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Mangler PCB - Hybrid build possible?

Started by Bret608, December 01, 2011, 02:57:42 PM

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Bret608

Hi everybody,

I'm gearing up for my second build and am thinking about a Mangler. One question--would using a hybrid Si/Ge transistor array work as long as they had the same grounding? I noticed Smallbear sells a transistor set for Aron Nelson's "Hornet" (PNP I think) and was interested right away. Otherwise, I am seriously thinking about the CV7112s. Perhaps Jake Fuzz could weigh in here!

Thanks for any pointers!

Cheers,

Bret

JakeFuzz

#1
Yep, as long as they have the same junction type structure you're fine. I do hybrids all the time and they sound very cool. Joe Gagan makes some pretty sweet sounding hybrids. I think the biggest difference with a Si in Q1 is clarity, you cut through a little of the muddy/no note definition thing that goes on with all Ge FF's sometimes.

And well about the CV7112's everyone knows those are my favorites  ;D. They are very smooth and have this crazy harmonic that rings out when you let the notes sustain.

I would try a combination of both of your ideas! the DIYSB store still has a few CV7112's in odd gain ranges. I find that with the CV's you get two gains so you have a better chance of getting something in the range you want. I would get one or two of those and a 2N2369 from SB or another lower gain Si for Q1. This would be a very cool sounding hybrid. The OC140 FF pair from SB is always a safe bet too though.

Let us know what you decide to go with and how your results come out.

Joe's hybrid vid:

Bret608

A hybrid with Si in Q1 and a CV7112 in Q2? That sounds awesome! I did see those in the DIYSB store as well. If I do this, I will definitely report back and will likely be asking about gain ranges. Thanks for including Joe's demo--that's exactly the kind of sound I had hoped a hybrid would deliver!

JakeFuzz

Definitely set up a gain tester. I have a little handheld one i built out of an old dimarzio pickup case. The gain of Q2 definitely changes the sound. The higher the gain the more sustain and compressed it gets. I have found that my builds are very sensitive to the gain value in Q1, I've tried really high values and things just don't work. For me the perfect gain range in Q1 has been anywhere from 65-90, anything above or below that and I get weird sounds that aren't very useful.

Bret608

Darn, it looks like DIYSB is down or something...will check back. Smallbear definitely has the 2N2369.

That makes sense on the Q1 gain. Is there a particular gain range that works best for Q2? Or is it more based on your ears provided it's a bit higher gain than Q1?

Gain is measured in hfe, right? My DMM actually has a transistor tester built in for both PNP or NPN. I was able to use it on my Pepper Spray build to verify the pinout on the 2n3565--it was around 220 hfe. Let me know if I'm understanding this correctly.

Thanks!

JakeFuzz

I like anywhere from 90-200 for Q2, it operates under a much wider range. It is also difficult to describe the differences in sound when you are changing the gain for this position. If I have time this weekend I will try and record some clips of different gains in Q2, one of my FF's has been acting funny and I need to poke around inside anyways.

Quote from: Bret608 on December 01, 2011, 05:38:12 PM
Gain is measured in hfe, right?

Yes, Hfe (or as I learned it beta) is just the ratio of input current (current going into the base) and the output current (current at the collector). It is unitless (or Amps/Amps to some people). Most people use the DC tester that Keen has outlined on his Fuzz Face technology page and I have found that it works pretty darn well. I don't know how the DMM's are measuring gain. I would like to see more frequency response charts to see how the output gain changes as a function of input frequency, this would be useful in choosing trannies to get specific sound but I haven't seen many.

joegagan

i like this!

the fuzz in the vid was sold to a studio in atlanta.  i like motorola or generic 2n3906 for q1 and germs of 110 - 130 hfe ( using RGs method) for q2. been doin it since 99

jimmybjj

Quote from: joegagan on January 24, 2012, 07:20:35 AM
i like this!

the fuzz in the vid was sold to a studio in atlanta.  i like motorola or generic 2n3906 for q1 and germs of 110 - 130 hfe ( using RGs method) for q2. been doin it since 99

Do you use a specific hfe for q1 or just any 2n3906?
Pcbs no longer available

joegagan

i don't recall measuring Q1 hfe. i had a lot of motorola 2n3906, i think they are pretty consistent. i will measure a few when i get a chance.