Tube screamer TS808 with clipping switch mod

[El_Diablo572]

General build question really. Using one of lvlark's plans which i'l post below, i'm a little unsure of the wiring on the clipping switch, can somebody explain to me how i should be wiring the diodes and LED's to the switch?

The layout appears to show the diodes wired to a switch with 6 posts, whereas mine only has three..?

[rocket88]

hey man. you're using the wrong switch. if yours has 3 posts and it's On-Off-On, you've got an SPDT switch, where as you want a DPDT On-Off-On switch. once you have the right switch wire the clipping diodes as shown in the layout. so on one side you're going to put on one side 2 1N4148 diodes asymetrically to lugs 1 & 4, and on the other side you're going to put 2 LEDs asymetrically on lugs 3 & 6, while lugs 2 & 5 go to the board as shown. does that make sense?


and i not sure if you were asking this too, but the LEDs on the switch are not indicator diodes, they're used as clipping diodes. you should get more headroom, less compression, and as some would say more "tube like" distortion.

[Sphere80]

Try this:

[El_Diablo572]

I had a feeling it was the wrong switch...

Thanks sphere, i'll try that and see how it works

This is only my second build, the whole building and wiring part/physical aspect of pedal building comes pretty natural, but electronics is very new to me, i have a basic understanding of what i should be doing but things like this tend to trip me up because i just don't have the relavent knowledge, so, thanks again guys, any help is greatly appreciated

[El_Diablo572]

Hmm. I tried that but the pedal didnt seem to work how i expected it. Less of a scream, more of a flat fart...

I dont know if this has anything to do with it, but if i got rid of the switch and diodes, and i just connected the led's to the circuit for more distortion, that should work, shouldn't it?

Gain control didnt appear to do much other than act as a second  volume pot, is the number 3 terminal on the gain/drive pot supposed to be connected to something?

One more..... If i use a superbright LED with my bypass switch, will this affect anything?

[El_Diablo572]

I'm still stuck with this one. I got rid of the switch and just wired the LED's into the circuit permanently. It worked, a little better this time, controls appear to do what they're supposed to, etc, but it still sounds like shit. Drive is really weak, and its quite muted and flat sounding. Has anybody else built one of these?

[velouriafx]

For me, you are explaining how a tube screamer sounds haha

[El_Diablo572]

To be perfectly honest, i've never used a tubescreamer to know what it should really sound like, but when you're playing an EMG equipped thru-body into 50watts of marshall combo, if it sounds weak usually something is wrong....

I just expected more i guess. Looks like this one is going in the junk box for salvage at a later date.....

[eve-the-frog]

You should try this : solder two diodes in parallel  (reversed, like the layout) between the sw1 wire and sw2 wire. You use no switch at all.

I've built it and always use this position of the clipping switch...

I also recommend trying several 4558 ICs from various manufacturers... but not from Chinese ebay seller !

Here's mine

[El_Diablo572]

Yeah, that's basically what i did, but with the LED's instead. I'm gonna play around with it a little, try different components and see what happens. I'm not going to bother boxing this, i think i'm just gonna keep it on my test board and use it for experimentation, eventually i might find something with just the right amount of grit