So I finished salvaging parts from my Lowrey organ find today, one of the last things out was a Bell & Howell cassette recorder. I was about to toss it, but I figured I'd better look inside to see if there was anything good. I found:
2SB22 AC188K equivalent 3 peices
2SB405 AC188K equivalent 1 piece
2SD30 AC187K equivalent 2 pieces
2SD186 AC187K equivalent 1 piece
I have seen some nice Fuzzface clones with AC188's. A Ge Fuzz would be a nice addition to my board. After looking at the Japanese datasheets All have gains in the 100-200 hfe range. Would be nice to know what the pinout is, but that was in Japanese and a PDF so I couldn't even use a translator program.
What would you guys build if you had found these?
EDIT: I used google translator and entered emitter base and collector one at a time translated from english to japanese and figued out the pinout! Normal EBC, hooray!
depending on the gains and leakage. I'd build a "Face-Bender" A MKII tone bender variant that you can switch the first transistor stage out of so you can get Fuzz Face-like tones as well as bender tones. I have a spare Fuzz Face enclosure that I've had sandblasted down to the bare aluminum, for building either one of those, or a "Trem Face" clone.
NPN Buzzaround! Definitely!
So I breadboarded a buzzaround but it looks like I gotta mess with the biasing to get that right. Off the bat changing the 470k on Q1 to 270k helped and dropping the 10k on the emitter to 6k8 helped too. I am not getting unity gain at the loudest settings yet though.
Okay, I rebiased the buzzaround and it was better but not, "knock-my-socks-off" great. So I breadboarded a Fuzz Sound MKIII/IV and I am in love. Freaking awesome. The trannies are NPN Sanyo Germainums, 2SD30 for Q1 and Q2, 2SD186 for Q3. Gotta order a Pastyface PCB now if anyone has one and wants to trade for 3 of the PNP transistors (2SB22 AC188K equivalent, 2SB405 AC188K equivalent) let me know.
Glad it worked out! :)
There is one great application for ac187k and ac188k, a 3W guitar amp!
The original is called "Tengo Na Minchia Tanta" from an italian author. I didn't have time to build one but I will when I can. My idea is to have a nice portable battery germanium transistor guitar amp! :D
http://freestompboxes.org/viewtopic.php?f=2&t=5881 (watch for updated schematic here)
http://topopiccione.atspace.com/PJ21TPCTengoNa.html
http://topopiccione.atspace.com/pjimages/TPCTengoNaMinchia.sch.jpg
http://topopiccione.atspace.com/pjimages/TPCTengoNaMinchiaBuffer.sch.jpg
http://topopiccione.atspace.com/pjimages/TPCTengoNaMinchia.lay.gif
http://topopiccione.atspace.com/pjimages/TPCTengoNaMinchia.PCB.gif
Please report if you try it !!!
Best,
Fernando
(Barcelona, Spain)
The Keeley Fuzz Head uses an AC187 apparently. Ian etched me a board to try based on the schematic--not verified, but looks like there shouldn't be any problems. I'll let you know if it works out and you can do one too!
Now I just need to find an AC187 myself!
Built a NPN Pastyface with the 2SD30's and 2SD186:
http://www.madbeanpedals.com/forum/index.php?topic=4592.msg40501#new
So awesome!