DIYstompboxes.com

DIY Stompboxes => Building your own stompbox => Topic started by: mth5044 on November 08, 2009, 05:36:31 PM

Title: High voltage readings on Colorsound Overdriver? (Powerboost?)
Post by: mth5044 on November 08, 2009, 05:36:31 PM
Alright, I built the Colorsound Overdriver from the layout and schematic from Fuzz Central and Bill Lawrence

Schematic: http://fuzzcentral.ssguitar.com/schematics/overdriverschem.gif
Layout: http://fuzzcentral.ssguitar.com/pcbs/overdriverlayout.gif

I followed the layout pretty closely. Substituted 22uF in for the 3 25uF, but wired them off board because I got ones that were way to big  :icon_cry:

I am using 2N5088 transistors.

It does not pass any signal when engaged.

Voltages:

2N5088

Q1
C 8.75
B 7.79
E 8.88

Q2
C 9.44
B 8.75
E 8.94

Q3
C 9.44
B 8.81
E 8.93

Also, the pinout of the 2N5088 does not match the direction the transistors are facing in the layout provided at the top. Atleast I don't think so.

Any help would be greatly appreciated.

Thanks a lot  :)
Title: Re: High voltage readings on Colorsound Overdriver? (Powerboost?)
Post by: mth5044 on November 08, 2009, 06:28:14 PM
Alright, just connected the PCB to ground  ::)  ::)  ::)  ::)   ::) ::)

and am getting these readings:


Q1
C 1.40
B 0.59
E 0.12

Q2
C 6.56
B 1.40
E 0.63

Q3
C 7.52
B 1.10
E 0.51

Sound: I'm not getting a boost when the gain and volume are full, just some gritty (although nice sounding) tone. Tone controls work.
Title: Re: High voltage readings on Colorsound Overdriver? (Powerboost?)
Post by: mth5044 on November 08, 2009, 06:59:11 PM
Sorry, volume control works, gain does not.
Title: Re: High voltage readings on Colorsound Overdriver? (Powerboost?)
Post by: .Mike on November 08, 2009, 08:09:55 PM
Hi,

I don't have any insight into what's wrong with your circuit, but I just went ahead and measured the voltages for you of the one I built. I used this schematic (http://web.archive.org/web/20070208065227/http://home.hawaii.rr.com/stompbox/CSOVR.JPG).

V+: 9.52

Q1
C: 1.66
B: 1.02   
E: 0.51

Q2
C: 5.06   
B: 1.66   
E: 1.05   

Q3
C: 5.41   
B: 1.53   
E: 0.95   

I don't know if that will help, but I hope it does. :)

Mike
Title: Re: High voltage readings on Colorsound Overdriver? (Powerboost?)
Post by: mth5044 on November 08, 2009, 11:12:17 PM
Thanks so much .Mike  :) I really appreciate you going through the trouble  :)

I couldn't seem to find any voltages out there for this project, so these definitly help.

Thanks so much!

Title: Re: High voltage readings on Colorsound Overdriver? (Powerboost?)
Post by: petemoore on November 08, 2009, 11:28:31 PM
  Was gonna say Q3 looks a little high, of course the voltages are all relative to the supply voltage.
Title: Re: High voltage readings on Colorsound Overdriver? (Powerboost?)
Post by: mth5044 on November 08, 2009, 11:32:58 PM
Ah, sorry. I am using a power supply which read ~9.5v IIRC
Title: Re: High voltage readings on Colorsound Overdriver? (Powerboost?)
Post by: .Mike on November 08, 2009, 11:38:09 PM
Quote from: mth5044 on November 08, 2009, 11:12:17 PM
Thanks so much .Mike  :) I really appreciate you going through the trouble  :)

I couldn't seem to find any voltages out there for this project, so these definitly help.

Thanks so much!

You're welcome. :)

It's probably worth noting that, according to the schematic I used, the 1.8K resistors should be adjusted so that the collectors of Q2 and Q3 sit at 5V.

Now that I look at it, I believe Q3 on mine is misbiased, although it sounds fine to me.

Mike
Title: Re: High voltage readings on Colorsound Overdriver? (Powerboost?)
Post by: petemoore on November 09, 2009, 10:34:13 AM
  Bias has always seemed like a ballpark thing.
  It does help to know where people are tending to hit homeruns, in any particular field/circuit.
Title: Colorsound powerboost 18v issues
Post by: Axr280 on August 04, 2022, 05:23:15 PM
Hello
I've built a colorsound power boost 18v exactly from the original board, except transistors are BC109, and I've used two 4.7Ks and one 1K liked together instead of using a 10k resistor. The board connects to a 18v adapter, but bass and treble pots don't work and the volume pot (10k) doesn't work from zero, it starts working from about a quarter and when I turn it all the way up sound level is too low.
Does anyone know what is wrong?
(https://i.postimg.cc/146XwPbF/16596481140797962308077767904238.jpg) (https://postimg.cc/146XwPbF)
Title: Re: High voltage readings on Colorsound Overdriver? (Powerboost?)
Post by: Rob Strand on August 04, 2022, 07:47:00 PM
QuoteDoes anyone know what is wrong?
It's possible you have some electrolytic caps installed the wrong way around.
To some extent, the fact two areas of the circuit are misbehaving confirms this.

Another possibility is shorts on the PCB or soldering.

FWIW, you might want to dig through some of the forum archives for posts by Electric Warrior.
There were some errors on the some of the Colorsound schematics and those errors
were transferred to some of the older layouts.