Brett's 12B4 schematic?

phrarod · 14th February 2009, 04:22 PM

Anyone have a link to this? I searched the forum and there's post but nothing with an actual schematic

colinB · 14th February 2009, 07:07 PM

Hi,

See attachment for schematic of Brett's 12b4 linestage - hope this is the right one.

Cheers
Colin.

Brett · 14th February 2009, 11:09 PM

That's the one Dave did the drawing for, but there were many variations, including transformer and CCS loading, parafeed with Tx output etc.

Also try the R loaded version with a string of cheap low output red LEDs in series like SY's Red Light District amp in the cathode with no bypass cap.

phrarod · 14th February 2009, 11:11 PM

Thanks! Love to see the one with the Trans ouput.

Brett, did you ever have a favorite sonically?

Brett · 14th February 2009, 11:53 PM

Quote:

Originally posted by phrarod
Thanks! Love to see the one with the Trans ouput.

Brett, did you ever have a favorite sonically?

SE: Pimm CCS loaded plate, parafeed with a Lundahl OPT, forget which but probably a 1660 as I was using them around this time. One of the IXYS units would do fine as CCS too I reckon.

PP: CCS in cathodes with Lundahl OPT. This was my preferred version, but I don't like most SE amps.

I'd start with the resistively loaded one with 5 red LEDs in series in the cathode.

Sorry I don't have any pics as I don't use a preamp in system any more so they were disassembled and returned to the parts box.

phrarod · 15th February 2009, 12:16 AM

Thanks Brett! And Colin.

14th February 2009, 04:22 PM	#1
phrarod diyAudio Member Join Date: Aug 2005	Brett's 12B4 schematic? Anyone have a link to this? I searched the forum and there's post but nothing with an actual schematic

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14th February 2009, 11:09 PM	#3
Brett diyAudio Member Join Date: Jan 2002	That's the one Dave did the drawing for, but there were many variations, including transformer and CCS loading, parafeed with Tx output etc. Also try the R loaded version with a string of cheap low output red LEDs in series like SY's Red Light District amp in the cathode with no bypass cap.

14th February 2009, 11:11 PM	#4
phrarod diyAudio Member Join Date: Aug 2005	Thanks! Love to see the one with the Trans ouput. Brett, did you ever have a favorite sonically?

15th February 2009, 12:16 AM	#6
phrarod diyAudio Member Join Date: Aug 2005	Thanks Brett! And Colin.

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