Big Muff v4: bypassed signal is boosted? How?

[lux_interior]

I wanted to ask a question about my EH Big Muff from '78. It's a version 4 (the one with the top switch to turn it off). The guy that I bought it from had said that it's not true bypass, and that it incorporates some sort of circuit that boosts the signal when I hit the stomp switch to deactivate it. He also mentioned that Jack White likes this function and keeps his unmodded to true bypass for this reason (that's weird because as far as I know, Jack White doesn't use a v4 but a current production USA one).

In any case, it turns out I really, really like what it does to my clean tone. It compresses it a bit, and adds a bit of a sparkle, but not as a general treble increase, which is just perfect. There is something like an 8db boost when the pedal is off, and I am not thinking of converting it to true bypass in any way.

What I wanted to know is how this is accomplished. Is it just an ordinary clean boost circuit, and it seems my amp simply likes the extra push on the front end, or is it something special? I have gone through the pages of KitRae and I haven't found any info on this. I would be grateful for any comments...

[dcmak5]

I love my V4 and never really noticed

I've refused to join the "tone suck" club, and buy a nice buffer, but I feel like a '77 Muff is going to be prime example of what destroys your tone. Idk anything about how the buffer circuit works in the muff, or what it does to your bypassed tone
I've always just piled them on, boss, no buffer, old pedals, etc. I've never noticed any problems that I couldn't compensate for by turning up the knob on my amp

bump for someone else who has knowledge about this particular pedal

[whoismarykelly]

Do you have pictures of the inside of the pedal? AFAIK, no muff has ever employed any sort of active boost while in bypass.

[lux_interior]

Yes, I can certainly take some pictures and post them... I will do that very soon. I also have a true bypass loop, and I will try it there to be 100% sure, but the boost is very easy to tell. As far as the tone suck goes, there is no tone suck whatsoever with mine, on the contrary that clean boost is fantastic, and I have a bit of experience with boosts too... I am thinking of keeping it always in off mode, without turning it on (I don't think I'll need so gainy sounds with the current band I'm thinking of joining).

[Angle Loss]

What you are experiencing is normal. Some of the opamp muffs do have an active bypass, which has your signal going through an opamp. I have one that I true bypassed because I didn't like having my whole signal boosted. You can drop a 3pdt switch in their and circumvent the active bypass just like you would the crappy output switched bypass of a regular muff--though it sounds like you enjoy what it does.

Just one out five of the opamp muffs I have had had it.

[Angle Loss]

If you scroll down to the opamp version schematic on this page you can see how the bypass works for our model:

http://www.pisotones.com/BigMuffPi/p...P_versions.htm

The signal is being amplified by a 4558 whether the fuzz is engaged or bypassed.

[whoismarykelly]

Oh OK. I thought we were still talking about a transistor version.

[lux_interior]

Thanks a lot for all the answers... I will post pictures (just for the record) tomorrow or on Friday. So this boost is coming from a JRC 4558... I didn't know they can be used in squeaky clean boosts (ok, tubescreamers can do that, but with limited dbs of clean boost before clipping, which is also not completely clean).

[lux_interior]

For the record, here are the pics, but the PCB is only visible from the bottom side, so I tried to take some side photos of the components:

[Angle Loss]

Hey lux, that is the exact same version as the one that I have. It is one of my three 'go to the grave with' muffs. Most of the opamp versions are labeled 1322, but this has retained the transistor version number. That's a great pedal. I did true bypass mine, but I'm glad you are enjoying yours as a tone enhancer.

[analogsystem]

Mine did it too but it was boosted as well as dark and muffled as hell, totally unusable. I had to have mine true bypassed (added an LED and normal power jack at the same time). Man I love that muff. It just recently died on me, hopefully no big deal to fix.

[lux_interior]

Originally Posted by Angle Loss

Hey lux, that is the exact same version as the one that I have. It is one of my three 'go to the grave with' muffs. Most of the opamp versions are labeled 1322, but this has retained the transistor version number. That's a great pedal. I did true bypass mine, but I'm glad you are enjoying yours as a tone enhancer.

Where can I see the transistor number, and where would the "1322" label be?

I enjoy it a lot, but it lacks a bit of clarity... it seems I can mostly play powerchords with it. For Siamese Dream tones it is THE pedal (naturally) but not much use for different needs... do you believe that other units might sound a bit more delicate? I am not looking for sounds of older versions, and I have some experience with Muffs, but sometimes it seems too much.

[Angle Loss]

The model number is on the bottom of the board (non-component side). Yours reads EH-3003. Most of the opamp circuits read 1322. The "3003" label was usually used for the transistor versions (regular 70's muffs). Your muff has no transistors, it just uses opamps. Both parts amplify the signal. None of the muffs of any version sound very delicate, lol. I'd say the "Civil War" muffs are pretty mild...but even then they are still distortion pedals.

[lux_interior]

Thanks a lot for your answer. I know, it's the nature of the beast. I love Muffs and I know very well how far they can go in terms of versatility (almost zero!!) but... call me crazy, but I believe the new Big Muff w/tone wicker (that I also have among others) is a tiny bit more clear in chords.

The funny thing with this is that it's a really weird unit: not only does it have the 3003 label but on the exterior, it says "tone bypass" which would make it a version 5. However, the switch is not wired for the "tone bypass" function but for the "on-off" one like version 4. I don't know why. Someone might have been lazy or had a few extra drinks the previous night, and wired it as a v4 instead of a v5... Do you know anything about this?

[Angle Loss]

Interesting...mine is both wired and labeled as a Tone Bypass, which is what yours should be also. Someone may have switched the top case or they might have used up an old case or as you said just plain wired it up wrong. Check the pot codes. It should start 137yyww (year=yy ie 80 is 1980, 33 is the 33rd week of production that year). That will help you date it. The pedal will be made on that year or later.

I can't remember...but I think these were made around 1980. Yours has the 1980's style knobs. Take a look at yours and I'll take a look at mine and get back to probably tomorrow morning. I'd be curious to find out more.