bleedthrough, one for each stage. (CV and VOL) To calibrate, monitor the audio from the output with all controls at full CW. First run a 10VPP audio signal into the CV jack and adjust the 20R* trimmer for minimum amplitude. Then repeat with the VOL jack and 100R* trimmer.

* = I may have these reversed. I'm building a handful of these as we speak, when I calibrate them I'll fix this description. [/list]
Last edited by negativspace on Fri Jul 17, 2020 10:42 am, edited 5 times in total.

User avatar
Seaweed Sound
Veteran Wiggler
Posts: 566
Joined: Sun Jan 23, 2011 8:12 pm
Location: Austin, TX
Contact:

Post by Seaweed Sound » Wed Oct 03, 2018 10:37 pm

What is the output level like on this?

With all three controls at max and a 10Vpp sinewave going into the input, the output yields:

1000 Hz sine ==> 2.1Vpp
150 Hz sine ==> 360mVpp

All controls and CV inputs seem to operate correctly but the output is fairly quiet and seems to decrease as input frequency decreases (bass rolloff) making it unusable for basslines.

+/-12V rails measure okay and the +V pad is at 4.95V. I believe it's calibrated correctly and have checked component orientation and for bad solder joints. Any ideas?

pppier
Learning to Wiggle
Posts: 22
Joined: Sun Feb 26, 2017 3:06 pm
Location: Italy

Post by pppier » Tue Nov 13, 2018 1:57 pm

hello
I'm building 2, finding something does not match
so bom says 1x 680R; 1x6.8K; 47K* (...)
but on pcb I find 2x680r; 68k; 47K
cad you clear it please?
and what about ptc ad ferrite, what you imegined in designing?
(thanks for you modules 8-) )

User avatar
Seaweed Sound
Veteran Wiggler
Posts: 566
Joined: Sun Jan 23, 2011 8:12 pm
Location: Austin, TX
Contact:

Post by Seaweed Sound » Thu Nov 15, 2018 4:26 pm

Yes use the resistor values as listed on the PCB (2x 680 ohm and 68k).

Also my bass rolloff issue above was due to an incorrect capacitor value: the 1nF film cap is mislabeled and should be a 1̶0̶0̶n̶F̶ 1uF cap. I'm sure there'll be an official update from MA but heads up in the meantime.
Last edited by Seaweed Sound on Wed Nov 21, 2018 1:13 am, edited 1 time in total.

jimi23
Common Wiggler
Posts: 73
Joined: Thu Mar 28, 2013 9:24 am

Post by jimi23 » Thu Nov 15, 2018 4:59 pm

Thanks for the tip off. My pcb and panel set should arrive next week

User avatar
breadman
Common Wiggler
Posts: 166
Joined: Mon Jun 18, 2012 6:22 pm
Location: PDX yo
Contact:

Post by breadman » Mon Nov 19, 2018 1:40 pm

Every MA thing I've built has stayed in my rack long after most of my earlier stuff. I expect this one will be no different!
Need a synth built? Get in touch!

email: jschnvr@gmail.com
IG: @jackssynthbazaar

User avatar
negativspace
Manhattan Analog
Posts: 6577
Joined: Tue Apr 13, 2010 2:50 am
Location: Manhattan, KS, USA
Contact:

Post by negativspace » Tue Nov 20, 2018 11:04 pm

Yep, as Seaweed Sound says, the 1nF film cap is a typo on the PCB. It should be a 1uF cap. (I know he said 100nF, but I mis-typed my explanation to him in the email so that is also my fault.)

Eventually I'll sort out where and how many zeroes this all needs. :deadbanana:

That aside, though, everything else seems proper and correct with the silkscreen. :tu:

(I also added the Mouser # for the PTC fuses to the BOM. Corrected the number of 680R resistors. Clarified the beads.)

jimi23
Common Wiggler
Posts: 73
Joined: Thu Mar 28, 2013 9:24 am

Post by jimi23 » Wed Nov 28, 2018 3:36 pm

All done!! Paired with the Haible Living VCO and SVVCF :hyper:

One idea for normalisation, rather than normalising 5V to both jacks, you can normalise 5V to Vol, and then normalise the output of Vol to CV.

Plugging a cable into VOL, it becomes normalised to both and you can set both pots to create a variable snappier response. Plugging into just CV, youve got VOL still connected to 5V so its normal operation.

