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They are in all but the most expensive audio equipment now. I know at first they were taboo. Has their technology improved? I am considering a new integrated amp and I want the best sound I can get.
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Hi
the Gaincard is built around one "power" op-amp per channel.
And it caused quite a stir when it came out for the high quality of sound.
Also the Jeff Rowland Concentra integrated is a parallel of many power op-amps and quite well received.
Never heard them by the way.
Kind regards,
bg
Edits: 06/28/15
This $25k phono stage is op amp based. At least the original version I owned about 15 years ago was. Sounded pretty good to me.
I currently have a Lounge Audio op amp based phono stage ($300) that sounds very good.
Ron Sutherland is another great designer who uses op amps in his products.
My point is that op amp based designs, cheap or expensive, can sound very good in the hands of a good designer.
d
Edits: 06/26/15 07/06/15
Hi i would not call this cheap ... with an original price of 23,800 USD.
I do not know it is now out of production ... i guess its sound is still ok by the way.
Kind regards,
bg
as tepid a review you'll find. He repeatedly pointed out what other SS and tube products do better.
Hi and i understand. Tepid maybe.
Nevertheless they placed it among the "Class A" units in 2013.
I have got another opinion that in one of the best sounding room at a Axpona show the 6010 was singing very fine with a analog tape source.
Kind regards,
bg
Edits: 06/28/15
They are best avoided. There are plenty of linestage options without them. (Just about every tube preamp available on the market)
Op-amps take some of the guesswork out of amplifier design.... Although the ultimate designs are with discrete components, one must really know what he's doing in order for his discrete design to demonstrably outperform a competent one using op-amps. And it's too easy to mess up a discrete design to where it won't outperform op-amps.
I'm not sure op amps are addressed, but this is classic John Curl talking amps and various other topics as well. Worth watching.
...excellent talk but he doesn't mention them.
I'm about an hour into the 1.5 hour video, and, yeah, he hasn't mentioned opamps yet. Still, even you might have learned something by this point.
John is clearly not in his element when speaking contemporaniously in public, but don't let that distract you from what he's teaching you.
:)
...even me?
Then for you it must have been mind-blowing ;-)
I hadn't watched that video for over a year so couldn't remember about whether or not op amps were mentioned. I personally would stay away from op amps. Discrete circuits/designs were the reason we paid more. So what happened? Can't tell me op amps got that much better. I'd have to hear it.
.
...personally I have found few solid state amps I could live with for any length of time - there was something always irritating about them, a glare in the upper midrange or some sort of subtle distortion that bothers me.So I have ended up with tubed amps and couldn't be happier.
One of the things Curl talks about in your video is the problem of 7th harmonic distortion with solid state amplifiers.
It's a problem they all have and he has had to overcome it in the design of Parasounds. He says it gives the amps and edgy, amusical sound and has to be avoided.
2nd and 3rd harmonic distortion are musical so they aren't much of a problem.
Any 7th, he says, no matter how little is a killer.
Edits: 06/26/15
What you describe is why I currently do not own a solid state amp and (I'm guessing) part of the reason there are so few women in high end audio. The glare can be brutal but most don't hear it unless their high frequency hearing is still intact.
...nah I hear it in the upper midrange where your ears are more sensitive.
That's probably because my HF hearing rolls off around 12k.
Even the A21 or the older HCA models?
I wonder if that's also why I never liked the Neumann KM84 and AKG C-451E microphones. They both have an edgey "brittle" sound (especially the KM84). (As condenser mics, they have an amplifier built into them.)
:)
"Even the A21 or the older HCA models?"
I never heard the older models. But I did review the JC-1. The JC-1 had bigger issues than just a brittle edge. And yes, I did discuss them with John Curl. In fairness, the amp I reviewed was an early version and I'm sure any issues have now been corrected.
My comments were not targeted at Parasound, but solid state in general based on my experience over the years.
