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DIY Stompboxes => Building your own stompbox => Topic started by: stefcuypers on September 04, 2007, 07:25:17 AM

Title: boutique boost question
Post by: stefcuypers on September 04, 2007, 07:25:17 AM
Hello,

I builded the boutique boost from GGG. Like the pedal and the boost but the gain control is a little to low for me. Is it possible to change some components to give the pedal more gain? I used these schems:

http://www.generalguitargadgets.com/pdf/ggg_joam_lo_b.pdf
http://www.generalguitargadgets.com/pdf/ggg_joam_sc_b.pdf

thanks for reading, Stef
Title: Re: boutique boost question
Post by: ~arph on September 04, 2007, 08:20:42 AM
I answered in the dutch forum, basically I was suggesting to put a MOSFET boost in place of the 500k gain pot
Title: Re: boutique boost question
Post by: jaytee on September 04, 2007, 09:20:24 AM
Lowering the value of R5 will give more gain. Also raising the value of R2 and R3 to origonal values of 10meg.
Title: Re: boutique boost question
Post by: petemoore on September 04, 2007, 10:01:30 AM
  MPF102 = low gain
  J201 = high gain [J202 is supposedly high-er gain?]
  NTE458 = highest gain Jfets I've found/heard of, but also imparts a 'hardness' tone in builds I've tried them in.
  That extra gain stage or OD boosting for pre-Mu drive is a good one, Mu Amps are one of my favorite 'drive 'em hard' type circuits.
  There was something about a 1k placed between the Jfets, at Geo [IIRC], which increases output, the Mu Amp article is worth a look at any rate.
Title: Re: boutique boost question
Post by: jaytee on September 04, 2007, 02:35:58 PM
Also, output impedance is quite high on these, about 200k. I got more gain putting a buffer on the output. Maybe a 500k vol pot would help there.
Title: Re: boutique boost question
Post by: nooneknows on September 04, 2007, 05:42:07 PM
With J201 high gain and humbucker equipped guitars I've always found some kind of 'dirt' using this circuit, the best tranny to my ears is the 2n5457 or some bf245B. try put a socket on the lower FET (the most important) tasting different devices.
Title: Re: boutique boost question
Post by: petemoore on September 04, 2007, 09:57:47 PM
  Yupp, nice clean fill dirt..
  That circuit does well to distort or help distorter.
  doesn't take much to goose the input, does well at handling distorter outputs, also that kind of grit lends itself to being further distorted.
  Maybe impedance could be lowered at the sacrifice of some of the output volume? [I ran mine around 1/2' volume].
  Yupp, even J201's added a bit of hardness which I found undesirable, I fore-went any further internal gain increasing, opted for the added gain stage ideas.