TS-808 clone low output

[harrisxr650]

Hi people.

I've build last night, since i had some parts laying around a ts 808 from the bellow layout




It supposed to be a CJOD clone without the buffers and with an added pot to control bass
the schematic the layout is based should be this one but i'm not 100% sure.



aside that the 100uf cap and the protection diode are wrong in the layuout can any one spot any other errors?

I've build this last night but i get a really low output.

All pots are responsive when turned, i can hear tone, gain, volume and bass changes
The clipping option switch doesnt make a changes to the tone but i might have a bad solder somewhere.

Also i didnt use the layouts the messy wiring for the 3pdt,
instead i used this one




OpAmp voltages seems ok


1: 4.73
2: 4.75
3: 4.51
4: 0
5: 4.72
6: 4.73
7: 4.73
8: 9.47

thanks

[GibsonGM]

Hard to say what's really up, since you already know there are errors on that layout.  Someone may take the time to trace it on here, I don't bother - not enough time in the day!   And uncertain which schematic this is based off of.

What I'd do, tho, is double-triple check the resistor values around the 2nd half of the opamp.  Voltages look good.  If you have some R's put in the wrong locations that may explain the lack of signal level at the output...usually the problem is ours, when we build it, we make errors    Then an audio probe to find where it goes quiet.  HTH

[harrisxr650]

Thanks for looking into this. I will try to debug it with a probe Tonight. But I won't spend much time.maybe I go for a verified layout and be done with it 🙂.

[italianguy63]

[harrisxr650]

ok... i gave up on previous layout.. had too many errors.

i build the verified version on tagboardeffects

http://tagboardeffects.blogspot.com/2012/12/son-of-clay-jones-overdrive.html

Sounds amazing (at least for my taste) but having a small issue.
The volume pot doesn't change much the outpout  until 3/4 of its rotation. At the last 1/4 its seems ok...
Its supposed to work this way?

Also i got a small squeal when the tone pot is cranked. replaced the electrolytics in case they are bad with no luck,
also  instead of the 51pf i used 47pf, also  replaced that one too with no luck

the squeal stops when i touch the leds on the solder side of the vero.

opamp is a JRC4558DD

Voltages

psu: 9.47

1: 4.95
2: 4.76
3: 4.42
4: 0
5: 4.95
6: 4.95
7: 4.95
8: 9.47

And they seem fine

Thanks

[Steben]

What make and taper is the pot? A, B, C, F, L?

[harrisxr650]

What make and taper is the pot? A, B, C, F, L?

Alpha pot B25k

[Steben]

What make and taper is the pot? A, B, C, F, L?

Alpha pot B25k

Wow, a linear one. Should behave as lots of volume change in the first half 

[harrisxr650]

What make and taper is the pot? A, B, C, F, L?

Alpha pot B25k

Wow, a linear one. Should behave as lots of volume change in the first half 

B25k for the tone pot. The volume is 100k linear as well.

[kaycee]

I have one laying around, built from the same layout. Just put it on my board and it's the usual TS behaviour volume wise, about 1/4 up is unity, there isn't tons of volume in all, but I wouldn't expect there to be. I'd of used the stated pot values, I suggest you check for shorts around the output and switch wiring.

[harrisxr650]

I have one laying around, built from the same layout. Just put it on my board and it's the usual TS behaviour volume wise, about 1/4 up is unity, there isn't tons of volume in all, but I wouldn't expect there to be. I'd of used the stated pot values, I suggest you check for shorts around the output and switch wiring.

The volume issue doesn't bother me. I never had a ts and I didn't know if it was common. It goes well above unity and since I can dial in the volume level I want  it's fine.

The problem is the squel from the tone pot when maxed. I've noticed that, besides touching the LEDs, if I reduce the gain from the gain pot it stops.

[Vivek]

Alpha pot B25k

Does it boss over the other pots and order them around ?

[harrisxr650]

Alpha pot B25k

Does it boss over the other pots and order them around ?

I'm not sure if i understand what you mean
can you please explain further?

Thanks

[idy]

Squealing at high gain is often wires too close to each other or pot too close to part of the board. Sometimes the stomp switch is the culprit; some use the 'outside' poles of the switch for the signal switching (and the middle pole for LED) to keep a bit of space between the in and out wires.

Shielded wire on in/out may help (ground the shield at one end only).

Also possible to up that 51p cap in the feedback loop. Tack solder another 51p to it. You will loose some highs, most noticeable when gain is maxed.

[kaycee]

The volume issue doesn't bother me. I never had a ts and I didn't know if it was common. It goes well above unity and since I can dial in the volume level I want  it's fine.

The problem is the squel from the tone pot when maxed. I've noticed that, besides touching the LEDs, if I reduce the gain from the gain pot it stops.

If I turn up the tone and gain fully on mine, it begins to squeal as the volume pot approaches halfway. Most likely due to the layout of the vero. You could try building it on a TS PCB with a good layout and I expect you would have no problem as long as your wiring was laid out well too.

The settings at which mine squeals at are of no use to me, hence I'd not noticed it happening. I have Tone at 1.00 o'clock, Gain at 11.00 o'clock and volume at half, into chorus and bit of delay and a small clean valve amp, and its a very nice tone I think.

[harrisxr650]

Squealing at high gain is often wires too close to each other or pot too close to part of the board. Sometimes the stomp switch is the culprit; some use the 'outside' poles of the switch for the signal switching (and the middle pole for LED) to keep a bit of space between the in and out wires.

Shielded wire on in/out may help (ground the shield at one end only).

Also possible to up that 51p cap in the feedback loop. Tack solder another 51p to it. You will loose some highs, most noticeable when gain is maxed.

I think that the cap in the feedback loop might do the trick. I connected in a hurry the leads of a 10pf the leads of the 51pf and the squel gone with all settings at max. will solder it later to see if its indeed works

[harrisxr650]

Sadly it didn't fix it. The larger the cap the more it reduces the squel but also it cuts all the high freqs and it sound awfull...