Need Zu Definition Pro Subwoofer Array Amp for $1k


Hello everyone! I'd appreciate your guidance. I also sent an email to Adam at Zu to get his feedback.

I'm trying to match a stereo amp or pair of monoblocks (or dual mono amp) for my Zu Pro speakers passive woofer arrays. The front arrays are driven by a Yamamoto A-08S.

My other gear:
Canary CA-903 Line Stage Preamp
Ayre CX-7e CDP
Roksan Radius 5 TT w/Zyx Airy S cart.
Canary CA-400 Phono stage preamp
Rane PEQ55

My budget for the subwoofer amp is around $500-$1000, though I could stretch that a bit if an amazing deal surfaced. After spending a few days reading through MANY, MANY, MANY posts and on-line reviews, here are the options I'm considering:
Emotiva XPA-2
Nomad Niagra
Classe CA-100 or DR-9
Carver Silver 7t monoblocks (a SS copy of the Silver 7 tube monoblocks)
Odyssey Stratos
Belles 150A Hot Rod Version or 350A
McCormack DNA-1
Krell KAV250a or KST-100
Bryston 2B-SST or Bryston 4b Pro
Musical Fidelity Supercharger 550K - ok, this is out of my price range, but do I need this much power to control the woofer array?

One other consideration is I'd prefer, though not a requirement, that the amp accept XLR connections b/c I must pass the signal from my preamp through the Rane PEQ55 to the subwoofer amp. This will allow me to filter the signal below 40-65hz and below for the subwoofer array (the subwoofer drivers go down to 16hz and up to 1khz). The Rane PEQ55 has XLR connectors only and RCA/XLR cables are harder to come by on the used market (I prefer not to use cheater plugs), so an amp with XLR connectors would be a better option for me. Of course I can get around this with an XLR to RCA cable, but I'd prefer XLR to XLR.

Thanks,
Mark

PS I found a post on Agon about the Pro woofer arrays that was kind of helpful:
12-01-06: Miklorsmith
While the rear arrays of the Pro's seems easy, with their high efficiency, my experience has been anything but.

First, I had a Bel Canto e.one 300, which should have plenty of output. It didn't. Sean at Zu told me to try a conventional Class A/B amp. I found an Adcom 555II, which has 200 wpc and should have been a champ. It wasn't.

I then tried an inexpensive NAD amp which fared no better. All these amps had the same problem of insufficient output and insufficient definition.

Then, I tried the amp circuit of a 60 wpc Audiolab amp - here we go, much better! Then, I went to the local stereo shop and traded the Adcom for an old Hafler 220 DH, with about 110 wpc. I'm sure it gets better, but this amp at $210 is the best I've had.

I'd call Sean and get his votes. Zu has certainly heard more Pro setups than anybody and can surely direct you well. Don't accept anything less than superlative bass. And, don't be afraid to cross over higher than 40 hz. Try 65 hz, which feels to me to blend very well with the fronts and provide some excellent midbass pop which is not possible with the front array.

INSERT FROM ME: The poster ultimately went with a Crown K2 amp which he swears by, though I'm not leaning toward the Crown amp because of the other options I listed above.
aceboympk
Reviews and applications are never always in line...The SM 100 is not quiet as good for really critical Audiophile needs as the SM 70's are. Don't worry about it, trust me the Monarchys are capable of the best and for your application its even sillier as they are in fact only going to do low frequency anyway if you go with the 100's. I believe Monarchy will give you a trial run and you will be a charged a re-stock fee if they did not work out. Yes speak with C.C. Poon he will guide you. I know they would work rather well, but again you could go for something with a little more power and less heat no doubt.

That is strange on the Velodyn? I would almost try it if its possible and return, but that would be ABSOLUTELY silly if in fact Velodyn one of the Kings in subwoofers did not produce a unit that would play down to the standard 20 hz range capability... Hell the Monarchys even though the spec. does not say it I believe will drop in well under 10 hz!

By the way I am still on board for the Velodyn, I think it will produce the frequencies just fine, by the way you will have a nearly impossible time getting anything under the 'A on a steinway piano or whatever at 27 hz to play, the speaker and the room just will not probably do it, you will get some feeling, but thats all that occurs anyway. Even cutoff at 25 hz will play 99.9% of any Techno/ artificial Rap music with all the low end power and authority possible. Rock, Jazz don't get to hung up on specifics, go hear something and use something that works for you.

