Sherwood Newcastle A-965/Boston Acoustics A7200 amps

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DS-21

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Has anyone noticed how cheaply these things go for?

I recently saw one (the Sherwood, but from research the Boston one appears to be identical) on clearance at a local dealer, while returning an amp that was ideal in configuration but ultimately unsuitable to my intended application*, and after a quick search on my iPhone pulled up Dr. David Rich's review of the circuit design that revealed it to be a bit of a hidden gem. I did a noise test on it.**  It performed better on my noise test than any separate amp not branded "Bryston," "McIntosh," or "Anthem Statement," and was no worse than those much more expensive amps. (All of them were, effectively, silent.)***

While I'm not going to talk about its "sound" (it's just an amp, after all), after I brought it home I connected it downstream of my Anthem MRX 300. It gives me everything I wanted in a mains amp, except light weight and compactness. :) It has a 12V trigger, so it turns on when the MRX tells it to. It has no turn-on thump, and indeed makes no spurious noise at all except for the expected and brief relays-clicking sound after being roused or returned to standby. (No transformer hum, for instance, even with my ear on the case.) Oh, and it certainly has way more grunt than I'll need for my intended application (six channels will be dedicated to an active crossover for my Tannoy 12 DMT II-based mains, and the seventh is a bonus that I'll use to power a high-mounted sub in a multisub array calibrated per Geddes). But considering the speakers' efficiency, low noise is way more important than high power. And this amp just doesn't add any noise to the sound. It also has one nice ergonomic touch: RCA jack insulation and binding posts are helpfully color-coded per CEA-863B.

Honestly, the only criticisms I have of it are that it's gigantic, and that the binding posts are a little short. The sawtooth-blade bananas I was using stuck out a bit, so I switched to spades lest the kittens get back there and electrocute themselves on banana stems... (Also, for those who use balanced connections, it doesn't have 'em.)

Also, I guess I overpaid compared to the going rates for used pieces, and some of the closeouts I subsequently discovered in looking for reviews were offered on Amazon last year (under $700 shipped for an 80 pound amp!), but there's something to be said about being able to simply drop it back off if it doesn't fit my needs for some reason.

But if you're looking for a multichannel amp, and you're willing to eschew a modern compact/lightweight/efficient Class D unit for an 80lb Class AB gorilla...I don't know of anything else in the middle three-figures it seems to go for today that has as completely black a background as this amp. While the casework isn't as pretty, in performance it's in the Bryston/McIntosh/Anthem Statement class.

*Rotel 6-channel, I think 60W/ch ICEpower unit. It failed "self-noise" test, described below.

**I take a very efficient horn tweeter - Eminence APT on their square horn, not exactly a high-fidelity device but at over 100dB/W/m sensitivity very good at revealing low-level hiss - connect it to each input with no source connected, and hold it a few inches from my ear. If an amp passes that test, I repeat with a source connected to each input.

***Honesty compels me to admit that another amp that passes my noise test with flying colors is the old Panasonic XR55 AVR, which was widely available for under $300 six-seven years ago. If it had a direct input with more than 5 mains channels, I wouldn't have been in the amp market. I'd just use my currently dormant XR55.

Letitroll98

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Re: Sherwood Newcastle A-965/Boston Acoustics A7200 amps
« Reply #1 on: 15 Mar 2012, 02:28 pm »
I don't see the price you paid for the unit or where you were able to purchase it.  There are no current listings on eBay for either amp and only one completed listing for each, both about $550 w/shipping.  If either could be sourced for under these amounts it would truly be a cheap and cheerful multichannel solution.

We would highly disagree on whether the sound of an amp made any difference, so no need to get into that useless argument.

DS-21

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Re: Sherwood Newcastle A-965/Boston Acoustics A7200 amps
« Reply #2 on: 15 Mar 2012, 07:22 pm »
I don't see the price you paid for the unit or where you were able to purchase it.

The price I personally paid is only the business of me and the relevant local retailer. Note that I didn't list the price of the Rotel amp I returned for failing my noise test, either. The name of the local dealer is also irrelevant, because it was their only one. Besides, I'm not an audio reseller, and I have no reason to drive traffic to one.

I was subsequently able to find that a seller on Amazon blew them out for last year ($650-700; there's a post on AVS from last October that states,
"The Sherwood Newcastle A965 (http://www.amazon.com/Sherwood-Newcastle-965-Channel-Amplifier/dp/B004Z1S8TK) has been on Amazon for $699 for quite a while. Unfortunately its not available at the moment - it was in stock just a week or so ago."
I wish I had known that beforehand, because the dealer seemed very motivated to get that big box out from under his clearance table. Oh well.

There's also one on Agon for a mere $425 and shipping, though it's a bit beat up cosmetically.

