Tim O...

I'm going to expose the limits of my knowledge here, but this is something I want to know. I've read explanations of it before but I'm still not completely clear on it.

What is the advantage (if any) of a receiver/amplifier with high current capability? Harman Kardon (and other HK owners) wants me to believe that although my 525 is only rated at 70 Wpc, all channels driven, it favourably compares or even surpasses competing models in terms of output and sound quality because of its HCC: +/- 45 amps. What exactly does this mean and how does a receiver/amp's current capacity affect output levels, sound quality, distortion, etc.? As I said above, unless my mind played tricks on me, I noticed significantly more output, and *clean* output, over my previous Sony DE685 (I think that was the model #). I also noticed a fuller, richer sound. I know that the HK's 70 Wpc was "honest" compared to the Sony's 100 Wpc (IOW, all channels driven, 20-20,000 Hz). But does the higher current capacity play a role here and if so, what is it?

Shiu

Paul, if I fail to tell the difference, do I have to pay them?

Anyway, my Energy Veritas 2.3i are not very efficient. When I A-B them at the dealer's place with a pair of the Energy C-9, every time I switched to the Veritas, I had to turn the volume (ARCAM-AVR300) up by about 5 dB. I think an entry level Sony (the DE series) would have hard time driving the Veritas.

Shiu

I think you are right since you are referring to the Sony's DE models. If you compare the 525 to a Sony STR-DA4,5, or 7ES, then I would say that the 525's all channel output will be as good, or better than the Sony 4,5 or 7ES. However, based on lab test measurements that I have read over the past two years my guess is that the 525's 1 & 2 channel output will be significantly less than those Sony ES models. Those Sony ES models have hugh heat sinks. The HK's 45A ratings are not continuous ratings. It is likely that the Sony ES models can deliver high currents on short burst basis. HK tends to emphasize their high current capability and all channel driven power. Still, if you read the fine prints of their product literature, they are not designed for driving 4 ohm speakers.

Paul S

Shiu, read through all links provided about the challenge, Article 13 reads as follows:

13. Cost to take the test is $100.00. $300.00 for people representing companies. Payable in advance, scheduled appointments only. Done correctly the test takes several hours.

Shiu, I don't see how you can possibly say you can tell the difference in amps when you aren't even listening to them on a matched volume a/b setup. Anyone will always pick the loudest sounding amp as best sounding every time which is why volume between amps has to be perfectly matched when making any comparisons. Also switching has to be instantaneous. You can't listen to one amp and then listen to another several minutes later. Aural memory is something in the order of several seconds at best.

Chu Gai

Which is why men always forget what their wives told them to pick up at the store.

PaulDA

I would like to throw in, for consideration, the following hypothesis:

When comparing amps to amps (separates), adjusting for level matching and other variables (using the same speakers, whichever they might be), telling one from another in a double blind test is probably impossible.

However, when comparing receivers to receivers, the presence of increasingly complex electronics physically attached to the amps (not connected by interconnects), coupled with the fact that in many receivers it is difficult, if not impossible (despite the presence of "Pure Audio" switches--and only a minority of receivers have this feature) to completely disable the DSPs (in the old days, STEREO was not a DSP, but today it is on most receivers), makes it likelier that the confluence of amplification and electronics could generate a "sonic signature" that could be (I'm not betting on the likelihood, though) identified in a double blind test.

Discuss.

Never try to teach a pig to sing. It wastes time, and it annoys the pig.

Tim O...

I would generally agree with that Paul.

Martin Rendall

First, I would like to point out that the subject should have been:

"revealing" and "dull" receivers

Even the terms we use colour our perceptions of what is good and what isn't.


I put it too you that the goal should be to have the most pleasing sound. That is, you should be able to subjectively "like" one amp over the other, consistently in a DBT, even with a few seconds or minutes between amps. If you can't, that is to say, if you need an aural memory to determine a difference (supposing for a moment that you can in fact do this), then I claim that the differences are inconsequential, and you should consider other factors, such as price, better impedence handling, and even wattage, feature set (for receivers), and the like.

And a room treatment will have the largest effect on "detailed" versus "dull" - way more than an amp or even the speakers (excepting a few obvious exceptions, like horns).

Thoughts?

Martin.

Hopelessly out of date DVD Collection Listing

Martin Rendall

I also want to point out that the $10000 challenge has been widely critized for setting up conditions where it would be unlikely for anybody to determine a difference even if one amplifier were truly inferior to the other.

Suppose for a second that there differences between two amplifiers.

The idea is that amplifiers will differ at the edge of their tolerances, such as at full power output, or with difficult to drive impedence curves. The challenge deliberately keeps both amplifiers well below such tolerances, keeping the "better" amplifier restricted to performing at a level comfortable to the "worse" amplifier. Now compare them, and the argument goes that of course they will sound very close to each other. But what happens if you turn them both up 25dB, or swap in some MLs?

Anyway, I thought it worth mentioning.

Martin.

Hopelessly out of date DVD Collection Listing

DanaA

Exactly. An amp is largely defined by how it does when pushed
under load. If they establish parameters which circumvent this, they can only truly come to findings which are accurate within the limitations they tested under.

Besides, there are a lot of other factors that need to be considered when buying: price, warranty, flexibility, customer service, reliability, etc. Even the dimensions and appearance need to be considered in a lot of setups.

I would never buy a product under the guise that every 100 watt/channel amp will perform the same.

Shiu

Paul S, I did read the link, thanks. Actually, I have to agree with you. I don't think I can tell the differenct between even an entry level Sony and my 3805 under a restricted condition, but I think at least there is a good chance (ok I did say I was sure and I'll retract that..)I can tell them apart if they are hooked up to my veritas 2.3i and have the volume crank up to say 85 dB level.

This is getting interesting, keep it going guys.......