Review and Measurements of Accuphase E-270 Amplifier

[anmpr1]

Where are the DBTs showing that your claim has been demonstrated time and time again ??

https://www.audiosciencereview.com/forum/index.php?threads/catalogue-of-blind-tests.8675/

Above is a link on the topic.

 

[Feanor]

It has nothing to do with 'feeling'. What I meant to say, and what others have stated, was that it has been demonstrated time and time again that if you match levels and don't overdrive the gear then you will not be able to reliably tell any sonic differences.

However, if you don't do that, if you don't match the levels and if you know the brands and which device is playing at any given time, you will discover all sorts of 'differences'.

With this in mind, there is no reason to presume that the Accuphase will be any different.

The line of argument here is pointing in the direction that all amplifiers sound the same, aside from gross defects or defective design.

I'm wondering then what the point is in the sort of detailed testing the Amir does, (which I'm personally grateful for), when really only detection of gross defects is necessary. Why bother 'recommending' amongst the large majority of amps that are essentially OK? Isn't it just anal to worry about presumably inaudible SINAD differences for example?

 

[anmpr1]

The line of argument here is pointing in the direction that all amplifiers sound the same, gross defects or defective design aside. Why bother 'recommending' amongst the large majority of amps that are essentially OK? Isn't that just anal to worry about presumably inaudible SINAD difference for example?

a) It's all predicated on whether the amplifier reacts to the speaker load within certain parameters. If you compare the Accuphase to, say, a Futterman OTL and use them to drive a low impedance current hungry speaker (such as the old Apogee) then sonic differences will be readily apparent. Right before the explosion. In fact, even the small Accuphase integrated may not 'sound' very good with such a speaker as it's power capabilities could likely be taxed beyond its design limits. That's what it's about.

I have no doubt that when audible differences are real, it is due to an unusual interaction between the amp and the loudspeaker, and not something intrinsic within the amplifier itself. What 'subjective' reviewers often do is try and convince their readers that the amplifier, in and of itself, has a particular and demonstrable sound.

[Further, the idea that any competently designed DAC has it's 'own sound' is ridiculous from the get go. The idea that an ethernet cable has a 'sound of its own' is twice as ridiculous from the get go. And so on...]

b) The studies I've seen indicate one to two percent distortion on test tones, possibly three to five percent on dynamic music is reliably discernible. But why put up with that? What would be the point of that? It's important to know the design and how it measures in order to know who is doing the best engineering given the design constraints. Even if it's not audible, I want to buy the best engineering I can afford. If pretty good is good enough then it wouldn't be an issue.

c) FWIW, when I inserted an AHB2 into my system I immediately thought that the sound was 'cleaner and more dynamic'. Could I detect this within an ABX protocol? Well, the item it replaced was a 60 year old tube amplifier design that I built from a kit. What about an Accuphase? How would it compare with levels matched, etc.? I don't have to ask that question because I already know the answer. That said, there are certainly reasons for owning an Accuphase... it's just that its intrinsic and unique 'sound' is not one of them.

 

[Feanor]

a) It's all predicated on whether the amplifier reacts to the speaker load within certain parameters. If you compare the Accuphase to, say, a Futterman OTL and use them to drive a low impedance current hungry speaker (such as the old Apogee) then sonic differences will be readily apparent. Right before the explosion. In fact, even the small Accuphase integrated may not 'sound' very good with such a speaker as it's power capabilities could likely be taxed beyond its design limits. That's what it's about.

I have no doubt that when audible differences are real, it is due to an unusual interaction between the amp and the loudspeaker, and not something intrinsic within the amplifier itself. What 'subjective' reviewers often do is try and convince their readers that the amplifier, in and of itself, has a particular and demonstrable sound.

[Further, the idea that any competently designed DAC has it's 'own sound' is ridiculous from the get go. The idea that an ethernet cable has a 'sound of its own' is twice as ridiculous from the get go. And so on...]

b) The studies I've seen indicate one to two percent distortion on test tones, possibly three to five percent on dynamic music is reliably discernible. But why put up with that? What would be the point of that? It's important to know the design and how it measures in order to know who is doing the best engineering given the design constraints. Even if it's not audible, I want to buy the best engineering I can afford. If pretty good is good enough then it wouldn't be an issue.

c) FWIW, when I inserted an AHB2 into my system I immediately thought that the sound was 'cleaner and more dynamic'. Could I detect this within an ABX protocol? Well, the item it replaced was a 60 year old tube amplifier design that I built from a kit. What about an Accuphase? How would it compare with levels matched, etc.? I don't have to ask that question because I already know the answer. That said, there are certainly reasons for owning an Accuphase... it's just that its intrinsic and unique 'sound' is not one of them.

