MJM - London Fuzz

analogguru · Post by **analogguru** » 21 Jan 2008, 09:07

Some guts:

http://i19.ebayimg.com/03/i/000/d2/7c/7531_1.JPG
http://i4.ebayimg.com/03/i/000/d2/7c/78a3_1.JPG

If you want to buy it for further analysis of the mojo-components:
https://cgi.ebay.com/MJM-London-Fuzz-98 ... dZViewItem

analogguru

MKB · Post by **MKB** » 21 Jan 2008, 14:34

Nice pots...

MoreCowbell · Post by **MoreCowbell** » 21 Jan 2008, 15:25

MJM makes some VERY nice sounding pedals...BUT....I had to repair one a couple years back, and the soldering was pretty bad. Hopefully it's improved.

I notice that this auction is yet another that is tacking on well over an extra $100 OVER the NEW pedals price....its nice that it's for charity and all, but why spend the extra $125 on a used one ?

http://www.mjmguitarfx.com/mjm_london_fuzz.html

MoreCowbell · Post by **MoreCowbell** » 21 Jan 2008, 15:31

Its interesting that direct from MJM, the "germanium" London Fuzz is $14 LESS than the "silicon" London Fuzz II !

http://www.mjmguitarfx.com/mjm_london_fuzz.html

http://www.mjmguitarfx.com/mjm_london_fuzz2.html

Oh...and better gut shots of the London Fuzz !

http://www.clusterstudios.com/sale/imag ... uzz_02.jpg

http://www.clusterstudios.com/sale/imag ... uzz_03.jpg

soulsonic · Post by **soulsonic** » 21 Jan 2008, 18:49

MKB wrote:Nice pots...

I agree. I think it's nice to see someone use something other than those cheap Alphas for a change.

MKB · Post by **MKB** » 21 Jan 2008, 20:53

soulsonic wrote:
MKB wrote:Nice pots...
I agree. I think it's nice to see someone use something other than those cheap Alphas for a change.

Indeed, but unfortunately on second look it appears to have one of those most horrible junky DPDT footswitches in there. I bought a bunch of those from MCM Electronics a few years ago, every single one went bad in just a few months. If you heat the pins too much, the plastic melts. Pure junk.

MoreCowbell · Post by **MoreCowbell** » 21 Jan 2008, 21:00

MKB wrote:
soulsonic wrote:
MKB wrote:Nice pots...
I agree. I think it's nice to see someone use something other than those cheap Alphas for a change.
Indeed, but unfortunately on second look it appears to have one of those most horrible junky DPDT footswitches in there. I bought a bunch of those from MCM Electronics a few years ago, every single one went bad in just a few months. If you heat the pins too much, the plastic melts. Pure junk.

I replaced the X-wing switch in the London that I fixed...the switch still worked, but I knew it was only a matter of time....

soulsonic · Post by **soulsonic** » 21 Jan 2008, 23:32

Well.. I guess we can't win them all.

Starman · Post by **Starman** » 22 Jan 2008, 07:05

I fixed one of those London Fuzz pedals a few years a go for a friend. It had black plastic jacks, and the board looked pretty much the same. The problem was that the chassis was not grounded. He must have overlooked it on this one unit because I can't imagine all of them being that way. This thing buzzed when I touched it!

seniorLoco · Post by **seniorLoco** » 23 Jan 2008, 01:43

I hope Mr.MJM goes easy on the glue gun ....

TubeDude22 · Post by **TubeDude22** » 23 Jan 2008, 02:26

Hmmm... I've seen those parts somewhere. Can you say, "Fuzz Face Clone"?

analogguru · Post by **analogguru** » 27 Feb 2008, 08:42

Hmmm... I've seen those parts somewhere.

Hmmm... I would suggest that this was in the TV-set of your grandma...

Well, here is another one with guts:

https://cgi.ebay.com/MJM-London-Fuzz-gu ... 0204314062

analoguru

briggs · Post by **briggs** » 27 Feb 2008, 11:54

Another gut - It's a straight fuzz face, modified values. The input cap was 0.047uF and the output cap was 0.47uF, the big green bypass cap was 10uF. Pots = 1K and 500KA. Resistors, well you can see the colour codes on the two pictures... I thought I'd taken a picture of the trace side of the board but, oooooops, must have deleted that one! Still, a scheme is not to hard to work out from there

http://bp0.blogger.com/_y4AYtND8Hz8/R8V ... fuzz_1.jpg
http://bp2.blogger.com/_y4AYtND8Hz8/R8V ... fuzz_2.jpg

JimiB · Post by **JimiB** » 27 Feb 2008, 19:16

The input cap was 0.047uF and the output cap was 0.47uF

it looks like the oposite to me but I don't have one in hand. Can you double check that?

HydrozeenElectronics · Post by **HydrozeenElectronics** » 14 Aug 2009, 03:57

seniorLoco wrote:I hope Mr.MJM goes easy on the glue gun ....

What's all the glue for? is he building these "Dead Bug" style and needs the glue to hold it together until it's soldered or is it for durability?

Got any pics of the underside of the board?

thanks

monkeyxx · Post by **monkeyxx** » 20 Jun 2011, 04:21

I'm quite interested in the fuzz face circuit right now so I mapped this one out based on briggs photos and notes

thanks for the tip about the in/out cap possible switch! I will have to make note of that and do some testing in my build to see which is right

should be verifying this soon

any commentary welcome

monkeyxx · Post by **monkeyxx** » 20 Jun 2011, 04:30

based on the values in red being slight variations from the original arbiter fuzz face (black are arbiter orig values left unchanged) I would guess that the .47 would be the input cap and the .047 the output, I will probably try that arrangement first. the arbiter and most fuzz face "clones" I've seen have the input cap being the much larger value of the two. I'll update the schematic if this proves to be true

tyronethebig · Post by **tyronethebig** » 23 Jun 2011, 15:15

If this begins to oscillate when the fuzz is cranked, would changing any of the bias resistors to the transistors help?

tyronethebig · Post by **tyronethebig** » 01 Jul 2011, 13:36

played with the pedal and answered my own question. *DOH*

monkeyxx · Post by **monkeyxx** » 05 May 2013, 19:12

This is probably the final schematic. I'm almost done building mine I'm just not in pedal mode right now.