[AVAILABLE] TTSH V4 Build Thread

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by KSS » Sat May 02, 2020 3:39 pm

Do the TTSH kits use mica or polystyrene for the 680p and .015u timing caps? If polystyrene is involved, it may have been damaged during soldering. Less likely for other fim caps, but still possible.

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by fuzzbass » Sat May 02, 2020 10:09 pm

KSS wrote:
Sat May 02, 2020 3:39 pm
Do the TTSH kits use mica or polystyrene for the 680p and .015u timing caps? If polystyrene is involved, it may have been damaged during soldering. Less likely for other fim caps, but still possible.
Synthcube kit includes styrenes for the 680p on the 4027-1 and C0Gs for the 15n caps on the VCO sections.
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Re: [AVAILABLE] TTSH V4 Build Thread

Post by KSS » Sat May 02, 2020 10:37 pm

Thanks fuzzbass. Surprised they're not using silver mica 680p.

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by amir » Sat May 02, 2020 11:11 pm

I have regular film 680pf from the mouser cart and cog 15n. I can try swapping those out but I am pretty good at soldering and haven’t overheated any of those parts. The sawtooth is in a better state than the square. I am guessing the issue must be closer to the square part of the circuit and leaking slightly back to the sawtooth a bit.

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by KSS » Sat May 02, 2020 11:22 pm

The COG's are likely fine. You told us LFO mode was smooth. In your shoes, I'd take a long term look at it to be sure its not also drifting, but slow enough to appear stable in a short viewing.

What type film? Don't sell yourself short on these three important caps. Even if it's not the source of this problem, a polyester film cap here is not doing you any favors. 680p mica's are not terribly expensive, all things considered.

The square of VCO1 and pulse of VCO2 and 3 is a comparator setup. If it's wildly varying then you should look to see that the main power rails to the board are stable. Measure at the comparator op amp. Then check the reference voltage for the comparator. It also should be stable.

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by amir » Sun May 03, 2020 11:50 am

KSS wrote:
Sat May 02, 2020 11:22 pm
The COG's are likely fine. You told us LFO mode was smooth. In your shoes, I'd take a long term look at it to be sure its not also drifting, but slow enough to appear stable in a short viewing.

What type film? Don't sell yourself short on these three important caps. Even if it's not the source of this problem, a polyester film cap here is not doing you any favors. 680p mica's are not terribly expensive, all things considered.

The square of VCO1 and pulse of VCO2 and 3 is a comparator setup. If it's wildly varying then you should look to see that the main power rails to the board are stable. Measure at the comparator op amp. Then check the reference voltage for the comparator. It also should be stable.
Actually made a mistake the 680p are cog as well, hadn't flipped them over yet. At the time I built this, I was still a noob and I assumed the mouser cart had the best picked parts in it, it was not about money at all. With everything that I've picked up on these past few years, I would probably have built this thing very differently and now have to go back and change things around. These are the cogs in there now: https://www.mouser.com/ProductDetail/810-FK28C0G2E681J

I have some extra lm301s and lf411 on hand, I will try swapping those to see if it makes any difference. I am also going to order some new caps and see if those make a difference as well. thanks

Edit: also the voltages on the regulators are exactly at 15/-15. At the opamp they are 14.96 and -14.97 this also matches the power header in that section.

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by amir » Wed May 13, 2020 3:27 pm

Just an update; I swapped out the opamps and 680p caps and it didn't make a difference. I pulled out all 3 cards and tested them all in different combos and by themselves and got similar results from the outputs. This leads me to believe that the actual cards don't have an issue, its somewhere on the main board. I then thought about leaving my scope on the PWM output of vco2, since this is the output that is acting the strangest, without the card in vco2.

with no cards plugged in vco2 PWM output sits at zero.
with a card plugged only into vco1, vco2 PWM output starts to fluctuate at very low voltages but there is definitely movement.
same as above with only a card plugged into vco3, vco2 PWM again outputs exact same fluctuation.

The only links I see between these combos is vco2 sine output (which is perfect on scope) to each of the other two vco and the fact that they all receive the same cv and ground connections.

I have checked the following:
-vias are ok, I have trimmed all my jacks.

-I am getting around 100mv of resistance between the ground pin and cv pin of all three keyboard input jacks. I checked this in vcf area and getting same. is this normal?

Any of you guys have any clues what the problem might be?

