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Lumpy's 73 Boost

Posted: 03 Oct 2013, 12:57
by zosotone
Really cool pedal. I rewired some wires and the toggleswitch. Pictures of mine:

Re: Lumpy's 73 Boost

Posted: 03 Oct 2013, 13:39
by zosotone
Checking the two blue caps and the voltages...

I added two pull-down resistors (blue in pictures).

Re: Lumpy's 73 Boost

Posted: 03 Oct 2013, 13:48
by sinner
Thanks mate, nice to see new members contributing

Are you going to draw schematic for it, or do you mind if I do it?

Re: Lumpy's 73 Boost

Posted: 03 Oct 2013, 13:50
by zosotone
"684" on C2 and "471" on C1

Re: Lumpy's 73 Boost

Posted: 03 Oct 2013, 13:53
by zosotone
Of course, you can make the schematic... thank you.

Re: Lumpy's 73 Boost

Posted: 03 Oct 2013, 13:56
by sinner
67k is in fact 68k
100k next to it is actually 1M
270R is 2k7
another 1M in place of 100k next to it
10R is actually 100R
You have missed 68k resistor next to 47uF, and one resistor under the board

Re: Lumpy's 73 Boost

Posted: 03 Oct 2013, 13:58
by sinner
zosotone wrote:"684" on C2 and "471" on C1

that makes C2 - 680nF and C1 - 470pF

Re: Lumpy's 73 Boost

Posted: 03 Oct 2013, 14:08
by zosotone
I added the two 1M's, on the input and other under the board on the output for the popping. I omitted the 68k beacause it's for the led resistor. Thank you for your corrections.

Re: Lumpy's 73 Boost

Posted: 03 Oct 2013, 14:11
by sinner
zosotone wrote:I added the two 1M's, on the input and other under the board on the output for the popping. I omitted the 68k beacause it's for the led resistor. Thank you for your corrections.
68k for the LED? It's not for the LED my friend :) 10k resistor for LED limiting is the maximum I have seen. Beside, if you look closer you will find LED limiting resistor connected straight to the lug of LED

Re: Lumpy's 73 Boost

Posted: 03 Oct 2013, 14:17
by zosotone
I rewired the led and the resistor because cause problems with the board.

Re: Lumpy's 73 Boost

Posted: 03 Oct 2013, 14:22
by sinner
Now I'm lost :) I think I will stop here

Thank you anyway :thumbsup

Re: Lumpy's 73 Boost

Posted: 03 Oct 2013, 14:28
by zosotone
The led was soldered directly betwen the 15nf and the 68k.

Re: Lumpy's 73 Boost

Posted: 03 Oct 2013, 14:35
by zosotone
Like this.

Re: Lumpy's 73 Boost

Posted: 03 Oct 2013, 19:57
by rocklander
sinner wrote:
zosotone wrote:I added the two 1M's, on the input and other under the board on the output for the popping. I omitted the 68k beacause it's for the led resistor. Thank you for your corrections.
68k for the LED? It's not for the LED my friend :) 10k resistor for LED limiting is the maximum I have seen. Beside, if you look closer you will find LED limiting resistor connected straight to the lug of LED
I use a 3K3 (or 3K6) usually but when I use the LED from an optical mouse that's crazy bright so I insert an additional 200K trim pot.. even at full resistance (200K) it's still VERY visible.

Re: Lumpy's 73 Boost

Posted: 04 Oct 2013, 04:42
by Lumpy's Tone Shop
If the LED was blue, the limiting resistor may have been 68K. The 2 100K resistors in your layout are wrong, they should be 1M. The one is a pulldown resistor, not sure why you soldered another in unless you were having popping issues?

There are various version of this pedal. The one pictured was a custom build with the mustard caps. The .015uf mustard caps would otherwise be .022uf.

The toggle switches between the source bypass cap, .68uf and .022uf.

The V3 version was sort of a hash of the earlier versions with one or two things from an EP-3 preamp. The other versions were quite different. V1 had a high pass filter at the input, more of a treble booster. V2 was similar to my current SLPre pedal, but included the typical Marshall 470k/470pf filter with a switch that for the mixer cap, don't remember the value. There were a few custom V2s with switchable output buffers. All in all its just a simple JFET boost voiced to my liking.

And looking back on it, my veroboard layout sucked as I used the toggle switch to keep the board in place. You'd be better off with a new one.

Re: Lumpy's 73 Boost

Posted: 04 Oct 2013, 10:14
by zosotone
Hi Tommy, thank you so much for your answer. I love this thing, sounds amazing.

The led in this model it's white (a little bit darker) and I put a 2k2 resistor directly to the LED. Also, had a bad connection on the board.

I soldered two 1M's (in and out of the board) because I had problems with popping. The toggle switch was placed directly to the board too and I resoldered the switch.

So, the 100k's should be 1M's for the correct layout right? Those values ​​you mention (15nf's) are incorrect in this model?

Should I remake the board?

Re: Lumpy's 73 Boost

Posted: 07 Oct 2013, 10:51
by zosotone
Well, some corrections and the voltages.

Re: Lumpy's 73 Boost

Posted: 08 Oct 2013, 18:47
by OnTheTundra
Whats up with the trimpot underneath?

Re: Lumpy's 73 Boost

Posted: 08 Oct 2013, 21:30
by zosotone
I thing that it's for biasing the second transistor (2N5457)

Re: Lumpy's 73 Boost

Posted: 08 Oct 2013, 22:42
by Mbas974
hey guys check the picture on top... I can count 8 resistors
also
2N5457 Drain is direct to 9V ?

I think it's better start with a schematic rather than a vero layout.