T W on the BB with Chuck and Gator: Hellbender/Pagebender Hybrid

[temol]

What is the preferred hfe range for q2 and q3? Below 100? Below 60?

 

[Chuck D. Bones]

No hard & fast rule. Lower HFE on Q3 makes for smoother clipping I think. They could both be anywhere from 50 to 100 and work well. Most of the 2N2221s I have clock in in the 90s and they sound good.

 

[temol]

Thanks!

I found a few pieces with relatively low values - I chose 64 and 88. Works as it should

 

[The Gator]

Oh cool! On the one I built I used bc549c on Q1 and Q4 (flipped around for proper pinout), and some 2N3903 for Q2 and Q3.
Hfe of 70 and 80 approx. I had sc9018 transistors on the breadboard for these two as they were what I had at the time with a low Hfe of around 100. It is slightly easier to clean up with lower hfe.
The original circuits used Bc549c and 2N2222A transistors in the middle for Q2 and Q3. They do not get clean.
They have external bias control and no mid control.
With this circuit, you can get original Hellbender tones with the mid at approximately 11 to 12 o'clock. If you really want gritty, take the bias voltage down from 5vdc to about 2.8vdc.(of course gated tones can be had with bias at 1.0 to .7vdc). Crank the Fuzz and play some Sabbath. Or your favorite Rival Sons Scott Holiday licks!
Original Page Bender tones can be had with the mid control dimed. It also had less gain originally. Put the Fuzz around 11 or 12 o'clock, lows at 11 and the highs at 2 or 3 o'clock. Grab your Les Paul and play your favorite Page licks. Yes, play the whole Lotta love lick!

 

[temol]

That's some cool info, thx! Here, I have bc109c for Q1 and Q4, KSY 62B for Q2 and Q3. I don't have too many low hfe candidates stashed.
I could not source any 2N3903 locally. In my collection I found other potential victims - BC211, BF258, BF257, KF507, 2N2193, BSX61, all large metal can, TO39 package.

 

[The Gator]

Even though I love the germanium sound, I avoid the search for the germanium transistors. If I can find low gain silicon to take its place, that's the path I'm going to take. That's just me. You can build this circuit with Q2 and Q3 at 100 hfe and it will sound good.
KSY 62B? Interesting!
I need to come across another stash of transistors locally. Getting few and far between...

 

[MattG]

That's some cool info, thx! Here, I have bc109c for Q1 and Q4, KSY 62B for Q2 and Q3. I don't have too many low hfe candidates stashed.
I could not source any 2N3903 locally. In my collection I found other potential victims - BC211, BF258, BF257, KF507, 2N2193, BSX61, all large metal can, TO39 package.

Because of my infatuation with the Animals Diamond Peak mod, which is a similar circuit that also calls for low-gain silicon transistors, I've got some notes on some you might be able to find:

• 2N4123 - Tayda - HFE 84-106, most at 94
• MPSA42 - Tayda - HFE 85-108, most 85 or 95
• 2N2369A (plastic case) - CircuitSpecialists - HFE 55-106, most around 94
• 2N2218A (TO-39 metal can) - StompBoxParts - HFE around 64
• 2N2369 (metal can) - Smallbear - HFE 59
• 2N1613 - StompBoxParts - HFE 77 (*see note)

(*) I got four 2N1613, and they were identified as NPN transistors with HFE of 77 via my CCT. However, I could not get them to bias to the right voltage in my implementation of the modified Diamond Peak. I tried several several combinations of two transistors, all with the same result. I have enough other low-gain si trannies that all work fine, so I didn't spend any more time looking into why they didn't work.

The MPSA42 is one of my favorites, and it's fairly cheap and readily available.

 

[The Gator]

Thank you very much for sharing this info!
Great stuff!