Are differences just in our heads or just mine?

[Avonessence]

I came across an old Rotel RA820 integrated (dating from the early 1980's) under the stairs the other day.

Having given it a good cleaning and plugging it in, I am quite suprised with what it is doing (let alone that it was working), with a hi-end CDP and very efficient floorstanding speakers, the result is very enjoyable and engaging music. So much so that on well mastered recordings there is very little difference.

Has anyone else had such an experience?

 

[kraut]

I compared Quad 405 against a bryston 4BST on Kef 104/2 - no difference. I listened to some old sanyo amps - amazing. I compared the Bryston to Hypex class D amp - same difference.
To me - any amp that fulfills the specs expected from a hifi amp and is driven within its range sounds the same.
My experience.

I run a rotel receiver for my dining room speakers.

 

[Gaius]

Yes, and with a Rotel 965BX CDP, pluged it in through my 72/Hi/180 at the time, a real giant killer. Quite startling.

 

[Gaius]

What is this, the Rotel secret society!

 

[kraut]

Not really - I run a Harmon Kardon 330 in my guest room. With a micromega stage two on Kef C15. I also run the computer output through them.

 

[S-Man]

A Rotel 820 was one of my first hifi amps - rather good and desgined by Stan Curtis. However, it did not really do much in the way of deep bass. What are you comparing it to and using it with?

 

[stevec67]

A healthy Nytech from 1980 will match most modern stuff. So will a number of integrateds. I'd stack a Thorens 150/160 against most record decks up to £1500 these days, so it goes on. Maybe Class D may offer some progress, but the transistor amp hasn't come far recently.

 

[tones]

Peter Walker of Quad famously did a test of amplifiers, to show that all amps driven within their limits sounded the same. Some very famous golden ears in the hi-fi business, at least one of whom had said very publicly that amplifiers clearly sound different, participated and were seriously embarrassed by their inability to detect the supposedly obvious differences.

One of the failures, John Atkinson, editor of "Stereovile", sought to explain away his failure by stating in a "Stereovile" article that blind testing, the standard method for all scientific work, didn't work for hi-fi, because the poor dears were put under pressure and couldn't therefore do the job properly. What he really meant was that their inflated egos and self-aggrandising positions as golden ears were threatened when they could no longer see what was playing and thereby justify the judgments that they had already made.

 

[louballoo]

Well said Tones.

 

[Avonessence]

A Rotel 820 was one of my first hifi amps - rather good and desgined by Stan Curtis. However, it did not really do much in the way of deep bass. What are you comparing it to and using it with?

Interestingly, with the Zu Essence speakers the Rotel RA820 is producing relatively deep bass, and on some recordings can get the ornaments rattling.

The other amp is an integrated, albeit an expensive one in comparison to the Rotel.

 

[kraut]

the Rotel RA820 is producing relatively deep bass

If an amp produces bass, something is seriously wrong. An amp should just take the original signal and pass it on amplified. If bass is there, it will be amplified but not produced. Production means to create something from something else. Just my nit to pick.
And if an amp is rated at +/- 0 deviation of the FRC at 20Hz it will amplify those 20 Hz and below; any amp that is rated at those specs will do that. To claim otherwise is just silly.
The premise - the manufacturer didn't lie about it.

 

[Avonessence]

If an amp produces bass, something is seriously wrong. An amp should just take the original signal and pass it on amplified. If bass is there, it will be amplified but not produced. Just my nit to pick.
And if an amp is rated at +/- 0 deviation of the FRC at 20Hz it will amplify those 20 Hz and below; any amp that is rated at those specs will do that. To claim otherwise is just silly.
The premise - the manufacturer didn't lie about it.

I'll reword it for the pedantic among us

The amp is not holding back the deep bass that is on certain recording's.

 

[S-Man]

I
And if an amp is rated at +/- 0 deviation of the FRC at 20Hz it will amplify those 20 Hz and below; any amp that is rated at those specs will do that. To claim otherwise is just silly.
The premise - the manufacturer didn't lie about it.

Your opinion is as valid as anyone elses. However, stating your opinon as a fact is potentially shortsighted and certainly arrogant.

By the way, manufacturers do bend the truth. Remember PMPO?

 

[kraut]

However, stating your opinon as a fact is potentially shortsighted and certainly arrogant. By the way, manufacturers do bend the truth. Remember PMPO?

First, I premised my statement with that proviso.
Second, if an amp tested passes a 20Hz signal at +/- 0 db deviation from the frequency response curve: to claim that it will not do so - who is arrogant here?

The only conceivable difference is the speaker response, and maybe speaker/amp system, especially concerning the damping factor. The latter however has only real meaning in active x-over systems.

 

[Joe P]

tones,

...blind testing, the standard method for all scientific work, didn't work for hi-fi, because the poor dears were put under pressure and couldn't therefore do the job properly.

I've heard that argument before and while it's documented that fear of failure increases the chances of actual failure (i.e., performance anxiety), I have to question just how stressful a blind audio test is.

It's not as though if you get it wrong you'll be summarily executed or zapped with 500 volts.

When I've tried blind tests, instead of being stressed or embarrassed by the outcome the process was more like, "Hmmm, as I can't reliably distinguish a 200-pound interconnect from an interconnect made of a Kit-Kat wrapper, Yale key, piece of solder and a twist tie that revelation has saved me a few squid."

Joe

 

[S-Man]

First, I premised my statement with that proviso.
.

Yes, you did, but in your earlier post, not is the one I replied to. Anyway, apologies!

Second, if an amp tested passes a 20Hz signal at +/- 0 db deviation from the frequency response curve: to claim that it will not do so - who is arrogant here?

The only conceivable difference is the speaker response, and maybe speaker/amp system, especially concerning the damping factor. The latter however has only real meaning in active x-over systems.

I dissagree. FWIW I have a pal who is very objective about audio. I lent him my grounded grid preamp and he remarked that it seemed ot boost the bass and treble compared to his ss preamp. He admitted he was baffled as to how and why because he measured the GG and it had a very flat and extended frequency response and very low distortion (as did the ss premap). Not proof of course, but certainly fod for thought.

 

[dim_span]

my old Pioneer SA-9800 amp does the trick for me and have never been 'shy' to compare it against modern gear

works well with my old B&W DM2 speakers and Marantz CD63 MKII K1 signature cdp

many a bargain to be found on vintage gear .... just do your research, and find out what other components work well together

 

[kraut]

I lent him my grounded grid preamp and he remarked that it seemed ot boost the bass and treble compared to his ss preamp.

Tube amps are known to have higher second order harmonics than SS amps. Not always, but mostly.
This can definitely influence the sound especially in the bottom range.

 

[S-Man]

The measured THD was below 0.0!% IIRC, by your logic this should sound identical to a ss amp with the same THD (and FR and o/p impedance etc.).

 

[Stu_cj]

Like most things THD spec is meaningless really as a means of comparison - exactly which harmonics are being summed to give the Total harmonic figure? One amp could have more 2nd harmonic distortion and another amp have more 3rd but give the same THD figure theoretically. Then it depends at which output power and frequency it is measured at, it is normally only quoted x Watts and at 1kHz or something - what about 100Hz or 10kHz and every frequency and volume in between

Sure on some material and in certain systems there can be surprisingly little difference between 2 amplifiers, but to say thay all sound the same when driven within spec is just nonsense.