User avatar
williamcarthief
Common Wiggler
Posts: 233
Joined: Mon Nov 03, 2014 12:08 am
Location: Spokane, WA

Post by williamcarthief » Fri Dec 28, 2018 1:07 pm

Can someone be so kind as to spell out for me exactly how to wire the jacks. Or just upload a close up picture. The only pic I can find of the wiring is below from Schneiders and it isn't entirely revealing as to exactly what to do. It appears the unlabeled pad to the left of the +V pad is also used - what is happening with that? Also, jimi23, your way of wiring the jacks sounds interesting but my ignorance of circuitry keeps me from knowing exactly what you mean. I can assemble, I can't improvise.

Image

User avatar
JanneI
Wiggling with Experience
Posts: 391
Joined: Mon Oct 19, 2015 3:28 am

Post by JanneI » Fri Dec 28, 2018 4:50 pm

That +v needs to go to CV and VOL jacks SWITCH, the pin that isn't TIP or GROUND. What exactly? It depends on what type of jack you use. This information is in the top post of this thread.

User avatar
williamcarthief
Common Wiggler
Posts: 233
Joined: Mon Nov 03, 2014 12:08 am
Location: Spokane, WA

Post by williamcarthief » Fri Dec 28, 2018 5:33 pm

Thanks for your response, JanneI. I'm using these jacks:

https://www.taydaelectronics.com/3-5mm- ... ocket.html

Please forgive my ignorance, but I do not know which pin is which on these jacks. Neither a magnifying glass nor a google search have helped me figure it out. I have assembled quite a few modules successfully, but I guess I had more explicit instructions / images to guide me prior to this.

From above:
The CV and VOL jacks need to have a 5V signal applied to the N/C connection. That's what the +5V output pad is for. I simply run a resistor clipping between the two jacks' normal lugs and then connect that to the PCB.
I had seen that prior to posting but I can't decipher it. What is the "N/C connection?" What is / where are the "two jacks' normal lugs?" Is that the lug closest to the front of the jack, which I believe corresponds to the sleeve on a plug?

What is the black wire in the picture I posted going to?

A picture from a better angle would be so helpful.

User avatar
JanneI
Wiggling with Experience
Posts: 391
Joined: Mon Oct 19, 2015 3:28 am

Post by JanneI » Fri Dec 28, 2018 6:42 pm

Don't get me wrong..but.. I strongly advise to google around (normalized mono jacks), this is basic stuff. Finishing modules with step by step build guides is fine, but most of the basic electronic stuff is really, really simple to learn. Like this one you have now.

You have an eurorack patch cable and a multi-meter? If not, buy one! Plug the patch cable in to that jack and with continuity mode figure out which is which. Patch cable tip is signal, sleeve is the ground. The third connector in the jack is the switch (N/C), which is connected to the tip when there's no cable in the jack and when cable is connected this normalization breaks.

Try, fail, try again and learn! Good luck!

User avatar
williamcarthief
Common Wiggler
Posts: 233
Joined: Mon Nov 03, 2014 12:08 am
Location: Spokane, WA

Post by williamcarthief » Fri Dec 28, 2018 8:29 pm

Ok. Thanks for responding again, JanneI. I will google some more. Have you built this module? Could you just tell me how to wire the jacks or take a pic of your jack wiring for me? If you haven't built the module and you're just trying to be helpful, thanks. I do appreciate it.

I have a multimeter. I will google what "continuity mode" is. Looking back, I think everything I've built either had a pic of any wiring or they were just pcb mount components. Maybe I'm just more of a visual learner.

I can see how my ignorance of "basic stuff" might seem silly, but frankly I don't really care to know what exactly I'm doing. I just want to finish my current crop of DIY modules. DIY has just been a much cheaper way to try to get the sounds I'm after, but I think I'll be done with DIY after this. It's been more than a year since I built anything and this time it's more tedious than I remember. It's taking too much time that I could be spending making music. I remember now that's why I stopped DIY in the first place.

I still would like a pic or some specific instructions. I don't feel like it's too much to ask for. Perhaps if negativspace sees this. I'm sure a picture of the jack wiring in this thread would be helpful for future builders of this module.

