B&M Sola Sound - Fuzz Unit  [schematic]

Discussion regarding early stompbox technology: 1960-1975 Please keep discussion focused and contribute what info you have...
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thorpy6
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Post by thorpy6 »

I had the right pots (Citec, look like the originals) but the thread on the pot wasn't long enough to go through the pcb, enclosure and not short on the inside of the case. Shame but it woeks nicely and looks ok inside so i'm not too fussed.
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peps1
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Post by peps1 »

thorpy6 wrote:I had the right pots (Citec, look like the originals) but the thread on the pot wasn't long enough to go through the pcb, enclosure and not short on the inside of the case. Shame but it woeks nicely and looks ok inside so i'm not too fussed.
is that a cock up my end, using 2mm board, or a enclosure thickness issue? :?
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Electric Warrior
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Post by Electric Warrior »

or maybe a wrong bush type issue?

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thorpy6
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Post by thorpy6 »

enclosure and bushing on pots,the enclosures really thick. the board was as expected. robust and old school.
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beenabadbunny
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Post by beenabadbunny »

I've got one of these:
140320112366.jpg
140320112363.jpg
140320112362.jpg
140320112361.jpg
I love the sound but the low output means I can't play it live. Don't want to mod my original one so I have ordered one of peps1's PCBs. I'll leave out the 220K output resistor when I build it. :)

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beenabadbunny
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Post by beenabadbunny »

sonicvi wrote:The pots are usually either all log taper or log for the volume and sustain and linear for the tone.
It might not be too easy to see in my pics above, but mine has a linear pot for volume and log pots for sustain and tone.

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sonicvi
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Post by sonicvi »

I said "usually" :) I've seen different combos. All linear taper would be fine either way.

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beenabadbunny
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Post by beenabadbunny »

Did they just use whatever came to hand? I suppose ultimately a 100K pot is a 100K pot.

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ringworm
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Post by ringworm »

I've knocked up a version of the B&M after peps1's layout and have a question:
Does the tone pot work in reverse?
I get all my high end through with the tone knob maxed counter clockwise, if I max it clockwise it gets very wooly and there appears to be a bit of volume drop. Sustain and volume work as expected.
I made up a modified version of the original layout to fit in a 120x95 enclosure and followed the trace that peps1 had made of the unit.
Here's my project file:
jumbo3.pdf
(188.06 KiB) Downloaded 236 times

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John Lyons
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Post by John Lyons »

The original did this as well I believe. (which is the same Peps layout)
The schematic you linked is set up with the treble on the right though.

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ringworm
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Post by ringworm »

Ok, thanks. I made the schematic and layout in Eagle CAD and they are consistent on the error check. Lug 3 goes to the 3n9 and lug 1 goes to the 10nF as per the original tracer layout, and my posted schematic.

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ringworm
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Post by ringworm »

Went de-bugging and found my 3n9 capacitor was dead. swapped it for a 4n3. Unusual as I'd measured it just before I put it in.
Tone control behaves normally now, low to the left and bright to the right.
Attachments
guts.jpg
guts.jpg (58.17 KiB) Viewed 3763 times
Photo0377.jpg
Photo0377.jpg (35.17 KiB) Viewed 3763 times

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Nocentelli
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Post by Nocentelli »

What a great looking build!
modman wrote: Let's hope it's not a hit, because soldering up the same pedal everyday, is a sad life. It's that same ole devilish double bind again...

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ringworm
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Post by ringworm »

Cheers! :thumbsup
My second go at using toner transfer onto the enclosure. Couple of bits didn't transfer and then the clearcoat made my sharpie fill-ins run. I probably should've left the "fuzz unit" text off too but I'm pleased with it. (especially now it's working properly!)

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szetszho
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Post by szetszho »

i am building the fuzz unit base on the layout from one of the member here
Jumbo copy.pdf
Layout
(986.59 KiB) Downloaded 179 times
Image
Image
Image

buti cant get any sound out of this
i have try BC184 and BC549

but when i use my finger touch the red circle area
there are sound with volume and tone knob working but not the gain
Image
what happen?

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modman
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Post by modman »

szetszho wrote:[ Image ]
what happen?
you forgot to clean off toner after etching?
why are the groundplanes on the pots still black and that piece top right corner?

two questions:
where's the schematic?
did you really go to a thread download this layout and started a new thread and uploaded same layout to new thread?
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szetszho
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Post by szetszho »

modman wrote:
szetszho wrote:[ Image ]
what happen?
you forgot to clean off toner after etching?
why are the groundplanes on the pots still black and that piece top right corner?

two questions:
where's the schematic?
did you really go to a thread download this layout and started a new thread and uploaded same layout to new thread?
sorry about having a new thread cause i saw the last reply is in 2012 so i am just start a new one

and i am using the pre-sensitized PCB and what it said i can just leave the green layer there so as to protect the copper

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peps1
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Post by peps1 »

szetszho wrote:and i am using the pre-sensitized PCB and what it said i can just leave the green layer there so as to protect the copper
You can leave the green masking on to protect the copper from oxidising until you are ready to solder components, at which point it needs to be removed, and the board soldered, or tinned.
Image

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szetszho
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Post by szetszho »

peps1 wrote:
szetszho wrote:and i am using the pre-sensitized PCB and what it said i can just leave the green layer there so as to protect the copper
You can leave the green masking on to protect the copper from oxidising until you are ready to solder components, at which point it needs to be removed, and the board soldered, or tinned.
ok i see. thanks mate. i will remove it next time .but i have soldered all the copper layer so it should be working..am i right?
i got sound when i touch the red area it seems there is problem out there

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