Rolling 6AU6 tubes?

[specialidiot]

I have a pair of Allen 60 amps that utilize a 6AU6 tube per amp. Currently in the amps are RCAs, I have a handful of other 6AU6 tubes on hand and was wondering what others have used?

Here's the Allen 60 schematic, if that matters
http://www.jwaudio.us/allen60/allen60schematic.jpg

 

[gearhound]

My DIY flea amp uses a pair of 6AU6 tubes.
RCA black plates are my favorites, followed closely by Tung-Sol (USA).
Even NOS 6AU6 tubes are cheap, cheap, cheap.....so tube roll away!!

Steve

 

[audiodon]

I second gearhound's comments on RCA black plate 6AU6s.

 

[spaceman]

Most of the ones I've seen are GE, which is pretty decent, and I finally found a few RCAs not long ago, but they're not really matched very well, darnit. But while looking for RCAs, I realized that 3 in the stash are Mullards or Phillips, made in Gt. Britain, & test very strong.

 

[specialidiot]

I have the RCA black plates in there. I have a couple other RCAs, a Tungsol, Raytheon, and something I can't make out. Mostly orange writing and I can see "made in USA".

 

[audiodon]

Yeah, that sounds like RCA. They have that "wish I were red" kind of orange.

 

[BinaryMike]

If that was my amp, I would be wondering if I couldn't be rid of that 6AU6 voltage amplifier stage altogether. One way to find out would be to remove the tube and temporarily connect one of the input jacks directly to pin-1 of the first 6SN7. If the sensitivity is high enough, then you could have cleaner sound for essentially zero cost. If not, well then it was a nice try.

Edit: Upon reading a bit more about this amplifier, I suspect that you really do need the extra gain. It's an easy thing to try, but the loss is unlikely to be tolerable.