Mid-Fi Electronics - Demo Tape Fuzz  [traced]

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Beedoola
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Post by Beedoola »

Anyone have one/good take some gut shots? Or have any info on the circuit?

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9520575
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Post by 9520575 »

here.

This is my first trace ever. Sorry if there is any errors. I've build this using this schematic I made, So I know it works
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demo tape fuzz sch.png
demo tape fuzz sch.png (7.62 KiB) Viewed 6849 times

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Nocentelli
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Post by Nocentelli »

Thanks for this. Looks like it works just by slamming the rails to create clipping: I might try a diode pair across the opamp feedback loop on a switch. Unverified vero of the stock circuit here:

https://www.freestompboxes.org/download/ ... &mode=view
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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Nocentelli
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Post by Nocentelli »

This is A LOT of fun: Don't bother with the diodes, bashing the crap out of the 4558 sounds lovely by itself. I'll probably use log pots for volume and treble, it is exceptionally loud and bright with the linear pots specified in the schematic.
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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9520575
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Post by 9520575 »

Nocentelli wrote:This is A LOT of fun: Don't bother with the diodes, bashing the crap out of the 4558 sounds lovely by itself. I'll probably use log pots for volume and treble, it is exceptionally loud and bright with the linear pots specified in the schematic.
Loud and bright thats the pedal. I rarely turn the volume past 25%.

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Post by pinkjimiphoton »

nocentelli, is your vero verified yet?
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Nocentelli
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Post by Nocentelli »

I haven't actually built it, but that doesn't mean it won't work! (no guarantees it will, either...) :wink:
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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Post by Intripped »

a more readable schematic...
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Demo Tape Fuzz schem.png

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9520575
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Post by 9520575 »

:oops:

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Intripped
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Post by Intripped »

:mrgreen:
thanks for YOUR schem buddy!

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doug deeper
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Post by doug deeper »

The diode goes in line with v+, not to ground, and add a 47uf cap from pin 5 to ground.
Then it's 100% correct.

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Intripped
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Post by Intripped »

updated schematic and ...
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DTF schem.png
NOT VERIFIED!
NOT VERIFIED!
1Uf CAPACITORS - if you use electrolytic caps please mind the &quot;+&quot; symbol for correct orientation<br />a logaritmic pot is noted for the volume - the original taper is linear<br />OUT from pin2 of volume pot
1Uf CAPACITORS - if you use electrolytic caps please mind the "+" symbol for correct orientation
a logaritmic pot is noted for the volume - the original taper is linear
OUT from pin2 of volume pot

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Nocentelli
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Post by Nocentelli »

pinkjimiphoton wrote:nocentelli, is your vero verified yet?
OK, this one is now verified:
Demotape_vero_nocentelli_verified.gif
Demotape_vero_nocentelli_verified.gif (27.96 KiB) Viewed 6311 times
In my actual build:

I used a C100k pot instead of the 25kB for trim, giving a wider range of lower gain sounds with humbuckers which tend to overload it. I also used log 100k pots for volume and treble, putting the most useful settings closer to noon.
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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doug deeper
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Post by doug deeper »

Also,
There are a handful of 4558 versions of this pedal, but all the newer pedals use a TL072.

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Rooster72
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Post by Rooster72 »

Intripped wrote:updated schematic and ...
Nice work guys, interesting to watch what you guys do after a person has been doin it for awhile.
Would this schem. be verified yet or no? Id like to make an etching but I am very new to building, wish I would have done this years ago. I can see this is going to be a time bandit. Not for me of course ,but others who might be waiting. Ehh Ill give em a stomp for Christmas.
Really love the sound on this baby, instant, thats it reaction...
Cheers

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roseblood11
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Post by roseblood11 »

Yes the schematic is verified. Why etching a board for such a simple circuit? Nocentellis layout looks good, if you use that, you can build this pedal in one hour...

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Post by Rooster72 »

roseblood11 wrote:Yes the schematic is verified. Why etching a board for such a simple circuit? Nocentellis layout looks good, if you use that, you can build this pedal in one hour...
ok ,well I will go with your advice.

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Post by VanPorter »

Nocentelli wrote:
pinkjimiphoton wrote:nocentelli, is your vero verified yet?
Nocentelli wrote: OK, this one is now verified:
Hi, I need to know if it's necessary to put the diode and the 1M resistor, because they are in the above circuit but not in this one. If so, the diode goes between 9V and the 47 micro cap in row i? And the 1M resistor goes from "row e - column 1" to row h (ground)?

Thank you for your help!

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Nocentelli
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Post by Nocentelli »

Yep, the 1M could be mounted on the footswitch if you don't want to add an extra column to the left hand side of the vero; The diode won't fit on easily without a bit of rejigging the layout, or a bit of a kludge with the diode wired point-to-point from the DC jack to the veroboard.

I don't think either are particularly neccessary, it doesn't pop with grounded-input footswitch wiring, so the pulldown is not needed. The power diode will drop the voltage slightly, which might affect the sound slightly, but I doubt it would be noticeable.
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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Post by VanPorter »

Just built it, and it's really great!

I tried it with a Schecter Demon 7, and it's really powerfull! The thing I've noticed is that when the trebble is at minimun or maximun, a "piiii" noise appears, but if I put it at 9,5, it disappears. I used a 500K linear pot, could it be that?

Thank you very much to Nocentelli for his vero!!!

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