TubeScreamer Mod question…

[AlanR]

Hey guys...

I've got a TS7 that I've modded. I started with a Monte Allums mod then did a few other tweaks.

D3 -I swapped out the stock diode for 1N4002 diode
D4 -I swapped the stock diode for a red LED

I also swapped out two resistors.

R27 - I changed to 22kohm carbon film resistor

R85 - I changed to 3.3kohm carbon film resistor

It's much more suited to my needs now.

But I read where some people swap the R27 resistor for an even lower value like 12k to reduce the gain present when the Drive knob is at zero.

I was considering this but didn't have anything of that value. I do have 10k resistors around. How much difference could there be between a 10k and 12k resistor?

I already have a TS variant on my board so I'm playing with this one and trying to make it serve my purposes more so as a clean boost.

[Keppy]

You should post a schematic when you ask these kind of questions, as different ones will number the components differently.

First, read this: http://www.geofex.com/article_folders/tstech/tsxtech.htm

If you're talking about the feedback resistor in series with the gain pot (51k on GEOFEX, 47k on some schems) than the difference between 10k/12k will not be noticeable. It will reduce the volume at minimum gain though, so it should improve your "clean" at the expense of your "boost." You might be better off raising the clipping threshold. Replacing a clipping diode with an LED is a good start, but the 4002 won't offer much more headroom than a 1N914. Try another LED in that spot (if you want them to be different for asymmetrical clipping, try a different color) or use two regular diodes in series to clean up the sound without losing the boost.

[AlanR]

Here is a link to the schematic.

http://elektrotanya.com/PREVIEWS/63463243/23432455/ibanez/ibanez_ts7.pdf_1.png

I think I'm wanting asymmetric clipping still. So I will try out another LED.

Any tips on what to try?

Thanks for the link as well. I'm trying to learn what I can as I go.

[J0K3RX]

If you are trying to make it a clean boost maybe try it with no diode clipping at all? Put the diodes on a switch so you can add them in if you want...

[Keppy]

Here is a link to the schematic.

http://elektrotanya.com/PREVIEWS/63463243/23432455/ibanez/ibanez_ts7.pdf_1.png

I think I'm wanting asymmetric clipping still. So I will try out another LED.

Any tips on what to try?

Thanks for the link as well. I'm trying to learn what I can as I go.

Try a 5mm instead of 3mm, or a superbright instead of diffuse, or just the same kind as you have but a different color. They'll all work similarly, but with different amounts of asymmetry when paired with a 3mm red LED. I believe that larger LEDs, superbrights, or colors other than red will all have a higher forward voltage than 3mm reds, but I may be wrong about that.

[AlanR]

I don't have much lying around and I was hoping to try some tweaks without ordering parts or running to radio shack.

I've got some 3mm red LEDs and 5mm Green LEDs.

What would you recommend I try first.

Considering I'm leaning towards a clean boost should I try symmetrical or asymmetric first? I never really found a clear answer on a preferred method.

I'm wanting the tone to be full and round when it's all saod and done.... or as full and round as possible with a TS mod.

[Keppy]

A green one should produce a nice asymmetry with the red one you're already using. With a higher voltage drop for the green one, you'll have a little less distortion on that side of the wave, which matches your goals. Just to be clear, keep the red one you already have in the circuit and replace the 4002 with the green LED. That should give you quite a bit of headroom for boosting, at least compared to a stock TS.

[soupbone]

Hey guys...

I've got a TS7 that I've modded. I started with a Monte Allums mod then did a few other tweaks.

D3 -I swapped out the stock diode for 1N4002 diode
D4 -I swapped the stock diode for a red LED

I also swapped out two resistors.

R27 - I changed to 22kohm carbon film resistor

R85 - I changed to 3.3kohm carbon film resistor

It's much more suited to my needs now.

But I read where some people swap the R27 resistor for an even lower value like 12k to reduce the gain present when the Drive knob is at zero.

I was considering this but didn't have anything of that value. I do have 10k resistors around. How much difference could there be between a 10k and 12k resistor?

I already have a TS variant on my board so I'm playing with this one and trying to make it serve my purposes more so as a clean boost.

Another change you can do(ala keeley) is change the two 1uf/50v electrolytic caps to metal film.(panasonic) I haven't looked at the schematic,but it seems like they should be in there,right by the opamp.Another little touch that some people like,including myself is changing the 51pf ceramic cap to silver mica.

[AlanR]

Keppy - Sounds good. If my newborn cooperates I will give it a shot this evening.

Soupbone - What results did you get from those changes?