So, from the public data one can reasonably expect to find them (when they pop up as used or NOS) to be in the middle three figures. For an amp with a noise floor this low (especially important for this of us who prefer high-efficiency speakers, far more so than ultimate output I'd argue), UL electrical safety certification (unlike many internet darlings such as Emotiva), and this much grunt, that's a steal. Even though it is also huge and heavy.

As for amp "sound," I prefer to judge amps on real audible things, like whether their circuitry prevents turn-on thump through the speakers, noise floor, transformer hum, grounding efficacy, etc... some of those things do contribute to an amp's "sound," mind. Especially noise floor. For instance, an amp that hisses or hums through (as many so-called "high end" pieces do) will obscure low-level detail and in my experience contribute to listener fatigue.

Letitroll98

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Re: Sherwood Newcastle A-965/Boston Acoustics A7200 amps
« Reply #3 on: 16 Mar 2012, 04:46 am »
Well it's not at all unusual for someone to mention the price paid for something they start a thread about, especially on C&C where we have certain price ceilings listed in the posting guidelines, or to mention where they bought it.  However "they are available for" and "local dealer" is certainly acceptable if that is your preference.  With that criteria they are bouncing a bit over single component guidelines, but could still be shoehorned into a musically acceptable system under $1000.  From the scarcity of examples I assume discontinued?  If so the price should be dropping even more, a boon to either multi-channel setups or active crossover implementations like yours.

Of course we'll never agree on amp sound, but I completely respect your position and your right to have your opinion.  It's interesting that someone so esoteric as to have Tannoy 12 DMT II drivers mounted in a custom low diffraction cabinet (I'm jealously admiring here) is in the objective camp on amp sound.   Is this a new project or finishing the old one?  In any case I'm sure they sound magnificent.  I've always lusted after some big box Tannoys.

Back to the amp, we over on the dark side sometimes find lower priced mass produced transistor amps a bit steely and flat.  Yet I have a cheap Pioneer receiver with a chip amp (touted by the Dr. Geddes you referenced) that sounds gorgeously transparent and sweet.  Other than the noise level, do you notice any differences with this amp?  Perhaps something resultant from the lower noise floor or maybe more dynamics, a difference in frequency response, etc.?  Thanks in advance for any insights.     

django11

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Re: Sherwood Newcastle A-965/Boston Acoustics A7200 amps
« Reply #4 on: 16 Mar 2012, 01:01 pm »
Axiom Audio carries Sherwood.  They used to have more models, now only one higher end.  I remember wondering about the low prices...   http://www.axiomaudio.com/sherwood_main.html

DS-21

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Re: Sherwood Newcastle A-965/Boston Acoustics A7200 amps
« Reply #5 on: 17 Mar 2012, 12:37 am »
From the scarcity of examples I assume discontinued?  If so the price should be dropping even more, a boon to either multi-channel setups or active crossover implementations like yours.

Yes. A few years ago I assume. But honestly, given the mass of the thing and the build quality, as well as the low noise, I can't see anyone ever asking less than $500 for one in good condition. Paying more on the used market for something with higher gain, much higher noise levels, and no electrical safety certification from an OSHA-approved NRTL, such as an Emotiva, strikes me as foolish.

It's interesting that someone so esoteric as to have Tannoy 12 DMT II drivers mounted in a custom low diffraction cabinet (I'm jealously admiring here) is in the objective camp on amp sound.

Once one has the speakers sorted, then one realizes what little difference the trifles really make. :)

But they're speakers anyone with an empirical bent will love. They're designed thoroughly along the accuracy model, between their reasonably well-controlled midrange directivity and on-axis smoothness of response. And diffraction is something that has been demonstrated as clearly audible, so minimizing it is a very "objective" thing to do.

They're also very efficient, so they have serious dynamic jump-factor as well as amazing micro-dynamic shading. Also, in practice in a domestic living room thermal compression will never be an issue But what IS an issue is that they never really "sound loud." That is to say, you don't get the distortion that tells you to turn it down. Often, the only way to tell how loudly they're actually playing is to try to speak aloud, or clap your hands. People used to 7" 2-ways are always stunned by that factor of actual high-fidelity loudspeakers. :)

Is this a new project or finishing the old one?

A little of both. I had Nathan Funk make the cabinets for me while in 2006 or 2007. (There's a picture of one of them, sans driver, in that link.) Here's a bad shot of the front three in my old condo:



But going active is new.  In fact, the box I'm going to use (miniDSP 8x8 in-a-box) isn't even available in that form. (The raw board is currently available, but I don't enjoy DIY electronics assembly.)

