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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
darkmoebius
900 posts
 
Might I step in here with another budget suggestion?

A classic(or two) Hafler DH-500 amp run about $250-$350 ea. These 50 lb beasts are legendary for driving just about anything and are bridgeable to 800 watts into 8 ohms. They were mainstays in the Pro audio world for decades and thousands are still in use. There are also companies that do extensive(& expensive) mods to them.
Power Rating: Less than 0.025% total harmonic distortion at any power level up to 255watts continuous average power per channel into 8 ohms at any frequency between20 Hz and 20 kHz with both channels driven.

Frequency Response into 8 ohms:
-3 dB, 0.5 Hz to 120 kHz at 1 watt
+/-O.5 dB, 5 Hz to 40 kHz at 255 watts

Input Impedance: 47,000 ohms
Input Sensitivity: 2.35 volts for 255 watts into 8 ohms; 0.145 volts for 1 watt
Damping Factor: 200 to 1 kHz into 8 ohms; 60 to 10 kHz into 8 ohms
Rise Time: 10 kHz, 80 volts p/p square wave, 10% to 90%: 2.5 us.

"The over-sized power transformer, the conservative operating levels of the MOSFETs, the computer-grade electrolytics totalling 40,000 microfarads, the enclosed relay, the use of film capacitors in signal circuits-all are evidence of the design efforts to achieve exceptional reliability simultaneously with state of the art sonics and specifications. So rugged is the DH-500 that it can deliver over 20 amperes into a short circuit!"
Obviously, Undertow's experience with Zu's speaks for itself, he really knows his stuff. But the Haflers are worth considering for any subwoofer application. Do a web search on the DH-500's or the pro equivalent D-500, it has a long and illustrious history. I found the fan in the D-500 to be too loud for home applications, but DH-500 works well.
undertow
1,033 posts
 
Aceboympk
Hmm, that is interesting I was not aware the SM 70 was the only config with the true balanced XLR from monarchy. Not that its super critical as it will still work without an adaptor if you chose the SM 100's and a standard XLR cable will work just fine from the Rane to the amps.

Or as stated above by Darkmoebius, go with an older cheap amp that will do the job and hook it to the rane, or simply try a full on solution if you prefer to try and do this easier eliminating the extra EQ in the path, dumping the Rane....

I mean if you can get an amp or something local to just HOOK up to these speakers to try out would be your best bet just go to any guitar center, or sam ash, buy a decent pro amp make sure you have the 30 day return policy, and go hook this sucker up and have a little fun and knowledge!

At least this way you can get the Rane with a pair of cheap Mic/XLR cables going, by the way all you need is the HOSA brand type XLR cable sold at all your music shops for like 10 to 20 bucks a pair maybe radio shack. Then make a decision if the rane is going to work out for you and chose an amp based on if you want to keep the rane in the system or buy an all in one solution with some extra convienence factors on it like the Gallo or the Velodyn.

If you keep the rane then order a crown or something better if you feel thats how you will like to continue, my thing is learn the Rane system, and see how good of results you can get tweaked in which if its good and works well for you, and you love the sound than you found the answer.

Again these are all going to work for subwoofer control, don't get too caught up on specific attributes.

You did say your preamp is RCA only? Well if you don't want to mess with all this I can tell you whether you spend another 300 or 3000 your gonna be within 5% of what your going to get out of this system. So bottom line is if you want the simplest, most quality, effective purchase its probably going to be eliminating the Rane from the mix due to the conversions, the extra gear plugged in, and the extra dialing in needed. However you have it already, and it is the more expensive solution as it stands so add a 300 dollar pro amp and get to it!

Like I said take very little risk going to a local pro shop grab an amp, and a pair of XLRs, and for the second set of cables from preamp to rane either make them up using RCA jacks you can pick up at the local Radio shack to hack the ends off one side of the XLR, or get some cheap adaptors, which actually I believe radio shack or many guitar centers etc... do carry to convert your xlr to RCA.
aceboympk OP
33 posts
 
Undertow,

Thank you for the direction. If I didn't sense getting kicked out of the nest on this one (possibly a case of paralysis through analysis) I'd ask if Crown or QSC is better.

But, realizing that I have to DO rather than ASK I'm going to get a couple of pro amps and start getting familiar with the Rane.

Adam from Zu also suggested three pro amps to use and the K2 was one of them (Threshold and MC2 were the other two).

Unfortunately, the K2 isn't available new any more, but it is available via ebay.

Time to do. I'll report back my findings. Thanks again for your patience and guidance. Audiogon needs to make gift giving via Agon credits possible.

One last question: can you email me with the price for your XLR to RCA cables? I'm at mark.kellman at gmail

Thanks,
Mark
macrojack
1,303 posts
 
Mark - I am also a Zu Def Pro veteran. The Crown K-2 is what I used for my bottom end ultimately after employing Pass and Bryston. Use a dbx Drive Rack PA instead of the Rane and don't worry about the quality of cables for low frequency. True balanced circuitry cancels noise and you needn't be too concerned below 60 Hz. anyway. I found that $15 mic cables from the music store worked quite well for low end.

There really isn't much to be missed below 50 Hz. on music programs. Home theater is where the bottom is most appreciated.
audiofeil
4,011 posts
 
>>07-04-09: Macrojack
There really isn't much to be missed below 50 Hz. on music programs. Home theater is where the bottom is most appreciated.<<

Baloney.

Using Zu as an example, one need only hear Druid alongside Definition or Presence to know this is untrue. There's a lot of music to hear and feel under 40Hz.

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