madbeanpedals::forum

Projects => Tech Help - Projects Page => Topic started by: Obie bong kanobie on August 30, 2016, 03:12:58 PM

Title: GPCB colorsound OD issue, gated sound
Post by: Obie bong kanobie on August 30, 2016, 03:12:58 PM
Ok so I've finished the pedal but the sound is really gated. I used micro electronics bc109 transistors and I did check the pin outs before installing them( I have no sockets left right now)

Could someone please verify if that's the issue.  Voltages are Q1 E.58 B 1.0 C 1.6. Q2 E1.0 B 1.7 C 5.8.  Q3 E .6 B 1.2 C7.5

(http://i1305.photobucket.com/albums/s548/jessebelanger1988/Mobile%20Uploads/image_zps349rlvgt.jpeg)

(http://i1305.photobucket.com/albums/s548/jessebelanger1988/Mobile%20Uploads/image_zpsmvq0r2nn.jpeg)
Title: Re: GPCB colorsound OD issue, gated sound
Post by: m-Kresol on August 30, 2016, 05:04:18 PM
do you have a schematic/build doc for us?

just eyeballing, I'd say that at least your base is always the correct amount above the emitter. still need a schematic for the collector.
Title: Re: GPCB colorsound OD issue, gated sound
Post by: mattlee0037 on August 31, 2016, 02:42:42 AM
Collector voltage on Q3 seems a tad high. I think it's supposed to be aroun 5.5-6.5? maybe check your resistors around Q3 on the schematic.
Title: Re: GPCB colorsound OD issue, gated sound
Post by: Bret608 on August 31, 2016, 01:57:56 PM
You could also try flipping the orientation of C10 on GPCB's schematic (i.e. make the positive side point toward Q3's collector). Most CSOD schematics in the DIY community have their roots in the Fuzz Central schematic, which has that capacitor oriented opposite to what is found in actual vintage units. It's not for certain that will always fix the fizzy decay some report on their builds, but it seems to play some role.
Title: Re: GPCB colorsound OD issue, gated sound
Post by: Obie bong kanobie on September 01, 2016, 09:22:20 PM
http://www.guitarpcb.com/PDF%20Files/ColorTone%20Overdrive%20v2.pdf

the schematic is right in there, I'll try the cap 10 idea and I'll also check all of my resistor values are q3 as suggested