Less popular/Alternative tubes in amplifiers

With the price of NOS 12ax7, 6L6, 6V6, etc., going through the roof, how many DIY amp builders have turned to alternative, less popular tubes?
One of my better sounding amps, has surprisingly been a little 1.5 watt flea amp, using a 6au6 driver tube, and a 12b4a power tube.
NOS 6au6 and 12b4a tubes are only $3-$4 dollars on flea-bay.
I'm working on another small amp right now, using inexpensive 6aq5 tubes.
I purchased a QUAD of NOS Raytheon 6aq5 tubes on flea-bay for $12.
There are literally MILLIONS of NOS tubes out there, that are adequate for amplifier duty.
Just because Fender and Gibson didn't use them, doesn't mean they cannot sound as good?


Steve :rolleyes: :idea:

6AQ5s are great. Keep the voltage low, 250 "by the book" or 300 max. They're a "poor man's 6V6". Ssshhh! If we all jump on 'em at once they won't be cheap for long... :lol:

4x6AQ5 into something like a Pro Reverb OT gives you approx 25 watts.

Next pick: 6146s. Used as a PA in any number of transmitters, Ampeg used them in very early SVTs. They're a big burly power tube that makes 6L6s quake with fear. :twisted: Try to get good 6L6s for ten bucks each. I can get 6146s for $20 a matched pair.

I wish there was a good alternative to the ubiquitous 12aX7... :sad:

It's a matter of knwing where to get your 12AX7s cheap. :lol:

NOS 6eu7 tubes are half the price of NOS 12ax7 tubes now.
Except of pin-out, they are virtually 12ax7 tubes.


Steve

NOS 6eu7 tubes are half the price of NOS 12ax7 tubes now.

Steve

Hmm. I'm surprised. Last time I checked they weren't. That's because they're used in a lot of hi-fi circuits and those guys will pay a premium for their tubes.

5751s used to be cheap before everyone got hip to them. They're not cheap anymore.

Seriously, 6eu7 tubes USED to be expensive, compared to 12ax7 tubes.
I have a late 50's Magnavox 8802 stereo amplifier that uses a pair of 6eu7 tubes.
I picked up a pair of NOS Mullard 6eu7 tubes, for under $50.....delivered.
A tube vendor that I know, clued me in on this, when I inquired about rewiring the Magnavox tube sockets, to use 12ax7 tubes.

He told me......................"Why bother"?


Steve

I'm thinking the other direction. I'd love an amp made from 2a3's or even the really cool 845 directly heated triodes. Might just have to build one myself.

There are so many cool tubes out there if you are willing to experiment. Look for tubes with odd heater voltages, or unpopular sockets, 12v6 come to mind, and so Loctal dual triodes. A 6AR8 just screams "Intrograted PI, MV and tremolo", and there are so many thing you could use it to do that wouild be brand new uses.

Remember, Leo largely looked to the HiFi camps for his early work, There linearity is king, but to make tone, non linearity is your friend.

I've got a pair of 6GK6 tubes, which are basically EL84 with a slightly different pinout. They are currently waiting on a project, but you can find these much cheaper than '84s.

I've got a few 6AQ5's laying around as well - I have most of the parts I would need to build a nice Micro Champ. Just need to find some of those 7 pin sockets!

One last tube I recall reading about on AX84 is the 6AR6 - an octal tube supposedly somewhere between a 6V6 and a 6L6 power wise.

I bought a bunch of NOS Cinch 7 pin sockets for 99 cents each on flea-bay.
Try doing an e-bay search.


Steve

My new favorite tube is a ECL86. Designed primarily for early '60 stereo HiFi, it's basically half a 12AX7 and an EL84 wrapped up inside one tube. Marshall used it in the short lived model 1930 Popular, and it has been used by Magnatone, Guild and a few others. Hammond used these in a small reverb amp, which is one of my favorite conversions. Still pretty plentiful and reasonable on eBay. Also goes as 6GW8. Check 'em out.