|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
75.82.52.72
In Reply to: RE: I will add, not all people... posted by tube wrangler on June 01, 2012 at 19:55:17
"If a person involved in audio playback CHANGES this in some way-- to fit a certain taste, then it is no longer the same recording.... it has been perverted."
I agree. I also agree with much of what you say in this post like, "reproduce the STUDIO RECORDING accurately", etc.
So why do you use a driver tube that can't fully drive the Miller, causing high frequency roll off?
Why do you use a power supply filter that causes instability of the B+ voltage?
Why are your cathode bypass caps (both driver stage and output stage) undersized to the point of changing the frequency response?
I think you are the one who is building to "to fit a certain taste".
If you can't (or won't) explain this in a normal, technical way I will go on believing that you are the one building to suit a certain perverted taste.
I tried to ask you about this on the phone but you got weird about it and wouldn't talk sense with me.
You talk a lot about truth. Truth does not fear examination but every time I try to examine your claims you start with the mumbo jumbo instead of talking sense in a normal technical way.
It's a shame.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Follow Ups:
OH! My Gosh! DARN it!
I've gone and done it again! Designed a totally new Linear Power Supply for Music Servers.
Terrible! Horrible! THREE (3) of them in ONE BOX! It looks nice and professional too!
AND it hasn't failed in over 1200 hours of testing, and neither have its cousins. It runs cool.
It's much worse than that! It makes Music Servers sound MUCH more honest, dynamic and real than the same computers run on ANY other Power Supply!
As you can see, I don't know what I'm doing! Not only that, I can't even handle telephone calls from telemarketers, crackpots, intimidators, and fools! After about 1/2 hour, I hang up on them!
Sometimes even sooner!
Gosh! Maybe I better invent something else real quick! Oh, No! I forgot! I don't know what I'm doing and it's much worse than that! I can't explain it to TRE either!
Oh well! At least the music seems real around here....
---Dennis---
I was talking about your 2a3 amplifier and you go off with mombo jumbo talking about your PS for digital.In light of your statements,
"I use the best parts and methods that I can find or invent in order to reproduce the STUDIO RECORDING accurately"
"I would state that if we do the best we can-- up to keeping all of the music intact as it's coming out of the amplifier"
"What to do? I would still use the most accurate amplifiers"
Defend you use of undersized cathode bypass caps.
Defend your use of a driver with high output impedance.
Defend your use of a PS filter that is unstable.
Why won't you do this? What are you afraid of?
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Edits: 06/02/12 06/02/12 06/02/12
One should be able to understand the following:
(1) Conventional tube amplifier technique chooses cathode bypass caps by their Micro-Farad values. I choose them according to measured and listened performance under actual musically driven conditions.
(2) A high impedance driver is not a problem in this design because the HI-MU driver chosen is far more than capable of driving any good 2A3 vacuum tube way beyond the levels that this design requires.
The high-gain/fast response capability of a good HI-MU driver is exactly what I want-- fast, ultra-dynamic response to signal change. I also want the gain factor designed into TWO amplification stages, not three or more.
The reasons for this are self-evident-- there are too many parts involved in any 3-stage amplifier. The musical information losses in all 3-stage tube amplifiers renders their performance musically boring to me.
If you doubt this, simply compare the best 3-stage tube amp you can find out there to a good Solid-State amp. If you want pace, rhythm, and musical timing to come out correctly, the difference will at once be obvious.
A tube amp CAN be designed to perform with the best Solid-State. It requires a MAXIMUM of TWO amplification stages that are directly connected together, and are powered in such a way so that the two tubes operate as a SINGLE gain device.
Ideally, the "gain architecture"-- that is, overall amplifier gain-- will be in the 18-to-21 db area.
Such a gain figure will ideally match up to industry standard source outputs which ideally range from about 3.3 volts to about 5.6 volts single-ended, or double those figures for balanced.