Hope I don't sound like a jerk or anything. I'm just a bit weary and frustrated at the moment I guess.

pppier
Learning to Wiggle
Posts: 22
Joined: Sun Feb 26, 2017 3:06 pm
Location: Italy

Post by pppier » Wed Jan 09, 2019 3:31 am

about wiring,
I connected the pads:
- (minijack ground all together) then to the last point near the power header.
- the one named V+ to normalled pins of CV and VOL as instrucion (it depends on the minijack you use, as said before one is ground, one is tip of patched cable, one is normalling connection, connected when no cable, disconnected when cable inserted)
- OUT, VOL, CV, IN to respective minijack pins.

about behaviour,

[edit: now I realize behaviour is coherent with the Jason's description on thonk's page, of DRIVE as gain stage and CV and VOLUME as 2 cascaded vcas, so a nice sounding vca with 2 cv in for dynamic uses. no offset but it's the design, an external one can be used for this, so I was looking for something that was not on the module, happy to know]

I built 2, I have the same behaviour, but I expected somethings to behave differently (all components are in the right place, and I used the 1u film cap)

- no cv cables, signal at input: I have a signal at out only if all the 3 pots are open, if 1, no matter wich, is CCW it closes the signal.
- the 3 pots behave in the same way: drive does not saturate, cv pot acts like vol,

I think it can be logic as it has the 5V as offset, and disconnecting the 5v from cv minijack silences the module...
but I imagine CV pot as attenuator for incoming cv signal, in this case CV doubles the VOL pot/cv acting as offset. as practical exapmple: if I pacth a singal at in, all pots at CW, if i turn CV pot CCW the signal closes

I expected to have 1 offset, so to open the vca, then sum an external cv to desired response, or I simply think about vca and this module is intended differently? (so "volume" make me think to the out overall volume, "drive" to a gain stage and "cv" to an attenuator af an incoming signal)
? :hmm:
Last edited by pppier on Wed Feb 06, 2019 11:26 am, edited 1 time in total.

JUNLAIS
Learning to Wiggle
Posts: 11
Joined: Thu Feb 24, 2011 12:39 pm
Location: SPAIN

Stripboard Veroboard versión.

Post by JUNLAIS » Fri Jan 11, 2019 12:12 pm

Hello, there's any Stripboard/Veroboard version? Circuit it's very simple and easily Stripboardable.

Skilling
Common Wiggler
Posts: 99
Joined: Sat Feb 25, 2012 5:25 pm

Post by Skilling » Sun Apr 28, 2019 2:33 pm

williamcarthief wrote:I still would like a pic or some specific instructions. I don't feel like it's too much to ask for. Perhaps if negativspace sees this. I'm sure a picture of the jack wiring in this thread would be helpful for future builders of this module.
It would!

I'm about to build one myself and really would appreciate if someone would like to share a pic. I've built my fair share of equipment, but this looks a little tricky due to not so clear instructions (I need instructions for noobs).

Not demanding anything and I totally respect a good old "google it, motherfucker!", but it would be helpful.

EDIT: Ok, I found another pic on Schneidersladen and that will be a piece of cake. But that's what I mean, sometimes I need to see it to get it, even if it's pretty simple and after I've seen it also obvious. :)

Cheers! :guinness:

Valstip
Learning to Wiggle
Posts: 2
Joined: Fri Jan 02, 2015 8:07 pm

Post by Valstip » Thu Jun 13, 2019 9:29 am

Hi! What is the final word on the resistor values?

BOM says 3 x 680 and 1 x 6.8 but the silkscreen shows only two 680, one 6.8K and one 68K (not in BOM).

Thanks for the modules!

honeyb
Common Wiggler
Posts: 144
Joined: Sun Jul 29, 2018 1:37 am
Location: Luxembourg

Post by honeyb » Tue Oct 29, 2019 6:40 am

Valstip wrote:Hi! What is the final word on the resistor values?

BOM says 3 x 680 and 1 x 6.8 but the silkscreen shows only two 680, one 6.8K and one 68K (not in BOM).

Thanks for the modules!
Bumping this question. Just got the panel/PCB and am preparing the mouser order.

Workaround is to just buy 3x680, 1x6.8 and 1x68. Resistors are cheap. Solder up the rest of the kit and then sub out the resistor in question, with the first test using the silkscreen as the reference/most likely value.

