BC184C picked for gain higher than 600

JLM Products support and what's new

Moderator: mixmup

Post Reply
whoops
Posts: 7
Joined: Sat Feb 13, 2016 2:04 pm

BC184C picked for gain higher than 600

Post by whoops »

Hello Joe,
would love to ask you a question about your BA283 page if you have the time.

http://www.jlmaudio.com/neve_ba283.htm

At the above page you describe
T1 = BC109 or BC184C picked for gain higher than 600 to minimise input noise

I was searching over my Neve docs and can't find any info about, neither any reference for selecting transistors for these cards and circuits.

Could you please let me know the HFE higher than 600 should be measured at which base current?

thank you so much
Best regards

User avatar
Joe Malone
Site Admin
Posts: 1654
Joined: Wed Jan 24, 2007 11:35 pm
Location: Brisbane, Australia
Contact:

Re: BC184C picked for gain higher than 600

Post by Joe Malone »

whoops wrote:Hello Joe,
would love to ask you a question about your BA283 page if you have the time.

http://www.jlmaudio.com/neve_ba283.htm

At the above page you describe
T1 = BC109 or BC184C picked for gain higher than 600 to minimise input noise

I was searching over my Neve docs and can't find any info about, neither any reference for selecting transistors for these cards and circuits.

Could you please let me know the HFE higher than 600 should be measured at which base current?

thank you so much
Best regards
When we used to restore to new condition hundreds of old Neve vintage modules we would fine ones that would be 2 to 3 dB quieter than most modules in our test setup. So I don't think Neve tested for this at all. We tested these quieter one to work out why and they always had a very high gain first input transistors. We just tested the transistors in a multimeter hfe tester @ 1mA from memory. And by changing input transistors on other modules we could make them quieter in most cases.
Joe :-)
JLM Audio
Capturing Audio without Injury

whoops
Posts: 7
Joined: Sat Feb 13, 2016 2:04 pm

Re: BC184C picked for gain higher than 600

Post by whoops »

Thank you so much for the knowledge Joe.

Best Regards

Post Reply