GGG ITS8: TroubleShoot

[thedefog]

I finally got my DRRI re-tubbed and it sounds better than ever, turns out the old tubes were biased cold. So I just tried out my pedals again, and still have the same problems as mentioned before. With either of them engaged by themselves with the gain turned all the way down and the volume maxed, the tone is grainy, basically I want the clean sound only with more sustain and compression. It just sounds crackly and distorted. I am starting to wonder if this is because the way I modded the pedal. I I did the expensive boutique mod which was suppose to have given the pedal more gain. Maybe I should revert it back to a regular un-modded tube screamer and it will be less grainy?

Hey there Wes,

Did you try adjusting the bias pot on your amp before buying new ones?

As for your tube screamers builds - Like an earlier post said, tolerances on components could play a major part in consistency.  20% tolerance Carbon comp grab-bag resistors from radioshack are going to vary in their values significantly in comparison to if you used metal film 5% or better tolerance. A 100k resistor at 20% tolerance could measure out at 80K and still be banded as a 100k. That could make a noticeable difference in a tone stack of a circuit. Did you measure all of the resistors before placing them in the circuit? Also, transistors can vary greatly from one to the next, and measuring and matching transistors is important if you're going for two identical builds. I'd socket them and the ICs so that you could try a few of them to find a more consistent sound. Measuring voltages helps as well. Are you running off of batteries or a regulated/unregulated power suppy?

[WesMVaughan]

No I did not test them, and that was my next guess as to the problem I am having. My engineering teacher mentioned the same thing about the % differences between resistors, he also mentioned the caps as well. How do big pedal manufactures make sure there pedals sound identical if this is the case? Anyways I am going to have to do some altering to the pedals. Are you very familiar with the GGG ITS8? I did the expensive boutique mod which was supposed to add more gain. I am thinking this is why it sounds to gainy even when the gain pot is turned all the way down. Thanks for your input b/c I am in the dark here!

[WesMVaughan]

bump?

[thedefog]

No I did not test them, and that was my next guess as to the problem I am having. My engineering teacher mentioned the same thing about the % differences between resistors, he also mentioned the caps as well. How do big pedal manufactures make sure there pedals sound identical if this is the case? Anyways I am going to have to do some altering to the pedals. Are you very familiar with the GGG ITS8? I did the expensive boutique mod which was supposed to add more gain. I am thinking this is why it sounds to gainy even when the gain pot is turned all the way down. Thanks for your input b/c I am in the dark here!

Try different 4558s. Remove the ones you currently have in there, put in an IC socket and try out different ones. That's about all I can tell you. You can also try replacing R7 with a jumper. That'll essentially turn the pedal into a unity gain buffer when the drive is all the way down. If I'm wrong about that though, don't hold it against me.

[petemoore]

  component tolerances aren't what they're sometimes cracked up to be, such as cases of debugging and being irrelevant to getting it working ~perfectly.
  er about the same as standard sedan consistancies one to the other, a little better overall I guess.
  On to the debug.
  Wanting to have 'adequate' gain is what 'gain bump' mods are for [who knows whappened here, gain can be bumped in many a way]. Otherwise if the gain knob doesn't go low enough, gain could be bumped down.
  Or if it for some reason is very important to have the right gain setting with the knob at 12:00. Otherwise, adjustable gain that encompasses the desired range, set to the present desired setting. Hotter source or gain elsewhere makes the pedal gain useful for fine tuning.
  Someone more experienced with modding/fixing once reported that TS is often liked-used by players who mostly use it for the frequency specific boost, and the 'internal gain' of the diode clipping creates unwanted artifacts etc. if set to clip hard.
  I'm late comer to this thread, bump the diode threshold up, turn the gain down, then see.
  The mid-hump [or other?..since mods were mentioned] of the TS then may start to matter if you have various mid-hump shapes to try to find a fit with.
  For that amp, probably something with low-mid more than low lowend eq bump, then the HF's...I find they just tell me about it, and I have to listen a few times [loud, soft etc.] and the tone control then takes care of it.
  Yepp, when pushing ''little'' [what I use, so little means preferred] tube amps, it's the low end that swamps funny sometimes [depending on it's depends on stuffs] and gets outta hand or is too tight/hard to get corrected to 'just right'...because all that changes when the amp Vol setting or even the room setting changes.
 

[WesMVaughan]

how do I bump the diode threshold up? i was thinking of just reverting the pedals back to there original build. Thank you for your help. Defog thank you as well, I will try different ICs.

[Projectile]

how do I bump the diode threshold up? i was thinking of just reverting the pedals back to there original build. Thank you for your help. Defog thank you as well, I will try different ICs.

To get a higher diode threshold you can either stack more diodes in series or use LEDs which will have higher bias voltages.

[WesMVaughan]

What could I do to the pedals to get less gain from them...I have one that gives me a great rhythm sound with the volume maxed and gain all the way down. However when I run another tube screamer, it becomes to distorted even with the gain turned all the way down. What caps or resistors should I change to get less gain from the second pedal?

[Govmnt_Lacky]

What could I do to the pedals to get less gain from them...I have one that gives me a great rhythm sound with the volume maxed and gain all the way down. However when I run another tube screamer, it becomes to distorted even with the gain turned all the way down. What caps or resistors should I change to get less gain from the second pedal?

I am a little confused 

Are you saying that you are doing an A/B test and one sounds different than the other?

OR

Are you saying that you are feeding on TS with another and you do not like the gain?

