Big Muffarray

[jubal81]

Sounds really spectacular! I'll have to give it a shot. Thanks for sharing.

[SpencerPedals]

Zombie thread I know, but I've been thinking about an array'd Muff for a while and just came across the MPQ2484, which led me to this thread to see if anyone else had tried it already.  A lot of the NPN arrays are lower gain and a low gain array Muff has always sounded like a waste of time to me.  Any chance you still have the schematic you used kicking around somewhere, digi2t?

[digi2t]

Zombie thread I know, but I've been thinking about an array'd Muff for a while and just came across the MPQ2484, which led me to this thread to see if anyone else had tried it already.  A lot of the NPN arrays are lower gain and a low gain array Muff has always sounded like a waste of time to me.  Any chance you still have the schematic you used kicking around somewhere, digi2t?

Sounding like a waste of time, and actually sounding like a waste of time, are two completely different beasts. For time to time I hear that BMP transistors need to be these high gain, fire breathing beasts, when in reality, the best sounding BMP's I've ever built are with relatively low to mid range gain transistors. I mean 150 to 200 max. High gain transistors make a BMP sound harsh to my ears, which only gets aggravated when you use a gainier channel on the amp. A great BMP (for me) is like my Civil War Muff; sounds like a medium overdrive on a clean channel, and serves to boost the sustain on a medium or high gain channel. Amp is on the 'O line, BMP is the water boy.

As for the schematic, I don't have one in front of me at the moment, but I tend to go with a mix of Triangle and Ram's Head values, with bias towards the Civil War version in some places. Nothing's set in stone, it's really a "season to taste" affair. Honestly, I haven't built two identical units to date.

[SpencerPedals]

I've tried several different types of transistors with varying gain (measured individually) in the Mayo Muff variant, and personally, I prefer the higher gain fire breathing beasts for a Muff.  Quite obviously that's a matter of preference, but you get a lot of thickness and sear and sizzle from those higher gain transistors.  The upper end of your max gain range is a third of my preferred gain range.  The 2n5088 might be everyone's go-to, but it bores me.  Also, you and I use them in entirely different manners.  Gain low on the amp, Muff in the foreground for me, when I'm using one.  Muffs change things too much for me to use it as an amp booster.  I may have listened to one too many Pumpkins albums.  I do plan on playing with a more overdrivey and less conventional Muff in the coming months, but will likely try out some germanimums with gain ranges in your preferred ballpark for that.  Or any of a number of old TO-106 packaged silicon transistors I have in those gain ranges.  Anyhow, thanks for the response!

[digi2t]

No worries. BMP is just one of those circuits that it's easy to modify to get what you want out of it. You're more Pumpkin. I'm more Gilmour. That's cool.

Like I said, I've built several of these, using a bunch of different transistors, high and low gain. Yes, there most definately is a place for the high gain transistor, especially for the kind of grind that you prefer, so I think I'll reveal a secret. Haven't seen anyone mention these transistors yet on the ether-net, but here it is. My top choice for high-gain BMP transistors is...

BCY 59X

There we go. My cat is officially out of the bag. They're obsolete now, but you can still find them on Ebay, principally from European sellers. They're metal cans, like the BC109's, but there's a certain je ne sais quoi about these puppies that puts them over the top where the typical high gain transistor choices for BMP are concerned. A certain edge, which would lead one to believe that you're plugged into an op amp BMP. At full bore, they've simply flattened any 2N, BC, or 2SC offerings. That's my story, and I'm stickin' to it.

Insofar as germaniums in a (PNP) BMP, there's a thread already on that in here. Ge in all four stages? Not so hot. Very noisy. Ge in the two middle stages? Yes. Very nice. A silicon input and recovery stage helps keep noise to a minimum (2N5087's), while the Ge's work their magic in the gain sections. Use Ge diodes as well, with 500pf caps, nice well rounded sound.