JozeyWhales
Common Wiggler
Posts: 100
Joined: Thu Jun 25, 2015 5:15 pm

Post by JozeyWhales » Mon Nov 04, 2019 9:12 am

This would be really cool if there was a surface mount component kit so that the module was not so deep.

Sjaak Reuzel
Learning to Wiggle
Posts: 4
Joined: Mon Sep 23, 2019 7:24 am
Location: Netherlands

Re:

Post by Sjaak Reuzel » Tue Dec 31, 2019 5:02 am

honeyb wrote:
Tue Oct 29, 2019 6:40 am
Valstip wrote:Hi! What is the final word on the resistor values?

BOM says 3 x 680 and 1 x 6.8 but the silkscreen shows only two 680, one 6.8K and one 68K (not in BOM).

Thanks for the modules!
Bumping this question. Just got the panel/PCB and am preparing the mouser order.

Workaround is to just buy 3x680, 1x6.8 and 1x68. Resistors are cheap. Solder up the rest of the kit and then sub out the resistor in question, with the first test using the silkscreen as the reference/most likely value.
I'm almost done building my first one of two, and as far as I understand it , you are to beleive the silk screen.
So, 2 x 680, 1 x 6.8 and 1 x 68k.

Don't take my word for it though, I'm a total noob and as far as I understand the package MA sent me was incomplete:
in a double kit (so 2 modules) I only had 2 x 680 and no 68k's!

According to about anyone in this thread the text on the PCB is right though.

I could use some help with connecting the jacks though. I get that this is basic stuff, but again I'm a total noob and english is not my first language.

Sjaak Reuzel
Learning to Wiggle
Posts: 4
Joined: Mon Sep 23, 2019 7:24 am
Location: Netherlands

Re: [BUILD] Manhattan Analog Discrete Transistor Amplifier (DTA)

Post by Sjaak Reuzel » Tue Dec 31, 2019 5:09 am

And then I find this...
Image

User avatar
veets
Wiggling with Experience
Posts: 427
Joined: Sat Oct 31, 2015 5:54 pm
Location: New York's Finger Lakes
Contact:

Re: [BUILD] Manhattan Analog Discrete Transistor Amplifier (DTA)

Post by veets » Tue Dec 31, 2019 5:57 am

You found that even as I was preparing this for you:

MA DTN Wiring.jpg

I'm sharing for future reference (mine).
You do not have the required permissions to view the files attached to this post.

Sjaak Reuzel
Learning to Wiggle
Posts: 4
Joined: Mon Sep 23, 2019 7:24 am
Location: Netherlands

Re: [BUILD] Manhattan Analog Discrete Transistor Amplifier (DTA)

Post by Sjaak Reuzel » Tue Dec 31, 2019 11:49 am

Thanks Veets, that helped me check if I soldered the jacks right (and I did!).

My signal is very quiet though. After checking I found that I used the wrong pot for the CV (I bought two kits for this is my starter project), so I fixed that.
Everything kinda works, but I have to crank the DRIVE all the way up to make an audible sound. And a 5V LFO on the CV input is barely noticable, whereas I can make some FM-like effects with an LFO on the VOL.

User avatar
veets
Wiggling with Experience
Posts: 427
Joined: Sat Oct 31, 2015 5:54 pm
Location: New York's Finger Lakes
Contact:

Re: [BUILD] Manhattan Analog Discrete Transistor Amplifier (DTA)

Post by veets » Tue Dec 31, 2019 4:22 pm

I wish I could help with that, too, Sjaak. Unfortunately my troubleshooting skills are limited to the things you've already tried. I'm struggling myself right now with a Plum Audio Wavelet that lights but won't pass audio. :bang:

Best of luck!

orbist
Learning to Wiggle
Posts: 2
Joined: Wed Jan 16, 2019 8:33 pm
Location: Auckland

Re: [BUILD] Manhattan Analog Discrete Transistor Amplifier (DTA)

Post by orbist » Tue Mar 31, 2020 5:36 pm

Hi all, so to confirm the BOM is wrong, and the silkscreen is correct.

The required resistors are :
2x 680R
1x 6.8K
1x 68K

I just spent several hours debugging mine, no sound, replaced all the transistors as I'd got a real cheap batch from Aliepress that I thought maybe suspect before I realised two of the jack's I'd used (for CV and VOL) weren't switching! DOH!

Post Reply

Return to “Music Tech DIY”