Yes. That is one of the general listening consensus for a long time from "the unwashed masses'.
In learning what pro-con there are with CFA, we have a lot of data but only speculation as to the root cause for repeated listening impressions that CFA listeners say they hear compared to some VFA.
Maybe OS will have some designs to compare with of same output power etc etc.
THx-RNMarsh
this forum is full of data and designs. Its all right here to look at and decide.... from SIMs to measurements. And, if not enough here - in products and their T&M results. There is plenty of data just
(1). Not the relevent measured data... something else. Or, (2) not understanding the full and complete significance of the data we have in front of us.
Or as some believe... no difference at all... the listening data from uncontrolled experiences should then lead to random noise for results.... regardless of what many people have and continue to say are characteristic of the CFA.... trends instead of random results. Amazing dicotomy.
Thx-RNMarsh
(1). Not the relevent measured data... something else. Or, (2) not understanding the full and complete significance of the data we have in front of us.
Or as some believe... no difference at all... the listening data from uncontrolled experiences should then lead to random noise for results.... regardless of what many people have and continue to say are characteristic of the CFA.... trends instead of random results. Amazing dicotomy.
Thx-RNMarsh
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I'm too cheep to buy the epoxy ... let it be thermally stable in the wind.
I decided to use the Servo (ahh , the "evil" servo - below 1). But , one jumper
in the servo section (that I will add) ... bypass the servo to use just a trimmer.
At least the servo is 0 phase from .1hz to 1mhz (no inversions).
I also used a simple (yes) ... LED CCS X 2 . (below 2 -whole contraption).
Besides having 30 or more DB PSRR , it is the same as my baseline VSSA
simulation at 1.1mhz UG. (below 3)
DID the temp-co , slightly negative from 10-50C ... led CCS cancels the
hawksford led's. SW is perfect and THD20 is 15ppm. Very good for a 2 device
"toy like" IPS - actually as good (or better)than a symasym or leach.
Off to the "races"
.asc below (as well)..
OS
Thx-RNMarsh
Can someone please build two versions of perhaps one of Ostripper's amps that are virtually the same except for the fact one is compensated as a cfa and the other is a vfa version, only the feedback being different and actually make real measurements so we can compare the two? That would sure go a long way to answering some questions and would even give those who are only going to believe real measured response differences something to think about. Someone with perhaps an Audio Precision test setup so we can see real measurable difference, or show that there aren't any measurable differences.
there are always going to be measureable differences - and I see no reason to believe it will be easy to converge on agreement as to what is a "fair" comparaison
I have shown how the same number of Q, but signaificantly rearranged completely changed the conculsions from one such - "I just change the front end to diff pair and the CFA wins" sim
do any believe CFA vs VFA is a bigger divide than tubes vs SS? - then please explain the Stereophile/Carver Challenge results
I have shown how the same number of Q, but signaificantly rearranged completely changed the conculsions from one such - "I just change the front end to diff pair and the CFA wins" sim
do any believe CFA vs VFA is a bigger divide than tubes vs SS? - then please explain the Stereophile/Carver Challenge results
Yes, I will build the version of CFA dan VFA with OPS modular like Ostripper's. Unfortunately, I have only cheap OSC now
. I am curious why my VFA amp and my CFA sound different, but my VFA use BJT OPS and my CFA use Lateral. Do you have a guts to prove it?
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jcx,
I would assume that the difference between the cfa and vfa are much less than any tube vs ss are going to show. Similar devices and similar topologies can't be that far apart in measured response.
ps. Thanks for that Bimo, it would be great to have a true comparison without two totally different topologies. I wish I had an Audio Precision II but can't say I do. Perhaps someone in your part of the world near you has the test equipment to answer some of these basic questions?
I would assume that the difference between the cfa and vfa are much less than any tube vs ss are going to show. Similar devices and similar topologies can't be that far apart in measured response.
ps. Thanks for that Bimo, it would be great to have a true comparison without two totally different topologies. I wish I had an Audio Precision II but can't say I do. Perhaps someone in your part of the world near you has the test equipment to answer some of these basic questions?
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I don't know who has such instruments here. But long years ago I worked for company which have such instruments and I can not find those instruments in University.
I want do some experiment. First, build the two amp for best that I can, then reduce the slewrate of CFA amp, so it is comparable with VFA amp.
But then you would not be building them "as best as you can" ??
To do this , while still being CFA ... reduce CF to <5ma , 70V/us or less ye shall
have.
OS
It is experiment. Of course, I will return it to its original CFA design with high slew rate. I want to prove if the different of sound characteristic cause by the slew rate or by the topology.
I have several SOTA analyzers/generators which can be counted on. But, I will be wandering the world from the Asian side of the planet after May and I dont know when I will feel like returning. I have a condo in Bangkok to visit as my port in the region. So, sometime between now and then I can do some tests and/or after I return.
First, I would like to see some SIM's using multi-tones and results. Can that be done with LT or other software?? What is max number of tones that can be used? need as many as possible.
Thx-RNMarsh
First, I would like to see some SIM's using multi-tones and results. Can that be done with LT or other software?? What is max number of tones that can be used? need as many as possible.
Thx-RNMarsh
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Richard,
It seems that ostripper is the closest person here to you and if he could make two versions of the boards and send them to you for testing we could get some real answers.
Sounds like you will be gone for quite awhile after April. We never did get you going on the speakers side of things. Just got a request to use my cone drivers in a new pro monitor application. Will have to change a few parameters for them to work in a smaller enclosure.
It seems that ostripper is the closest person here to you and if he could make two versions of the boards and send them to you for testing we could get some real answers.
Sounds like you will be gone for quite awhile after April. We never did get you going on the speakers side of things. Just got a request to use my cone drivers in a new pro monitor application. Will have to change a few parameters for them to work in a smaller enclosure.
I have several DSP EQ/x-overs still in boxes for that and for subs. rats! Got to get back to it. Thx for reminding me... I was gone a lot last year and sold a loft here and on and on.
Now I have a place to use them (cabinets)... in my other place in Bangkok! But now I dont have any amps - blew my last one up. No music !
-Richard
My BenchMark DAC2 just arrived and I cant listen to it !! AAaaaahh !
Now I have a place to use them (cabinets)... in my other place in Bangkok! But now I dont have any amps - blew my last one up. No music !
-Richard
My BenchMark DAC2 just arrived and I cant listen to it !! AAaaaahh !
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yes, of course. If we ever have a winter in california again, i plan to be over there in our winter and visa-versa. But I can still do fun electronic stuff there as well as here via the factory and use their test equipment and engineers/techs etc. When not looking for art. I have a painting up for auction in Feb and will need to replace it on my now bare wall. email me about your speaker as I know of Asian company who might be interested in making them or using them for their local area retail sales.
I need at least 200-250W/channel into 2-4 Ohms. CFA only.
-RM
When not looking for art. I have a painting up for auction in Feb and will need to replace it on my now bare wall. email me about your speaker as I know of Asian company who might be interested in making them or using them for their local area retail sales. I need at least 200-250W/channel into 2-4 Ohms. CFA only.
-RM
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