The never ending amp journey

[Irvrobinson]

I think you're right. The line from the review is "the source impedance was on the high side for a solid-state design, at 0.65 ohm."

I see. Atkinson was just discussing output impedance from the perspective of the speaker, so it's "the source". Same thing. 0.65 ohms is high for a solid state amp. An awesome output impedance would be something like 0.05 ohms.

 

[Irvrobinson]

IMO, at a bit over $3k MSRP, and I'd imagine a lot less for a good negotiator, I agree that it's a good value, if one considers the additional cost of a dedicated 20A line as well, for the power it offers. To look at it another way, it's much cheaper than a Bryston, McIntosh, or Anthem Statement amp of equivalent power. (I mention Anthem Statement in the same breath only because of these rather stunning test results. All that power in an AB amp is pointless for people who (unlike you) don't have 20A circuits to feed it, though.

That Anthem amp is impressive, though the most impressive measurement is the SNR, at -113db below 2.83v. I don't think I've ever seen a measurement that low. Stereophile seldom sees an amp with an SNR better than -90db below 2.83v, so I'm actually wondering if the test methods are comparable.

The 20amp circuit is, IMO, not as important as you'd think. Most of the reason to get a very high power home amp is for peaks, and most peaks last only fractions of a second. As anyone can attest by a turn-on surge of an amp or an electric motor, even a 15amp circuit is capable of transmitting well over 50 amps for a couple of tenths of a second without tripping a circuit breaker. Secondly, I would think that sinking more than 20w or so on a continuous basis is going to heat up your voice coils so much you'll get more thermal issues than anything else.

All of that said, when peaks come along they need to be LOUD to be realistic, and that takes lots of power. I'm still convinced the ATI sounds better than the Levinsons into the Salon2s mainly because of 4db of additional headroom on peaks. (My previous speakers, the Legacy Audio Focus, and the speakers I chose the Levinsons for, had a much lower impedance than the Salon2s, especially in the bass, where the silly things looked more like 3ohm resistors for the first three octaves than speakers. The Levinsons are amazing voltage sources so they just dumped more current, and the Legacy's have a sensitivity at least 9db higher than the Salon2s. The match must not be so good for the Salon2s.)

 

[PENG]

That Anthem amp is impressive, though the most impressive measurement is the SNR, at -113db below 2.83v. I don't think I've ever seen a measurement that low. Stereophile seldom sees an amp with an SNR better than -90db below 2.83v, so I'm actually wondering if the test methods are comparable.

I don't think -113 dB is that hard to achieve using "A" weighting. At -112.28 dB, also by HTM, the lowly Denon AVR4310 wasn't that far behind.

"The signal-to-noise ratio with 2.83 volts driving an 8-ohm load from 10 Hz to 24 kHz with “A” weighting was –112.28 dBrA. " The 4311 would likely do even better but HTM has not tested one yet.

I think Stereophile doesn't use the "A" weighting, hence the much lower numbers.

 

[Irvrobinson]

I think Stereophile doesn't use the "A" weighting, hence the much lower numbers.

Much to Atkinson's credit, he typically lists both weighted and unweighted SNRs. Even most manufacturers have specs that make those -113db measurements suspect. Most amps are rated for something like <-120db below full output. Since most amps have 27-32db of gain, that means most manufacturers think they can achieve about -80db to -90db below 2.83v. -113db implies more than -130db below full power, which is quite remarkable. (And nearly immeasurable?) I'm not sure what to think.

 

[PENG]

Actually I shouldn't try to compare the S/N of an avr with that of an amp. For avr, S/N is an overall S/N not just for the power amp.

 

[anaogrules]

looking for amp

I will say My ABI 900A is dam nice amp, 350 per side and very easy to listen to.The Emotiva gear is ok , but sound glassy . I had the UPA2 . Theta sound nice , not sure what the price is ? I was looking for great sound , at great price also . ABI amp will compete with many HI FI amps New 1,600. US used can find them for 200. 350 @ 8 ohms 590@4 ohms and more and can be bridged . Massive PS and used Malory Caps ,10 MR transistors per chan. Built like take in Cal. and still in biss . They are very warm, detailed , not harsh or hard like some others mentioned. I have compared to Rotel, PS audio , hafler , B&K NAD, Adcom , and more My beloved VSP Trans Moss 200 gold . The ABI 900A sound huge even at low volume and very well balanced at the very hard for any amp to achieve for that matter. To me its like a tube amp. Well have fun!!

