Best Digital Amp for Legacy Focus 20/20?

Handling them is not quite the issue. As someone how makes amps like that (disclaimer: I build and sell amps), there is one small caveat.

The Ear amps, the H2O amps, the Rowlands, Red Dragon, the ones I make......a bunch more, use ICEpower amp modules. The only drawback is that the frequency respsonse is load dependent. You need to keep that in mind if you audition them on another system.

They should work with a tube preamp, but almost all of the ones mentioned above have the stock input impedance of 8K ohms. If the tube preamp is capacitor-coupled, there may be a slight loss of bass.

Emphasis on "slight" and "may". Depends on the design.

The only consistent comments that I hear about the EAR designs is that they are a real pain to attach speaker cables to. It is quite possible that they have some newer designs that don't have that problem.

Your speakers are close to a resistive load. It may be a very low one, but it is still close to being resistive.

As you go from 8 ohms, down to 4 ohms, the respsonse tends to level out some. But drop below that impedance and it starts to fall off rather rapidly.

Ribbons and planar magnetic speakers are a nice, constant resistance. Cone drivers have peaks and dips in their impedance curve. What us technical types like to refer to as a complex load. Complex in that it has resistance and reactive components to the impedance.

So......in general.......amps like reistive loads better, until they get too low. Such as your speakers. Yes, that does create problems.

ICEpower is a different beast. By its very nature, it has to have a low-pass filter on its output. It will interact with the load to make it sound dull into a higher impedance speaker, and more bright into a lower impedance speaker. (May be that it has just the right amount on your system, which could explain why you are so enthusiastic, and others don't get it.) This is why some listeners will say that one sounds bright, the next will say it is too dark.

With a cone loudspeaker, with all of its variations in impedance, it can be difficult to predict exactly how an ICEpower amp will respond. Granted, we are talking usually less than 0.25 dB variation at 20 kHz, but that is more than enough of a change to have a very noticeable effect. One that is clearly heard.

So........the guy wants to buy an Ear amp. He hears at a buddy's house, sounds good, and he buys one. He brings it home........hooks it up to his 4 ohm load, and it is too bright. He hates it, maybe.

So.....the point is: listen one on the the system that you are buying it for. Listening to one on another system may skew the results enough to make a marked difference in how it sounds.

So........since we are discussing it:

In my experience:

The 250 will interact with the load less than the 500. The 1000, which only comes in the ASP series, will interact a great deal. I do not think that you could use one on your Scintilla system. Yes, it would drive the daylights out of them, but the roll-off with that value impedance would not be to your liking.

Unless you like almost -2 dB drop at 20 kHz. Who knows.......maybe you will.

Anyway.....as an amp designer, this minor wart is the sort of thing that gnaws at me. Maybe at some other time I will discuss some of my approach to this problem. This isn't the right place, though.

It is a fact of life, not my opinion. Simple as that. Maybe Henry takes steps to minimise that, I don't know. But he can not eliminate it any more than I can.

Facts is facts, bub.......

The point is......perhaps it was buried........you need to audition an ICEpower amp on the system that you intend to use it on. Auditioning it on a much different system could give the wrong impression.

BTW.....I have heard mine on 4 of the ones you mentioned. My comments stand.

See.......it wasn't that hard to agree with me. Was it?

Anyway......if you look at the data sheets......it is there for all to see: Frequency response for 3 different load conditions. All 3 are different.

Can't you find any common ground? I'm trying hard here, bub......

Ok, you don't know what mine sounds like, and I don't know what yours sounds like. OK, find a reason to argue that.

But you missed the point, I am afraid. I am pointing out differences in frequency response as load Z changes, and you switch gears to THD.

I am not talking about THD, I am talking about frequency response aberrations. I am not making it up. ICEpower clearly states it. I use that as a reason why it is important to audition one on the system it will be used on.

OK.......back to the subject. The guy is asking about a "power hungry load". I do not think that you can judge how it will work just based on weight. Yes, a lot of the amps are light. Some are light (Rowland for example) because it has a SMPS. Others (H2O) have large transformers. While someone will obviously disagree, you can not say "A" will and "B" won't simply because of weight. Sure , they will probably sound somewhat different, but weight alone is no indicator of much.

If you examine how much current the speaker will actually use, most of the current comes from discharging the filter caps. So, it is possible to drive such a load with what may appear to be a small transformer based supply.

Bottom line is........you will just have to try them. Or use the advice of someone with the same setup.

I think we are looking at the same graph. In some of mine, they are in color, in others it is multi-color.

So.....assuming that we are......look closely at the area between 10 kHz and 20 kHz. You will some slight variations.

At first, you may not think that little change is audible. I can assure you that is. Very audible. Which is why you need to listen to one on the system you intend to purchase one for.

Look......all amps will interact to some extent with the speaker. These amps just happen to have a particular type of interaction that will be much more audible to the average listener.

At some other time, I can relate a story about RIAA networks, and how very noticable a difference of 0.25 dB is. If not, let me say that most RIAA networks have a hump of around that much from 250-500 Hz. Very hard to take out. Very few products take it out. (Some leave it in on purpose..........)

You can verify this by listening to CDs and LPs that you have in both formats. Some will prefer the warmer sound of vinyl, and others the "accuracy" of CD. Not the point which is better. Just to demonstrate how little of a frequency change can make very large changes in perceived sonics.

Anyone wanting info on stuff that I make, or have made, is welcome to send me an e-mail or PM. I would rather discuss items of technical nature that interest me, than bang the drum for our products. OK?

(There is more than one thread that deals with not being able to identify myself and my company without screaming "www.buy.my.amps.com".)

Uh.......there is no "dead short" data. I think you mean "open" data. It won't work into a dead short, will it???

Yes, it may very well be pristine on yours. As I stated, it could be that it works out to be the right amount on your system. No one is questioning that it sounds right on your system. We are ecstatic that it has worked out so well for you. (Maybe the amp you had before it had too much, or too little HF roll-off on your system.)

It just may not sound right on the next guy's. And the chances are mine won't either in that case. That is the point.
I do think that you need to look closer at the graphs, though.

As for the ASP......some may not hear what you feel is an objectable amount of noise. In a HT system, it may well be the ticket. Lots of power in a small, light, cool running box, that is short circuit protected, has soft clipping, and will most likely be very reliable. I don't use them in any 2-channel products, but that may also have to with the user's perception of what a serious power amp should be like. Somehow, the idea of something that only weighs (say) 10 pounds putting out 500 watts seems impossible to some.

As for your generous offer.........I know how my amps stack up to the competition. Enough prospective customers have auditioned mine along with the competition. I suspect most will agree that is a more diverse, and possibly un-biased, cross section of the market.

Again, I don't think that there is enough of a difference between all the competing brands to say one stands out above, or below, the others. I tend to dismiss comments of that nature, I hear them all the time.

The only comment that makes me stand up and take notice concerns speaker cables. I have heard......many times, many sources..........that high capacitance speaker cables suck all of the midrange out of the sound. Some of that can be borne out in the performance data supplied. "Designed to be stable for capacitve loads up to 470 nF." Luckily, no load, even a 'stat, is purely capacitive.