Archimago strikes again

[blackmetalboon]

I do find myself having to defend Vitus here, the amplifiers history is a little vague, it could be anywhere between 5 & 9 years old (not long for a piece of hifi) but for all we know it has been pushed hard for every day of its life. I feel these things must be taken into account as it's not a "brand new" off the factory floor unit.

But, and it's a big but, this article has been posted on various forums and received the usual objectivist/subjectivist debate and all of them so far have not addressed the elephant in the room.

Why should a $13,000 amplifier have audible transformer hum from 10' away? This would drive me insane as I do enjoy occasional late night, low level listening sessions.

 

[Don Hills]

Comment on the capacitor pics posted by Amir:
1. The PSU caps with the "bulged" black ends are fine. The black plastic decorative disc on the cap end warps over time due to the tension of the shrink wrap.
2. The two small caps with "goop" at the bottom? Thats likely one of the standard "goops" used to secure tall / heavy components and protect them from vibration.

 

[Jinjuku]

I do find myself having to defend Vitus here, the amplifiers history is a little vague, it could be anywhere between 5 & 9 years old (not long for a piece of hifi) but for all we know it has been pushed hard for every day of its life. I feel these things must be taken into account as it's not a "brand new" off the factory floor unit.

But, and it's a big but, this article has been posted on various forums and received the usual objectivist/subjectivist debate and all of them so far have not addressed the elephant in the room.

Why should a $13,000 amplifier have audible transformer hum from 10' away? This would drive me insane as I do enjoy occasional late night, low level listening sessions.

Vitus is always free to post their own measurements.

 

[tomelex]

Also, given how good Class D is these days, what's the point of owning a big, heavy, hot Class A/AB amp these days at all?

I do not know a lot about class D from actual hands on, however, between class A and class A/B, generally, the class A amp will do better on an actual load. Stereophile sometimes has that information. Do better as in present a less distorted current waveform to the real world speaker load.

 

[watchnerd]

I do not know a lot about class D from actual hands on, however, between class A and class A/B, generally, the class A amp will do better on an actual load. Stereophile sometimes has that information. Do better as in present a less distorted current waveform to the real world speaker load.

Stereophile fairly recently reviewed the Bel Canto Ref600M as a Class A Recommended Component. It's a Class D amp using Hypex chips:

http://www.stereophile.com/content/bel-canto-eone-ref600m-power-amplifier#4OMmEIUYDS06fOp2.97


In the measurement section, JA concludes with:

"Bel Canto Design's e.One REF600M amplifier packs a huge amount of power into a small package, and offers impressively low levels of distortion and noise.—John Atkinson"

 

[Sal1950]

Interesting stuff as always,
http://archimago.blogspot.co.uk/2016/12/measurements-what-does-us500watt-stereo.html
Keith

A honest, factual, and to the point write-up from Archimago as always. Very little could be added to or criticized there.

I think sal has a emotiva dac, maybe he can open it up so we can take a look inside?

I could do that if you'd like. Quite a few good stock photos of the DC-1 already exist.

 

[Sal1950]

There is one important aspect that is missing in his write-up: reliability. I seriously worry about this factor because amplifiers are nasty, heavy beasts with tons of high-current circuits. When I buy an amp of this class, I don't want to even think about sending it in for repair. I like to buy from a local dealer and have them deal with picking up and dealing with the weight. And at any rate, the quality of components needs to be looked at.

I have no defense for Vitus amplifier other than unanswered question of its construction quality. I just searched for pictures of its guts but only found low resolution images. What is there is exceptionally clean and high-end. Emotiva on the other hand is quite utilitarian. I don't know what random brand caps, reject parts, etc. they may have used.

Not that I really disagree with you Amir but we have been down this road in discussions before. I've witnessed the large numbers of high end amp and components in general that had issues while under review by the glossies. DOA, up in smoke, didn't meet spec, any manner of problems that can become a component has occurred with the most pricey of gear on the market. Not to mention the problems our own Mr Savage has experienced with the very expensive amps he owns. (can't remember the brand) Parts overheating and literally falling off the the PCB. On another occasion something else went pop and dumped DC into his speakers blowing the drivers.
I really see very little correlation between price and reliability in some corners of the market. But yes, if you stick with known, well respected companies like Krell, Pass, Bryston, etc and you have a good chance of getting a solid product. But IMHO to dump $10k+ on pieces from these fly-by-night, never heard of their name, manufacturers is playing Russian roulette with your finances. High end audio is full of "designers" with $ signs in their eyes looking to cash in on the audiophoolery of today's market. Let the buyer beware!