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by KSS » Wed May 13, 2020 7:45 pm

KSS wrote:
Sat May 02, 2020 11:22 pm
The square of VCO1 and pulse of VCO2 and 3 is a comparator setup. If it's wildly varying then you should look to see that the main power rails to the board are stable. Measure at the comparator op amp. Then check the reference voltage for the comparator. It also should be stable.
edit: with all the VCO sub-boards in place. /edit

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by amir » Wed May 13, 2020 11:10 pm

KSS wrote:
Wed May 13, 2020 7:45 pm
KSS wrote:
Sat May 02, 2020 11:22 pm
The square of VCO1 and pulse of VCO2 and 3 is a comparator setup. If it's wildly varying then you should look to see that the main power rails to the board are stable. Measure at the comparator op amp. Then check the reference voltage for the comparator. It also should be stable.
edit: with all the VCO sub-boards in place. /edit
The power rail voltages were/are stable at the opamps.

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by CollinRussell » Sat May 16, 2020 11:48 pm

Can anyone verify that their headphone output is pretty noisy? Just did all the testing and calibration. Everything checked out except the headphone jack was wired backwards (panned left = right, vice-versa), but i'm getting some serious noise from the headphone jack. No smoke, nothing cooked.

EDIT - All fixed. bad 3904/3906 transistor pair in osc core 2.
Last edited by CollinRussell on Sun May 17, 2020 9:12 pm, edited 1 time in total.

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by Wheelbreak » Sun May 17, 2020 7:59 pm

So I finished the build and started testing and calibrating. Everything works as it should, but almost none of my voltages are correct.

all of the oscillators are between 10.4-10.6 vpp even when swapped between the various sockets.
filter when closed after matching the output osc1 square wave to the input should be offset 5v dc and is 2.6v
filter sine is only 8v at 10hz instead of 14v I get up to 13v at about 100hz though
adsr pushes the vca output to 15v when fully up
all the reverb outs vary significantly depending on the frequency you feed from too low to too high
noise outs are very high white+20v pink=18v low freq=27v
s&h outputs 12.4vpp pretty sure this has to do with the noise outs being high.

edit: I have been testing a bunch of my euro modules and those numbers seem fine on the oscillators. The filter goes up to the 14v at 150hz so I can definitely live with that. I'm thinking there may be a misplaced resistor in the noise circuit so I will be testing those today. I'm not the best with schematic. I can kind of read them, but am not confident in those skills. I was hoping someone could point me to the opamp that provides the gain in the noise circuit.

Also, a confirmation that the adsr isn't that out of whack. If so would I just add a higher resistor in series with the trimmer? It seems in the guide that it is intentionally over powered to force the vca to clip. So, I'm not sure if it's actually okay.


Are any or all of these acceptable variances? I've made a couple of simple patches on the bench and it sounds great. I would really love to put this in the case. I have a case with a removable back so I can still get to things, but don't want to have to take all of the jack nuts off if I need to replace parts.

This thread is a god send.

Thank you much for all the work you have put into the build guide fuzzbass.

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by fuzzbass » Mon May 18, 2020 11:36 am

Wheelbreak wrote:
Sun May 17, 2020 7:59 pm
So I finished the build and started testing and calibrating. Everything works as it should, but almost none of my voltages are correct.

all of the oscillators are between 10.4-10.6 vpp even when swapped between the various sockets.
filter when closed after matching the output osc1 square wave to the input should be offset 5v dc and is 2.6v
filter sine is only 8v at 10hz instead of 14v I get up to 13v at about 100hz though
adsr pushes the vca output to 15v when fully up
all the reverb outs vary significantly depending on the frequency you feed from too low to too high
noise outs are very high white+20v pink=18v low freq=27v
s&h outputs 12.4vpp pretty sure this has to do with the noise outs being high.

edit: I have been testing a bunch of my euro modules and those numbers seem fine on the oscillators. The filter goes up to the 14v at 150hz so I can definitely live with that. I'm thinking there may be a misplaced resistor in the noise circuit so I will be testing those today. I'm not the best with schematic. I can kind of read them, but am not confident in those skills. I was hoping someone could point me to the opamp that provides the gain in the noise circuit.

Also, a confirmation that the adsr isn't that out of whack. If so would I just add a higher resistor in series with the trimmer? It seems in the guide that it is intentionally over powered to force the vca to clip. So, I'm not sure if it's actually okay.


Are any or all of these acceptable variances? I've made a couple of simple patches on the bench and it sounds great. I would really love to put this in the case. I have a case with a removable back so I can still get to things, but don't want to have to take all of the jack nuts off if I need to replace parts.

This thread is a god send.

Thank you much for all the work you have put into the build guide fuzzbass.
I have built a crap ton of these, and the P-P output voltage of the VCO Saw and Squares, as well as the EGs is anywhere from +9 to 11V. There is no adjustment for these.

