Low gain Si transistor recommendations

[newfish]

Hi All,

Have been auditioning transistors for negative ground Rangemaster and Fuzz Face clones to save all that polarity messing on my pedal board.

Fuzz Face has 2 x AC176s in - so is still Ge, *but*, after having played with the Rangemaster clone, I came across 2N2369 and BC184 transistors.  The 2N2369 is lower gain, and warmer sounding to my ears, whereas the BC184 gives a bit more 'push', but is not as shrill as a BC108 / BC107.

Auditions were carried out using 'stock' Rangemaster circuit values (as per the excellent GEOFX article), with the gain pot all the way up - well, why wouldn't you?

If anyone is looking for low(ish) gain Silicon devices, I hope they find this information useful.

Cheers!

Ian.

[brett]

+TIPs (low-medium),  MJEs (low), BD139/140 (medium), piggybacked anything (v v v low to normal)

[FlyingZ]

NM

[valdiorn]

I built a modded Fuzz Face last week and found that 2n3904 and 2n5088, while they sounded cool, the gain was just too much and the vintage character of the pedal was lost. So I tried flipping them, connecting emitter as collector and vise-versa. This actually sounded quite good.

Connecting most npn transistors backwards will still allow them to function, but very poorly. A rule of thumb is that the gain is ~1/10 of what it should be, but with a beta in the 500-800 range (high) this could translate to a very usable 50-80x gain

Try it, you might like it

[newfish]

Cool idea!

Thanks!

[Derringer]

2N3903

http://www.datasheetcatalog.org/datasheet2/d/0kzaoyuk3heutdcx1ia4x10swyfy.pdf

I've bought batches that have had hfe in the 110's and batches in the high 70's/low 80's

[mac]

Of all low gain silicons I tried, 2369s are the best, but the problem is that they tend to catch RF.

mac

[soggybag]

There's always the 2n3053. You can get these at RS. I think they are about 50 to 100 hfe.

[LucifersTrip]

Hi All,

Have been auditioning transistors for negative ground Rangemaster and Fuzz Face clones to save all that polarity messing on my pedal board.

Fuzz Face has 2 x AC176s in - so is still Ge, *but*, after having played with the Rangemaster clone, I came across 2N2369 and BC184 transistors.  The 2N2369 is lower gain, and warmer sounding to my ears

I used 2N2369's and there simply wasn't enough fuzz. I had a pot on all resistors and couldn't get anything good with all the tweaking.
I picked the 2N2369's with the highest hFE in the batch I had, whcih was around 80

I used this:
http://www.muzique.com/lab/yaff.gif

Ironically, I swapped em with BC108's and of course got a much hotter sound with more room to vary the tones, but when I turned the
fuzz all the way up, I got a hum which I could only get rid of by turning  the fuzz down to 90%

I'm only a beginner so I have no idea how to get rid of that other than adjusting resistors [which I did] and caps [which i didn't do yet]

good luck

[soggybag]

I recently built a silicon Tonebender. I used BC109s. I took some time to experiment with other transistors. I tested the 2n3053. It didn't have enough gain for Q1. But the 2n3053 worked as Q2 and Q3.

[zombiwoof]

Hi All,

Have been auditioning transistors for negative ground Rangemaster and Fuzz Face clones to save all that polarity messing on my pedal board.

Fuzz Face has 2 x AC176s in - so is still Ge, *but*, after having played with the Rangemaster clone, I came across 2N2369 and BC184 transistors.  The 2N2369 is lower gain, and warmer sounding to my ears

I used 2N2369's and there simply wasn't enough fuzz. I had a pot on all resistors and couldn't get anything good with all the tweaking.
I picked the 2N2369's with the highest hFE in the batch I had, whcih was around 80

I used this:
http://www.muzique.com/lab/yaff.gif

Ironically, I swapped em with BC108's and of course got a much hotter sound with more room to vary the tones, but when I turned the
fuzz all the way up, I got a hum which I could only get rid of by turning  the fuzz down to 90%

I'm only a beginner so I have no idea how to get rid of that other than adjusting resistors [which I did] and caps [which i didn't do yet]

good luck

If you used hfe 80 transistors for both positions, there wouldn't be enough gain IMO.  You should follow the recommendations of hfe 70-90 for Q1 and 120-140 for Q2 to get the best sound out of a FF.  The FF's that had the higher gain BC's in them changed a resistor in the circuit to try to make up for the higher gain.

Al

[LucifersTrip]

Hi All,

Have been auditioning transistors for negative ground Rangemaster and Fuzz Face clones to save all that polarity messing on my pedal board.

Fuzz Face has 2 x AC176s in - so is still Ge, *but*, after having played with the Rangemaster clone, I came across 2N2369 and BC184 transistors.  The 2N2369 is lower gain, and warmer sounding to my ears

I used 2N2369's and there simply wasn't enough fuzz. I had a pot on all resistors and couldn't get anything good with all the tweaking.
I picked the 2N2369's with the highest hFE in the batch I had, whcih was around 80

I used this:
http://www.muzique.com/lab/yaff.gif

Ironically, I swapped em with BC108's and of course got a much hotter sound with more room to vary the tones, but when I turned the
fuzz all the way up, I got a hum which I could only get rid of by turning  the fuzz down to 90%

I'm only a beginner so I have no idea how to get rid of that other than adjusting resistors [which I did] and caps [which i didn't do yet]

good luck

If you used hfe 80 transistors for both positions, there wouldn't be enough gain IMO.  You should follow the recommendations of hfe 70-90 for Q1 and 120-140 for Q2 to get the best sound out of a FF.  The FF's that had the higher gain BC's in them changed a resistor in the circuit to try to make up for the higher gain.

Al

Yes, that's what I found out...2 x 2369's with hfe 80 didn't cut it.  I used 2222 as Q2 and it sounded much better and 2 x 2222 even hotter.
Regarding changing the resistors  when using BC's, I just couldn't pull it off. I had pots in there for all resistors, tweaked them all and simply couldn't get  rid of that hum when the fuzz was jacked...only think I could do was turn down the fuzz or remove the treble. As I wrote, I didn't experiment with the caps yet.