|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
184.70.169.107
In Reply to: RE: Dropping the Power Stage posted by Mr_Steady on November 23, 2014 at 11:13:58
Late to the party here, but I will throw in my two cents as you all have been so helpful on my recent posts.
This is in essence a bad idea... the driver stage in any amplifier (except where grid current is expected) is designed to make voltage, not power. The 6AG7 is a strange beast too, I have a whole bunch of them from an ex NORAD site, and the best use I can find is to try to turbo charge the RF amplifier stages in an old shortwave radio.
I think you'd be way better off taking a purpose designed audio tube, and designing a small amplifier around it. For example, triode connect a 6L6, or maybe an EL84... that would give around 1 - 2 W of output in a single ended configuration and super easy to maintain.
Follow Ups:
Max,
I think you hit the nail on the head. The driver stage is a voltage amplifier. That's something I knew, but didn't recongnize the significance of in this situation. Many thanks.
Jamie
Big speakers and little amps blew my mind!
If you want to try some unconventional tubes, there are some things to look for. The triode curves should have a small bend at the low end and fhen be almost perfectly straight, with even Spacing between the lines. The plate dissipation rating should be over 10W or so (usually) go be useful too, preferably much higher. If you leaf though and RCA tube manual and look at a pile of random triodes, then look at a 2A3 and go to western electric.com and download the 300B data, it becomes obvious fast why people like these tubes so much. Designing tubes is a huge compromise - if you improve one thing, others get worse. Optimizing linearity was not a big priority for many tubes, because given the circuits they were designed to work in it just wasn't necessary. In our type of circuit (no NFB single ended) one needs the most linear tube possible, or all you will hear is distortion.
Hey Max,I just snagged a BH shunt regulated 2a3 Paramount on the Asylum trader. It uses a 6DN7 for a driver. I guess I got my low gain amp with a fancy schmancy power supply. How 'bout that!
And I got it for the price of the kit alone. I'm glad I farmed the design work out to Paul Joppa. It saved me a ton of work, and it got done better.
Jamie
Big speakers and little amps blew my mind!
Edits: 11/25/14
That amplifier looks like a real beauty, I saw it on trader - nice buy
Post a Followup:
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: