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I moved it to the garage system to see how it would do there driving the Acoustat 1+1s. The cabling was a bit different in that I used single ended connectors with the SP9 found there.
The results were not as good. Sound is decidedly grainier. Perhaps it is part impedance mis-match to the speaker as the Acoustat has lower impedance over most of the range than the Sound Labs, pre to power mis-match (ARC recommends minimum 50k input impedance where Crown is 10k) and/or the lack of a balanced connection. Not terrible, but clearly not as open as the Stasis that lives there. I still have one pair of New Advents that I formerly used there. That is perhaps a better match since they are a bit more opaque from the outset. The amp will, however, drive them pretty darn loudly!
The amp clearly clips (and not gracefully) before the clipping LED lights and is darned sensitive even with the lower setting. I found the best arrangement was to run the attenuators on the amp about 12:00 to allow the preamp's gain to be in the 11:00-2:00 range.
Summary of this exercise? This is no giant killer. It's decent for the money but its not going to replace what I've been using in the music systems. I'll probably keep it for a while and then move it on the 'bay.
Follow Ups:
your findings are exactly what I expected you would find just by looking at the amps technical data.
The grain you heard is the sound of 0.5% transistor distortion.
It's not nice.
with low impedance loads. That is clearly not the case with this unit. As for the grain, it was not always present. It varied depending upon the speaker driven and the level. With the Acoustats (worst case), it sounded ok at lower levels, but got exceptionally grainy well below clipping.
The distortion I heard was clearly many multiples of 0.5%. Consider that my VTL tube amps are rated at 2% and never sound grainy or strained below clipping.
... like LabGruppen, Crest or MC2, not a prosumer pastiche thereof.
If you google your amp, as I did because it does not appear on the manufacturers web site (its a stripped down special they made for Guitar Center and Musician's Friend) you'll find that even their rep recommends that particular amp to be only used for subs as it is 'a bit dirty'.
Personally I've been using MC2s for quite some time now, they start at £1000 ($1600).
Over the years and across a number of fora I've heard of people preferring them to Chord, Boulder or FM Acoustics. to name just a few.
Not sure if you would call an amp that costs around £2000 and beats those a 'giant killer'.
...not a prosumer pastiche thereof.
That's pretty funny. Perhaps there's a Crown fan here who might take exception to your description of that companies products.
you'll find that even their rep recommends that particular amp to be only used for subs
I'd love to see your reference. Would you kindly provide a link?
I have no issues with Crown amps per se, just these particular bottom-of-the-range models.
Go to post 8 in the link below. Not the original but somebody quoted it verbatim.
Nor does it...
"...or go down to 2 ohms stereo "
I discovered that would be 4 ohms stereo.
Note that the distortion figures are identical to "less dirty models" like the XTI series of switchers
...all I'm saying is that in the end a $300 amp will sound and behave like a $300 amp, regardless if it is aimed at semi-pros or consumers.
Some people say that all amps sound the same but I'm not one of them.
Where pro amps shine is the upper end of the market since they don't feature the almost grotesquely inflated prices of domestic ones.
Once you get into the thousands of dollars per unit level it is quite possible to find pro amps which easily hold their own compared to domestic amps costing tens of thousands.
Then you have to decide for yourself if getting rid of the cooling fans is worth that much extra cash to you. Personally I've made my decision and if the fans annoy me I just turn up the music a notch or two! ;-)
Once you get into the thousands of dollars per unit level it is quite possible to find pro amps which easily hold their own compared to domestic amps costing tens of thousands.
That's always the claim, isn't it? Somehow the *pro* designers have discovered something that others haven't. LOL! Maybe that makes those who own them feel better about the compromises. Requiring fans to me is an indication of poor design. I guess if your primary listening is to Black Sabbath and dub at high levels, then I suspect you'll never hear the difference!
If, however, your musical taste runs to wide dynamic range acoustical music, then fan noise at any level is intolerable. I'll pass on any design that requires such crutches.