 

[Cosmik]

Managing to get a few components mounted on a PCBs isn't rocket science. I am neither impressed nor appalled by the photos (and yes, the "goop" is just to stop large components vibrating).

I am always a little wary of the 'Chinese' serif font that appears on some of these PCBs, just like those $2 amplifier modules from eBay which all feature those same cheap, brightly coloured through-hole caps and resistors that you used to buy thirty years ago.

On the 'boutique' amps we see 'home made' techniques for connecting connectors to the board, and always heatshrink, heatshrink, heatshrink - the universal solution to amateur wiring ugliness.

The reason why some boutique amps blow up is because their creators think they, alone, have thought of something that no amplifier designer has done before, and it usually involves high bias currents and 'innovative' ways to regulate them. I, too, would be wary of connecting one of these drastically dodgy and under-tested things to any of my speakers, and I wouldn't leave them turned on unattended. I would be much happier with something cheaper from a large corporation.

 

[Thomas savage]

Thanks sal, just thought possibly looking inside yours might show what the insides look like when emotiva are not expecting photographs..

I'm sure it's fine though

So, nothing really wrong with the insides of the emotiva stuff. Certainly looks safer than the last lampi product i saw inside ( but I'm no electrical engineer) .

 

[Frank Dernie]

I would vote for buying locally from an established manufacturer. Unreliable equipment isn't hifi at all, it is a bane.
As an impecunious student I bought a well reviewed amp which misbehaved from new but by the time I returned it the manufacturer had folded. I took it to a local repair shop which also went bust so I had no amp and no money. It was before any sensible consumer legislation so I ended up with no money, no amp so no functioning hifi for months.
I am more circumspect now, and only bought a Devialet amp after much soul searching because I knew I could get recompense nowadays.

 

[Sal1950]

Thanks sal, just thought possibly looking inside yours might show what the insides look like when emotiva are not expecting photographs..

Though Emo knew the unit would be looked at, the photos were taken by Audioholic's for the unit under review.
http://www.audioholics.com/gadget-reviews/emotiva-stealth-dc-1

I really see very little correlation between price and reliability in some corners of the market. But yes, if you stick with known, well respected companies like Krell, Pass, Bryston, etc and you have a good chance of getting a solid product.

Don't know why I failed to mention my own experience with "High End" products. Here's just one.
For MANY years I spend much more of my income on audio toys than I ever really should have. In 1990 I really (for me) made a stretch to get some VTL tube amps to drive my Klipsch LaScala's. VTL was fairly new in the US at the time but the amps were getting these "greatest since sliced bread" reviews from everyone, Stereophile, TAS, just everybody, and I got the "had to have them" fever. Started with a Stereo 75 but it had a loud hum with my high efficiency LaScala's that I couldn't live with. Dealer said a set of Compact 80 Monoblocks would be much quieter so I stepped up for them. At $2,000 plus tax, that was right around 15% of my yearly after tax income at the time. Dealer was right, no hum from the monoblocks, but something else was amiss, one amp had about 6db or more gain than the other? I was pissed but dealer was good and just took them back and handed me a second pair immediately. They were fine, for about a two weeks, then the exact same inbalance issue? I was an old tube guy and even had my own tube tester that I'd owned since the 60s. Tested them, measured bias, all that, nothing wrong I could find? I was determined to get passed this and took them to a friend of mine that was a super tube tech and ran a antique TV and Radio museum/repair in Chicago. He found a bad solder joint on the pc board in the feedback circuit on one amp. He fixed that up and also said he touched up some other solder spots on both boards that he didn't like. I found out years later that VTL was having a lot of problems with board soldering at the time.
That was 25+ years ago and I hope VTL has improved QC since. I knew David Manley, he was a brilliant designer/recording engineer, and a nice person IME, but those are the facts of VTL's reliability in the early years of production.

