6EU7 in an Express

[andresound]

I wonder if anyone has tried this tube in an Express (v1). I have 2 NOS in a box RCA tubes! I realise the pin out is different for the heaters etc. Wondering if noise (especially hiss), would be less.

[RJ Guitars]

I'll subscribe to see what happens... Don't know much about the tubes though.

I sorta consider hiss in an Express is part of the price of success but I wouldn't be opposed to it if you can take it away.

[martin manning]

6EU7 is a 12AX7 redesigned for reduced heater hum. Maybe given that they're designed for low-noise applications, there's a good chance of getting low hiss too.

[andresound]

So far, the best tube I have found for V1 is a very old "box" plate Mullard. This tube apparently was also designed for milspec/low noise use. When I get a tube adapter sorted, I will try the 6EU7 and report

[pdf64]

http://www.mif.pg.gda.pl/homepages/fran ... 6/6EU7.pdf
I suspect that the point of the rearrangement of the basing is so that the heater wires can be twisted right up to the socket terminals, thereby reducing the potential for interference with signal circuits.
With the likelihood that would be continued up from the the tube base to the relevant tube electrodes.
So for that to be of benefit, the wiring / lead dress to the socket should best be done to take account of that; hence an adapter to make a 6EU7 work in a socket wired for a 12AX7 seems pointless.
The lead dress of the wiring in the adapter may even make inference worse.

[andresound]

Good point pf64! That definitely makes good sense. As it turns out I have just acquired a 55year old Epihone combo (posted in technical forum) that uses these tubes. So guess where the newly acquired NOS IB are going