Finally! Tubes in the house!

Here's the story. A few years ago, I was gifted a pair of Quad esl57's from my wife's uncle. He also gave me his Onkyo TX-4500, which he had used to drive the Quad's, I assume since new. I used this set-up for a little while, but was always a little nervous powering those delicate Quads with 60 watts of solid state. I also felt that while the Onkyo is a fine receiver, the Quads deserved better. So, I was on the lookout for a tube amp that wouldn't cost a fortune, like most of the amps people recommend for 57's do.

First, I found a Zenith tube console. I thought I could either strip out the amp, or just run the Quads from the amps speaker line out, as is. Here is the story of that.
http://www.audiokarma.org/forums/showthread.php?t=549438

Well, I realized that I would have to recap that amp among other things before allowing it near the Quads. Also, I felt it was it too good condition to gut.

So, I finally bit the bullet and got this little RCA rs177j console pull from ebay, at a great price. It was recapped and ready to go. I just put in better rca plugs, speaker terminals, and banged together a simple maple case. It uses two 6FQ7, four 6BQ5, and one 5AS4 tubes.

For the first few weeks, I had it hooked up to my Rectilinear III's, and boy did it sound great. It didn't have quite the punch of my Marantz 140, but at what I guess to be around 12-15 watts, it sure made the Rects sing. The sound is so three dimensional and smooth. I had heard that these amps have pretty low gain, so I'm definately pushing the preamp higher that usual, but there is plenty of volume at my listening level. I also finally get to see the meters on my SAE Mark 1M preamp actually move!

Yesterday, I finally pulled out the Quads and had a listen. So good! The quickness of these speakes, combined with the silky smoothness if the tubes, is just amazing.

So, it's another step in my audio journey. One that really has me smiling.

As a final note, is there anything I should know, as a new proud parent of tubes? Things like, is it bad to turn it on and off too much? Is it bad to leave it on for long periods? Anything I'm missing?

Thanks!

Aside from the standard safety recap, use it as it was intended. It was probably played or left on for hours if not days. I know we had a Packard-Bell tube stereo growing up and I can't ever recall when it wasn't on.

If you are old enough then you would know that tubes were in everything, and places like malls, schools and/or shopping centers used tube PA sound systems that would be left on 24 hours a day. This is just a few examples.

If its got good parts, run it as long as you wish. Don't turn it off and on again without at least a minute to cool off in between, but really thats about it. These aren't delicate flowers that will die if you look at them crossly. I wouldn't leave it on if you aren't actually using it, but thats only because it wastes power and tube life.

Welcome from the dark side of silicon into the light of tubeage. :thmbsp:

... and, best of all, pp EL84 is a pretty good match for the rather stringent requirements of the ESL-57

Which ever amp I have up at bat gets to see a lot of hours every day... usually 14-16 hours a day. As long as the components are in good shape, play music to your hearts content, but I would recommend not to leave it on unattended as in going somewhere w/o turning it off. As far as turning it on and off, wait a few minutes to turn it back on after a shut down... give things a chance to stabilize.

A cautionary note.... one tube amp is never enough. Beware of the addiction and include SWMBO with future projects.

Congrats! Nice Amp!

Actually 2 rules:

Never run them without a load (speakers or big wattage resistors) as the output transformers can get a voltage spike ruining them.

And as mentioned let the tubes cool well before restarting as they (the tubes) don't like that.

Congrats! Very nice.

Nice tube amp, once you get one you'll get more.

Tube

Is there a fuse in your amp? A lot of consumer level gear back then didn't include one.
I'd have no problem running it 24/7 so long as it has ample ventilation and is fused properly.

DrRick1955 said:

Is there a fuse in your amp? A lot of consumer level gear back then didn't include one.
I'd have no problem running it 24/7 so long as it has ample ventilation and is fused properly.

Click to expand...

Yes, there is a fuse in it. I'm not sure it's original or if the guy I bought if from put it in. And yes, it's quite well ventilated, both on top and bottom, as it's sitting on half inch rubber feet I stole from an old Tivo.

Thank you all for the comments and advice. It's funny, I didn't realize that EL84 was actually the same as 6BQ5. I had heard a lot of good things about EL84 amps, especially with Quad 57's, and was a little bummed that I didn't find one. What a nice surprise!

yep, same tube, just depends which side of the pond you live on.

Tubes use thermionic emission, which very gradually depletes the material which emits the electrons. They also use filaments which get red hot to cause the emission from the cathodes. Filaments also get depleted. Tubes age with usage. So there probably is a limit to both hour on and turn-ons but I'll be durned if I know what the optimum usage pattern is. Also recall that tubes are now extremely expensive compared to the few dollars they used to cost back in the day.

Maybe we should put our collective heads together and figure this out, enough to give ourselves some rough, objective guidelines.

Congrats that is a nice looking amp. Nothing like a good tube amp enjoy.