A Collection of #124 Information (Schematics, Layout, etc.)

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splgeo
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Re: A Collection of #124 Information (Schematics, Layout, etc.)

Post by splgeo »

Mr. Dumble also used 150k slope with .05 mid caps. If your after that Robben ford tone go with skyline. If you want more of a Carlso tone go with the classic. The most important thing to do is to keep your caps and resistors to the same type Mr. Dumble used
bluesfendermanblues
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Re: A Collection of #124 Information (Schematics, Layout, etc.)

Post by bluesfendermanblues »

splgeo wrote:Mr. Dumble also used 150k slope with .05 mid caps. If your after that Robben ford tone go with skyline. If you want more of a Carlso tone go with the classic. The most important thing to do is to keep your caps and resistors to the same type Mr. Dumble used
....Or that you tweak the caps and resistors to your guitar and playing style like Mr. Dumble did ;-)
Diva or not? - Respect for Mr. D's work....)
Bombacaototal
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Re: A Collection of #124 Information (Schematics, Layout, etc.)

Post by Bombacaototal »

jelle wrote:Wow, how do you simulations on that tone stack calculator? Did the Dumble tonestack get added?
I usually use Fender as a rough approximation
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jelle
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Re: A Collection of #124 Information (Schematics, Layout, etc.)

Post by jelle »

ah. You could use SPICE.
Bombacaototal
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Re: A Collection of #124 Information (Schematics, Layout, etc.)

Post by Bombacaototal »

jelle wrote:ah. You could use SPICE.
Thanks, I will look into it!
Bombacaototal
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Re: A Collection of #124 Information (Schematics, Layout, etc.)

Post by Bombacaototal »

If using the exact skyline (1988 #124) tonestack with 250ka and .01uF for the mid, what difference does the slope 150k vs 100k make to the final sound

I am considering leaving mine at 100k like the 3rd generation including a higher treble cap

From the simulation it seems that the 150k has less gain but the tonestack slope curve looks identical to the 100k

Does anyone have sound samples of the original #124?
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norburybrook
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Re: A Collection of #124 Information (Schematics, Layout, etc.)

Post by norburybrook »

from what I gleaned from building my #124 is that the 'original' spec version is just conjecture based on previous amps.

#124 when it was photographed and reverse engineered was the skyliner version shown in the schematics/layouts.




Marcus
splgeo
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Re: A Collection of #124 Information (Schematics, Layout, etc.)

Post by splgeo »

the slope resistor allows more or less to go to the mid and bass controls, 150k less 100k more
Thenewguy
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Re: A Collection of #124 Information (Schematics, Layout, etc.)

Post by Thenewguy »

I'm just starting a #124 build and I can't find a replacement or a substitute for the Sprague Atom, TVA 1628 ,350V, 300µF capacitors. Does anyone here have a suggestion or a workaround for this?
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ijedouglas
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Re: A Collection of #124 Information (Schematics, Layout, etc.)

Post by ijedouglas »

Thenewguy wrote: Mon Sep 28, 2020 7:56 am I'm just starting a #124 build and I can't find a replacement or a substitute for the Sprague Atom, TVA 1628 ,350V, 300µF capacitors. Does anyone here have a suggestion or a workaround for this?
You can use F&T 220uf 300V.
Ian
Stephen1966
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Re:#124 FAQ

Post by Stephen1966 »

7) Are de-gooped pictures available?
Yes, here: ( www.roblivesey.com/dumble )
This appears to be a dead link [October 2020] however, the content appears to have been ported over to https://thesubjectmatter.com/dumblearchive.html
Stephen
www.primatone.eu
libtech
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Re: A Collection of #124 Information (Schematics, Layout, etc.)

Post by libtech »

What are guys using for the 350k trim pot? thanks
rootz
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Re: A Collection of #124 Information (Schematics, Layout, etc.)

Post by rootz »

Scraped 250k pot. Or just a normal 250k pot with a 330k preceding it. Works, unless you normally turn the trigger up to 10. Which most never do.
TimDude
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Re: A Collection of #124 Information (Schematics, Layout, etc.)

Post by TimDude »

I notice the schematic for the #124 calls for 0.1uF caps in the foot switch while the wiring diagram calls for 0.01uF caps in the foot switch. I'm curious if I'm reading this wrong? Regardless, I'm curious which way I should go? Also, I'm curious which voltage caps I would need? Would 100V do it? I see that's all that's on the manual switches. Thanks!
Stephen1966
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Re: A Collection of #124 Information (Schematics, Layout, etc.)

Post by Stephen1966 »

TimDude wrote: Fri Sep 30, 2022 9:28 pm I notice the schematic for the #124 calls for 0.1uF caps in the foot switch while the wiring diagram calls for 0.01uF caps in the foot switch. I'm curious if I'm reading this wrong? Regardless, I'm curious which way I should go? Also, I'm curious which voltage caps I would need? Would 100V do it? I see that's all that's on the manual switches. Thanks!
Those caps are only there as snubbers for the DC supply feeding the relays to suppress the switch pops, .1uF are a reliable choice. I use them on both the chassis switches for the pedal and in the pedal as well. 100V rated would be more than enough.

https://cz.mouser.com/ProductDetail/KEM ... UB7Q%3D%3D

Stephen
Stephen
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