TS808 diy clone or Strat noise

[vinceg]

Hi, I'm new in stompbox building. I assembled a ts808 clone. It works well with my two humbucker guitar, but when I plug a stratocaster too much noise. My strato if plugged directly in amply is more quiet, with screamer too much noise. My Prs is quiet with screamer, only little wish when drive turned to max. what could be the problem?

[ElectricDruid]

Welcome!

If the pedal is quiet with humbucker pickups and more noisy with single coil pick-ups on the Strat, there probably isn't anything wrong with it at all. That would be what you'd expect, and that's why people invented "hum bucking" pick-ups in the first place - the single coil type are a bit noisy!

HTH,
Tom

[GibsonGM]

The pedal is probably amplifying noise that is "not hum-bucked", like Tom says.   That makes it MUCH more obvious!

Welcome to the forum, Vince!

[phaeton]

A side effect of the 'out of phase' wiring in a Strat is that the two active pickups act like a humbucker.  If you flip your pickup selector into 2 or 4 position on the Strat, I'll bet that all (or a whole damn lot) of the noise disappears. 

Like the other guys have said that noise is always there, just very faintly.  The TS808 is just amplifying it.  I have a strat with a pair of H-90 single coils on it.  If I use any sort of distortion at all I pretty much have to keep both pickups on to silence the noise.

[vinceg]

Hi, thank's for welcome in this forum and for yours answer.
So, despite my Strat is quiet in bypass mode, it's normal a noise with effect turn on.

And why the pot volume of both guitars, one with single coil and one with humbucker, scratches when turned with effect on?

[thermionix]

And why the pot volume of both guitars, one with single coil and one with humbucker, scratches when turned with effect on?

Volume pots get scratchy if they're in need of cleaning, or if they have DC voltage across them.  You can measure for DC with a meter, it will likely be a very small voltage if present.  If you do find DC it may be leaking from a faulty input cap in your pedal.  If not, clean the pots with DeOxit or similar.

[vinceg]

And why the pot volume of both guitars, one with single coil and one with humbucker, scratches when turned with effect on?

Volume pots get scratchy if they're in need of cleaning, or if they have DC voltage across them.  You can measure for DC with a meter, it will likely be a very small voltage if present.  If you do find DC it may be leaking from a faulty input cap in your pedal.  If not, clean the pots with DeOxit or similar.

I mean guitar's volume pots, I do non think they have a DC voltage and they are new pots and I cleaned them

[vinceg]

Sorry, about noise, first I forgot to say that I reduced the 4k7 resistor with 2k2. Can this mod increase noise?

[thermionix]

And why the pot volume of both guitars, one with single coil and one with humbucker, scratches when turned with effect on?

Volume pots get scratchy if they're in need of cleaning, or if they have DC voltage across them.  You can measure for DC with a meter, it will likely be a very small voltage if present.  If you do find DC it may be leaking from a faulty input cap in your pedal.  If not, clean the pots with DeOxit or similar.

I mean guitar's volume pots, I do non think they have a DC voltage and they are new pots and I cleaned them

Right, I'm talking about the guitar volume pots too.  Assuming your guitars have passive electronics, the only way to get DC on the pots is for it to come from whatever you plug into.  Tube Screamers and most other pedals have an input cap that should block DC from working its way back up the signal chain, but if the input cap is leaking DC it can happen.  It only takes a fraction of a volt to make the guitar pots audibly scratchy.  If you have a meter it's an easy test, you don't even need the guitars handy.  Just plug a cable into the pedal, with the effect on, and measure for DC voltage between tip and sleeve of the plug at the other end of the cable.  Set your meter to the lowest scale if it isn't autoranging.

[vinceg]

And why the pot volume of both guitars, one with single coil and one with humbucker, scratches when turned with effect on?

Volume pots get scratchy if they're in need of cleaning, or if they have DC voltage across them.  You can measure for DC with a meter, it will likely be a very small voltage if present.  If you do find DC it may be leaking from a faulty input cap in your pedal.  If not, clean the pots with DeOxit or similar.

