madbeanpedals::forum

Projects => General Questions => Topic started by: jonrhee on March 04, 2012, 04:21:51 AM

Title: Volume on the Dirtbag
Post by: jonrhee on March 04, 2012, 04:21:51 AM
I just built the Dirtbag Deluxe with MN3005's and am quite pleased, but the volume boost makes it a bit unusable even all the way down. Like its fine if its on all the time but in comparison to my dry signal I'm not able to really turn it off and have a unity gain. I was wondering if anyone else had a similar result?
Title: Re: Volume on the Dirtbag
Post by: madbean on March 04, 2012, 05:42:22 AM
Re-check R2 to make sure it's 100k and R3 is 22k. My guess is one of those might be incorrect in your case.
Title: Re: Volume on the Dirtbag
Post by: marmaliser on March 04, 2012, 08:57:53 AM
Yep, there is something wrong. Mine is at unity at pretty  much 12 o'clock
Title: Re: Volume on the Dirtbag
Post by: jonrhee on March 05, 2012, 03:17:08 AM
Checked them with a multimeter, both R3 and R19 which are meant to be 22k are 200k. Strange because they were labeled as 22k but the colour codes and multimeter both have them in at 200k.

Would that make sense as to why the volume is so loud?
Title: Re: Volume on the Dirtbag
Post by: jkokura on March 05, 2012, 04:18:32 AM
Possibly. However, when you measure parts while they're installed in the circuit sometimes they don't read properly. Try taking them out and then measuring them.

Jacob
Title: Re: Volume on the Dirtbag
Post by: jonrhee on March 05, 2012, 04:59:32 AM
Well, the colour codes are 200k or backwards they are 130R 2%. Since they read at 200k on the multimeter I'm pretty sure thats what they are.
Title: Re: Volume on the Dirtbag
Post by: madbean on March 05, 2012, 12:21:23 PM
With R3 at 200k, this means your minimal gain on 1C1A is 2, which is why you cannot get down to unity. A bit different situation with R19 since that is for the LED, so it is not influencing the actual audio path. But, I would replace both with 22k.
Title: Re: Volume on the Dirtbag
Post by: jonrhee on March 05, 2012, 02:10:33 PM
Awesome, thanks!