Now on the flip side, early Nelson Pass designed Adcom amps.
I owned a Adcom GPA-535 amp for 22 years and it gave flawless service in my video system the whole time. I currently own 2 GFA-545 II's, a GFA-5400, and a GFA-535. The 5x5 II amps PC boards dated 1990 and the 5400 1995. Purchased used, I opened them up for a clean/inspect and none appear to have ever been serviced in any way, nor show any signs of capacitor bulging or leaking.
You can do a search on ebay for GFA-5x5's or 5x00's and find tons for sale, all in good working order. Finding one for sale inop or parts only is fairly rare. Like a Timex they take a licking and keep on ticking.
Point again being MSRP doesn't on it's own give you any guarantees of reliability.

 

[amirm]

2. The two small caps with "goop" at the bottom? Thats likely one of the standard "goops" used to secure tall / heavy components and protect them from vibration.

Usually a goop that is used is elastic and all the way around the component. Look at it around the caps from the DAC that Sal just post:

That's proper stuff. Now compare it to what was around the caps in the amp picture I post:

Note that it is not all around the cap so can't do a proper job of holding the cap anyway even if that is what it is.

Ultimately it is hard to know with certainty what is there. But what we do know is that the caps are China special, likely with next to no quality control. The ratings could be fake, etc.

I mean think about it. It is just impossible to build things that cheap without cutting corners.

 

[amirm]

On the dac:

Those yellow boxes are relays. Usually a relay is a sign of higher quality design as opposed to using electronic switches that may have more leakage. But the brand of those relays raises eyebrows. It is Huigang. A search shows no company and only ebay parts.

None of the major distributors (Mouser, Digikey, Arrow, etc.) carry the brand. Is it going to get noisy sooner? Stop working? Who knows.

The rest does look clean and is a step up from China special products but ultimately I can't give it a thumbs up based on what my antenna picks up.

 

[Sal1950]

That's proper stuff. Now compare it to what was around the caps in the amp picture I post:

Yes, you can see where the caustic nature of the substance is causing a deterioring of the boards surface and contacts. Not good.
Photo is of my Adcom 5400's power caps. The substance appears and feels expoxy like, hard with just a tiny bit of surface give to a fingernail push. But it could be a silicon after 20+ years of aging?In any case, no nasty looking eating of the board's substance. Normal.

The rest does look clean and is a step up from China special products but ultimately I can't give it a thumbs up based on what my antenna picks up.

Three years into 5 year warranty and no issues yet. At $400 if it should fail past the warranty I'll just get something new. That kind of money in the changing DAC market can be considered disposable.

 

[amirm]

The manufacturing date on the adcom is 1995 so that PCB is 22 years old yet it looks brand new!

 

[Sal1950]

The manufacturing date on the adcom is 1995 so that PCB is 22 years old yet it looks brand new!

Yep, all 4 of my Adcom amps look like that internally. All I did was dust them with compressed air.

 

[Thomas savage]

The manufacturing date on the adcom is 1995 so that PCB is 22 years old yet it looks brand new!

Unlike the guy who took the photos of the emotiva device you posted sal does not empty his Hoover bags into his hifi

 

[amirm]

Unlike the guy who took the photos of the emotiva device you posted sal does not empty his Hoover bags into his hifi

How about when Sal is drunk? Does he not mistake them for the urinal???

 

[Thomas savage]

How about when Sal is drunk? Does he not mistake them for the urinal???

I think I'm the only one here that does that... Explains a few things

in my defence when I used to have big krell amps it would just evaporate.. These class a/b things ... Not so much

Another reason I could never have class D amps

 

[RayDunzl]

that PCB is 22 years old

Long ago, like, in the sixties, I seem to remember folks thinking transistors would, due to the physics of the junctions, have a life of about 20 years. Admittedly, there were no 20 year old transistors then for reference.

What happened to that?

My RCA Victor 8 Transistor 1963 pocket radio that I won for my bicycling skills at the local park still works after 53 years.