Which 2SB transistors?

rousejeremy · May 16, 2009, 10:05:11 PM

A local electronics shop has a few 2SB transistors that end with different numbers. Which ones should I look for?

gmr1 · May 17, 2009, 08:20:35 AM

2SB172, 2SB175 and 2SB176's are the ones I've had the most luck with. Between the 3, you can cover most gain ranges used in the popular circuits. Really nice sounding transistors.

rousejeremy · May 17, 2009, 10:06:32 AM

I think they also had some with lower numbers.

Do certain numbers represent higher gains?

mac · May 17, 2009, 01:46:24 PM

There is a datasheet for the 2SB17x family, check alldatasheet.com or datasheetarchive.com.
Similar to some BCxxx transistors, the lower the letter the lower their gain.

Killer Ge BTW. Of the hundreds I have, almost no hissy or faulty devices.
See also the chart with my tests at,

http://diystompboxes.com/biascalc/

mac

rousejeremy · May 17, 2009, 01:54:34 PM

Quote from: mac on May 17, 2009, 01:46:24 PM

There is a datasheet for the 2SB17x family, check alldatasheet.com or datasheetarchive.com.
Similar to some BCxxx transistors, the lower the letter the lower their gain.

Killer Ge BTW. Of the hundreds I have, almost no hissy or faulty devices.
See also the chart with my tests at,

http://diystompboxes.com/biascalc/

Excellent! Thanks for the info.

mac

gutsofgold · May 17, 2009, 03:20:13 PM

Hmm I pulled a few of those exact transistors out of a radio a few months ago, had no idea they were suitable for pedals. Will have to a leakage/gain test on them.

jrod · May 18, 2009, 11:32:47 AM

Hey guys! I really like the Mitsubishi 2SB175's I bought. They sound really good in a Fuzz Face. I bought about 50 and most are in the 70-120 range and low leakage. There were some lower gainers, but I don't remember any being higher than about 120. I have also tried Matsushita 2SB176's and they were higher gain and higher leakage (still under 300uA). Not as consistant as the 175's. They do sound really good!

newfish · May 18, 2009, 12:12:50 PM

Holy Crap!

I have one of these (big one at the top of the photo) - and it sounded great in a booster I once tried it in.

I can feel a swap-out coming on...

mac · May 18, 2009, 02:19:46 PM

The best thing is that I pay about a dollar each! And 8 blocks away from home...

If you want to get closer to a AC128 maybe a Hitachi 2sb77. Toshibas are brighter, Matsushitas are fat sounding, fuzzier.

If you find Matsushitas buy a few and check their gain and leakage. A kick-in-the-head fuzz is 100% guaranteed.

QuoteI have also tried Matsush*ta 2SB176's and they were higher gain and higher leakage (still under 300uA)

I used them in my Germanium Big Muff

A farewell to silicons!

mac

jrod · May 18, 2009, 03:07:13 PM

Quote from: mac on May 18, 2009, 02:19:46 PM
The best thing is that I pay about a dollar each! And 8 blocks away from home...

If you want to get closer to a AC128 maybe a Hitachi 2sb77. Toshibas are brighter, Matsush*tas are fat sounding, fuzzier.

If you find Matsush*tas buy a few and check their gain and leakage. A kick-in-the-head fuzz is 100% guaranteed.

QuoteI have also tried Matsush*ta 2SB176's and they were higher gain and higher leakage (still under 300uA)

I used them in my Germanium Big Muff A farewell to silicons!

mac

Awesome, Mac. Thanks for the suggestion. What is the gain range of the 2SB77's you've tried and what circuit do you like them in?

A little OT, but why is Matsush*ta a naughty word on this forum?

mdh · May 18, 2009, 03:53:33 PM

I also have a few 2SB324s (I don't even know how or when I acquired them, but it was long before I even thought of picking up a guitar), and out of 4, at least 2 make a nice FF pair. IIRC, leakage is within reason on 3 out of 4.

any · May 18, 2009, 10:24:44 PM

The 2sb172's are excellent for FF circuits if you can get them, buy them.
I had about 800 of them and they had a very good yield of useable ones.
Usual gain is between 70 and 130 which is perfect for a lot of the classic fuzz tones.
They blow most of the usual germanium's out of the water, actually haven't heard a better sounding one yet...
(maybe some nos NKT275's would sound better, but I never played nor heard one.)

Cheers,

Electric Warrior · May 19, 2009, 03:41:14 AM

NKT275s are lower gain. 2sb172 sound a bit brighter and bring out the octave nicely. They don't clean up as well as the NKTs.

gmr1 · May 19, 2009, 08:55:28 AM

Quote from: Electric Warrior on May 19, 2009, 03:41:14 AM
NKT275s are lower gain. 2sb172 sound a bit brighter and bring out the octave nicely. They don't clean up as well as the NKTs.

