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EHX - Muff Fuzz

Posted: 09 Jan 2008, 21:53
by alteredsounds
Will get better boards pics up shortly.

Image

Image

Posted: 09 Jan 2008, 21:59
by DWBH
I just love those knobs.

Posted: 17 Jan 2008, 19:26
by analogguru
Interesting, on all units I have seen until now (7 pcs) there were 3 ceramic caps (100n/12V) mounted on the solder side.

Is there a possibility for a photo of the component side ?

analogguru

Posted: 17 Jan 2008, 19:44
by alteredsounds
sure mate, will get to it.

Posted: 23 Jan 2008, 04:24
by Meanderthal
Hey! The input is a jack, not a plug. How come I never saw one like this before? It doesn't look like a mod. Edit: or is it? The masking tape, the solder glob...

Posted: 24 Jan 2008, 10:47
by prehistoric
hi meanderthal, a special albuquerque hello
i remember the progression of the EH effects from the 70s
at first they followed the dan armstrong example, effects you could plug into your guitar. i also recall that they were available with the male plug on either the amp or guitar side, can anyone else confirm this?
popular feedback from the dealers (guessing, educated guess) caused EH to switch to double female jacks by the early to mid 70s. the picture shown is 2nd generation graphics,
i had an LPB1 in the late 70s but it was a very early model with the first generation graphics, simple block letters. had the male input plug.
the circuit was the famous 'flying lead 'style, it was a mess inside.
but it drove my 68 twin into overdrive which i needed at the time.

Posted: 24 Jan 2008, 11:00
by prehistoric
2nd gen graphics on lpb1
Image

Posted: 26 Jan 2008, 19:08
by fatrack
Speaking of messes - I've got what looks to be a 2nd gen muff fuzz that has seen better days; a friend gave it to me hoping I could repair it. I don't have any electronics background but I've built a couple of pedals and am enjoying learning about this hobby as I go. I've tried to get a schematic that matches up to this pedal, but the only one I could find for the opamp muff fuzz was at g.g.g. and indicated incorrect capacitor values. I tried to trace out the circuit but it never seemed right to me. The jacks are gone, as is almost all of the hookup wire. It seems clear upon looking at alteredsounds *very* enlightening photos that somebody went wild with the iron on this thing - there are scorched marks and traces melted together. Also, there are only two capacitors, both of which have a broken lead. Anyway, I took a series of photos, including the component side that might prove interesting. I've enjoyed lurking around here and learning from the members, so perhaps this will be helpful to you all.
John
https://s237.photobucket.com/albums/ff3 ... ff%20Fuzz/

Posted: 27 Jan 2008, 17:51
by alteredsounds
god someone made a mess of that! I'll try and compare bits of mine to urs and post results etc

Posted: 27 Jan 2008, 19:30
by analogguru
Nice (and complete) guts deserve a nice:

EH Muff Fuzz schematic (1977)

enjoy,
analogguru

Posted: 28 Jan 2008, 16:35
by fatrack
Very nice, this forum is great :D
Analog - thanks for that; even with my imprecise skills I should be able to make some sense of this circuit now...
Altered - thanks for the help! I've looked around for just such pictures but never found them until I started hanging out here. Ironically, I looked for info on the opamp muff fuzz when I first signed on to this board and found nothing. A couple of days ago I photographed my mangled muff, looking to appeal to the board's members for assistance, and I found your thread while performing a courtesy search on related topics immediately prior to posting. What perfect timing! Either way - right on the real, death to the fakers - freestomps(and specifically the people that hang out here i.e.altered and a.g.) has been a tremendous source of knowledge for me.
thanks
John

Posted: 28 Jan 2008, 22:24
by alteredsounds
Just tryna get the thing apart right now and will get the pics :)

Posted: 01 Feb 2008, 18:54
by Rodgre
I have a Muff Fuzz (my first pedal!) that I bought brand new, and while it had two jacks, instead of a jack and a plug, it had the same blobby solder and masking tape. That's how E-H rolled!

I need to dig it out and remind me of what my youth sounded like.

Roger

Posted: 03 Feb 2008, 16:19
by patafix
analogguru wrote:Nice (and complete) guts deserve a nice:

EH Muff Fuzz schematic (1977)

enjoy,
analogguru
What is the resistor that determines the input impedance of this pedal ?

Is the input impedance of the opamp Muff Fuzz higher than that of the transistor Muff Fuzz ?

Thx

Posted: 03 Feb 2008, 16:33
by analogguru
patafix wrote:
analogguru wrote:Nice (and complete) guts deserve a nice:

EH Muff Fuzz schematic (1977)

enjoy,
analogguru
What is the resistor that determines the input impedance of this pedal ?
It is R1.... 100k
Is the input impedance of the opamp Muff Fuzz higher than that of the transistor Muff Fuzz ?

Thx
Yes... slightly.... I would assume the transistor muff fuzz at approx 50k

analogguru

Posted: 03 Feb 2008, 19:41
by JHS
Different circuits of the opamp Muff-Fuzz are common, 'cos EH had done some revisions over the years and adapted parts to the IC they used to use.

JHS

EH - Muff Fuzz

Posted: 12 Apr 2009, 07:05
by moaner70
I built an transistorized Electro Harmonix Muff Fuzz clone from the schematic at the GGG website.

http://www.generalguitargadgets.com/ind ... Itemid=121

Thought I'd build one as one of my favorite bands Motorpsycho use one on the Bass. Gives the bass more presence and a driven tone with the mere hint of a bit of fuzz. I used a couple of 2N3904 transistors in the circuit as I had them left over from the last project.

Here is a vero layout. I can vertify it works. The off board wiring is a simple DPDT switch where the tip of the jack can be switched bypassing the effect.

Image

Project name: Muff Fuzz
Credits: Project credits...

Group Name Value Part # Quantity

Capacitors C1 47uF 1
Capacitors C2, C3 0.1uF 2
Circuit boards Board 1
Circuit boards Board 1
Diodes D1, D2 1N4148 2
Jacks J1 (Stereo) 1
Jacks J2 (Mono) 1
Potentiometers VR6 100K 1
Resistors R1, R3, R4 100K 3
Resistors R2 10K 1
Resistors R5 2.7K 1
Transistors Q1, Q2 2N5088 2 (I used a couple of 2N3904)


Created with freeware DIY Layout Creator

Re: EH - Muff Fuzz

Posted: 13 Apr 2009, 22:24
by Siddh
Thanks for sharing the veroboard layout. I'm going to breadboard the Muff Fuzz some day to see if I like it. Motorpsycho is one of my favourite bands too by the way. I don't think the Muff Fuzz is something Bent has been using the for bass though. He mostly uses just one pedal, a Electro-Harmonix Fuzz Wah, which I think has been mistaken for a Muff Fuzz.

Re: EH - Muff Fuzz

Posted: 14 Apr 2009, 00:19
by bumblebee
The transistors are in backwards. And shouldnt the strip be cut at D13?

Re: EH - Muff Fuzz

Posted: 14 Apr 2009, 07:04
by moaner70
Bumblebee, the transistors are 2N3904 and are in the right way round. The collector of Q1 connects to the base of Q2 and therefore no cut needed at D13, as per the schematic.

Siddh, thanks for the tip on the Electro-Harmonix Fuzz Wah, I'll have to see what one of them sounds like, could be my next project!