I mean guitar's volume pots, I do non think they have a DC voltage and they are new pots and I cleaned them

Right, I'm talking about the guitar volume pots too.  Assuming your guitars have passive electronics, the only way to get DC on the pots is for it to come from whatever you plug into.  Tube Screamers and most other pedals have an input cap that should block DC from working its way back up the signal chain, but if the input cap is leaking DC it can happen.  It only takes a fraction of a volt to make the guitar pots audibly scratchy.  If you have a meter it's an easy test, you don't even need the guitars handy.  Just plug a cable into the pedal, with the effect on, and measure for DC voltage between tip and sleeve of the plug at the other end of the cable.  Set your meter to the lowest scale if it isn't autoranging.

Wowww I did not know about this. I will test as soon as possible. In case I find DC voltage can I replace with any cap?

[GibsonGM]

If possible, you'd open the effect the DC is coming from and find which cap is bad, and replace with the same value or as close as you can find.  Using other values can make the effect sound different (tone-wise.....those caps are like "AC resistors").

[phaeton]

...or if they have DC voltage across them.

I did not know this.  Thanks for the... tip.

Of course, I roasted a pickup in one of my guitars with a shorted input cap, so I *always* always ALWAYS check any new circuits for DC on the inputs and outputs before I plug anything into them.  Every time.

I learned this one the hard way :-/

[vinceg]

The cap sholuld be C1 and should not make effect in the sound, is not it?
What could happen if it is larger?

[phaeton]

Lest I'm misreading that schematic, if that switching jack is wired like that, then it won't run off the battery at all.  It's designed to disconnect the battery after you insert the cable.  Mind you, there will probably be a quick blip of DC in the cable right as you insert it.  If it's mis-wired, it could inject constant DC into your guitar.  Best test is to plug a cable into the effect, and measure for DC Voltage between tip to ring on the other end of the cable.

There are a few other things about that subset of schematic that are a bit odd as well, like the ground symbol connecting R4 to the junction of R5.  I'm guessing they're not supposed to be connected, but the schematic might suggest they are.

[phaeton]

To answer your question though, yes the cap can change the sound.  Generally, smaller input caps cut off bass response, larger ones let more in.  This is especially true when you have resistor nearby creating an RC network.  It's a tad complicated and someone else can certainly answer it better than me.

IIRC the TS has around a 0.022uF cap on the input, but something within 15 or 20 % probably won't cause THAT much difference.  You can always try it and see.  You may like the difference.

That said, you generally want that cap between all power connections and the tip of the cable.

For reference, here is GGG's true-bypass TS-808 that is tried and true.  Note how the battery is switched in/out using the ground (ring) of the cable.

[vinceg]

To answer your question though, yes the cap can change the sound.  Generally, smaller input caps cut off bass response, larger ones let more in.  This is especially true when you have resistor nearby creating an RC network.  It's a tad complicated and someone else can certainly answer it better than me.

IIRC the TS has around a 0.022uF cap on the input, but something within 15 or 20 % probably won't cause THAT much difference.  You can always try it and see.  You may like the difference.

That said, you generally want that cap between all power connections and the tip of the cable.

For reference, here is GGG's true-bypass TS-808 that is tried and true.  Note how the battery is switched in/out using the ground (ring) of the cable.

This is how I assembled th circuit, can you see if there is a mistake on the switching jack

[vinceg]

I plugged a cable in imput jack and measured DC voltage. I found a 2.8V DC 
I changed 22nf C1 but nothing changes, there is a 2.8 DC voltage between the ring and the other end of the cable.

[Slowpoke101]

Is the cable that you used a mono cable (tip and sleeve) or a stereo cable (tip, ring and sleeve)?

The wiring diagram of your input jack wiring looks OK. But I'm not sure about the DC jack's positive (red) wiring. Those wires may need to swapped over.

[vinceg]

Is the cable that you used a mono cable (tip and sleeve) or a stereo cable (tip, ring and sleeve)?

The wiring diagram of your input jack wiring looks OK. But I'm not sure about the DC jack's positive (red) wiring. Those wires may need to swapped over.

The cable is a mono. The DC jack's I think is ok, I've 9V in the correct point. The problem is a 2.8V DC in the imput cable

[Slowpoke101]

Very odd. Is there any chance that you can upload a picture of the pedal's wiring and a close-up of the input jack's connections?

A DC voltage certainly explains the scratchy noises from the guitar's volume control. I can also understand your concerns about ruining any pickups - not cheap.