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DIY Stompboxes => Building your own stompbox => Topic started by: Colman on April 19, 2023, 01:11:21 PM

Title: GGG klon failure
Post by: Colman on April 19, 2023, 01:11:21 PM
Hi everybody .I had to re-register but under another name cause it's been long I forgot the password( I was originally Aharon).
So after many years I decided to build A GGG klon,got the kit from JD and started to work.I had high hopes but it didn't work.
I built the true bypass option.
Symptoms are: no signal either way engaged or bypass, not even hiss or hum,although there was some scratchiness on the gain pot when turned(very faint).
Indicator light works.
Voltages are as follows:

Battery:8.58V
IC1:  1-4.27
        2-4.25
        3-1.17  !!!!!!! should be3.6V
        4-0
         5-4.13
         6-4.23
         7-4.21
         8-8.45
IC2:   1-4.20
          2-4.20
          3-4.16
          4- -7.93
          5-4.15
          6-4.20
          7-4.22
          8-14.91
IC3:   1-8.41
         2-4.30
         3-0
         4- -3.88
         5- -7.90
         6-3.40
         7-4.08
         8-8.38
         
Title: Re: GGG klon failure
Post by: Govmnt_Lacky on April 19, 2023, 01:43:00 PM
Rule of thumb (for a true bypass circuit):

If you are getting no signal when the effect is bypassed, then you have an issue with the 3PDT, its wiring, the jacks, or the wiring going from the jacks to the 3PDT.
Title: Re: GGG klon failure
Post by: Colman on April 19, 2023, 02:43:15 PM
Thanks for the answer.I put another 3PDT and another output pot rewired everything ,also put in new TLO72s ,now I got hiss no signal either way so I'm going to recheck wiring as suggested.
Thank you
Aharon
Title: Re: GGG klon failure
Post by: Colman on April 19, 2023, 03:02:28 PM
Thanks for your suggestion ,now it works ,it was an input jack wiring problem,I feel sooooooo dumb :icon_redface:  .
Thank you again Govmnt-Lacky
Aharon
Title: Re: GGG klon failure
Post by: Colman on April 20, 2023, 10:20:50 AM
I tried it yesterday plugged into my DIY champ (running a 12" eminence).Sounds good to say the least. I was lucky I found some 1N34A in my parts box so that's what I used.All in all a fun project, thanks JD and Gvmnt Lacky
Aharon
Title: Re: GGG klon failure
Post by: duck_arse on April 20, 2023, 11:09:11 AM
..... and, welcome to the forum!


but post build docs, please, when asking questions.
Title: Re: GGG klon failure
Post by: Colman on April 27, 2023, 09:18:49 AM
(https://i.postimg.cc/0rYRc0Mm/20230427-095109.jpg) (https://postimg.cc/0rYRc0Mm)



This is the klon from general guitar gadgets, sounds awesome and like I said I had some 1N34A diodes from the 90s still and installed those in the PCB.
The quality of the kit was top notch ,no missing or wrong pieces,I thank JD again.The build docs can be found at the GGG site.
Aharon