Tube equal to one section of a 12AX7?

[jrevillug]

Ahh. That explains it.

Thanks SY.

[Stormrider]

I thought the 6C4/EC90 was half a 12AX7. Not going to be much cheaper than just using a 12AX7 though...

[SY]

Originally posted by oshifis
~ 6AQ4 (EC91)

Similar mu, but otherwise quite different. Great for RIAA stages when used appropriately.

Stormrider, no, I don't think they're the same.

[kevinkr]

Originally posted by Stormrider
I thought the 6C4/EC90 was half a 12AX7. Not going to be much cheaper than just using a 12AX7 though...

Sy's right, for audio applications the EC90/6C4 single triode is equivalent to a single section of a 12AU7. (Besides audio applications the 6C4 was commonly used in HF/VHF oscillators which was not a recommended use for the 12AU7, implying some other slight differences in internal construction.)

For convenience sake I would just stick to 12AX7A and wire the added sockets in each PAM so that the opposite triode is used, that way at tube replacement time you can just swap and save on purchasing two new tubes.

[dsavitsk]

Originally posted by SY
Lower cost? I think it will be more expensive. You're limited to NOS and need twice as many.

High quality 12AX7s are pretty inexpensive. JJ is under $10 brand new.

NOS 6AV6 is on sale at AES for $2.48 right now. They are $3 at RES, and $3 at the tube center.

[audiowize]

The 6D10 and 6C10 are compactrons with three triodes per tube, each equivalent to a 12AX7. Compactron sockets are also available/cheap now.
-Paul

[Pyre]

Originally posted by dsavitsk


NOS 6AV6 is on sale at AES for $2.48 right now. They are $3 at RES, and $3 at the tube center.

Wow thanks! Now thats a reasonable price. I am going to go check them out.

Originally posted by audiowize
The 6D10 and 6C10 are compactrons with three triodes per tube, each equivalent to a 12AX7. Compactron sockets are also available/cheap now.
-Paul

Interesting. The whole thing could be done in one tube. Do you think there would be any problem with doing all 3 sections in one tube?

[audiowize]

Interesting. The whole thing could be done in one tube. Do you think there would be any problem with doing all 3 sections in one tube? [/B][/QUOTE]

Likely not. You need 3 halves per channel, so you can isolate each channel into one tube. If you have some direct coupling/cathode followers and you need two different heater supplies, that's the only issue I can find. Also, 6C10's and 6D10's can be a little expensive here and there, but I bet you can find some pretty cheap pretty easily.

[Pyre]

Originally posted by audiowize
The 6D10 and 6C10 are compactrons with three triodes per tube, each equivalent to a 12AX7. Compactron sockets are also available/cheap now.
-Paul

AES does not have any 6D10's but they have 6C10's but says they are a delay relay.

6C10 - DELAY-RELAY, AMPERITE
• 6.3 volt heater
• Normally closed contacts
• 10 second delay
• Standard 8 pin octal base


Six 6AV6's with sockets ring in at just over 22 bucks. Thats well within my price range SOLD

[audiowize]

Originally posted by Pyre



AES does not have any 6D10's but they have 6C10's but says they are a delay relay.

6C10 - DELAY-RELAY, AMPERITE
• 6.3 volt heater
• Normally closed contacts
• 10 second delay
• Standard 8 pin octal base

Here's the datasheet:
http://www.mif.pg.gda.pl/homepages/f...127/6/6C10.pdf