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Re: Big Muff Plus
Posted: 30 Mar 2010, 21:04
by SpencerPedals
mictester wrote:Yes, but all you get of you remove the second diode pair is rail-bashing which sounds horrible, and if you remove the first pair, you have to increase the gain of Q2 a bit (I reduced the emitter resistor). This gives you the Super Tonebender, which is just the same sound as the Big Muff but with reduced sustain (and often gives increased noise).
For some reason I was thinking that the transistor that was hacked off to yeild the Jumbo Tonebender was the Muff's Q2. My mistake. I'll still play around with it. I've never worked with that version of the Tonebender before, just the MKII.
I do plan on jumpering Q2 for the diode removal project, and experimenting with as much gain as I can get in there to drive things harder.
Re: Big Muff Plus
Posted: 02 Apr 2010, 17:22
by mictester
Another update. I've included the bypass circuit, indication, gain recovery stage at the output and input buffer. This thing is truly amazing!

- BMPlus.PNG (9.26 KiB) Viewed 3248 times
Enjoy!
Re: Big Muff Plus
Posted: 04 Apr 2010, 08:25
by RnFR
i usually see the buffer before the tone control if it isn't in the last stage. is there a reason you kept it the way it is?
Re: Big Muff Plus
Posted: 04 Apr 2010, 12:24
by mictester
RnFR wrote:i usually see the buffer before the tone control if it isn't in the last stage. is there a reason you kept it the way it is?
The final clipper stage has the right output impedance to drive the passive James tone control. The output of the tone control is looking for a load of about 500k, so the FET stage sorts that out! The FET stage then drives a normal bipolar amplifier, and that's it! Sounds amazing, by the way!
Re: Big Muff Plus
Posted: 06 Apr 2010, 18:00
by soggybag
mictester wrote:SpencerPedals wrote:mictester wrote:
...
Board layouts and modifications to follow soon! Also - how to use a CA3046 to make your Big Muff complete with LED indicator. Also - new project - using a 3046 for perfect transistor balance for your frequency doubler in a Superfuzz!
I just found this thread and notice that you mention using the 3046 for a BMP or Super Fuzz. I tried this a few years ago and had just come back to the idea again. I'm curious to see what you come up with for this. I always thought this was a great idea. But my lack of skill has kept me from finding a good solution.
Re: Big Muff Plus
Posted: 07 Apr 2010, 16:56
by mictester
soggybag wrote:
I just found this thread and notice that you mention using the 3046 for a BMP or Super Fuzz. I tried this a few years ago and had just come back to the idea again. I'm curious to see what you come up with for this. I always thought this was a great idea. But my lack of skill has kept me from finding a good solution.
I've just started the write-up, so it will be on here later. The Superfuzz octave sounds amazing when you have truly balanced transistors. You also have to match the resistors on the bases of the long-tailed pair (then you don't need the trimmer), and you can make the board a little smaller. The spare transistor can be used to drive the status LED, and the thing sounds superb!
Re: Big Muff Plus
Posted: 07 Apr 2010, 18:07
by soggybag
Right on! I eagerly await. Like I said I wanted to do this some time ago. Alas, my skills were not up to the task. So I moved on to some easier projects. I had recently had found a 3046/3086's in my parts bin and started thinking about it again.
This time I was thinking about doing a BMP. I figured this would be easier. I had built a few BMPs already. One thought I had was that the transistors in the 3046/3086 are pretty low gain compared to what you typically see in a BMP. They are 100hfe. I was wondering how this would effect the sound. I'm guessing it might not make that big a difference, since we only need enough gain to over come the clipping threshold of the diode pairs. The tone section needs enough gain to drive the signal through and recover some gain after. I figured with the extra transistor this would be possible to do.
I also ran across an interesting tremolo based on the 3046. Basically arranges all of the transistors into a VCA. I could post a link if anyone is interested. This looked like an interesting project.
Re: Big Muff Plus
Posted: 07 Apr 2010, 22:17
by mictester
soggybag wrote:
I also ran across an interesting tremolo based on the 3046. Basically arranges all of the transistors into a VCA. I could post a link if anyone is interested. This looked like an interesting project.
Yes please.
Re: Big Muff Plus
Posted: 08 Apr 2010, 00:07
by soggybag
Here's a link to the image. Go up a directory to get a list of all of the pages in this article.
http://www.moosapotamus.net/IDEAS/stomp ... age_14.gif
Re: Big Muff Plus
Posted: 09 Apr 2010, 11:55
by SPeter
THANKS!