Mike

 

[walter duque]

I will say My ABI 900A is dam nice amp, 350 per side and very easy to listen to.The Emotiva gear is ok , but sound glassy . I had the UPA2 . Theta sound nice , not sure what the price is ? I was looking for great sound , at great price also . ABI amp will compete with many HI FI amps New 1,600. US used can find them for 200. 350 @ 8 ohms 590@4 ohms and more and can be bridged . Massive PS and used Malory Caps ,10 MR transistors per chan. Built like take in Cal. and still in biss . They are very warm, detailed , not harsh or hard like some others mentioned. I have compared to Rotel, PS audio , hafler , B&K NAD, Adcom , and more My beloved VSP Trans Moss 200 gold . The ABI 900A sound huge even at low volume and very well balanced at the very hard for any amp to achieve for that matter. To me its like a tube amp. Well have fun!!

Mike

I guess you and I have the same interest in amps. (1) 600A and (2) 900A, you are talking about AB International, right? Bob is also OEM for a few other high end amp companies. He just came out with the new cinema series.

Now this is a first, I thought that I was the only one that ever owned VSP Labs Gold Edition. This is a scan of one of my old rigs. VSP straight wire pre-amp (2) VSP Gold Edition power amps and a couple of SAE amps. These where one of the best amps that I have ever owned. I bought all their stock when they got bought out by Video Concept.

 

[fuzz092888]

I actually just found a great deal on an ABI amp, the 800.2. I e-mailed Bob to find out how old it is with the serial number and it's from July 25, 2010, second one sold that day. Talk about keeping track of his products. Anyways, seems like a great deal and a steal for what it's going for. I just wish I had seen the 1400.2 that was for sale not too long ago that Bob said I had just missed out on.

 

[anaogrules]

Its nice to see someone had VSP! The 200 gold was something ells ! I see you have two in the pic. If I ever find another one I will grab it! I sent mine up to guy in PA to to check out, I never seen it again !! Needless to say i will never do that again!! I do have a 900a now I like it allot and Im selling a 1100a that I just picked up. Very clean amp with slam like now other. I would like to compare my to a Bryston or my friends krell lol! I really dont think there would be that big of a difference to justify the price of a Krell or even a used Bryston with the same power.Now I did read on this thread that it is a class H. I talk to the owner of the company now and he said that they are a class AB2 if you read the owners manual it does state that it is a class AB2 amp not class H. these are commercial amps but they are hi end as well! I have put my amp against lots of great reviews mid fi gear and a few hi end amps and this amp a keeper! In my last post I stated that it was warm, well i take that back! After removing the tube pre I was using i like better , It does sound like Bryston to me . Its smooth, musical , just a tad tad hard , very balanced and sound great at low volume, with I really like since I dont use tone controls! Rt now Im running strait from a cd play , just a old sony I had in the closet. that player is hard and not the most detailed and sound good. In old friend of mine up north from 20 years ago have bin chatting in FB has a Fote 2 pre amp that I might try, not sure yet. Out of all the amp that i have owned threw the years this amp never stops putting a smile on my face , the fullness of this amp is great. Please know that all ABI amp are class AB amps , hence AB International! That was just told to me from the owner as Im writing this wright now! Its bin fun!! O never give those VSP amp up!!

 

[nhdmtnd5565]

Hi anaogrules,I have a Gold edition VSP lab 200w/per channel and a straightwire preamp.Have not used them for about 15 years but still in good working condition,no issues.If you are interested,please give an offer or trade?Thanks for consideration.

 

[richkid]

Hi Walter,

I found out you are a collector of the VSP Labs equipment.

I have just recently purchased a couple of VSP Labs equipment and am floored by how they sound. The Straightwire I purchased did not have any of the manuals included. I was wondering if you have a copy of the manuals you could share.

Thanks,
Rich

I guess you and I have the same interest in amps. (1) 600A and (2) 900A, you are talking about AB International, right? Bob is also OEM for a few other high end amp companies. He just came out with the new cinema series.

Now this is a first, I thought that I was the only one that ever owned VSP Labs Gold Edition. This is a scan of one of my old rigs. VSP straight wire pre-amp (2) VSP Gold Edition power amps and a couple of SAE amps. These where one of the best amps that I have ever owned. I bought all their stock when they got bought out by Video Concept.

 

[fuzz092888]

Hi Walter,

I found out you are a collector of the VSP Labs equipment.

I have just recently purchased a couple of VSP Labs equipment and am floored by how they sound. The Straightwire I purchased did not have any of the manuals included. I was wondering if you have a copy of the manuals you could share.

Thanks,
Rich

Probably not, that's a pretty old picture.