Are these transistors hot enough?

Started by Burstbucker, November 03, 2004, 10:19:03 PM

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Burstbucker

I have a pair of NOS NKT 275 transistors that I purchased off the internet, I did a quick check for gain with my multimeter and one transistor looks to be around 70hfe and the other one is appx. 90 hfe.

These were listed as "a matched pair of NKT 275 transistors".

Assuming that the meter readings are fairly accurate, are these transistors hot enough for a really good FuzzFace clone?

I've been really busy lately and haven't had time to build this FF and I'm just wondering if these transistors are going to be hot enough.

Any thoughts?

brett

QuoteAssuming that the meter readings are fairly accurate,
Unfortunately, meter readings are usually way out (too high).
Build RG Keen's simple tester (geofex.com) and check their real values.
There's a good chance your high hFE transistor will make a good Q1.  That's cool, because Q1 is always the hardest to get.  Q2 can even be a power Si device such as a BD139 (NPN) or BD140(PNP).

good luck
Brett Robinson
Let a hundred flowers bloom, let a hundred schools of thought contend. (Mao Zedong)

phillip

Quote from: BurstbuckerI have a pair of NOS NKT 275 transistors that I purchased off the internet, I did a quick check for gain with my multimeter and one transistor looks to be around 70hfe and the other one is appx. 90 hfe.

These were listed as "a matched pair of NKT 275 transistors".

Assuming that the meter readings are fairly accurate, are these transistors hot enough for a really good FuzzFace clone?

I've been really busy lately and haven't had time to build this FF and I'm just wondering if these transistors are going to be hot enough.

Any thoughts?
I don't worry about the whole "ideal transistor gain" thing for the Fuzz Face too much.  I used a pair of SK3861 NPN Germanium transistors in the Germanium Axis Face with gains of 64 and 68.  They sound terrific and have more than enough gain to fuzz things up real good.  Just put a 20K trimpot on the collector of Q2 to dial in 4.5-5V and it'll work fine.

Phillip

Burstbucker

Thanks for that info guys.  Yeah, I'm going to build that little test circuit that's on GEO and check these out again.

Cheers.

birt

i don't really match transistors. i just pick 2 and listen what they sound like :?
http://www.last.fm/user/birt/
visit http://www.effectsdatabase.com for info on (allmost) every effect in the world!

lightningfingers

If it SOUNDs good, it IS good. :wink:
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