News:

Forum may be experiencing issues.

Main Menu

Green bean to SRV special trouble

Started by murdog47, July 16, 2013, 10:09:32 PM

Previous topic - Next topic

murdog47

So I used a green bean board to plug in the specs from the SRV special. It pushes a faint signal (very quiet signal, I have to crank the amp to 9 really hear anything and it still isn't much) that sounds terribly compressed. When I adjust the pots I get all kinds of old school Atari noises. Traced through it a couple times and it looks good but something is wrong. Here are my voltages. I'll get pictures up as soon as I can.

IC - JRC4558D
1. 8.49
2. 8.51
3. 8.45
4. 0.00
5. 8.45
6. 8.49
7. 8.46
8. 9.14

Q1

8.46, 8.45, 9.15

Q2

8.43, 8.43, 9.15

Fishy eh?

Also to keep with the SRV Special Schematic I did the following

C2 jumper
R5 omit
C3 omit
C8 jumper
C9 jumper
R15 jumper

along with the value changes that applied
here is the schem I used

http://www.aronnelson.com/gallery/main.php/v/ulysses/ulysses_layouts/ulysses_ts_srv_special/matsumin_ts_srv_special_schem.gif.html?g2_imageViewsIndex=1

RobA

Which transistors did you use? Could it be the pinouts? The voltages look kinda like an ECB in an EBC position.
Affiliations: Music Unfolding (musicunfolding.com), software based effects and Rock•it Frog (rock.it-frog.com), DIY effects (coming soon).

murdog47

I can't believe I failed to check the transistors. If there was a smiley hitting his head against a wall I would insert that here ___. Thanks for assisting in removing my head from a place it did not belong  :D

RobA

It's good that it's an easy fix. I wouldn't feel too bad about the transistor orientation either. Just a bit ago, I blew up, literally, two LM337's because I was convinced I had the pinouts right. It was only after the second one blew shrapnel all over the living room that I figured I should re-read the spec sheet a bit more carefully.
Affiliations: Music Unfolding (musicunfolding.com), software based effects and Rock•it Frog (rock.it-frog.com), DIY effects (coming soon).

jimilee

Quote from: RobA on July 18, 2013, 03:02:50 AM
It's good that it's an easy fix. I wouldn't feel too bad about the transistor orientation either. Just a bit ago, I blew up, literally, two LM337's because I was convinced I had the pinouts right. It was only after the second one blew shrapnel all over the living room that I figured I should re-read the spec sheet a bit more carefully.
nice!
Pedal building is like the opposite of sex.  All the fun stuff happens before you get in the box.