Too bad you just missed a 4 day old ad on one of these from audiogon, sold quick, it sold for 600 bucks or something, its retail is like 950, its a little more muster and goes very low apparently against the velodyn! However no remote, or digital mic correction... But I have heard they are pretty good. see links They are all different links, but not sure why when posted to audiogon they all look the same! Just go to each one.

http://www.amplifiers.org.uk/anthony-gallo/anthony-gallo-reference-3-sa-amplifier/

http://www.petertyson.co.uk/ebuttonz/ebz_product_pages/anthony_gallo_reference_3_sa.shtml

http://canadianhifi.com/products/detailed/1329.htm

http://www.soundsandcinema.com/cgi-bin/hifi/REF3SA1.html?id=QNXynXU7

Good Luck
Undertow,

In Full Range mode the Gallo amp is 10Hz-28Hz. In Low-Pass mode the amp is 20Hz-180Hz. How can I get it to go down to 10Hz and up to 100Hz that you recommended? I think it would be one or the other, but the specs listed at the bottom of this post seem like the amp supports from 10Hz-200Hz. I just don't know *how* to set it up so that it goes from 10Hz to 100Hz that you suggested.

Is the amps impedence ok? Is it equal to the input sensitivity of 130mV? These are technical areas that are beyond my understanding.

I found them for $675 new with free shipping, so if you think it would be better than the Velodyne or the Monarchy amps I could still get one...or two.

I would have to run the Rane EQ if I use the Monarchy amps which is fine as long as it is the best solution. I would need a pair of XLR to RCA IC's, and I think you mentioned you still have pair.

Basically, I'm open to any of the three solutions you suggested. I just want to make sure whatever solution I use will be the best. Everything else I bought in my system is the best I could afford, so getting the best amp for the woofer arrays is my goal. I know I have a budget restriction, but these are three excellent options. Which do you suggest?

I understand there isn't a lot of music under 20Hz, but I do listen to classical and there are some organ pieces that get down there. The ability for the Zu's to get down to 16Hz was one of the principle reasons for my buying them over Cains, so I want a solution that will utilize the full bandwidth of the Zu's.

BTW, the Veloydyne SC-1250 was specifically made for the Velodyne SC subwoofers, none of which dip below 22hz. I think that's the reason the SC-1250 doesn't go below 30hz without a big drop off.

The Gallo has a "low noise" fan which I can't understand unless it is a class A amp. I don't think I'd hear it even at low listening levels anyway, but it's odd that it has a fan. I hope it isn't always on though. There are no specs for the noise level of the fan which I find odd given the amp is for stereophile applications.

Here are the technical specs for the Gallo:
The frequency response of this amplifier is 20Hz - 180Hz (Low-pass) and 10Hz - 28Hz (full range). It has 240 watts (stereo) or 600 watts (bridged) output. The dimension lists 17/19″ (W) (rack ears removable) x 4″ (H) x 14″ (D). It has possessed a weight of 25lbs. The input sensitivity is 130mV. Phases acquired are dual mono and continuously variable phases.

Output Power: 2 x 160 watts RMS @ 8 ohms
20Hz - 20kHz (stereo mode)
2 x 250 watts RMS @ 4 ohms
20Hz - 20kHz (stereo mode)
450 watts RMS @ 8 ohms
20Hz - 20kHz (mono mode)
650 watts RMS @ 4 ohms
20Hz - 20kHz (mono mode)

Distortion: 0.08% stereo, 0.1% mono
(low-pass @ 100Hz, level and xover at max, EQ at 0dB)
.01% stereo, 0.17% mono
(full-range, level at max)

Input Sensitivity: 130mV stereo, 110mV mono

Signal-to-Noise: 93dB stereo, 83dB mono
(low pass @ 100Hz, level and xover at max, EQ at 0dB)
93 dB stereo, 75dB mono
(full-range full-rated power @ 1kHz)

Load Impedance: 2 ohms or greater in stereo mode /
4 ohms or greater in mono mode

Bass EQ: 1W @ 35Hz (100Hz=0dB, level and xover at max, booster at 6dB)=6.2dB
1W @ 35Hz (100Hz=0dB, level and xover at max, booster at -3dB)=-3.2dB

Frequency Response: 15-200Hz low-pass (100Hz=0dB, level and xover at max, booster at 0dB)
<10Hz - 28kHz full-range (100Hz=0dB, level and xover at max, booster at 0dB)

Crossover: 40Hz low-pass, xover setting at minimum
200Hz low-pass, xover setting at maximum

Power Handling: 250 watts @ 4 ohms
160watts @ 8 ohms (In Stereo)
650 watts @ 4 ohms
450 watts @ 8 ohms (Bridged to mono)

12 Volt Trigger: Tip = (+) Sleeve = (-)

Auto-on Sensitivity: 5mV

Current Draw: 9A stereo, 13.5A mono
(level and xover at max, booster at 0dB)

Protection Circuitry: Short circuit, open circuit, RF burnout, over temp., speaker protection relays, Turn on/off transient protection, DC protection, and limiter circuitry

Temp. Protect: 60°C +/-5

Cooling: A low noise fan is utilized to draw cool air through the chassis using front and rear vents. Do not block the vents.

