Comments on: Overdrive 250

By: Dr Robb

Dr Robb — Tue, 27 Apr 2010 19:07:20 +0000

As this is Gauss’ design, I have NO DOUBT it must sound AWESOME and will definitely be building one…more of a boost for solonig in my pedal board.

However, this link references Tonepad and General Guitar Gadgets. After reviewing all of the schematics, they don’t even seem the say! :O Many components are different and also they go from symmetric to asymmetric clipping! :O

What gives??

By: Hector

Hector — Sat, 02 Jan 2010 11:31:15 +0000

i finaly got it to work!!
they where the diodes so i replace them and use only two.
I have to say that the sound is sweet,clean boost and hummless drive, this pedal is a must build!

thanks for your support Gauss.

By: gaussmarkov

gaussmarkov — Mon, 28 Dec 2009 19:34:28 +0000

hi! you are most welcome!

any 500k pot will work because the range of resistances is the same. the way the control will feel over that range depends on whether you have a linear, audio, or other pot type.

–gaussmarkov

By: Hector

Hector — Mon, 28 Dec 2009 19:19:23 +0000

thanks Gauss!!

i’ll check deeper into my wiring and the circuit.
one more question,is the 500k rev pot is realy needed?

by the way your site is awesome and realy helfull thak you!!

By: gaussmarkov

gaussmarkov — Mon, 28 Dec 2009 15:32:11 +0000

hi hector, sorry no — those subs do not explain your problems. try tracing through your circuit with a sound probe and you will find where things are going wrong. all the best, gauss

By: Hector

Hector — Mon, 28 Dec 2009 08:07:19 +0000

Hey Gauss:

i’m trying to get this pedal to work but i’m only getting a humming when i strum the strings then the sound dies.
i use specs on your pdf exept for the C3 25pF cap(i used a 22pF) and the 500k rev log pot, i could not find one so i used a linear 500k pot.
Is this what is causing the humming and lack of gain?

By: Immo

Immo — Tue, 08 Dec 2009 23:10:48 +0000

@Mario: That resistor and the 100µF electrolytic form a filter for power supply filtering (=less hum…)
http://www.diystompboxes.com/smfforum/index.php?topic=49603.msg369563#msg369563

By: Mário Calegaro

Mário Calegaro — Fri, 20 Nov 2009 04:35:13 +0000

What is the 100ohm thing? Why use this? GGG doesn´t explain why…

By: gaussmarkov

gaussmarkov — Wed, 29 Apr 2009 01:29:44 +0000

sorry, i cannot debug your OD250 here. but you should be able to get rid of the hum. i suggest you ask the good folks at diystompboxes.com.

all the best, gm

By: bambi

bambi — Mon, 27 Apr 2009 10:31:21 +0000

hi. . . GM, thanks for this site. i like it!!!, This 250 overdrive is really great sound. but, there is something a ground-noise. tell me what to do how to disappear these noise.

SORRY for my English words> b’cos i am Filipino. . .