[pretzel_logic]

Is it possible or worthwhile to use either a 6SN7 or a 6FQ7 in place of the 12AU7, and if so what would need to be changed and what values? I was reading about these tubes over in the Tubes Asylum and they supposedly are much better both in sonics and noise than the 12AU7

Brian

[GRD]

I've thought about the same thing.  The Octal 6SN7 and it's 9-pin equivalent the 6FQ7 would give better current drive than the 12AU7.  The 12BH7 would also do the same.  You'd have to tweak the heater voltage as they pull more current.  And change the bias voltage a bit.  Jim has a schematic somewhere in this Circle for the Octal Cornet that uses a 6SN7 for the cathode follower and you can reference that.

So far I've not made any changes and still use the AU7.  Since its used as a cathode follower, I suspect an AU7 is just fine (or in my case a 5814).  It works well for me with my set-up and my pre-amp input resistance is 22k so I don't think I'd benefit much from the extra drive of the SN7 family.    But if you do go this route, I'd be interested in your findings.

[vinylkid58]

I was reading about these tubes over in the Tubes Asylum and they supposedly are much better both in sonics and noise than the 12AU7.

There's no love for the 12AU7 over at the asylum. What tubes are you using now?

Jeff

[flocchini]

I highly recommend the 6SN7 Cornet 2. I have been using mine for about 2 years. When I built mine a friend was doing the stock version. To my ears the soundstage was wider and deeper and the midrange was more fleshed out. My primary motivation was based on my 6SN7 NOS collection. I have no regrets. I also did my Chime with 6SN7.

Best

Bob

[GRD]

Bob,

Is yours an Octal Cornet with 6SL7's and a 6SN7 follower, or a hybrid -12AX7's and a 6SN7 follower?

Grant

[flocchini]

Sorry

12AX7s + 6SN7