caferacer59
Active Member
Kward and Gordon thanks very much for the insights it is appreciated
new to tubes, heck new to hi fidelity.
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Dandy
Addicted Member
Yes, I've read that, e.g. at http://www.oestex.com/tubes/Data/Acro 1955.pdf
But, you'll recall that the Mullard Tube Amplifiers book allows for 5-10 amps running EL84s to use OPTs with 20% or 43% UL taps, or none. http://www.r-type.org/articles/art-003e.htm There is a trade-off between distortion and power. I hope we can avoid giving the OP the impression that he might have 'the wrong' OPTs. It's likely that there are other improvements to be made to the circuit.
triode17
Super Member
Well of course streaming is going to sound better than this TT setup (and i hate streaming) . If you are serious about playing records to their fullest extent, get a good TT and cart. (at least an Ortofon 2M Red). You have a good phono pre. in the receiver, you should use it.
caferacer59
Active Member
I’ll show him this and ask him to join.
On a separate note one tube went out this morning. Fortunately I live in a little town and it has no less than 10 musical instrument stores and a record shop. So I bought and put in 4 6v6gt tubes and the Sound is getting better than it was. They have been running all day and they have clarity.
On a separate note one tube went out this morning. Fortunately I live in a little town and it has no less than 10 musical instrument stores and a record shop. So I bought and put in 4 6v6gt tubes and the Sound is getting better than it was. They have been running all day and they have clarity.
caferacer59
Active Member
ctjetta
It's not a perfect world
Now, I'll admit to not being anywhere near as knowledgeable, but in regards to feedback isn't it's use more frowned upon in solid state amp design? Particularly global feedback?
In fact I think just the opposite. Most solid state amps employ more feedback than a typical tube amp.
I watched a YouTube video last night from PS Audio discussing their new BHK signature power amp. The designer Bascom H. King was answering questions. One question was asked of how much feedback was applied in his amp. His response; right around 40 dB global feedback! He said that provides an output impedance of .08 ohm and a damping factor of 100. That's iron fisted control over those woofers!
About the most you'll see in a tube output stage amp is 20 to 25 dB global feedback.
Im going from memory, but one exception is the Harmon Kardon Citation II, wherein I believe about 30 dB overall feedback is applied, but that is split between the global loop and several shorter local loops.
I watched a YouTube video last night from PS Audio discussing their new BHK signature power amp. The designer Bascom H. King was answering questions. One question was asked of how much feedback was applied in his amp. His response; right around 40 dB global feedback! He said that provides an output impedance of .08 ohm and a damping factor of 100. That's iron fisted control over those woofers!
About the most you'll see in a tube output stage amp is 20 to 25 dB global feedback.
Im going from memory, but one exception is the Harmon Kardon Citation II, wherein I believe about 30 dB overall feedback is applied, but that is split between the global loop and several shorter local loops.
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