The Half Life of Expectation Bias

[DaveyF]

A Hafler DH220 was my first amp. I bought it to power my Maggie's and I thought it did an ok job with them. However, I was using a converted HK A 500 integrated that I had modded to use as a preamp only and perhaps the overly warm preamp section mated well with the DH220. I do think that the DH220 was easily bested by any number of amps back then....BUT perhaps not for the price.

 

[mep]

I see that we have reached the point where expectation bias crosses over to fantasy.

 

[Phelonious Ponk]

I see that we have reached the point where expectation bias crosses over to fantasy.

Ah, good. You can join me over here at Fantacide Watch, where we keep a watchful eye on the ledge where personal taste stands ready to plunge into delusions of the presence of actual facts. We stay very busy here at WBF and can use all the help we can get. Welcome.

Tim

 

[DaveyF]

The DH220 like all amps has its strengths and weaknesess when it comes to personal taste in what one likes in music. For me, if it was a kit that was wired correctly as far as wire layout it works fine, but there may be some cases where wiring can be run so sloppily that the mosfets can break in to oscillations and this can be heard as a more "solid state" sound. IF this is not the case, the amp has its own harmonic spray and does just fine in the lows and mids and highs as long as it is not clipped. For me, the little know secret is how the amp sounds when it is mono bridged. It is effortless and the new harmonic spray pattern is enticing. And 450 watts of clean undistorted power is nice too.

If your idea of great sound is the romance of tube sound then don't expect it from the DH220 in stereo or bridged, it aint gonna happen. This is a high fidelity amplifier first and foremost. It does not have much extra dynamic range, that is, don't peak it out much above its rated power, it has about 1db or so of headroom, but if you have 440 clean watts at hand, then it should play loud enough for most anybody. Speaking of speaker interfacing, in the mono bridged mode you are looking at (per my measurments) atleast 400 watts from6 ohms to10 ohms and 350 from 5 to 15 ohms so it has a good power band, and this converts to freedom from listening fatigue experienced by lesser powered amps.

Having said that, no one should try to run nominal 3 ohm speakers with this amp as it simply loses too much power at that low an impedance.

Its a fine looking amp, a beautiful classy smoky color and the heatsinks are rounded so you don't cut yourself if you lift it up for some reason. The circuitry is a short discrete path with only 6 or so active devices per polarity, with only one cap at the input (for dc protection) then direct coupled all the way to the output. It is an elegant circuit and simple enough but not too simple. If you know solid state electronics you will appreciate the power and elegance of the circuitry.

In mono bridged it is superb IMO. David Hafler knew what he was doing at Dynaco, ortofon and the David Hafler company and I would not trust anyones opinion about the capabilities of this unit any more than trusting their opinion of any audio component. That includes trusting my opinion, but if you do listen to one, (they are 35 years old now) make sure it has been tested by a tech who knows what he is doing before passing judgement. AND listen to it in bridged mode......it will be saaweeeeet!

Tom, I hate to burst your bubble, BUT IMO the Hafler DH220, was and is, an amp that at BEST would be considered as 'midfi' by any serious a'phile today.
At the time...it was capable of driving my Maggie's in an acceptable manner, however, I soon replaced it with a small Melos tube amp that used four KT88's and put out about 45 watts/ch. The Melos ( cannot remember the model) was a FAR FAR superior sounding unit across the board...and it wasn't in the same league at all of my current ARC D70Mk2.

 

[DaveyF]

Davey, I hate to perhaps burst your bubble but your ears and mine are not the same and preferences are non-negotiable, and as a person skilled in the art of electronics there is nothing lacking in the performance of my amps, that's why I still use them after all these years. And, you might want to determine just what mid-fi means anyway, because if we look for the satisfying sound for us, then price should not be relevant, neither looks, nor hype...know what I mean there good man?

Tom, I couldn't agree with you more....what you hear and what I hear are clearly miles apart.
As to the meaning of mid-fi, well in my books, the Hafler amps- were and are- a perfect example of a mid-fi amp. IMHO, they were hard/brittle sounding, low in resolution, diminished in their sound staging abilities and easily bested by any number of contemporary and current amps. Clearly YMMV.

 

[mep]

I find it highly ironic that the person who says there is nothing lacking in the performance of their amplifier is the same person who isn't happy with the sound of their system and blames it on "POS." Meanwhile back at the ranch, outcomes a box of electronic do-dads from the same era as the DH-220 (DBX dynamic range expanders and other assorted goodies) and the switching in and out of a home brew SET amp all in the name of trying to get something satisfying out of the old system. And when all of that fails, he puts on his headphones and hits the keyboard to rail against the sound of stereo.

 

[Robh3606]

And, you might want to determine just what mid-fi means anyway,

Hello Tomelex

Yeah me too. Never got it myself, considering there is good sounding gear at many price levels. I have heard some expensive systems that meet Davey's definition. So it's more of a performance than price issue to me. That said it's still not clear to me how you would draw the line. Seems like a meaningless label to me.

I am sitting hear listening to my small upstairs system. Emotiva Preamp, power amps and CD player through my Revels. Love the system just fun all around to listen too. So I understand what you mean as far as your system making you happy.