Thank you for your reply, anmpr1. It seems to me that you make incontrovertible points regarding speaker loads and power requirements.

Audiophile undoubtedly fool themselves imagining they hear differences been ethernet cables or AC power cords. For myself, a couple of years ago I set out to evaluate several interconnects. Of course I used the same associated equipment, recordings, and volume levels to listen -- I did not attempt blind testing because I had no competent person to swap the cables. Bottom line is that while I thought I heard differences, but realistically it might have been entirely my imagination.

On the other hand I'm not so sure that I can't heard differences between at least some amps. Recently I compared an inexpensive tube preamp against a quality solid state preamp; the differences seemed quite blatant to me. On the other hand I'm not so sure I could heard difference between that s/s preamp and the direct output of my DAC.

Blind ABX testing is the scientific gold standard for judging whether listeners can hear differences between amps. But I think most scientists would allow that the more rigorous and repeatable an experiment is, the more likely the rigor is to constrain the test results. Blind ABX testing isn't the method most audiophiles use to evaluated their equipment -- certainly not mine.

 

[anmpr1]

On the other hand I'm not so sure that I can't heard differences between at least some amps.

I've heard 'differences' many times. But my auditions were always uncontrolled. So I take it for that.

Some reviewers measure amplifier FR/distortion characteristics at different loads--in order to simulate real-world loudspeakers. Anyone whose seen AudioGraph PowerCube reports realizes that there can be large electrical differences among different designs of similar specs, in dynamic situations. I certainly wouldn't discount audible sonic differences in an unusual amplifier design coupled with a really difficult loudspeaker load. But that's typically not the case.

However it is, the problem with this 'little' Accuphase is basic engineering (the interface between the pre and driver amp, the XLR-RCA interface, etc.), not any lack of 'liquid midrange' or 'grainy highs'.

Someone asked whether it would be audible? In an ABX test using a typical loudspeaker the answer is clear. There is no reason it would be given its FR and overall distortion characteristics. But for me that is not really the pertinant question. The better question is, Why would someone want that? At five thousand dollars? An even better question in this specific context is whether bad electrical engineering should necessarily cost more than better electrical engineering at a lower price?

I think with Accuphase, folks buy because of nice cosmetics and exclusivity. I get that, and IMO Accuphase gear is tops in the looks department. I'd certainly like to see an ASR test of one of their big machines. Just to see.

 

[MDAguy]

I think with Accuphase, folks buy because of nice cosmetics and exclusivity. I get that, and IMO Accuphase gear is tops in the looks department. I'd certainly like to see an ASR test of one of their big machines. Just to see.

right, let's see this one measured... 50W of pure class A, 100W RMS.

http://www.accuphase.com/cat/e-800_e.pdf

 

[Balle Clorin]

Here is my Accuphase A-48 measurements from Accuphase, specified 45 watt class A

 

[pma]

It is nice, however the rise of distortion at 20kHz is quite substantial - it indicates to worse high frequency linearity.

 

[Balle Clorin]

That is quite common for most amplifiers . Benchmark on one the few that avoids increased distortion at rising frequency. 0.01 % at rated power an 20khz is not any problem for my ears anyway.
What other manufacturer than Accuphase has the honesty and publish this data in the user manual?

Another amplifier half of the A48 price

An this 4 times the Accuphase price and 20watts;

 

[restorer-john]

What other manufacturer than Accuphase has the honesty and publish this data in the user manual?

Plenty of manufacturers did so in the past, just as Accuphase continue to do to the present. Accuphase's position and ethos is not dictated my marketing, returns to shareholders, or the endless desire for growth. As such, they remain pure in my book, very rare in this day and age.

Also, those graphs are a worst case example. They guarantee your amplifier will meet or exceed (mostly exceed) all their (conservative) published specifications.

 

[BlackH20]

