Lumpy's 73 Boost

mmolteratx · Post by **mmolteratx** » 09 Oct 2013, 03:39

Here's a schem, traced from the pics, not the vero layouts posted.

beedotman · Post by **beedotman** » 09 Oct 2013, 07:15

Nice!

Mbas974 · Post by **Mbas974** » 09 Oct 2013, 16:13

Nice !
Thanks mmolteratx

mmolteratx · Post by **mmolteratx** » 09 Oct 2013, 19:53

Oh, and just a heads up, the BAT46 is not in the original, I just figured any pedal should have at least basic reverse polarity protection.

Mbas974 · Post by **Mbas974** » 11 Oct 2013, 16:13

Breadborded today.
Nice clean boost !

C1 & C3 I've used 18n and it was biased with 15K

I think I will put it in fron of my screamer

zosotone · Post by **zosotone** » 11 Oct 2013, 19:14

Nice Mbas974! Any mod for this model? Maybe a gain pot? Here a vero by Silver Blues at Guitar FX Layouts:

Silver Blues · Post by **Silver Blues** » 12 Oct 2013, 00:04

Just thought I'd follow over here and reiterate that that empty column (column N) can be removed for a 14x11 board.

I forgot to shrink it after I was done.

Nocentelli · Post by **Nocentelli** » 12 Oct 2013, 09:12

zosotone wrote:Nice Mbas974! Any mod for this model?

I had a play about on the breadboard, and a 'fat pot' works quite nicely, I just replaced the 680n cap with a 22uf electro, and replaced the switch with a 2k pot.

Mbas974 · Post by **Mbas974** » 12 Oct 2013, 20:25

This circuit is Jfet boost + Jfet buffer... is it inverting the original signal or is it non inverting ?

Nocentelli · Post by **Nocentelli** » 12 Oct 2013, 22:57

The first boost JFET inverts the signal, the buffer is non-inverting so the output will stay inverted relative to the input.

zosotone · Post by **zosotone** » 13 Oct 2013, 21:32

Nocentelli wrote:
zosotone wrote:Nice Mbas974! Any mod for this model?
I had a play about on the breadboard, and a 'fat pot' works quite nicely, I just replaced the 680n cap with a 22uf electro, and replaced the switch with a 2k pot.

With 22uf instead of the 680nf, what is the polarity of the electro? Its the same?

Nocentelli · Post by **Nocentelli** » 13 Oct 2013, 22:14

Well the 680n shown in that layout is non-polar, but you'd need to connect the 22uF electro with the negative stripe towards ground.

zosotone · Post by **zosotone** » 13 Oct 2013, 23:19

Ok thanks, or use a bipolar or a tantalum cap, true? I will try the vero from Silver Blues these days and check it...not yet verified right?

zosotone · Post by **zosotone** » 10 Apr 2014, 09:57

Done!

Silver Blues · Post by **Silver Blues** » 10 Apr 2014, 21:18

zosotone wrote:Done!

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Nice one!