Rob

 

[mep]

I bet John Curl has a good definition of what constitutes mid-fi. He talks about it in the paper that Myles posted the link to.

 

[Robh3606]

Hello Mep

Not sure how old you are but from my perspective a transistor radio at the beach would be low, my TV would be mid and my stereo would be Hi.

Rob

 

[MylesBAstor]

Hello Tomelex

Yeah me too. Never got it myself, considering there is good sounding gear at many price levels. I have heard some expensive systems that meet Davey's definition. So it's more of a performance than price issue to me. That said it's still not clear to me how you would draw the line. Seems like a meaningless label to me.

I am sitting hear listening to my small upstairs system. Emotiva Preamp, power amps and CD player through my Revels. Love the system just fun all around to listen too. So I understand what you mean as far as your system making you happy.

Rob

That wins an award for the most twisted, convulated logic that I've seen lately. No that's bringing a high-end product down to mid-Fi. That hardly defines a component as mid Fi. But you're never going to do the reverse eg. Bring that mid-Fi component up to SOTA. No matter how much you want to argue.

And TV as mid-Fi? That's a first.

 

[Johnny Vinyl]

And TV as mid-Fi? That's a first.

Hopefully a last as well. I don't get it.

 

[DaveyF]

Of course, since there is no definition its a mute point as you said to bring it up. A $500K system that is two channel stereo and has only a left and right amp feeding a three way speaker system is not state of the art since bi and tri amplification was known about 50 years ago so its all a judgement call. SOTA is really what folks agree for it to be,(or scream and insult the loudest) not what actually IS the electrical truth.

What is the electrical truth?...IF that varies from the sound one hears at a "live" unamplified event, then the electrical truth isn't that much of a truth, IMHO. Again, Tom...YMMV.

 

[microstrip]

What is the electrical truth?...IF that varies from the sound one hears at a "live" unamplified event, then the electrical truth isn't that much of a truth, IMHO. Again, Tom...YMMV.

Vout(t) = Vin(t) x K checked with a null test , K should be a constant. If you believe that K can be a very complex function of V(in) that results in systematic better sound reproduction you are guilty of heresy.

 

[DaveyF]

Davey, see Micro response. Micro, that's close enough for now, in other words, what comes out is exactly what came in. That's electrical truth, and as you say, if it is no longer that, it is now some coloration to make it sound better to someone. And that now becomes preference. Its really (basically) that simple, is it not?

Preference is when your setup sounds to you more like the real thing(ahem, actually more like you want it to sound), whether that was by an excellent recording or the ability of your ear/brain to suspend disbelief at that moment. Electrical is pure measurments and nothing to do with preference at all. Nothing. Nada, Zip.

So, Micro and Tom...you are telling me that so long as it measures perfectly BUT sounds like crap; well that's good enough for you.

 

[treitz3]

Gentlemen, we have gotten a bit personal in nature with some of the recent posts. Remember to attack the post, not the poster. Also, please be cordial in your responses. Engage or respond to someone on the WBF that you disagree with like that person was your College Professor, not like the 12 year old neighborhood bully. We are better than that.

We are also grossly off topic. Please do not post anything that does not have to do with the original post.

Tom

 

[MylesBAstor]

This lifetime of this thread has exceeded the length of expectation bias by about 10^6.

 

[microstrip]

Davey, see Micro response. Micro, that's close enough for now, in other words, what comes out is exactly what came in. That's electrical truth, and as you say, if it is no longer that, it is now some coloration to make it sound better to someone. And that now becomes preference. Its really (basically) that simple, is it not?

Preference is when your setup sounds to you more like the real thing(ahem, actually more like you want it to sound), whether that was by an excellent recording or the ability of your ear/brain to suspend disbelief at that moment. Electrical is pure measurments and nothing to do with preference at all. Nothing. Nada, Zip.

No, it is not basically simple, unless you want to stop at a very basic level. As no one has ever built a perfect amplifier you do not know what perfection sounds like. So electrical comparisons are interesting but do not tell you any truth about sound quality, except for the easy stereotypes some people love to refer.

And you definition of preference is unacceptable by sound reproduction standards. You are still at the individual punctual preference phase, something that was overpast long ago.

 

[microstrip]

So, Micro and Tom...you are telling me that so long as it measures perfectly BUT sounds like crap; well that's good enough for you.

No DaveyF, I only told you the definition of gain. And yes, I am guilty of heresy ...

 

[microstrip]

Micro, I never said perfect. However, an amplifier playing music, that nulls that music on a speaker load to a level of 90 db, will be perfect as far as our ears are concerned as long as it does not play above 90db and that's the way it is. Are not modern amps able to do this?

Sorry it is not acoustically perfect. As you say may modern amplifiers achieve such result and sound different.

I am sorry..I have no clue what this means: And you definition of preference is unacceptable by sound reproduction standards. You are still at the individual punctual preference phase, something that was overpast long ago

Individual - of a single person
Punctual - a single time , verbal aspect that expresses momentary action or action considered as having no temporal duration, not in a systematic and long action.

 

[mep]

I think I made most of the points I wanted to make on page 1 of this thread. Now were stuck in the never-ending loop of people who want to claim they listen to specifications and not music.