GGG AMZ Boutique Mini Booster Volume Question

Started by gluedtogether, November 30, 2007, 10:36:44 AM

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gluedtogether

I had the board for a while and just decided to populate and wire it up. The pedal does fatten up the sound a bit, but in order to match the volume without the pedals, I have to turn the input gain and volume pot all the way to the right. The only part substituion I did was a 25K pot for the tone instead of 100K. Would this have caused the lack of volume control?

also I am open to any other part substitutions/mods anyone might have.

Thanks in advance for any suggestions.

petemoore

but in order to match the volume without the pedals, I have to turn the input gain and volume pot all the way to the right.
  TS Should provide hefty boosts.
  The debugging thread details how to make it do this.
Convention creates following, following creates convention.

SDRed

I just finished a boutique boost on perfboard and it fattens the sound up A LOT.  I don't like playing without it on now.  Wait until you get the volume issue worked out, you're going to love it.

gluedtogether

I didn't the ggg mini boost, not following the boutique layout and it was great, but I was making it for someone so I had to let it go.

Peter Moore, you are referencing the dubbing page on this site or a specific thread for the boost?

SDRed, what layout did you use?

Thanks for the responses

SDRed

I made my own layout from the boutique schematic.  It's hand drawn though, so unfortunately I can't post it. :icon_sad:

gluedtogether

Did you use the same part list on the GGG site? i checked and my parts match except the pot. I need to go out and see if I have the 100k. with my newbie knowledge, thats what I think it may be.

SDRed

#6
The only thing I did differently was use two 5pf caps in series instead of the 10pf.  I used the 457 JFets also instead of the 201s.  My guess is that it's probably the pot you used, but I'm really new to all this stuff so my opinion probably isn't worth much

Also, if you go through the "what to do when it doesn't work" stuff and post your voltages, people will usually help you pretty quickly. 

gluedtogether

Thanks, with my limited knowledge, I think its the pot as well. hopefully the local radioshack will have one...

gluedtogether

I finally got the 100K Linear pot and soldered it in. Definitely fattens up the tone and I agree, this pedal may be on all the time. The tone knob does have a great variance going from one side to the other.
I still don't get a huge volume increase, but there is enough to give it a slight boost. It is better than it was before I put the 100k in. I may try different jfets as you suggested to see what differences there are. I don't want to increase gain, just volume a bit. 8 seems to match the bypassed signal.

culturejam

Quote from: SDRed on December 02, 2007, 03:33:14 PM
The only thing I did differently was use two 5pf caps in series instead of the 10pf.

Putting caps in series caused the values to be added reciprocally (that is, 1/value), not linearly. It's the opposite of how resistors work.

http://www.aikenamps.com/AddingComponents.htm

QuoteFor example, if three capacitors of values 0.1uF, 0.022uF, and 0.01uF are connected in parallel, the total capacitance would be:

C = C1 + C2 + C3 = 0.1uF + 0.022uF + 0.01uF = 0.132uF


If the three capacitors are connected in series, however, they add in reciprocal, as follows:

1/C = 1/C1 + 1/C2 + 1/C3 = 1/0.1uF + 1/0.022uF + 1/0.01uF = 1/0.0064, therefore C = 0.0064uF

Looks like putting two 5pf caps in series will net you 0.4pf.

I mean, unless I'm totally misunderstand the math at play here (which is possible...I have an English degree :) ).

Sock Puppet

Looks like putting two 5pf caps in series will net you 0.4pf

Two 5pf in series will give 1/0.4 = 2.5pf.

Another way to work it out is product/sum, i.e. C1 x C2/(C1 + C2)

or 25/10 pf in this case.

S.

culturejam

Quote from: Sock Puppet on December 27, 2007, 11:23:46 PM
Two 5pf in series will give 1/0.4 = 2.5pf.

Hmm. Then the formula I quoted seems to be misleading (at least to me). I didn't understand that you also had to put the result in a denominator under 1. Interesting.

Thanks for the clarification. You never can be too careful with us humanities folks.  ;D

A better way for me to think about it is to write it like this:

1/Ct, where Ct = 1/C1 + 1/C2 + ... 1/Cn

SDRed

well, even if it worked out to 2.5 pf the thing still sounds great.  I made it as a gift and gave it away about 2 weeks ago.  When I build my own, I guess I should wire them in parallel?

culturejam

Quote from: SDRed on December 28, 2007, 08:16:34 PM
When I build my own, I guess I should wire them in parallel?

If it sounds great to you, then I wouldn't change it. But it couldn't hurt to at least try it wired parallel just to see which you like better. Hell, you could even put both options on a toggle switch and call it a feature!  ;D