freestompboxes.org

Hello lads,

Just came across a clip of this and I like what I hear. It's silicon and Bender-ish and that's about all I could find. Enclosed are two gut shots, sadly without visible what transistors are used and no shots of the trace side.

you can see more gut shots at 1:34-1:45 and 2:23-2:31 min

with several gut shots. The most important one (the PCB) is in view from 1:40-1:58 min.

Does anybody have more information ?

Thank you !

Cub

Try--basicaudio.net----for more info and prices....

rbstep wrote:Try--basicaudio.net----for more info and prices....

John Lyons (Basic Audio) is a member here. Just PM him, I don't think he's all that secretive...

Barcode wrote:John Lyons (Basic Audio) is a member here. Just PM him, I don't think he's all that secretive...

Thank you, I had no idea he was a member here ! I dropped him a PM, I hope I will get a reply.

Until then, here's a link to one of the coolest pedal demonstrations ever to hit YouTube:

Cub wrote:

Barcode wrote:John Lyons (Basic Audio) is a member here. Just PM him, I don't think he's all that secretive...

Thank you, I had no idea he was a member here ! I dropped him a PM, I hope I will get a reply.

No reply from John yet, but I've done a little digging and I think there might be a possibility that he got the inspiration for his Scarab and Scarab Deluxe from pedals with schematics similar to the ones posted in the Silicon Tone Bender thread:
viewtopic.php?f=13&t=7767

What do you lads think ?

That pedal demo is really awesome! So many classic fuzz tones are being achieved. I've seen some other demos of his Scarab and I remember being quite impressed. After hearing those original demos I decided I needed to build myself a silicon tone bender fuzz (not interested in germanium at the moment) similar to John Lyons. I'd say the link John posted on the first page is a good place to start. The schem mictester posted is pretty much identical.

Let's start.. here are the component values:



I've looked at three or four different gut shots for the values. (EDIT: To clarify: There are two places where to resistors are the same value left and right from the text.. This is the case with the 10k above the 100n? in the center and the 110R at the bottom center )

The values in white are educated guesses.

Most of them come from the tonebender schems on the web.
The 10n comes from the Hot Silicon. The FAT pot blends between the 10u and the 10n.
The tone cap values come from the Hot Silicon too (or mictesters )
Transistors probably 2N5089 or 2N5088, diode 1N400? something.

The bias pot biases Q3 as mentioned on Johns website. So it leads me to believe Q2 and Q3 are not on the same collector resistor.

Now we need a prelliminary schematic.

Ok, here is what I came up with. Please let me know what you think. This is after all a guess.



There are still some values missing/wrong

Nice one arph! That looks pretty close to what I was thinking, just a few changed values. Is there a reason you switched the order of the 2K2/8.2n side of the tone pot?

The order of those two does not matter to the sound. They were ordered that way on the schematic I used to create the one above. If you look at the gutshots it appears that they are the other way around so they should be switched. I was too lazy to do that... as it is not 100% accurate yet anyway.

I'd really like to know if that schematic is correct...
John, will you enlighten us?

Fairly close.
Remove R9
Remove the 750 in series with +9v
Put 1k in series with the Bias Pot (25K)
R5 is 1k
C4 is 100uf
FAT is 100k
1K off FUZZ pot is 750 ohms
C7 is .1
Q3 emitter goes to .1 then to the high side of the tone pot.
Split off the same .1 is 10k to the low side of the pot and
a .1 to 2k2 to ground. (Low pass only, shelved at that)

I started with the Hot Silicon as a base. Mic Testers schematic (which is the same)
was not on line at that time (for a few years actually)

I'm not a fuzz pedals lover, but this one!! And I really enjoy the demos!!

Many thanks, John!!!
I haven't built a fuzz over the last two years, because I've got more than enough, but I'll dfinitely build this...

So would this schematic be correct?

No, if I get it right:

John Lyons wrote:Q3 emitter goes to .1 then to the high side of the tone pot.
Split off the same .1 is 10k to the low side of the pot and
a .1 to 2k2 to ground. (Low pass only, shelved at that)

Yeah, that part confused me. But his description of the tone circuit made me think he may have meant Q4?

roseblood11 wrote:No, if I get it right:

John Lyons wrote:Q3 emitter goes to .1 then to the high side of the tone pot.
Split off the same .1 is 10k to the low side of the pot and
a .1 to 2k2 to ground. (Low pass only, shelved at that)

storyboardist wrote:Yeah, that part confused me. But his description of the tone circuit made me think he may have meant Q4?

Yes that's the way I interpreted it too. But John said the 100n goes to the high side and then a 10K down to the low side which to me sounds like the 100n from the emitter goes to the 10K/100n junction rather than as it is in the updated schematic going to the low side of the pot.

John Lyons wrote:Q3 emitter goes to .1 then to the high side of the tone pot.
Split off the same .1 is 10k to the low side of the pot and
a .1 to 2k2 to ground. (Low pass only, shelved at that)

Ah, so like this:

storyboardist wrote:Ah, so like this:

[ Image ]

Yes that looks like the way John described it, or at least that's how I understood it.