No matter what you do with them you cannot get around these fundamental limitations and in the best of cases they sound ok and in the worst they are the worst.
Let's take a step back for a second.
An Op-Amp has, by definition, very high gain and it is used with large amounts of feedback such that the closed-loop performance is determined by the passive feedback components and not the components within the op-amp.
So, if you don't like using lots of negative feedback don't use an op-amp. Simple.
Regarding too many transistors - this is an irrelevance considering the first point. A monolithic op-amp will use as many transistors as necessary to achieve high gain and whatever specs that are important. In open-loop terms any op-amp is very non-linear so using less transistors won't make it less 'bad'. This leads me to the topic of 'discrete op-amps' which, IMHO, is an oxymoron. Such a circuit may be justified to drive unusual loads but there is no justification on gain terms. If it is an op-amp it should have high gain and using discrete transistors to produce that gain does not make it more 'good'. One the other hand, if you want a moderate open-loop gain amplifier to use with a little feedback (in the style of a Nelson Pass power amp) then you probably have to design your own - but that isn't really an op-amp.
Regards
13DoW
I guess my point was that you pile on non-linear transistors and then try to fix the mess with feedback you can get something that measures well but sonically...well hey I'll let you decide.
Simpler seems to be better even for transistors as Pass has come to discover.
Cheever and some others have found that the best sound gear is the one that is the most linear, open loop and that closed loop performance is largely irrelevant soncially.
So, if you don't like using lots of negative feedback don't use an op-amp. Simple.
Regarding too many transistors...A monolithic op-amp will use as many transistors as necessary to achieve high gain and whatever specs that are important.
This is what both Brad and I have observed and why we're not fans of that approach.
.
For discrete transistors I am sure that there is some quality differences although i would not know which ones are good and which ones are not.
For opamps, it is usually specific manufacturer for a given opamp so if you have specific needs then there is likely not much choice in the chip you buy. A couple of companies now are making what they call "discrete" opamps, which are not using miniaturized transistors all on a die but normal small signal transistors that are arranged like an opamp circuit. I think Burson makes one of the more popular disrete opamps.
.
yet greats chefs elevate them to the highest culinary standards. Sometimes, it's not what ingredients are used, as long as they are fresh and the chef has an overarching talent.
Edits: 06/24/15
the sheeple run in the fields like it's May Day when the trend is announced from the jolly press; i.e., 47 Labs.
Indeed you can build an operational amplifier with valves.
There are a lot of potentially very good (op-amp) chips available now and for at least two decades.
Most need real attention to their grounding, heat sinking and Power supply arrangements as do everything else.
Even if you did mostly listen to simple stereo recordings and not to multiple mono-mike pop mix-downs the sound you hear has passed through quite a few op-amps. And if you are a typical audiophile, hundreds of them, over and over.
Warmest
Tim Bailey
Skeptical Measurer & Audio Scrounger
That is true. Philbreck made op amp modules that used a pair of 12AX7's.
Like anything else, it depends on the designer's skill in implementation. There are crappy sounding op-amp based products like there are crappy sounding products that use all discrete components.... and the other way around.One of the best sounding phono stages I've had in my system used op-amps, high speed op-amps to be more precise, sometimes used as video amplifiers. It was the Graham Slee Era Gold V MM phono based on the Analog Devices AD817 op-amp.
My Cambridge 640p phono used op-amps and it sounded pretty mediocre. Go figure.
Edits: 06/24/15 06/24/15 06/24/15
Audio, phonopre is the most simple amp there is, little amp with RIAA correction, 6dB/oct. Worth 3 dollar material, mostly the casing.
Many so called Super High End manufacturers take benefit of those glossy magazine readers who think they buy something space age special.
A big con the audio industry. They only want your wallet and what's in it.