Really the only "fault" I can find with the 2SB17* trans. - They don't clean up well at all. I've always wondered what was the cause of good clean up in a transistor. Any idea?

Some other findings with other Japanese transistors I've purchased:

I got a batch (200) of the 2SB178's not too long ago. typical hfe around 130 and leakage usually a tad below .30mA - a little higher than I like, but passable. Larger can than the rest of the 170 series.

I also have some 2SB175A's that are lower hfe - 65 typical with almost zero leakage. Figured they'd be nice in a rangemaster. I've been using the Hitachi 2SB77's in rangemaster with great results as well. The 2SB175B's are the ones I look for. Usually right around 100hfe

haven't found a good use for the 2SB75's as they usually top out around 50hfe (but with minimum leakage). Ideas? The Toshiba 2SB364's are about the same, with ever 10th one or so hitting around 70hfe.

NEC 2SB329 - little cans -same size as the modern AC128's floating around. green text on the can. 140-160hfe with low leakage. I got a bunch, and haven't put them in a circuit yet, but they look good on paper.

2SB172F's - a little lower gain 50-70hfe. I've used the upper end ones in Q1 of a fuzz face with great results.

I was getting 2SB176's from MCM for the longest time. They were always great - right to data sheet specs, etc. The last batch (from about 6 months ago) looks like a newer run (?). Different stamp on the can (same size can as the good ones) - 2SB176 in bold text with the tree logo, but no other markings. They look like re-stamps of something else (the stamp is fuzzy and more bold than any other Matsushita's i've seen) and the gains are about half of what I expected from 176's. Just a warning in case they come back in stock at MCM.

My Japanese germanium stash:

any · May 20, 2009, 12:41:51 AM

Quote from: Electric Warrior on May 19, 2009, 03:41:14 AM
NKT275s are lower gain. 2sb172 sound a bit brighter and bring out the octave nicely. They don't clean up as well as the NKTs.

Don't really understand your "gain" remark as the gain often varies greatly among germ's.
I used anything from 80 to 120 Hfe in the FF with great results.
I find the brightness to be a plus although the clean up is indeed not al that clean...cleaner then most I've tried though.
Anyway, If you can find some in a store, they are imho the best value for money!

Cheers,

Electric Warrior · May 20, 2009, 02:48:21 AM

30 to 90 according to the datasheet. I only have four, but they fall right into that range (40 to 72).

any · May 20, 2009, 09:49:17 PM

Quote from: Electric Warrior on May 20, 2009, 02:48:21 AM
30 to 90 according to the datasheet. I only have four, but they fall right into that range (40 to 72).

That's a bit strange, most of my 2SB172 trannies range between 70 and 120... ( proper test at room temp.)
leakage has been very low on nearly the whole batch, way better then most other germs I've tried.

mac · May 20, 2009, 11:55:22 PM

Clean up might be the result of the transistor input impedance or leakage...
Or maybe it is the hfe=hfe(ic) curve... a medium power ge gain (like ac128) could drop faster at lower guitar signals than a ge that is intended for smaller currents...
I'm guessing here.

Quotemac
Awesome, Mac. Thanks for the suggestion. What is the gain range of the 2SB77's you've tried and what circuit do you like them in?

Between 70 and 120, 200ua or so IIRC. I'd say that for a FF they are fine, but they can be used for anything.

QuoteA little OT, but why is Matsush*ta a naughty word on this forum?

This is an american forum! Look how an american transistor is displayed -->2N388

QuoteThat's a bit strange, most of my 2SB172 trannies range between 70 and 120... ( proper test at room temp.)
leakage has been very low on nearly the whole batch, way better then most other germs I've tried.

They are divided in hfe ranges like BC459 Si. Besides, data is sometimes taken at different base currents than 4ua RG test.
Power Ge I tested at 4ua were "out of specs" but as I said above they are intended for higher base current. When I scaled Rg test up, hfe were into the datasheet range.

mac

Tubedriver · December 28, 2009, 03:44:41 PM

Just received bold satmped 2SB176s from MCM, no logos. Hfe measured 48 - 64. Looks like re-stamps, not higher the gain. BEWARE!

gmr1 · December 28, 2009, 04:36:17 PM

Quote from: Tubedriver on December 28, 2009, 03:44:41 PM
Just received bold satmped 2SB176s from MCM, no logos. Hfe measured 48 - 64. Looks like re-stamps, not higher the gain. BEWARE!

I was grabbing them pretty regularly from MCM, then the last two bunches were exactly what you described. I actually have used a few of the higher hfe ones in rangemasters, and as Q1 in a fuzz face with pretty good results - but yeah, not like the "good ones" they had been stocking for several years. I'm prob. most responsible for cleaning them out of them, as I was checking pretty regularly and would grab the 100-200 or so they'd get every month or so - sorry about that! :-)

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Which 2SB transistors?