BBE - Windowpane  [schematic]

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jinx1499
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Post by jinx1499 »

mirosol wrote:Anyone seen the guts of BBE Windowpane?
Here are some gutshots of the BBE Windowpane.


Since it's based on a Fuzz Face, I'd love to get this gut close to an Eric Johnson Fuzz. Any ideas?
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Manfred
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Post by Manfred »

I create a incomplete layout copy according the guts here:
viewtopic.php?f=1&t=2072&p=273581&hilit ... ne#p273581
There are missing component values and tracks, thus the schematic is incomplete too.
The circuit is a Silicone-Fuzzface clone.
BBE_WindowPainLayoutPart.JPG
BBE_WindowPainSchematic.JPG
I would be very grateful if anybody can fill in the missing values.

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Post by mictester »

Here's my take on the circuit. If you include an additional 100pF from base to collector of Q2, it will sound very close to an old germanium Fuzz Face without the hiss!
Improved!
Improved!
Remember - you need to use the lowest Hfe transistors you can find. I've had great success with medium power devices (BFY50 used to be a good choice) and the transistors inside the transistor array chips.
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Post by Manfred »

mictester wrote:Here's my take on the circuit. If you include an additional 100pF from base to collector of Q2, it will sound very close to an old germanium Fuzz Face without the hiss!
BBE_WindowPainSchematic.jpg
Remember - you need to use the lowest Hfe transistors you can find. I've had great success with medium power devices (BFY50 used to be a good choice) and the transistors inside the transistor array chips.
Thank you very much for these helpfull hints.

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Post by modman »

moved the gut shots into this thread
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Post by jojokeo »

modman wrote:moved the gut shots into this thread
Thanks for all the info. but please enlighten on the polarity of C8? "normally" the signal should pass through an electrolytic cap on the +/pos leg first then head "downstream" through the circuit from the -/neg leg of the cap. I've seen this a few times on various circuits here and there and wonder it is reversed (seemingly) in this circuit? Please help me to understand why this is? Thank you.

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Post by jalmonsalmon »

jojokeo wrote:
modman wrote:moved the gut shots into this thread
Thanks for all the info. but please enlighten on the polarity of C8? "normally" the signal should pass through an electrolytic cap on the +/pos leg first then head "downstream" through the circuit from the -/neg leg of the cap. I've seen this a few times on various circuits here and there and wonder it is reversed (seemingly) in this circuit? Please help me to understand why this is? Thank you.
For NPN fuzzes C8 is correct.
If you want to really know what is up with this kind of circuit check these links. 8)
https://fuzzcentral.ssguitar.com/fuzzface.php
http://www.geofex.com/article_folders/f ... fftech.htm
https://www.electrosmash.com/fuzz-face

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Post by gght »

I know this is an old thread, but does anyone know what transistors were used in the Windowpane Fuzz?

Thanks in advance!
Dave

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Post by alecalfaras »

Amazing info. This is why I joined, many thanks

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Post by modman »

gght wrote: 10 Apr 2022, 03:20 I know this is an old thread, but does anyone know what transistors were used in the Windowpane Fuzz?

Thanks in advance!
Dave
Picture shows an MPSA18...

Image
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Post by gght »

modman wrote: 10 Apr 2022, 09:29
gght wrote: 10 Apr 2022, 03:20 I know this is an old thread, but does anyone know what transistors were used in the Windowpane Fuzz?

Thanks in advance!
Dave
Picture shows an MPSA18...

Image

Thanks! Apparently I need to mod my old eyes! 😄

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Post by mirosol »

Hmm. MPSA18 isn't that low on hFE. That should be close to a 1000 with a guitar signal and a 9V supply. https://pdf1.alldatasheet.com/datasheet ... PSA18.html

On a side note. Does that 3K9 + 5K pot in parallel really give out better sweep than, say a 2K linear pot?
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Post by cspar »

I think it's a MPSA10 selected for low gain.

If that's right then by the datasheet it seems you could use a selected MPSA11 as a sub.
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