Re: Big Muff Plus
Posted: 16 Apr 2010, 20:46
by devastator
What's the role of the input buffer ? what different it makes compared to the originale big muff ?
Re: Big Muff Plus
Posted: 17 Apr 2010, 08:52
by mictester
devastator wrote:What's the role of the input buffer ? what different it makes compared to the original big muff ?
The original Big Muff had a fairly low input impedance, which would load down most pickups - this would roll off the top end going in to the effect, and partially contributed to the "smooth" sound. In the modern world, where true bypass reigns, I like to put a buffered clean sustain circuit as the first pedal, followed by the Big Muff. There was a major change in "brightness" when using the guitar straight into the Big Muff - which demonstrated the impedance problem of the input stage of the Big Muff...
If you use a high impedance buffer at the input, the problems are mitigated, and the results are amazing!
Re: Big Muff Plus
Posted: 17 Apr 2010, 13:14
by devastator
thanks for the response mictester.
I always have a kind of hate/love feeling with the "big muff"

Re: Big Muff Plus
Posted: 21 Apr 2010, 10:50
by flood
here's my take on the BMP:
https://www.freestompboxes.org/viewtopic ... 89#p100089
this thread pwns it though.

Re: Big Muff Plus
Posted: 29 Apr 2010, 16:51
by GodSaveMetal
please anybody a PCB a LAYOUT of this!!!!!!!!!!!!!!!!!!!

yeahhhhhhhhh!!!!!!!!!!!!!!!!!!!!

Re: Big Muff Plus
Posted: 29 Apr 2010, 17:11
by mictester
GodSaveMetal wrote:please anybody a PCB a LAYOUT of this!!!!!!!!!!!!!!!!!!!

yeahhhhhhhhh!!!!!!!!!!!!!!!!!!!!

OK. Later. I've got some work to do at the moment, but will do a board for you.
Re: Big Muff Plus
Posted: 04 Aug 2010, 15:23
by mictester
mictester wrote:GodSaveMetal wrote:please anybody a PCB a LAYOUT of this!!!!!!!!!!!!!!!!!!!

yeahhhhhhhhh!!!!!!!!!!!!!!!!!!!!

OK. Later. I've got some work to do at the moment, but will do a board for you.
Board's nearly done.... sorry for the delay!
Re: Big Muff Plus
Posted: 06 Aug 2010, 03:36
by Grendahl
Can't wait!
![bump [smilie=bump.gif]](./images/smilies/bump.gif)
Re: Big Muff Plus
Posted: 27 Aug 2010, 10:32
by Nikifena
In my experience, I've build a few muffs, schottky diodes sounds better than 4148. Use two of them in series instead one 4048 to get typical voltage drop of 0.7V.
Re: Big Muff Plus
Posted: 27 Aug 2010, 12:57
by mictester
mictester wrote:
Board's nearly done.... sorry for the delay!
Sorry for the massive delay. I've had serious computer trauma (a power supply destroyed almost the entire machine, including three hard drives). I've got my machine working again (new motherboard,8 Gb RAM, three new 1 Tb drives, new sound card, new video card, new power supply) and it's on a UPS - it was a supply spike that killed the old one! I've just installed Mandriva Linux 2010 on it, and am configuring it to work just the way I want. I'll be back in the next day or two!