"phonopre is the most simple amp there is,"
A phono preamp that is well designed is the MOST difficult amplifier to engineer. Anyone can put together a simple filter with a 6dB/ octave slope, however that filter would not be close to the the RIAA curve. Further, it takes a real engineer design a circuit that is consistent in manufacturing and that does not degrade as the components age. Many in the DIY community build all sorts of power amps and preamps before tackling a phono stage. Anyone who believes that it is simple doesn't understand the process or the engineering.
RIAA slopes are 6 dB/oct with 2 crossoverpoints, more sophisticated rolloffs at 50 and 10 kHz.
Simple, 2 12AX7 triodes per channel, you are talking about VOODOO, victim of the audio accessoires for fancy prices.
I bet you use loudspeakercables 20 mm (1 inch) thick, gold plated, copper/silver alloy, 400 Dollar per meter. That is oke, good for economics.
True. But it goes to show what can be done with an inexpensive component in the hands of a good designer. The Graham Slee Era Gold V is a highly regarded phono.... as is the vacuum tube Aesthetix Rhea at 5x the price. Yet I preferred the sound of Graham Slee, op-amps and all.
The phono section in my pre-amp is an op-amp based unit. It has been replaced with a discrete, tube-based unit and the difference is night and day, with the discrete circuit sounding much better. Though this is comparing apples to oranges, I think that op-amps are still more limited sonically than discrete circuits, ceteris paribus!
By denying scientific principles, one may maintain any paradox.
Galileo Galilei
All opamps work in Class B with heavy negatve feedback [ transient intermodulation distortion ] to compensate crossover distortion and because many stages to reduce noise.
You only hear this after a while, listening fatigue.
But all this is masqued by solid state amp's (class B or AB), CD and other digital sources.
In an all valve setup with non-digital vinyl there is no place for opamp's, keep it pure I would say.With modern manipulated CD's , solid state amp's, radio, internetsources an opamp more or less is not relevant. HIGH FIDELITY is long gone, that's why merchandisers say: REAL DIGITAL QUALITY, STEREO SOUND, etc. Nobody say's HIFI anymore because it is not HIFI. Real HIFI stopped with digital, solidstate amp's, miniboxes,midiboxes, yes, even stereo imho.
Edits: 06/24/15
> > All opamps work in class B.
Really?
It's quite easy to bias an opamp to operate in class-A operation. One of many threads on the topic: http://ocw.mit.edu/courses/media-arts-and-sciences/mas-836-sensor-technologies-for-interactive-environments-spring-2011/readings/MITMAS_836S11_read02_bias.pdf
Yes, isn't that proof that opamps suck ? Doesn't help much.
And: what does that help the general musiclovers who trustfully and innocent buy their gear ? Technicians/hifi people know their way, does one have to be a thorough electronics expert to finally enjoy favorite music ?
Opamps are great building blocks for computers, phones, TV, telecom, medical gear but not for HIFI. Digital is for convenience, not for music. Stereo is an annoying special effect and so on, don't break my mouth open.
Maybe it's time to get out and listen to some new gear? Be sure to pick up one of these first and use it before doing so.
Your opinion is fairly misconceived, although very stereo-audiophile-typical.
No, you're wrong, I'm no audiophile or something weird like that.
I am a music lover and just ventilating my hangup's regarding bad sound.
Grown up with analogue and valves, until now. All "new" things sucked, stereo, solid state, quadro, digital, multichannel, you obviously defend new things because you paid lots of money, I understand, once I dreamed to, but now I see clear.
There are a bunch of op-amps that are really considered good. I think that using op-amps is hard to avoid unless the designer is very clever.
There is a phono stage, for instance, that has a discrete MC input and I am wondering whether it will be better than my current phono stage that uses op-amps exclusively, and ones that are not even noteworthy?
I think you have to listen to the gear to decide.
I think that using op-amps is hard to avoid unless the designer is very clever.
Audio Research uses them in the mute timer circuit. Ironically, that is the only thing that has ever failed with my twenty year old SP9 MKIII.