Nelson Pass' designs are robust enough to obviate the need for any such distractions. :)
You either need fan or heat sinks.
The rest is surprisingly similar. There are quite a few striking similarities between Nelson's higher powered designs and those of Terry Clarke and Ian McCarthy.
As for my musical proclivities: Those are mostly acoustic blues but otherwise cover everything from classical to aforementioned dub except Jazz and Heavy Metal.
You either need fan or heat sinks.
One maintains low level resolution while the other fails. In the pro world, who cares about low level resolution anyway?
Fans are a poor crutch for sound design.
nt
Dman
Analog Junkie
is most certainly "non-musical". :)
...define as clipping.
The way the maker of my amps and phono pre define it as the point when THD+N rises above -70dB (0.03%) and -80dB (0.01%) respectively.
By their measure that amp of yours is always 'clipping'.
By their measure that amp of yours is always 'clipping'.
Or, as I indicated overloaded past a certain output threshold while driving the low impedance Acoustats. Not, however, when driving the New Advents.
The results are load specific. The Crown by Harman amp (as touted on the box and manual) has difficulty driving low impedance loads.
...if you buy cheap amps: They get unstuck when faced with a difficult load.
Doesn't really matter if its a domestic or pro amp.
The XLS class-D amps with built-in crossover are the latest rage in the forums for sound quality and affordability. One can buy a B-stock XLS1000 for like $270 on ebay, which can be bridged to 1100 watts, or use 2 of them with the built-in crossover to bi-amp speakers without the need for electronic outboard crossovers.
Edits: 10/15/14
Remember that cheap ART dac that was "the latest rage" here a decade or so ago. There were a shitload of posts about mods to it that were gonna make it a giant killer. Gotta wonder if anybody's using one now.
Haven't heard the amp in question, but looking for giant killers for home hifi use amongst pro amps is a waste of time IME. Jeez, the amp is designed to be a PA amp. From your link.....
"....Crown's XLS Series amplifiers define the standard for portable PA systems...."
Curious, have you heard that Crown in your home system?
A man walks into the Nobel Prize committee session:
Man: "I would like to get 1/2 of the Nobel Prize!"
Committee: "What's your accomplishment?"
Man: "I discovered how to make butter from shit!"
Committee: "Wow.. that's truly revolutionary! Why only 1/2 of the prize then?"
Man: "Well... you see... I can definitely spread it over the piece of bread - but still couldn't get rid of the smell".
I only require a few watts. If I had traditional speakers, I could be encouraged to try a couple (or four! in quad-biamped setup) and still expend less $ than I did on my last audiophile power cord :)
They are efficient and lightweight and make perfect sense for pro use.
Unfortunately, they don't sound like music.
That must've been some malicious intent on your part! Did the garage survive the excercise?
Just kidding, of course - including the "1000W" part (although that joke is not mine).
Good old EIA rating. :)
I still have 2 Yamaha P-2200 amplifiers, aimed at the pro market back in the '70's. Great sounding amps, compared to the typical pro amps these days. I haven't heard today's Yamaha pro amps, so I don't know if they still sound decent, but the old guys are great.
I followed your link and read the content. It reinforced the notion that I have about pro amps. They have a different set of priorities where sound quality is not at the top. One of the touted features of the Yammie is:
"P2200's design allowed access to the inside of the amplifier via the front panel. This design made maintenance and exchange of components parts possible without taking the amplifier out of the rack in case of failures."
That's not particularly relevant to consumer based products. Nor typically is having compact 2U front panels, ability to drive 2 ohm bass bins or be rugged enough to be thrown around by roadies and put on the semi for the next gig.
Doesn't the place you bought the amp from have a return policy? If the amp is not meeting your needs I would just return it. You haven't had it that long. Nice job on the reviews BTW.......
I received an email from the vendor asking for me to review the amp. It also included their generous 45 day return policy that is pretty liberal:"Changed your mind? Not quite what you expected? We understand."