I'm assuming you worked the gain and offset trimmers on your VCF. With the filter opened, and resonance closed, your output (source audio frequency range) should be unity gain for a single input. If you installed the AC coupling, use the first audio channel (norm: RingMod), which is DC coupled, for this test. Patch source VCO in there. When the gain is properly adjusted for signals coming into the mixer, you will see your sine output, with resonance maxed, much hotter, maybe 16V p-p.

VCA adjustment: bring saw directly from VCO1 to first input and raise slider. Raise VCA level (the horizontal slider at the top). Adjust linear gain trimmer for unity gain at output. Reduce slider at the top. Patch AR EG out to Exp CV in and raise Exp slider to 70%. Press manual gate and adjust Exp gain trimmer for unity gain at output. Moving the Exp CV level control above 70% clips the signal - its a feature. Perform control rejection calibration as stated in 2600 service manual.

Before fitting your panel and all its little nuts, check everything, incl the lag and inverters, env follower, preamp, etc. Monitor S&H out on your scope or DMM, set the clock to really low speed and and watch for drooping voltage coming out of the S&H. It should hold at very slow clock speed.
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Re: [AVAILABLE] TTSH V4 Build Thread

Post by Wheelbreak » Mon May 18, 2020 9:23 pm

Thank you for the advice. I forgot about the AC coupling and that it could effect the calibration.

I think my trimmer for the exp CV was bad (looked like it was only functioning at 500 when I tested it on board even though the markings indicated it was 10k) so I tore it out. Unfortunately all I have are 100k in my parts bin. I live in the largest city in the USA, but we don't have an electronic components store. The only good one I know of looks like it closed since I last went out there.... I get a shipment of some on Friday. I will do the tests on that when I get a new one installed. It clipped when I tested it before as expected, but the manual said 10vpp and I was getting 15vpp. When I tested the ADSR CV on it's own, it was perfect. It only shot up when I fed signal through it. The AR worked fine. That's why I tested the exp trimmer.

I did all the other tests except the voltage processor section. The S&h is solid as a rock if not a little high vpp

I am very concerned about the noise out put voltage levels. Any ideas what to check. I looked at the schematic, but although I can follow signal paths I only have a vague concept of what does what. Also the way the boards are labeled, I have no idea how all the traces are running beneath the mask. I assume either I have switched two resistors or one of the opamps is bad?

I was going to by a grip of TL071's to just have, also thought if one went bad from a mistake I could just throw it in an IC holder. There are about 8 different variations by TI on mouser. I know other than size it's minor variances on what it handles, but are they all basically interchangeable in an audio circuit? The exact one from the BOM is obsolete.

Thank you again, you have no idea how much this helps all of us!

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by KSS » Mon May 18, 2020 10:20 pm

Have you used 071's instead of 301's throughout your build?

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by Jfettig » Tue May 19, 2020 11:17 am

Hi Guys!

I just wanted to take a minute and thank everyone on here for being thoughtful and attentive. This was my first build outside of a couple Eurorack kits, and I am really grateful to this community for existing and being supportive. A super big thanks to Fuzzbass and Synthcube for their organization and dedication, without whom I would never be able to dream of taking on this project. Here are a couple photos of my finished product which I am beyond pleased with.

Image

Image

Image

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by Wheelbreak » Tue May 19, 2020 11:30 am

KSS wrote:
Mon May 18, 2020 10:20 pm
Have you used 071's instead of 301's throughout your build?
I have substituted kind of willy nilly as I think I had the right amount of chips, but 10 were TL071's. I def changed out the one by the power supply as suggested, and kept all of the oscillator area chips 301's. From what I have read on here, most of them are interchangeable with the exception of the one in the wave shaper. While the TL071's are more stable, correct?

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by fuzzbass » Tue May 19, 2020 12:21 pm

Jfettig wrote:
Tue May 19, 2020 11:17 am
Hi Guys!

I just wanted to take a minute and thank everyone on here for being thoughtful and attentive. This was my first build outside of a couple Eurorack kits, and I am really grateful to this community for existing and being supportive. A super big thanks to Fuzzbass and Synthcube for their organization and dedication, without whom I would never be able to dream of taking on this project. Here are a couple photos of my finished product which I am beyond pleased with.
Looks great! :party:
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Re: [AVAILABLE] TTSH V4 Build Thread

Post by KSS » Tue May 19, 2020 10:48 pm

Jfettig wrote:
Tue May 19, 2020 11:17 am
Here are a couple photos of my finished product which I am beyond pleased with.
Looks great, Jfettig!

