# Don't Know about this amp - Very skeptical at rated output class 'a'



## 3fish (Jul 12, 2009)

Ultra Rare Furi HA2500 Class A amp us amplifier 2ch OLD - eBay (item 200567520179 end time Jan-27-11 12:12:51 PST)


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## [email protected] (Jun 12, 2008)

Its not a class A amp, we were talking about this over at the Phoenix Phorum. I dont think they even make class A amps that large for home use. That thing would practically melt, that was a joke, but it would be hot as hell and consume massive amounts of current no matter if it was at idle or full tilt.


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## 3fish (Jul 12, 2009)

BeatsDownLow said:


> Its not a class A amp, we were talking about this over at the Phoenix Phorum. I dont think they even make class A amps that large for home use. That thing would practically melt, that was a joke, but it would be hot as hell and consume massive amounts of current no matter if it was at idle or full tilt.


LOL,

I thought, briefly, but not long and going through the calculations for heat sink requirements for such a monster class 'a' amp.


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## Pdogg (Jan 24, 2011)

I like how it says Class "A" on it... yeah at those power ratings you'd have a heck of a nice space heater


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## DAT (Oct 8, 2006)

nice find, CLass A ? maybe it's 25w not 125w?


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## JAX (Jun 2, 2006)

nice but surely not class A maybe class "A" lol


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## Ultimateherts (Nov 13, 2006)

I remember when these came out... From an old Car Audio Mag they seemed to be very high end they had an MSRP of like $1200. Now I know price doesn't always equal quality, but it was the most expensive amp line they made.


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## Sleeves (Oct 22, 2010)

What the heck does "Optical sensing" mean? (3rd picture, input/output side)


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## rockytophigh (Apr 16, 2008)

I looked at it (at work now can't see it). Doesn't it say "Class A Series". That's clever wording.


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## Pdogg (Jan 24, 2011)

Sleeves said:


> What the heck does "Optical sensing" mean? (3rd picture, input/output side)


The LED driver must be Class A yeah that's it


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## rj671j (Jul 7, 2007)

How long ago where these made?


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## TrickyRicky (Apr 5, 2009)

I wouldnt buy from that seller. Had problems with a few months ago. And seems others have too (check out the thread "blue eyez wts"). He listed a amplifier as having sound problems, but when I inspected it, it had 2 wrong transistors, and a crappy bridge rectifier. I notified him and ebay about this poor repair and he stated "Not my amplifier, am not a tech so I dont open up amps". But the amp was clearly poorly repaired with wrong parts. No wonder it sounded like crap.

BEWARE. Some have good things to say about him but me, NO. He also took 8 days to ship my amplifier out, then another 5 days to arrive. He blamed the holidays when clearly I paid him 4 days before thanksgiving (more than enough time to ship it out before holidays). BEWARE.

By class "A", am pretty sure that's the name of the line. Have no idea what optical sensing is.


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## jkill1029 (Nov 28, 2010)

I understand if anyone is skeptical about this seller, thanks for the heads-up.

Let's talk about the amp though... So what is so bad about a class A/B design, which is what I assume this is?

Aren't all the Mcintosh A/B? And I love those amps!

-J-


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## JAX (Jun 2, 2006)

wow someone dropped $330 on it. 

nothing wrong at all with A/B except for size. some of these A/B beauties are really big and its hard to resist the new small mini amps out there.


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## [email protected] (Jun 12, 2008)

jkill1029 said:


> I understand if anyone is skeptical about this seller, thanks for the heads-up.
> 
> Let's talk about the amp though... So what is so bad about a class A/B design, which is what I assume this is?
> 
> ...


A/B is the standard and has been for a long time. There are differences in topologies, class a is more linear than class B. But class A is seriously inefficient. Class B has its ups and downs also, crossover distortion for one, also you can kind of think of it as a push pull situation. Class A/B was combining the 2 for clearer output than class b alone, but with better efficiency than pure class a. With class D coming on so strong, I wouldnt be surprised to see A/B dropping off the scales in a few years. 

Lots of good info on the web about topologies


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