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DIY Stompboxes => Building your own stompbox => Topic started by: EATyourGuitar on September 08, 2011, 10:41:05 AM

Title: what do you do with Hfe 62,000 darlington? any ideas?
Post by: EATyourGuitar on September 08, 2011, 10:41:05 AM
its a 2N6426 NPN darlington testing on the atlas DCA55 showing Hfe 55,000 to 63,000 on the same sample. after the first test it always reads about Hfe 62,000

I would be more interested in a fuzz pedal or noise generators with no input. whatever works. I'm just having fun with random part purchases and the breadboard sessions that follow.
Title: Re: what do you do with Hfe 62,000 darlington? any ideas?
Post by: Ben N on September 08, 2011, 06:15:38 PM
Power amp? "This device is designed for applications requiring extremely high current gain at currents to 1.0 A." (from the datasheet (http://www.fairchildsemi.com/ds/2N/2N6426.pdf))
Title: Re: what do you do with Hfe 62,000 darlington? any ideas?
Post by: Paul Marossy on September 08, 2011, 06:29:07 PM
It seems to me like it's intended to amplify very small signals at a "high current". Not sure that it would sound good as a fuzz pedal.
Title: Re: what do you do with Hfe 62,000 darlington? any ideas?
Post by: John Lyons on September 08, 2011, 06:59:00 PM
Define "good".  :D
Title: Re: what do you do with Hfe 62,000 darlington? any ideas?
Post by: toneman on September 08, 2011, 11:22:18 PM
power switch
Title: Re: what do you do with Hfe 62,000 darlington? any ideas?
Post by: LucifersTrip on September 09, 2011, 01:43:22 AM
(http://fuzzcentral.ssguitar.com/scrambler/scramblerschematic.gif)
Title: Re: what do you do with Hfe 62,000 darlington? any ideas?
Post by: EATyourGuitar on September 09, 2011, 07:42:50 AM
thanks, I'll try that. I only have one of those 2N6426 so I'll use MPSA18 for the rest. I'll shuffle them around to see what I get. whats a good substitution for the BC169B?

I have
BC108
BC548
2N5133 (Hfe 70 to 200)
2N2222
2N3904
2N5088


here is another idea. remember that small signal transformer I was posting in the other thread? how about a simple one transistor amp with the 2N6426 pushing the primary of the small signal transformer. then the secondary coil gets its own shielded cable with a cap on the tip and no connection to chassis ground at all. will this work? with 1A of power can I use it to push a tube as a completely passive device. use the tube as a diode or some kind of saturation, I dont know. there must be some whacked out applications here for fuzz and distortion.
Title: Re: what do you do with Hfe 62,000 darlington? any ideas?
Post by: digi2t on September 09, 2011, 07:55:36 AM
Quote from: LucifersTrip on September 09, 2011, 01:43:22 AM
(http://fuzzcentral.ssguitar.com/scrambler/scramblerschematic.gif)

If you try this with 2N6426's, let me know.
Title: Re: what do you do with Hfe 62,000 darlington? any ideas?
Post by: LucifersTrip on September 09, 2011, 09:51:19 AM
Quote from: EATyourGuitar on September 09, 2011, 07:42:50 AM
whats a good substitution for the BC169B?


datasheet shows hfe 240+, so prob any si npn hfe 200-300+
http://transistor-spravochnik.ru/description/bc169b/23727
Title: Re: what do you do with Hfe 62,000 darlington? any ideas?
Post by: mac on September 09, 2011, 04:34:54 PM
bazz fuss.
sounds better with darlingtons.

mac
Title: Re: what do you do with Hfe 62,000 darlington? any ideas?
Post by: R.G. on September 10, 2011, 06:16:27 PM
DANGER!! 50 Million Ohms!!