Power Requirements: 100 VAC 60Hz, 850VA
100-120 VAC 50/60Hz, 850VA
220-240 VAC 50/60Hz, 850VA

Connections: RCA inputs, 5-way binding posts
I just noticed the amp is 10Hz-28Khz. So, that answers my question about the amp supporting the full range you suggested from 10Hz-100Hz.

I wish I could edit my last message!

Regards,
Mark
Well even most amps rated to 20 hz will probably play 16 hz, you are going to have a hard time getting something to support the spec of actually "16hz" this has more to do with the fact the speaker is actually efficient and tunned to play that low, not really the amp spec. If the info is down that low with any kind of authority than it will pass, the amp and any amp that I would know of is definitely down probably 3 to 12 db anywhere around 20hz...

Now thinking back to a Zu rule, they automatically boosted their amps in the Definitions(the ones with built in amps) by actually adding 10 db of boost just in the 20hz alone setting. Almost anything playing on most recordings thru your speakers or anybodys will need a lot of help down that low, unless you have totally perfect room acoustics, with like built int 18 " free air subs built into your foundation or something to boost that much power at those frequencies, which you still might not hear from what I understand, but feel some of the air and vibration. I can tell you this, I have had some of the best speakers show me a spec of 30 hz and just under... They have had better bass due to the tunning was really capable of it.

Most speakers rated at even 20 hz which is obviously for the most part very high end ones that cost some money still in my opinion have difficulty proving or producing it in any kinda viable musical way that will make or break a system.

My suggestion again, Don't get caught up in that spec. even with the Velodyn I bet it will actually produce the signal lower than the 30 hz rating and even if it does will not be that noticeable, so yes honestly you will need about 12 to 20 db of bass boost in the 25, or 20, or 18 hz range to even hear it mostly! This will be hard to do without using pro gear like the rane totally cranked up to its max gain in those frequencies and an amp almost any will do it, but if you fed a signal that deep for any duration it would probably just putter out or overheat anyway in most cases, were talking most recordings will retain a 16 hz signal for about 1 second if your lucky, you will not miss much.

By the way vinyl for example has rumble filters many times on the phono amp to actually Kill off any of this noise at 25 hz and below! Mine can produce 20 hz even thru a speaker rated to be 30 hz.

This stuff is getting taken a little to far honestly, your problem and major wall to hit would be "So what if you did hit 16 hz" because you will probably NEVER produce it in your room, unless you have some money invested in testing the room acoustics, and probably even a lot more money in actually tuning your room to produce it. Pick a good setup for you, money, function, and overall will it sound good on your speaker? It will be fine with any of these amps, ultimately the choice will be whats best to fit your needs...

I will warn you worrying about the 16 hz spec will have you chasing the dragon. Again it was barely any difference with the 20 hz 10 db bass boost as most music never would produce it anyway, I don't care what the rating or specs are... Make sure you can hear and feel everything between about 40 hz and 120 hz and you will be knocking the walls down!

By the way those amps have some serious current draw it looks like... You will need for mono's at least 2 dedicated 15 amp power lines. 13.5 amp is not slouch thats about double any mono I have used, and a 15 amp circuit should really only be run up about 12 amps. Thats why many go with 20 amp breakers in this case. I would stick with Stereo versions or some kinda Class D efficient amps.
Wow, thank you for the explanation about lower frequencies! I had no idea. Learning something new every day!

Here is the feedback from CC Poon at Monarchy about an email I sent him inquiring about both of his amp. I used quite a bit of the information in your posts and described my application. Here is what he wrote:
Our SE-100 is a single-ended amp. The Hot and Cold Signals from the XLR are fed into the same input. (Hence "SE" )

The only True Balanced Amp we make is our SM-70 PRO, which uses two amps for a channel: one channel for Hot signal; the other amp for Cold signal.

Other than the architecture, the two amps are similar in size and price.

Both amps should met your needs for hum free, and good damping.

So, what do you think? Velodyne, Gallo or Monarchy? If Monarchy, which pair?

I don't have room treatments, though after I get all my equipment purchased, I will focus on that next.