A Digital source such as a good D/A converter, or a good CD player, etc., will have those output levels, and will prefer to see a constant load across its output of about 10K ohms-- in that range-- allowing proper output loading for the source.
These signal voltage levels (above) allow the inclusion in the system of a
passive preamp of about 10K loading continuously (A Ladder or L-Pad type attenuator), which eliminates the need for any musical-signal losing un-needed preamp amplification stages.
A further advantage of this kind of system is that interconnect cables are DRIVEN at voltages that actually allow such interconnects to work properly.
The amplifier's HI-MU driver stage is a necessary part of this overall "best possible" system approach-- it is very sensitive to interconnect cable output, and picks up musical details that lower-mu stages cannot respond to as well.
(3) The ENTIRE AMPLIFIER is designed as a modulated, distributed audio signal power supply.
To single out SOME OF the individual parts in that system and then claim that only those parts are the "power supply"-- and to further claim that it can't work is an incomplete assessment.
If one can envision an ENTIRE AMPLIFIER as a TOTAL ENTITY-- as I must do in order to get the performance that I require-- then it could be discussed intelligently by people who can see that it is an ENTIRE OPERATING SYSTEM.
I don't think that one can selectively pull parts out of an operating system, ASSUME that they're the only parts involved, and then make claims as to what one ASSUMES will happen in that SYSTEM.
In any case, it's easy to check out-- simply use the system and observe what it actually IS doing! What could be simpler than that?
---Dennis---
"(1) Conventional tube amplifier technique chooses cathode bypass caps by their Micro-Farad values. I choose them according to measured and listened performance under actual musically driven conditions."
The value necessary to fully bypass the cathode is a matter of math. The value you have chosen does not fully bypass the cathode. This make your amplifier, to use your word, "perverted". Not only will the frequency response be "off", the phase response will be off as well.
(2) A high impedance driver is not a problem in this design because the HI-MU driver chosen is far more than capable of driving any good 2A3 vacuum tube way beyond the levels that this design requires."
The high impedance driver is, by your own admission, a problem. You said it "starts to roll off at 15kHz". This makes your amplifier, to use your own word, "perverted". Not only will the frequency response be "off", the phase response will be off as well.
I didn't say anything about a three stage amplifier. Most of the rest of your post is a good example of you not addressing the questions and going off talking about other things.
You have done it again.
I didn't/don't assume anything. If the driver is not/can not fully drive the Miller that's a problem no matter what the rest of the circuit looks like.
If the cathodes are not fully bypassed that's a problem no matter what the rest of the circuit looks like.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Too many "IFs"!
---Dennis---
Those are not "Ifs".
Your driver can not fully drive the Miller by your own admission.
The cathodes of both the driver tube and the output tube are not fully bypassed.
No IFs.
You are doing the very thing you argue against. Making designing an amplifier that is perverted.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
This message has been moved to a more appropriate venue .
Disagreed.
---Dennis---
Too many bases not covered in your design.Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Edits: 06/02/12
I fully and completely disagree.
---Dennis---
You disagree with yourself?
You said that your amp starts rolling off at 15kHz.
The cathodes are not fully bypassed. That's just a fact.
If you disagree, show the numbers, show me wrong.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
All the amps I've owned before my SET have been flat from 20-20K with distortion well below 1%. None sounded nearly as good as the SET which doesn't have "the numbers".
If Dennis just said that his amps sound good I wouldn't say a thing.
But instead look at his response to your post,
"OH! But it DOES have numbers. It's been at University E.E. labs where it astounded their engineers."
With undersized bypass caps and a driver that even Dennis admits does not fully drive the Miller capacitance of the output tube, how can his amp have good numbers?
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Dennis,
Very nice answer. Best of all, your ending comment :
" In any case, it's easy to check out-- simply use the system and observe what it actually IS doing! What could be simpler than that? "
Any good listener understands this totally.
Jeff Medwin
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: