Pro Amplification

I can share two sets of experiences. One is in our reference theater. We have a set of JBL amplifiers powering our bi-amped fronts and side/surround channels. They are conventional linear designs but made for pro environment with forced air cooling and such. It is nice for rackmount work as they do not need any spacing between them. Down side is fan noise. You can see them stacked here with their blue lights lining up:



The sound quite nice and super dynamic given our horn-based JBL Synthesis speakers.

I suspect though you are asking about the switching/high-efficiency designs. We sell a ton of Crown amps. Believe it or not, most of them go into homes powering whole house audio. We like them because we can get units with DSP, letting us optimize the response of in-wall, in-ceiling speakers. They too have fans but it is temperature/load sensitive. Even there, you would need to place them outside as they would be too noisy otherwise.

I have compared the higher-end Crown amp against our Mark Levinson amps. Against the Mark Levinson 532 Reference, the Crown had more powerful bass. Its higher efficiency means it sucks more power out of the wall socket, enabling it push the large Revel Salon 2 speakers I tested better. On the high-end though, the Mark Levinson pulled ahead. Hard to describe but the high frequencies are just not as clear. The Mark Levinson 53 which is a high-speed version of a switchmode amplifier (effective switching frequency of 4 Mhz), matched the crown and has delightful high frequency response giving best of both worlds. But it is, far, far more expensive.

An interesting hybrid new option is the new Lexicon DD-8: http://www.lexicon.com/Products/Details/13



This is also a switchmode design but very compact and fanless. It gives you 8 channels, each at 125 watts, yet is in a tiny chassis and as mentioned, dead quiet. Its origins are in building amps that were light and efficient for cars. So Harman got together with TI and designed a highly integrated core amplification chip. We now use these in many whole house distribution environments. I have not done much side-by-side comparisons but just listening to them with Revels, they sounded pretty good. I am tempted to use them in my theater to bi-amp some of my channels.

amirm said:

I can share two sets of experiences. One is in our reference theater. We have a set of JBL amplifiers powering our bi-amped fronts and side/surround channels. They are conventional linear designs but made for pro environment with forced air cooling and such. It is nice for rackmount work as they do not need any spacing between them. Down side is fan noise. You can see them stacked here with their blue lights lining up:

The sound quite nice and super dynamic given our horn-based JBL Synthesis speakers.

I suspect though you are asking about the switching/high-efficiency designs. We sell a ton of Crown amps. Believe it or not, most of them go into homes powering whole house audio. We like them because we can get units with DSP, letting us optimize the response of in-wall, in-ceiling speakers. They too have fans but it is temperature/load sensitive. Even there, you would need to place them outside as they would be too noisy otherwise.

I have compared the higher-end Crown amp against our Mark Levinson amps. Against the Mark Levinson 532 Reference, the Crown had more powerful bass. Its higher efficiency means it sucks more power out of the wall socket, enabling it push the large Revel Salon 2 speakers I tested better. On the high-end though, the Mark Levinson pulled ahead. Hard to describe but the high frequencies are just not as clear. The Mark Levinson 53 which is a high-speed version of a switchmode amplifier (effective switching frequency of 4 Mhz), matched the crown and has delightful high frequency response giving best of both worlds. But it is, far, far more expensive.

An interesting hybrid new option is the new Lexicon DD-8: http://www.lexicon.com/Products/Details/13

This is also a switchmode design but very compact and fanless. It gives you 8 channels, each at 125 watts, yet is in a tiny chassis and as mentioned, dead quiet. Its origins are in building amps that were light and efficient for cars. So Harman got together with TI and designed a highly integrated core amplification chip. We now use these in many whole house distribution environments. I have not done much side-by-side comparisons but just listening to them with Revels, they sounded pretty good. I am tempted to use them in my theater to bi-amp some of my channels.

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How much is that Lexicon, Amir? I had forgotten Lexicon was purchased by Harman.

Tim

Phelonious Ponk said:

How much is that Lexicon, Amir? I had forgotten Lexicon was purchased by Harman.

Tim

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The retail is $2,500.

sierraalphahotel said:

Thanks for the reply.

Other than the mechanical noise, the JBL's are otherwise quiet? They don't exhibit any intrusive hum through the speakers or other nastiness?

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Yes, the JBL Synthesis amps are quiet. I just went into our theater which is a very quiet space and from about a foot, I could not hear a thing. Need a ladder to get any closer .

The Lexicon is interesting. The speakers I am considering don't allow for bi-amping and I worry that the 125wpc would be a little underwhelming, even though it is a very small room.

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Probably so. My plan was to use my Proceed amp to drive the woofers and the DD-8 for the tweeters.

I'm looking at using Procella Audio speakers in the room and unfortunately the models I am considering are not active. The fan noise is a problem and I'm already am fed up with the fan my Playstation 3 has. The amps will have to be out of the room! I heard good things about the now discontinued Crown Studio Reference series but I don't know if Crown every replaced these or what the contemporary models are?

Sean

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I am not up to speed on their model numbers or generations. But my chief designer lives and dies by them and knows all there is to know about them. He is probably the most experienced person with them in our region if not the country! So if you need more info, PM me with your email address and I will put you in touch with him and he can provide info/history on them.

HI, Sean! I have a big Krell EVO403 for my HT and I use an Emotiva XPA-3 for the rear channels (6.1). At 200 wpc, the Emotiva performs very well.

If you're going from stereo to 7.1, the XPA-5 would be a logical choice. Note that it has automatic 115/230 V switching. It's $899:

http://shop.emotiva.com/collections/amplifiers/products/xpa5



Lee

sierraalphahotel said:

The system is going to most likely be a Procella Audio HT, with the Theta CBIIIHD at the helm.

Sean

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Very nice!

Have you asked Dennis Erskine what he thinks?

I run Ampzilla 2000 for my mains but I do run a Behringer EP4000 EUROPOWER power amp for my Danley DTS-10 horn sub. It does a great job pushing 1400 watts per channel to the two 15's in a tapped horn sub. As mentioned before, there is the fan noise to deal with, but not a big deal for me as the amp and sub are actually in the next room. The sub fires through a hole in the wall into the home theater room.

Way back when (linear days), I used a lot of Crown MacroTechs, Fostex's, and Crests. For the mids I liked the Crest amps (we ran fully active). I always found them smoother and more refined. I never did get to try them in a home setting against the power amps we had.

I don't know what these brands are doing these days. I'm pretty sure though that if it's just bass duty, and fan noise won't be an issue, I'm all for 'em.