From wrigh–(at)–spto.gov Sat Aug 19 20:34:57 CDT 1995
Article: 120 of rec.audio.tubes
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From: wrigh–(at)–spto.gov (Dirk Wright)
Newsgroups: rec.audio.tubes
Subject: Re: 5751 vs 12AX7
Date: 19 Aug 1995 21:01:20 -0400
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Mark Garvin (mgarvi–(at)–anix.com) wrote:

: 5751 plate res: 58k transcond: 1200 Mu: 70
: 12AX7 plate res: 62.5k transcond: 1600 Mu: 100

: So why the reputation for being a plug-in replacement?

Probably because the lower impedance of the 5751 gave higher bandwidth, or
maybe lower distortion at higher frequncies in feedback circuits. Also, the
industrial design of the 5751 may have lower microphonics than a garden
varity 12AX7.

Dirk