FR-70 Fuzzrong  [traced]

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guitarmongot
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Post by guitarmongot »

This weekend I am planning on building a DAM FR-70 (Si Fuzzrong).It´s a Mosrite Fuzzrite Si
version : have done some research here and come across this photo : there´s a 100K (?) extra
resistor on VOL lug3 that goes to Output Ground(?)..Can´t see that on any other shematics or
board photos/veros.It´s in the upper right on this photo:
Perhaps someone can explain what that extra resistor does and if it´s 100K ?
Also seems to be a 220K between Q1 C and B (Mosrite has 470K ).
And a smoothering cap between Q1 C and B ( silver cap ) 100-220 pF ???
/cheers M
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rosetta
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Post by rosetta »

maybe this could help you.
Image

and read this thread, they explain what is that resistor for.
http://tagboardeffects.blogspot.ca/2010 ... zrite.html

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Post by beedotman »

Here's another gut shot
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Post by beedotman »

I've started drawing this some time ago, but haven't time to finish it...

This is what I have at the moment

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guitarmongot
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Post by guitarmongot »

Ok Beedotman : Thank you : I will buildt it from your vero and from schematics I got : looks very nice :-
and I´ll come back with a report on the build..
And I know all about the "DAM vero buisness" at Turretboard.org: so I won´t
publish or use this vero in any commersial way : I´m just a pedal-hobbiest who
looks for that ultimate fuzz-buzz-pedal.....here´s a video that shows
what a uber cool fuzz can do to some...: :D

Been busy with a Burns Buzzaround today : it´s really nice fuzz : but I have a lot of
hizz and noise when I hit the sweetpoint (Bias Q3 at -3V )..
Got 48-59-120 hfe GE PNP : any cool tips on killing some of the noise???
/cheers M

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Post by beedotman »

guitarmongot, this is not finished project, I think that at the moment this will not work as it suppose to...
anyway... I will try to finish it later and post here.

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Post by beedotman »

guitarmongot wrote: Been busy with a Burns Buzzaround today : it´s really nice fuzz : but I have a lot of
hizz and noise when I hit the sweetpoint (Bias Q3 at -3V )..
Got 48-59-120 hfe GE PNP : any cool tips on killing some of the noise???
/cheers M
Hard to say - try another trannies, shielded wires and remember to ground enclosure properly.
In Buzzaorunds first two trannies are in darlington pair - gain and leakage is multipied, so maybe this is the problem.
anyway - here's some info regarding biasing buzzaround:
viewtopic.php?f=10&t=17916

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Post by guitarmongot »

Mr B. It´s a little of topic here but : :D thanks for your input : i´ve read that tread :
I got a SolaSound MK3 with 49-59-90 hfe PNP.It sounds really nice
with Q1-2 C: -4V and Q3 c:-3V as pointed out in the thread.
And I got a DAM Greasebox GE with 48-59-100 hfe PNP GE : and thats LOUD and
wild sounding at Q3 -3V : almost "metalrock" sounding...
So thats how I started with Buzzaround: since its a MK3 type : but It got much more hizz and noise...
also tried a Si PNP in Q1 and Q2 (179hfe) but then it sounded more like a Overdrive:nice but
not that buzzing sparkeling Ge fuzz feeling at all : but less hizz and noise...
So I´ll guess I´ll just have to go thu my PNP Ge trannies and look for little leakage..

/cheers M

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Post by phibes »

guitarmongot wrote:Mr B. It´s a little of topic here but : :D thanks for your input : i´ve read that tread :
I got a SolaSound MK3 with 49-59-90 hfe PNP.It sounds really nice
with Q1-2 C: -4V and Q3 c:-3V as pointed out in the thread.
And I got a DAM Greasebox GE with 48-59-100 hfe PNP GE : and thats LOUD and
wild sounding at Q3 -3V : almost "metalrock" sounding...
So thats how I started with Buzzaround: since its a MK3 type : but It got much more hizz and noise...
also tried a Si PNP in Q1 and Q2 (179hfe) but then it sounded more like a Overdrive:nice but
not that buzzing sparkeling Ge fuzz feeling at all : but less hizz and noise...
So I´ll guess I´ll just have to go thu my PNP Ge trannies and look for little leakage..

/cheers M
The Buzzaround bias's itself so no need to try and bias, people go overboard these days with trimmers. The noise your hearing sounds more like a HISSY germanium transistor than a bias problem. Leakage won't tell you if the transistor is hissy, only your ears. Try other germanium transistors.
GuitarlCarl - "TGP = The Gear Polishers"

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guitarmongot
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Post by guitarmongot »

I got 2 sets of 3 x OC75 TB from SmallBear : I´ll try them .
Maybe less hiss from them :D
To my ears -3V on Q3 C sounds best for a TB mk3 : and sometimes you´ll
have to tweak some resistors to get there..
/cheers M

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Post by rosetta »

http://www.aronnelson.com/gallery/main. ... 8.jpg.html

this picture from the original fuzzrite shows a 22k resistor.

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Post by sinner »

rosetta wrote:http://www.aronnelson.com/gallery/main. ... 8.jpg.html

this picture from the original fuzzrite shows a 22k resistor.
Original Fuzzrite had 22k there http://www.turretboard.org/?p=669

D.Main's take is not 1-to-1 copy, it's his take of it

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guitarmongot
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Post by guitarmongot »

FR-70 Fuzzrong is a take on the Si NPN later version of Fuzzrite : and it´s a little diffrent
in the tone pot wirering from what I can see from some board pics I found:
also shows Q2 : 2N4401 NPN low hfe.So I´ll try 120-150 hfe for Q1 and 80-100 hfe for Q2.
The early Fuzzrite were GE PNP and thats Mr Main´s FR-69 : a diffrent animal.. :D
Mr Beedotman ; I can mail you those pics I found if it helps you to finish your vero ?
From what I can see your vero is correct : but you´re the vero expert here.... :D
And as for the "off topic" Buzzaround : I put a combo of OC71 (47hfe),OC75(67hfe) and OC75 (87hfe):
now we are talking...low noise,super sustain and that fat buzzy fuzz tone..
Q3 bias at -2V got that sound...and there´s no trimpots now...ready to box it up.
/cheers M

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Post by phibes »

guitarmongot wrote: And as for the "off topic" Buzzaround : I put a combo of OC71 (47hfe),OC75(67hfe) and OC75 (87hfe):
now we are talking...low noise,super sustain and that fat buzzy fuzz tone..
Q3 bias at -2V got that sound...and there´s no trimpots now...ready to box it up.
/cheers M
:thumbsup
GuitarlCarl - "TGP = The Gear Polishers"

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Post by beedotman »

I think this is it! :horsey:
Big thanks to agoldoor and sinner for support! :thumbsup

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Post by sinner »

B.man boy, move the torg signature off it please :)

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Post by beedotman »

good gut shots
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Post by beedotman »

sinner wrote:B.man boy, move the torg signature off it please :)
:slap: sorry, old habit... :hug:
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Post by sinner »

Cheers Bro :*

Good job :thumbsup

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Post by agoldoor »

Very awesome, thanks B. Man.

Heads up to anyone who is thinking of building this:
In terms of the sound, it's a muuuch more mellow version of the Fuzzrite. If you know the DAM Grease Box, I'd say that the FR-70 is to the Fuzzrite what the Grease Box is to the Tonebender MKIII if that makes sense?

But don't get me wrong, it's a fantastic pedal and I'm very much in admiration of Dave Main for the exploration he did to come up with the FR-70.

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