Ibanez Tubescreamer

adding_to_the_noise · May 28, 2006, 12:44:12 AM

Hey guys, i just have one quick question. For all of you working on or who have worked on a Tubescreamer project, where did you get your 51 pf capacitor? I can't seem to find one on small bear unless i'm not looking hard enough and i can't find them at too many other places.

markm · May 28, 2006, 01:20:30 AM

I had some old ceramic 51pf caps and used those but,
You could safely use a 47pf without any adverse effect I would think.

jimbob · May 28, 2006, 01:27:30 AM

Ive built 4 or 5 with the 47 pf and some from ordering 51pf's and couldn't tell the difference. It seems there are a lot of small changes one can make without noticing anything different.

d95err · May 28, 2006, 03:33:05 AM

The precision of ceramic caps is not particularly good. If you'd measure the cap in an original Tube Screamer, you'll probably see a big variation. If you have multimeter that can measure capacitance, you can probably find a 51p cap from a bunch of 47p (not that it matters for the sound).

oldrocker · May 30, 2006, 10:01:21 AM

Sorry to change the subject but I've been waiting for a tube screamer question to be posted. I've been wanting to build a TS. My question is on the schem layout it shows some components trailing off to Vb. Does that mean they all connect together? For some reason I'm not familar with this.

Mark Hammer · May 30, 2006, 10:10:46 AM

Quote from: oldrocker on May 30, 2006, 10:01:21 AM
Sorry to change the subject but I've been waiting for a tube screamer question to be posted. I've been wanting to build a TS. My question is on the schem layout it shows some components trailing off to Vb. Does that mean they all connect together? For some reason I'm not familar with this.

Yes. Vb is your"fake ground".

petemoore · May 30, 2006, 10:33:01 AM

the difference between 47pf and 51pf is really, really small, almost certainly an undetectable difference with such a small change in cap value in this position, these values are too close to call, like moving the tone control the smallest amount possible..or maybe not at all if tolerances are considered.

oldrocker · May 30, 2006, 10:39:21 PM

Thanks Mark. When I was looking at a PCB someone posted it looked like the Vb's were hooked together but I wasn't sure. I guess on schematics these days nobody uses the old hump for crossing over braches that don't hook together but cross over each other like when I was learning electronics back in '79.
I'm using a 49pf cap for my TS. Had to parrellel a few caps to reach that value. I hope that works OK.

chieljan · May 31, 2006, 03:00:02 AM

Hey! I'm going to build a TS too, they have the 51 pf ceramic disc cap at www.musikding.de . German site, but in english too, and they are sometimes even cheaper then banzaieffects.com, so it's worth looking in the other components too . Success building your TS!

3/4 North · May 31, 2006, 07:10:28 AM

i use 51pf silver mica from mouser.

oldrocker · May 31, 2006, 10:04:19 AM

I'm done! And!!!........It doesn't work.

so here I go with debuging. It's always disappointing when it doesn't work the first time but I'm getting used to it.
I need to order more of the components online. I usually scramble around gathering all the parts I need for each project prior to building it. I shoot over to RS and other electronic stores around my area. Or tear parts out of some old Ramsey electonic projects I've bult in the past. I need a better way so I'm going to try these websites to get my parts.
Now back to troubleshooting this TS.

bancika · May 31, 2006, 11:08:57 AM

The easies way is with audio probe. Good luck

oldrocker · May 31, 2006, 12:45:47 PM

Yes thanks I v'e been probing around with my probe but still working at it. I have a problem with two schematics. The one I used was from Tonepad and when I looked at the generalguitargadgets.com there is a difference. Where the diodes are at off of pin 2 there is a .047uF cap and a 4.7 resister. On Tonepad they trail off to ground and on GGG they go to Vb or Vr. Will either of these work or is one of these schems wrong?

oldrocker · May 31, 2006, 06:44:08 PM

Ok finished audio probing and found the problem. So stupid on my part. I realized that the signal was only making it past the first transitor to pin 3 on the IC. So I new the chip wasn't getting power and sure enough it was pin 8 not wired to +9volts.
Anyway I love this effect most of all so far. Nice clean distortion. All the knobs work like they're supposed to and the sound is amazing. I never owned a tube screamer in the 70's and always wanted one but couldn't afford one. If I knew back then that the TS 808 sounded this nice I would've bribed my mom into getting me one.
The 4.7k and .047uF do trail to true ground. I found this out on a tube screamer site dedicated to the stomp box so the GGG site is wrong unless it works going to Vb also. I'm not going to try it so unless someone else knows the answer I guess I'll find out some day.
Thanks to everyone for all your help on this build. I LOVE THIS STOMPER!!

chieljan · June 10, 2006, 08:53:29 AM

Hey did you use a ceramic or a silver mica 51 pf? Just wondering

bancika · June 10, 2006, 09:19:40 AM

I used 47pF silver mica there and it sounds great. I never tried with right value, so I can't compare but I'm sure that difference is very, very low

News:

Ibanez Tubescreamer