I have a couple of hundred to match.But how close should they be matched?
They are for discrete headphone and amblifier,
They are for discrete headphone and amblifier,
Depends on the grade (A-B-C), the design of the circuitry involved, and the vulnerability of the very circuit design to the variation within the grades.
This does not only counts for headphones, not specified various devices & other undefinded amblifiers...
This does not only counts for headphones, not specified various devices & other undefinded amblifiers...
Talk to the circuit designer. She will be able to tell you how closely they should be matched.
If that is inconvenient, hire an expert circuit designer who did not design the circuit. Show her the circuit schematic for the discrete headphone amblifier. Ask her (A) what her fee will be; and also (B) how closely those transistors should be matched.
If that is inconvenient, hire an expert circuit designer who did not design the circuit. Show her the circuit schematic for the discrete headphone amblifier. Ask her (A) what her fee will be; and also (B) how closely those transistors should be matched.
I Will ask the designer.
It is https://www.diyaudio.com/community/threads/gainwire-line-phone-non-gnfb-preamp.395695/
And The Wolverin.
It is https://www.diyaudio.com/community/threads/gainwire-line-phone-non-gnfb-preamp.395695/
And The Wolverin.
Given the E-deg & the involved circuit, start with unmatched parts and see how things mess up... or not.
Pretty much everything within 50% limits will suffice, I guess.
Pretty much everything within 50% limits will suffice, I guess.
Have you still got some left ? I'm building a couple of Lehmann BCL clones and 550/560 were the original transistors and appear, from the datasheets, to be potentially lower noise than the replacements. Happy to take 20 or 30 of each, assuming they're not all the outliers 🙂