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DIY Stompboxes => Building your own stompbox => Topic started by: RDV on August 20, 2003, 09:13:18 PM

Title: AMZ Mini-Booster completed(in 1 hour!) on perf
Post by: RDV on August 20, 2003, 09:13:18 PM
Great booster Jack! Really nice! I left out the 10uf cap. Does anyone like it better left in?

Also; I used a 2.2uf NP instead of 3.3, but it still seems to have plenty of low-end. This is a box-bound circuit for sure!

Regards

RDV
Title: AMZ Mini-Booster completed(in 1 hour!) on perf
Post by: Jered on August 21, 2003, 02:23:54 AM
Hi Ricky, try a hi quality .1 uF film cap in place of the 2.2 uF and then add the 10 uF and see what you think. What value source resistor are you using, 100 ohm, 1k?  MB is still one of my favorite building blocks.
  Jered
Title: AMZ Mini-Booster completed(in 1 hour!) on perf
Post by: RDV on August 21, 2003, 07:19:25 AM
Jered said:
QuoteWhat value source resistor are you using, 100 ohm, 1k?

I'm using the 1k. Is there a difference :?:

Regards

RDV
Title: AMZ Mini-Booster completed(in 1 hour!) on perf
Post by: Jered on August 21, 2003, 08:32:48 AM
I'm using the 1k. Is there a difference

 Yes, big difference. Lower resistance = more gain, and adding the by pass cap adds even more gain. You can put a 5k or 10k pot in place of the source resistor and hear what I'm talking about or just use it as a gain control.
   Jered
Title: AMZ Mini-Booster completed(in 1 hour!) on perf
Post by: RDV on August 21, 2003, 09:00:01 AM
QuoteLower resistance = more gain, and adding the by pass cap adds even more gain.

If you do both the pot and the cap, do you end up making it more of an overdrive by making the first JFet drive the second into distortion :?:

Regards

RDV
Title: AMZ Mini-Booster completed(in 1 hour!) on perf
Post by: Jay Doyle on August 21, 2003, 09:22:14 AM
RDV,

Look here:

http://www.geofex.com/Article_Folders/modmuamp/modmuamp.htm

It explains a lot and gives you some options to mod.

Jay
Title: AMZ Mini-Booster completed(in 1 hour!) on perf
Post by: RDV on August 21, 2003, 09:46:46 AM
Has anyone tried the 1K resistor between the source of the upper JFET and the drain of the lower JFET mod that R.G. talks about :?:

Regards

RDV