I think you may regret having those two toggle bats sticking out unprotected. I'd either cut a hole in the wood and put them on a panel mounted on the wood's inside face, or buy-bend a couple U-shaped metal switch protectors. Some kind of 'roll-bar' protection.

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by KSS » Tue May 19, 2020 10:55 pm

Wheelbreak wrote:
Tue May 19, 2020 11:30 am
I have substituted kind of willy nilly as I think I had the right amount of chips, but 10 were TL071's. I def changed out the one by the power supply as suggested, and kept all of the oscillator area chips 301's. From what I have read on here, most of them are interchangeable with the exception of the one in the wave shaper. While the TL071's are more stable, correct?
Did you also change-remove the 30pf compensation caps where the 071 was used?

Changing classic designs by 'upgrading' to so-called better opamps can create new problems. It's not usually as simple as stick the new one where the old one was. Besides the compensation caps, the higher slew speed of the -generally- newer opamps can increase current drain and noise, both audible and inaudible. 07x opamps can go into reverse lockuyp fromthings a lesser opamp wouldn't even notice.

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by Wheelbreak » Wed May 20, 2020 8:42 am

KSS wrote:
Tue May 19, 2020 10:55 pm
Wheelbreak wrote:
Tue May 19, 2020 11:30 am
I have substituted kind of willy nilly as I think I had the right amount of chips, but 10 were TL071's. I def changed out the one by the power supply as suggested, and kept all of the oscillator area chips 301's. From what I have read on here, most of them are interchangeable with the exception of the one in the wave shaper. While the TL071's are more stable, correct?
Did you also change-remove the 30pf compensation caps where the 071 was used?

Changing classic designs by 'upgrading' to so-called better opamps can create new problems. It's not usually as simple as stick the new one where the old one was. Besides the compensation caps, the higher slew speed of the -generally- newer opamps can increase current drain and noise, both audible and inaudible. 07x opamps can go into reverse lockuyp fromthings a lesser opamp wouldn't even notice.
I guess I better order more 301's then.

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by KSS » Wed May 20, 2020 9:00 am

You can make it work with the 071's. I'm not trying to promote 'magic' parts.

But it's not usually a straight changeover with no other attendant changes is more the point I hoped the emphasize.

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by Wheelbreak » Wed May 20, 2020 5:12 pm

KSS wrote:
Wed May 20, 2020 9:00 am
You can make it work with the 071's. I'm not trying to promote 'magic' parts.

But it's not usually a straight changeover with no other attendant changes is more the point I hoped the emphasize.
I understand. I just thought I read it was a straight switch out without any other changes. I would rather wait on the parts and just switch the ICs out of sockets then change out soldered parts. I'm always paranoid about ripping traces as I don't have the best luck pulling components.

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by Wheelbreak » Sat May 23, 2020 4:53 pm

So I just got my 10k trimmer in and it made no difference. I also looked and all of my problem areas don't involve any of the tlo71s. I just realized my noise had a high vpp but maxv was under 11v so that should be fine. Right now my only real concern is the 14.5 v max I'm getting from the adsr when it's all the way up with an input signal. As long as I keep it down when patching into my euro system, I guess I should be fine, or is this way out of whack? I tried switching 301's and no difference. Is this a result of the gate booster?

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by Wheelbreak » Sun May 24, 2020 11:38 am

I went through the calibration process again and the noise output is supposed to be 10vpp I am thinking of just upping the resistor on the output. Is there any reason why that would be a bad idea? Also when calibrating the VCOs I plugged a TR cable into the headphone out and got some smoke from the 2 10R resistors in the speaker amp section. The headphones worked fine as did the speakers afterword and the resistors weren't getting hot again. Did I wire something wrong or is it just a no no to plug a TR cable there? I want to get this in the case sooooo bad. I made another patch with it on my desk last night and it is begging me to start playing it!!!

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Re: [AVAILABLE] TTSH V4 Build Thread

Post by fuzzbass » Sun May 24, 2020 7:44 pm

Wheelbreak wrote:
Sun May 24, 2020 11:38 am
I went through the calibration process again and the noise output is supposed to be 10vpp I am thinking of just upping the resistor on the output. Is there any reason why that would be a bad idea? Also when calibrating the VCOs I plugged a TR cable into the headphone out and got some smoke from the 2 10R resistors in the speaker amp section. The headphones worked fine as did the speakers afterword and the resistors weren't getting hot again. Did I wire something wrong or is it just a no no to plug a TR cable there? I want to get this in the case sooooo bad. I made another patch with it on my desk last night and it is begging me to start playing it!!!
It is wrong to plug a TR cable into the headphone jack. You will short one of the the outputs and since this is a transformerless design, it won't tolerate it.
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