Well, I have had a P-300 Amp since 1981, bought it off a dental student that got carried away with the stock market, ran me $200. Still my daily driver 40 years later. Been in the shop twice (not in the last 10 years), both times they wanted to buy it off me. Specs came out over 180 watts into 8 ohms and under .1 percent distortion. Used to use a David Hafler pre-amp, but then that remote control device came out, and labels for the CD player, etc, so bought a used McIntosh. Can't get my pants in a wad over this one, don't think I would part with $4K for that low of power in an integrated amp. Accuphase used to be top-tier quality, was initially an off-shot of Kenwood to be the best in the business, Teac used to import them to the United States, maybe they have gone off the path, most companies do, some find their way back, some don't. McIntosh taught me in the 1980s under the CEOs Gordon Gow and Speaker Designer and Electrical Engineer, Roger Russel don't waste money on the wire, they used to actually have a demonstration. Imagine that, the CEO saying don't waste your money? Roger Russel even showed coat hangers to surpass the results of some high-end wire. Used to communicate with Roger back and forth a few times in the late nineties. Have used copper wire for forty years, many just lamp cord. The stores made them stop throwing in the free speaker cables. Thirty years later, Gordon's son-in-law was "selling wire" under his own company and McIntosh had put out some poor gear (but as long as they have the blue meters, people will swear by it). They have changed ownership numerous times, even Clarion, the Japanese car stereo bought them early nineties. Samsung owns about everyone since they bought Harmon, get some upstarts, but the music industry is dead (good musicians making money). Session work is gone, just have the computer auto-tune it with the lead singers. Steaming, don't even do it at home. Oh don't worry, the doctor says the hearing is off the charts, plus I can always turn it up.

 

[Wes]

Did the owner of the tested unit ever contact Accuphase and get a response?

 

[Balle Clorin]

Most sources huh? Consider most people don't even use a standalone CD player anymore, but even if they did, 2V could be 2.2V or 1.8V and only @0dBFS (full level). Most music and content sits well below that.

As for "relevant test points", one tests against rated specifications, not arbitrary numbers you've dreamed up. 150mV was a de-facto standard for line inputs for many decades. Accuphase is a company which respects and adheres to established standards and testing protocols.

Time to change the standard as it is not updated and representant sources we stopped using 30 years ago??

 

[Balle Clorin]

E213 and E280

why does these Measurements become so different, different input level signal?

Let's now re-measure the power versus distortion using the E-270's pre-amp:
Missing figure

 

[kschmit2]

slightly better quality caps from the Japanese manual of the Accuphase E-270:

 

[Balle Clorin]

…so 0.002 %thd at mid power from German test and Accuphase manual data. ASR gave 10 times higher with preamp ( presumably 2Vin and volumeknob adjusted for desired power?) None of this is detectable by ears, but I did expect better( flawless) from Accuphase

 

[alfa_cosmic]

...well, I didn´ t expect that from a company like Accuphase! I´ m running the previous model E-260 since nearly 10 years now - no issues regarding the balanced input here (confirmed with several spectrum analyzers from my workshop). I had a couple E-250 on the bench for repair and adjustment (mainly BIAS) - they all behaved well on the balanced XLR input. A net search regarding this XLR problem brought up many tests of E-260, 270 and 280 but non of this tests showed any indication that there is something wrong with the XLR input... it seems to me that there is simply a problem with the OPAmp responsible for the balanced to unbalanced conversion. I had a look at the service manual - it is just one OPAmp converting balanced to unbalanced - it just looks as if the specimen under test was faulty in that stage... That is not a design error.... ...just a malfunction... greetings, Don

 

[alfa_cosmic]

I can confirm that the preamp (AAVA as Accuphase calls it) on the first glance doesn´ t look bad at all- just as Amir wrote in his very helpful review.
The problem is that Accuphase puts to much amplification into the integrated amps. 18 dB at the preamp (AAVA) and 28 dB at the pwr amp!
For my understanding of how to develope the level over the stages this is way to much. Nearly all sources today come up with someting like 2 Volt RMS - why do we need 46 dB overall boost???

The preamp has a "fixed" noise and hum level which doesn´ t drop down when you turn the volume lower - it remains at the same level all the time and is nearly not affected by the volume knob and it´s attenuation. Despite it´s quite low level the problem starts when it hits the 28 dB boost of the power amp which has it´s own noise and hum level. The total sum of this "mixture" is the performance loss of nearly 10 dB when the preamp plays together with the power amp - very sad!

To proof this I just placed a -22dB attenuation between pre and pwr amp. Now the entire noise spectrum of the pre is lowered by 22 dB and does not bleed additionally through the pwr amp. It gives exactly the roughly 10 dB signal to noise back that Amir was missing when he checked the amp out. Please note that this was achieved on an earlier model E-260. Due to the very conservative design an evolution it seems decent to compare the two amps.

Greetings from Germany

Don

 

[Maximus89]

I just came across this on a random search and i wasn't registered, although i have read and do value reviews done here despite not being a pure measurements guy. I own an Accuphase preamp and noticed it also is listed as far less S/N ratio on it's Balanced INPUT vs unbalanced INPUT. I just want to ask if this is the case for OUTPUT as well to the power amp? If it's just for INPUT from a transport/dac, i should use single ended connection from now on and balanced from pre to power amp is ok?

Thanks

 

[alfa_cosmic]

@Maximus89 ...it would be helpful to know the exact model names of your Accuphase Pre & Pwr amp...