EHX - English Muffin

theehman · Post by **theehman** » 17 Jul 2009, 10:43

borislavgajic wrote:can someone please help with anode and cathode resistor values?

thanks

boris

For the 1st stage:
anode: 110K
Cathode: 845

For the 2nd stage:
anode: 162K
Cathode: 3.3K

For the 3rd stage:
anode: 162K
Cathode: 3.3K

For the 4th stage:
anode: n/a
Cathode: 110K

RnFR · Post by **RnFR** » 17 Jul 2009, 11:55

borislavgajic wrote: boxing is almost complete........now to electronic....I am making it point to point.......more in a fiew days
cheers
boris

boris that looks awesome! very sci fi! i dig it.

John_5 · Post by **John_5** » 17 Jul 2009, 17:41

Hey Boris,

when you are done, you can compare your findings to the factory schematic below.

It's a very neat design I think, could be transformed into a 2203 type preamp for sure... but why?

Some concerns:
1. The output impedance is rather high. A Buffer could help, but the only problem would be cable capacitance. But given the amount of high freq content this pedal can spit out... (see concern #3)
2. The RIDICULOUS power plug type and placement! How many of those had to be repared? How many players ditched the pedal because of that?

3. Doesn't play well with a Spector Bass with EMG pickups. Input is high and too trebly. Generates a nasty, spluttery artifact in the upper range, that really hurts your ears when playing with headphones on. I guess plugging a passive instrument is the way to go here. And playing through a real speaker!

Cheers,
Jan

(hope the uploading works - worked

)

theehman · Post by **theehman** » 17 Jul 2009, 17:47

borislavgajic wrote: boxing is almost complete........now to electronic....I am making it point to point.......more in a fiew days
cheers
boris

You should steampunk that.

borislavgajic · Post by **borislavgajic** » 17 Jul 2009, 18:14

theehman wrote:
borislavgajic wrote: boxing is almost complete........now to electronic....I am making it point to point.......more in a fiew days
cheers
boris

You should steampunk that.

yes.....and play it with guitar like this....
http://www.hollergram.net/wp-content/up ... itar_1.jpg

thank to you all....for helping

boris

mistermikev · Post by **mistermikev** » 18 Jul 2009, 03:36

I'll say this: I have one and I really like it. I've compared it to my hafler t3 and it's a winner IMO. I wasn't expecting a marshal when I bought it so that may have something to do with why I like it so much.

If u r still wanting guts LMK I'll check back in a few days and perhaps I'll yank it apart.

borislavgajic · Post by **borislavgajic** » 18 Jul 2009, 09:31

If u r still wanting guts LMK I'll check back in a few days and perhaps I'll yank it apart.

great....

....be carefull

boris

mistermikev · Post by **mistermikev** » 18 Jul 2009, 15:39

thanks, and good point. I do realize this guy is high voltage... but I wasn't exactly planning on doing much more than removing the back and shooting a pic... would that even be helpful?

Am I accurate in thinking that if I were to go further I would simply want to avoid bridging any large caps right?

borislavgajic · Post by **borislavgajic** » 19 Jul 2009, 08:09

Am I accurate in thinking that if I were to go further I would simply want to avoid bridging any large caps right?

you are right......better way is to play your guitar with Muffin,and just disconnect power ,and keep playing untill there is no sound at all...that will discharge those big electrolytic caps.......

if I were to go further

if you were, there is not much more to do...

....take off pot caps,unscrew all pots,jacks and switch(and one screw on pcb).......that should be all........(take out tubes first),and be careful not to scratch box

....and wow ..mistermikev....THANKS FOR THE PICTURES

boris

mistermikev · Post by **mistermikev** » 19 Jul 2009, 14:33

hmm, that's a great idea (play gtr and unplug the power).

looks like the main board will come out w/o removing pots... so just two screws and the input/output jack and voilla.

I'll try to go this final step in the next cpl of days...

borislavgajic · Post by **borislavgajic** » 19 Jul 2009, 19:42

mistermikev wrote:hmm, that's a great idea (play gtr and unplug the power).

looks like the main board will come out w/o removing pots... so just two screws and the input/output jack and voilla.

I'll try to go this final step in the next cpl of days...

.....hmmmmm ..I think you'll have to unscrew SW and jacks....about screw between tubes ...is it for voltage regulator fixation?

........

thank you for doing all this..

cheers

boris

mistermikev · Post by **mistermikev** » 23 Jul 2009, 02:35

save the applause till after folks (jk)

haven't forgot... just haven't gotten to it... stay tuned... top view of the board is coming soon.

borislavgajic · Post by **borislavgajic** » 27 Jul 2009, 16:27

and it is done....

clone of EnglishMuffin is ready to go........sound is very nice (like it more with humbackers)......sound samples soon.....

cheers

boris

borislavgajic · Post by **borislavgajic** » 28 Jul 2009, 11:11

samples

http://www.box.net/shared/btph0sattn
http://www.box.net/shared/jbnm6xej4f
http://www.box.net/shared/rxzajn31e6

strat...single coils......I prefer it with double couls.....hmmmmmmm

cheers
boris

himister · Post by **himister** » 28 Jul 2009, 12:51

Very nice build Boris!

It reminds me of old TOS Kirk and Spock gear.

Very retro.

soulsonic · Post by **soulsonic** » 31 Jul 2009, 07:27

I love how you do your boxes, Boris!

borislavgajic · Post by **borislavgajic** » 31 Jul 2009, 08:34

soulsonic wrote:I love how you do your boxes, Boris!

thank you himister.....

thank you very much Martin.....it is a big compliment

boris

Post by **modman** » 31 Jul 2009, 09:55

I just adore anything Boris builds. This looks like a futuristic military tank with tube titties!

It just has to be BIG BERTHA... How do you avoid drunken bass players from stepping on those tit...er I mean tubes?

borislavgajic · Post by **borislavgajic** » 31 Jul 2009, 10:49

modman wrote:I just adore anything Boris builds. This looks like a futuristic military tank with tube titties! It just has to be BIG BERTHA... How do you avoid drunken bass players from stepping on those tit...er I mean tubes?

.....oh man.......

...modman

...thank you........I'm going to putt perforated bumper to protect those..."titties".....hot hot boobs....

and for bass players I recomend this wall.........

http://www.inquisitr.com/31313/ninja-ga ... ith-boobs/

boris

Liquids · Post by **Liquids** » 29 Sep 2009, 17:43

OH man, I have been wanting to expiriment with a tube based pedal at high voltage but shied away from the difficulty of the transformer issue...I thought if I could find one to mod it might be better...

The EH stuff seemed intriguing but the Hot tubes seems to have a funky setup, the Mesa Boogie Bottle Rocket looked good but hard/expensive to find, the Duncan stuff availabut but unusual in tubes and circuitry....

This one looks perfect - a completely bog-standard 3 stage tube preamp with a cathode follower driven tone stack. Can find them used for under $150! A modders paradise to simply tinker with values! Some of the values do seem odd and it's unknown why you'd want such a mid-scooped amp-type EQ going into an presumably already mid-scooped amp...but easily moded.

Questions
1) what kind of voltage is on the grids of the tubes? I know the cathodes see low voltages, but I want to find out what wattage rating I'd need, to know what I'd need to order in key points in the circuit rather than the 1/4W resistors and pots I've got an abundance of. I'm assuming that I need bigger voltage/wattage ratings for resistors on the plate and coupling caps.

2) Boris, what transformer did you use? Just out of curiosity - I've seen that hoffman amps offers the same type transformer, and know that allied and weber offer larger sized version with similar voltages.

EHX - English Muffin [schematic]