If it is the first one, you could always open them both up and make note of the differences. Then mod the "not good" unit with the same parts as the "good" one 

[joeboo88]

WesMVaughan ...just a thought, did you do the "fat mod" on the second pedal?
I built 2 of these and the one with the fat mod wasnt as loud as the first pedal with no fat mod. I romoved the switch for the fat mod and now they sound identical.(well almost) no 2 pedals seem to sound exactly the same way.IMHO.
I would look at maybe you put a wrong cap or resistor size in by mistake in B, i've done that. Or your pots are wired differently from B to A.
Are the pots the exact sizes in box boxes?
If pedal A sounds like what a TS should sound like then there isnt much wrong after being fried. If it doesnt something in there might be fried and the pedal is just acting more like a big booster, like an electrlytic cap just passing juice and not doing what its supposed to.
I know i'm just typing to hear myself but, the more fuel you have the better.....Good luck bro.

Strangely to get SRV to my ears i use a blackstone mosfet OD (tribute/clone  ), with gain turned down on the trimmer and the gain pot almost off...go figure

[WesMVaughan]

haha! Thank you! I appreciate any comments. I have a Wampler Pinnacle on the way. I can get a decent rhythm sound. Last Night I reverted both pedals back to the original un-modded specs. However I still have the toggle switch in there for clipping options. In the mod.pdf it says that by putting the toggle to the off position, It is supposed to act as more of a clean boost. Last night both pedals sounded similar after I un-modded them. However, When both are engaged, even with the gain turned down to zero, the amp has too much distortion in it.

[joeboo88]

hey WesMVaughan  yeah, on mine the middle position is a clean boost, but with gain up/volume down it will distort. No getting away with that.
The other position is using  the 2 red LEDS that comes with the kit. and the other is the three diodes.
The Leds loses volume and gets into fuzz territory. The 3 diode position doesnt lose much volume but distorts quicker than in the clean position.
I hope I'm not rehashing if someone else said that.
BTW I'm halfway building a pinnacle, small world. cheers dude. 

[WesMVaughan]

Are you saying that you are doing an A/B test and one sounds different than the other?

OR

Are you saying that you are feeding on TS with another and you do not like the gain?

Both! At First my second build had a lot less volume than my first build. They were both built exactly the same! I modded them using the Expensive Boutique mods which was supposed to add more gain among other things. Now I reverted them back to the original specs because there is way too much gain. I was trying to use them the same way SRV used them by using one for a rhythm sound and then clicking on the other one for a lead sound. Now I am thinking that the Deluxe Reverb is just too small of an amp(22Watts). I am thinking about getting a Super Reverb (45 Watts). I learn this after dropping about $300 into the DRRI.

For the Drive pot does it matter if it is 500k or 1 meg if I have it turned all the way down? Zero is still zero right?

Joe, I hope the pinnacle sounds good...I got it for Van Halen tone. Thanks to everyone who has posted in this thread, as I have learned a lot!

[thedefog]

Both! At First my second build had a lot less volume than my first build. They were both built exactly the same! I modded them using the Expensive Boutique mods which was supposed to add more gain among other things. Now I reverted them back to the original specs because there is way too much gain. I was trying to use them the same way SRV used them by using one for a rhythm sound and then clicking on the other one for a lead sound. Now I am thinking that the Deluxe Reverb is just too small of an amp(22Watts). I am thinking about getting a Super Reverb (45 Watts). I learn this after dropping about $300 into the DRRI.

For the Drive pot does it matter if it is 500k or 1 meg if I have it turned all the way down? Zero is still zero right?

Joe, I hope the pinnacle sounds good...I got it for Van Halen tone. Thanks to everyone who has posted in this thread, as I have learned a lot!

Those DRRI are really meant to be dimed and played clean. If you're using a booster, then you definitely want something with more clean headroom. I used a twin reverb for years until I built a 6a14HP weber (40 watts), and now I can do either/or without having the cops called on me while recording.


For the drive pot, you could use a 1 Meg if that is what you have. The taper will just change so that 1/4 a turn has the same effect that 1/2 a turn had on the 500k.

[thegnu]

At First my second build had a lot less volume than my first build. They were both built exactly the same!

to expand on what people said about tolerances, typical capacitor tolerance is +/- 20%.  that means a 10uF cap can be 12uF or 8uF, which is not a big deal under most circumstances, but if you're chasing a specific tone, then it can be.  carbon film resistors are typically 5% tolerance.  metal film are typically 1% tolerance, though i just measured a 100 ohm metal film that was 120 ohms. 

if you're building it from a kit, you're getting decent components, but your tolerances are probably high.  i built a GGG ITS8 with components i purchased from mouser, and it's dead silent, even with a fair amount of drive.  i used tantalum caps on all the polar caps (with a positive/negative side), and WIMA box caps or silver mica caps for everything else.  ironically, building a dead silent tubescreamer will not give you the tone that SRV had, because he just played the pedals he thought sounded good, and they all had wonky tolerances, afaik.

[Mike Burgundy]

I am trying to get a SRV tone. I am using a Fender American strat with Texas specials into the 2 screamers into a Fender Deluxe Reverb Reissue. I use one screamer for rhythm and the other one for a lead boost.

What strings are you using? 95% of SRV's tone happens before the cable. Before the pickup, probably.
Guys of this ability and character do tend to be really, really picky (or even superstitious) about guitars, gear and tone, but because they sound good doesn't necessarily mean you will sound like them with that gear or that it is really good stuff. It just means they like it and it works *for them*. The nuances they might hear and get to fuss about are probably much, much more delicate than the amount their personal touch differs from the next guy.
Funny how people like Clapton, Beck, King, SRV sound like themselves on a cardboard ukelele from Sears.