I'm really only going active it because I want to soffit-mount them, and the crossovers are HEAVY. They're all air-core inductors and poly caps. One of the inductors, for instance, is almost 4" in diameter and maybe an inch tall! (It's also remotely located from the main PCB, presumably because it would break the PCB.) So replacing the xover board with a 4-pole Speakon jack will save a fair bit of mass. The cabinets were already designed to be very light for their size and stiffness, through curved walls, CLD panels, and such.)

Also, the multisubs are new. In that picture, the main sub was a closed box with an Exodus Audio Maelstrom-X. The other subs (multisub array calibrated per Geddes) are not shown. The five subs in my current  reference system all use Aurasound underhung neo-radial-motor woofers (18", 15", 2x12", 10") Not exactly, alas, "cheap and cheerful" stuff. :)

Yet I have a cheap Pioneer receiver with a chip amp (touted by the Dr. Geddes you referenced) that sounds gorgeously transparent and sweet.

For the record, Dr. Geddes' only claim about that AVR is only that its chip-amp has very low zero-crossing distortion. He's since replaced it with another model, and has written that "IMO, a good class AB amp is inaudible ***"

The main reason I didn't seriously pursue an AVR with 6.1 or 7.1 channel analog inputs and chipamps, like your Pioneer, is aesthetic, not sonic. (Though since I already have it, I would've used my Panny XR55 if it had a 7.1 rather than 5.1 analog input) 

For people who want to go active at the lowest possible cost, though, something like a used Pioneer 912 (the "Geddes receiver") downstream of a miniDSP is probably the optimal sonics-per-dollar solution. While they don't typically have 12V trigger turn-ons, one could program a Harmony remote to turn on both one's preamp (or main AVR) and the "amp" AVR at the same time. But IMO a preamp (or AVR) feeding a second AVR looks strange. So I did not choose that route.

Other than the noise level, do you notice any differences with this amp?  Perhaps something resultant from the lower noise floor or maybe more dynamics, a difference in frequency response, etc.?  Thanks in advance for any insights.   

Funny thing is, when I first hooked it up in my system*, my brain did in fact tell me there were differences. I thought I heard slightly snappier and crisper treble reproduction on a few tracks, and slightly image better definition at the edges of the soundstage, compared to the internal amps in my Anthem MRX 300 receiver. It was head-scratching enough to make me want to explore further.

Turns out it was all in my head, as these "differences" generally are.

With voltage matched (multimeter on the output terminals), it sounds exactly the same as the internal amps of my Anthem MRX 300 receiver, which I'm currently using as a pre-pro and surround amp. Which, in turn, in two-channel mode with ARC and Dolby Volume disengaged sounded exactly like the Denon AVR-4308ci/A it replaced. (The Denon's digital audio board died, knocking out Audyssey MultEQ/DynamicEQ and only allowing connection of 2-channel analog sources.) While the Anthem just has bog standard Chinese commodity class A/B discrete amps, they are competently implemented, though at that power level I'd prefer a chipamp ("power op-amp') solution over discrete amps because chipamps have theoretically lower zero-crossing distortion and theoretically better thermal tracking. If I played the system full-throttle for a while, I would expect the Anthem to lose some power because it has much less heat-sinking area, whereas I suspect the A-965 could be run wide-open for weeks on end with no material measurable differences before and after. Even on speakers that are much trickier to drive than mine. It's a beast.

*All music comes over HDMI, from either an Oppo BDP-83 or an AppleTV2 fed Apple Lossless files from a remote Mac.
HDMI wires are the one that came with the Oppo player, one that came with my fiancee's Sony blu-ray player (not in use), and Monoprice.
DSD->LPCM conversion for multichannel SACD playback is handled by the BPD-83.
An Anthem MRX-300 AVR does source switching, surround processing (I almost always listen to music encoded as 2-channel over Dolby PL2-Music, mostly because I vastly prefer the richness and palpability of soundstage a 3-channel front set can give, compared to a 2-channel front stage), room correction, D/A conversion, and surround side channel amplification (5.multisubs system).
A miniDSP 2x4 in-a-box provides EQ for the multisub system.
Interconnects, for those who think they have "sound," are Audioquest bulk mini-coax with tinned (allegedly silver, but who cares) solid 24AWG center pin, cut to length, terminated with Audioquest's neat ITC-24 tool-less, solder less RCA plugs. (No more expensive than quality-but-not-boutique ends like Canare or Neutrik, but quicker to install.)
Speaker wires, depending on length of the run, are 16AWG twisted-pair mil-spec silver-plated copper in Teflon, two runs of same, terminated in those compression spades from Home Depot that run $5/2pk, or 95-cent nickel-plated bananas from PE. (I like those speaker wires, not because they "sound" any different from anything else, but because the Teflon insulation is both very durable - i.e. cat claw proof - and very thin. So they're thinner than most 16AWG wires.)