More likely the effect of GBW product, depending on the circuit. Suggest run some simulations for various GBW of popular op-amps, and see the effect on top end of audioband if the circuit has high gain......
No, I mean bona fide slew rate in vinyl programme material is not significantly different from digital material - not noise or misc artefacts.
at the time (pre-sims) the only thing I could see was slight overshoot
It was probably oscillation due to incorrect use of the LF357, as it is not unity gain compensated.
For the record, there has been a lot of research on slew rate in program material published. That is where the 0.5-1V/us/Vpp criteria was developed, and in general it still holds. MORE is debatable, for the reason of slew rate alone should not do too much. LESS is recommended by those who have never made extended measurements of slew rate in audio. In fact, some of our greatest critics don't seem to have seriously considered the question at all.
For the record, there has been a lot of research on slew rate in program material published. That is where the 0.5-1V/us/Vpp criteria was developed, and in general it still holds. MORE is debatable, for the reason of slew rate alone should not do too much. LESS is recommended by those who have never made extended measurements of slew rate in audio. In fact, some of our greatest critics don't seem to have seriously considered the question at all.
Sorry, but it is not true with a servo system (feedback). How fast has-it to be to correct the errors, trying to follow trajectories accurately ?
The LF35X devices did not behave well when slewing.
My first pre used these in c. 1976/7 IIRC. They were a very big step up from the LM741 (which I never used in Any audio), but with low source impedances, no match for an NE5534 which came out a year or two afterwards.
On phono amps, pops and clicks have lots of HF content. You need plenty of headroom and fast controlled recovery to deal with them gracefully.
My first pre used these in c. 1976/7 IIRC. They were a very big step up from the LM741 (which I never used in Any audio), but with low source impedances, no match for an NE5534 which came out a year or two afterwards.
On phono amps, pops and clicks have lots of HF content. You need plenty of headroom and fast controlled recovery to deal with them gracefully.
Ok.
I have no proofs yet (too much time spent on threads like this), but in my experiments with my filters I find that altering/reducing system noise quite profoundly affects subjective performance, with results such as you describe, ie "better details separation, more fluid trebles, less fatigue on the long time".
To this I would add bigger, lower, more solid bass and more extended highs.
Interestingly running both channels signals through the one filter (line and/or speaker lines) results in pin sharp and perfectly narrow dead centre mid image, and wider side imaging.
Also absolute polarity becomes night and day, correct or wrong.
I suspect that VFA vs CFA subtly alters the audible products of device/component/system noise.
Like my signature reads "Never ignore the noise...".
Dan.
Very true, I've had to do circuitry simulations at an EE faculty some decades ago and found it rather boring soon after.
I can read books though, also what is written on forum threads, without the urge to resort to discourteous behaviour, I'm nasty enough as is in real life.
My previous post was a mere (and more humorous) attempt at reminding you haven't been around the EE block that long.
Granted, should have first asked you for permission to use your squid IP.
(btw, my brother in law's head looks a lot like yours, born not all that far from where you're at, but Malayan dialect mother tongue instead and even bigger than me. I try to keep my 4-decade practice up to date by daily reading/writing with my family members at fb, never found tok pisin much of an interesting lingo)
Guys
But why for example famous Accuphase manufacture all actual power amps and most of integrated are CFA based ? , Accuphase Laboratory, Inc.?Power amplifier
it is so maybe because they have some personal negative emotions against VFA ?, or is some other pure technical (sonic) reason ?
But why for example famous Accuphase manufacture all actual power amps and most of integrated are CFA based ? , Accuphase Laboratory, Inc.?Power amplifier
it is so maybe because they have some personal negative emotions against VFA ?, or is some other pure technical (sonic) reason ?
did anyone walk away with Richard Clark's US$10k with one?
https://www.google.com/#q=Richard+Clark's+amplifier+challenge
(hint: the answer is no)
maybe over a decade and "several thousand" tries no one ever showed up with a CFA power amp?
https://www.google.com/#q=Richard+Clark's+amplifier+challenge
(hint: the answer is no)
maybe over a decade and "several thousand" tries no one ever showed up with a CFA power amp?
Is it your opinion that current Accuphase power amplifiers sound all that different from their voltage feedback models of the past ?
(Accuphase also tried balanced output stages, P102. A lot of heat, not much class A power, and not much of a success)
Definitely yes ,
I consider people from Accuphase manufacture as very serious ,
they will Never go to this new CFA route if their actual power amps will sounds inferior compared with their previous generation of VFA based amps , even for iota percent , now they have simple evolved further with quality of the products .
---------------------------------------------
P-102 with no big success ? , no big surprise for me , it is VFA (balanced ) .
Bridged actually.
We must have different ears, I've never had issues with Accuphase preamps and their C27 phono stage is very OK (don't know about the C37), but their power amplifiers still is not my thing.
A bit like Yamaha, never heard one decent power amp of that brand, not even their expensive centennial edition.
Personally, I take every audio manufacturer that makes a quality product serious.
We must have different ears, I've never had issues with Accuphase preamps and their C27 phono stage is very OK (don't know about the C37), but their power amplifiers still is not my thing.
A bit like Yamaha, never heard one decent power amp of that brand, not even their expensive centennial edition.
Personally, I take every audio manufacturer that makes a quality product serious.
Hi. I have not heard nor tested his preamp. I would like to know also.
Something missing about slew rate..... IMO this has nothing much to do with the signal rise time etc from the source. It is why does a higher SR of the amplifier makes the amplifier more accurate. (even with input BW limited). It seems to need faster speed by a fair margin than the signal BW or Tr would indicate to sound best. It is something within the amp itself perhaps. Speed of correction? Or is it all the things a CFA brings - the combination -- which makes it better? Reduction of affect of non-linear C's in the devices?
A lot of audio companies (Japanese etal) noticed before us that CFA sounds better. Most of the High End models from various manufacturers get changed to CFA just for their top model.,,, and some do not mention it in their literature/marketing but need to remain competitive.
THx-RNMarsh
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Years ado my brother bought an old Triumph roadster which was fit only for restoration. He used it as a lawn ornament for a few years, then partially disassembled it and realized he couldn't afford parts, and didn't really like working on an old car. My father took it off his hands and restored it. When he got to the upholstery he needed some tools that he didn't own, went to a local upholstery shop and somehow convinced them to loan him the tools for the weekend. They probably thought he would show up Monday with a mess and pay them to fix it. Instead he showed up Monday morning and they offered him a job on the spot!
Here is a video my brother shot about that car: 1947 Triumph Roadster TD4 Video :: Wheels on Edge
(sense of deja vu, have I told this story here before?)
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