Since I always keep the original packaging, etc. (still have the box for my '81 Threshold amp) I think I may just send it back! Thanks for the suggestion.
edit: got an RMA and shipped it back today.
Edits: 10/16/14
That's a thought, but I would feel guilty invoking that cost to the distributor since I no reason to believe the unit is faulty. No, I think I can recoup most of my investment via resale and not worry about the "rental" cost to satisfy my curiosity.
I could depend on you for detail and a fair shake on this. Am I happy or do I feel vindicated by this post? No, it's like Joe Friday used to say, just the facts. That's why I am in the E-Stat fan club. (brown nose section now complete) There is no doubt the product is at minimum a decent value and probably more. I just posted on a Behringer I'm using for a job that is $199 and it is ridiculous all you get for that $$
ET
I could depend on you for detail and a fair shake on this.
Thanks! I'd like to believe that my assessment of various gear is not driven by cost or cosmetics alone. I remember some years ago hearing two completely unknown amps to me at Sea Cliff - the positively gorgeous Edge NL10 vs. the comparatively homely VTL Wotans. Guess which one I thought sounded better? Hint: look what amp is used upstairs. :)
As for "giant killers" I do believe they exist and own an example myself - the now discontinued Logitech Squeezebox Touch player. I remain amazed at how they function alone and especially when supplemented by an outboard DAC. I have two in service used in each of those modes (and a third NIB backup). While they really need a good server and network infrastructure to work their best, I already had such in place. Better certainly exists, but for considerably more of an investment.
but would be nice to know if the difference is caused by the load from the Acuostats or the mismatch between the pre and the amp.....
dee
;-D
True terror is to wake up one morning and discover that your high school class is running the country.
quote by Kurt Vonnegut
is the primary issue is with the speakers. While they have a more linear load than the U-1s, it is consistently lower - especially at the bottom. It stays below 4 ohms until about 200 hz before rising.
Most of my listening in the garage is not at high levels, but I cranked it a bit last night. Long before clipping, the amp's sound gets very unhappy. By contrast, the Stasis doesn't change character at all until clipping. I've had that amp for over thirty years driving Acoustats (initially 2+2s) and it has never failed. I'm putting it back in service today. :)
Excuse my laziness (looking in Inmate Systems, for example), but which Stasis Amp are you using?
I've got a few variations on the Stasis theme in my "used" amp short list...
Dman
Analog Junkie
About five years ago, I proactively replaced the computer grade Mallory PS caps and added bypasses. Other than that, it is bone stock since 1981.
I was considering a pair of Stasis 1s, BUT given the usual things (age and all that is entailed for repairs/upkeep, not to mention the rarity of those beasts), I was thinking more like Nackamichi PA-5 or 7s. The pricing is still a little bit "out there" (thank you, ePay).
So, I'm thinking (and still haven't decided on) a run of many different amps of varying classes (A, A/B, D, etc.). Ironically, I kind of gave up on tubes after I sold off my ARC D-76a. Loved the amp, just didn't love the fact that almost monthly, something went amiss, even after upgrading/replacing a bunch of things. In short, I'm just tired of even routine maintenance!
I'll pony up shortly and post my "short list" for everyone's revue/critiquing/criticism/flaming/etc.)...
Cheers, and thank!
Dman
Analog Junkie
"I was thinking more like Nackamichi PA-5..."
I have one that's about 30 years old (I bought it new) and have never had the top off. Most of the years it has been on 24/7 but the last few I've been turning it off when not in use to try and squeak a few more years out of the filter caps. Frankly I have no idea if the duty cycle has much effect but it makes me feel better. However it does need to be on a good 20 minutes on to sound OK and an hour on to sound great. Just one of those trade-offs...
On a dollar/hour (or year) basis it is the cheapest amplifier I've ever owned and I think the best sounding. Although it's not as efficient as my heat pump most of the time we heat here and the BPA electricity is relatively cheap so a warm amplifier isn't a problem, if you are in a hot climate it might not be the best choice.
Regards,
Rick
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