You can't hardly compare a LM555 digital timer in a standard SOIC package to an analog opamp. I guess you could... if you have no clue about what you're talking about.
Personally, I've never had an opamp fail and I've used a lot of them. OTOH, I've owned a number of high-end preamps that don't use opamps fail.
Regardless, this has nothing to do with the OP's query.
I've owned a number of high-end preamps that don't use opamps fail.
Sorry to hear that. I cannot relate.
Regardless, this has nothing to do with the OP's query.
Sure it does. Op amps do have their place. :)
but are still innately complex designs using lots of NFB.
There is no surprise to me that the best gear in my experience continues to use discrete components - be they triodes or JFETs.
Unfortunately opamps have drfifted to SMD technology ( Surface mount), For cerain application they are perfectly fine, In fact Rowland Research use LS opamps for his amps (at least at one time) claiming that their distortion specs are lower than what he could achieve with discrete components.
The issue I have with many opamps is that the traces are miniscule and thus ultimate dynamics often suffer as a result. That can occur with even opamp volume controls, which sometimes overload given a high input. I'm sure designers are working to alleviate this issue, but I remain a bit skeptical.
...they have improved but still it's the end sound of the component that really matters more than what's inside.
"...they have improved but still it's the end sound of the component that really matters "
How have they improved? Do you know about this stuff?
Our good friend John Curl can talk with you all day long (trust me) about opamps and other electronic gremlins.
For another discussion about them, go to the diyaudio 'lounge'.
:)
...I have talked to my friend John about them before.
Does he use any in Parasound products?
I'll bet he does.
Cost no object - that's a different story.
In most JC designs beyond the basic price-points, an opamp used as a DC servo to mitigate offset. He favors discrete gain stages. Though if you know Curl, you know he actually prefers tubes and always has.
Oh please. If nobody can ever mention a person's name, then everything said here means nothing.
I had lunch with John Hilliard, and he said...
I took lessons with Pierre Thibaud, and he said...
I talked with Bob Ludwig, and he said...
I had drinks with Linda Ronstadt.
I played craps with Madonna in Vegas.
Eschewing "name-dropping" is overrated. Everybody who's not a moron and has been outside their home during their adult life has spent some time with someone who is "famous".
It makes no sense to ridicule/berate someone who mentions someone's name, other than out of petty envy.
:)
...Vendetta Research head-amp I bought from him used j-fets.
And I believe he uses the same in his Blowtorch preamp design.
there's more possibility for innovation - NOT because he prefers the sound of ss.
I can't comment on that, 'cause I know almost nothing about circuit design.Ask me about recording techniques or psychoacoustics, and we can talk. I got that down - more or less.
:)
Edits: 06/24/15
You really can't generalize. Sorry.
Op Amps have gotten better and also more specialized so that helps. Implementation still rules however so it really boils down to the goals and competance of the designer.
I can tell you how to do some tests if you have a scope and Fn generator that can sort out some issues, but the real bottom line for just about all of us is to listen. If it sounds good in your system, you're in business. If it sounds bad, well that's interesting but try to find something that doesn't if you can. If most everything sounds off in your system you need to try to figure out why. It can be surprising sometimes...
As far as audiophiles making pronouncements from on high concerning the "sound" of this or that technology or part, take it with a grain of salt. Ask yourself 'how do they know where the problem really lays?' How do they know it's just one problem?
To thine own ears be true...
Rick
Since the bad old days of TLO72 and LF353 opamps have advanced beyond all recognition.
These days good opamps are far better than what is possible to achieve using discrete components.
Problem is the only way to find out which ones are inside is by opening the amp.
Don't know of many retailers who let you do that.
"These days good opamps are far better than what is possible to achieve using discrete components."
Really?? I think not.
You simply don't find them in the best gear.
If you want any even half-way reasonable/informative replies, post your question in the "Amp/preamp" asylum, or at the diyaudio.com forum.
:)
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