mono versus stereo ampflication

If one has for example 8K to spend on ss amplification for a two channel system, would one in general be better off using a stereo amplifier of perhaps dual mono design or using a set of monoblocks. If the answer is "it depends" what then are the likely trade-offs of each option and on what does it depend?
Do you have any recommendations of specific products for either option for 92db, 8 to 4 ohm speakers?
Thanks for the input. I did find some discussion of this issue on threads that are three years old but nothing recent.
Yes, I think "it depends." Key questions would be how much power do you need, and how much power can the speakers handle? Questions that would relate to how much power you need would be the size of the room, the distance to your listening position, and what kind of music you listen to. For instance, audiophile caliber recordings of symphonic music with loud crescendos or heavy bass drum whacks would require much more power than jazz or chamber music.

Also, do you have the physical room for two large monoblocks?

My instinct, given your price range, would be to go with monoblocks if you have the room for them, but specific recommendations would be dependent on your power requirements.

-- Al
Mono blocks will always be a better choice. They normally have better bits and pieces inside of them as compared to their stereo counterpart, but also have better channel speration and will have better dynamics. You can never have too much power, so buy what you can afford once.
>>They normally have better bits and pieces inside of them as compared to their stereo counterpart,<<

That folks, is simply BS.
I have a large room (22X38, eight foot walls to 10 foot peaked ceiling) I listen mostly to classical and 60's rock at volumes of what a normal symphony attains. I listen near field at about 10 feet from speakers but also like to load the room.
If you give an audio engineer $3000.00 and ask him to build a stereo amp and then ask him to build mono blocks of the same design, most of the money will be spent on the TWO chassis and the extra power cord, etc.etc. etc. when building the mono's, so actually you can afford to put better parts in a stereo amp. Hope that made sense?
Usually the builder offers mono amps as the very top offering in the line. Usually they DO offer the best parts and represent the very best effort of that builder - if offered.

I know that the power supply in my mono amps will not fit into the stereo version. That is just one example.

So contrary to the rather strong comment above, mono amps are often times the best effort available by a given company. The extra chassis does cost more and that is but one reason mono amps do cost more. Seems rather a simple question to me.

If it is just a matter of all the same parts in one amp vs splitting them up into two, then the improvement would come from better isolation of parts, less crosstalk etc.
But again, usually you get double the power supply and we all know that is where LOTS of an amp's improvement can come from.
I think that there are far too many variables involved to be able to generalize as to whether monoblocks or single-chassis designs will be better.

Gammajo, it sounds like you need lots of power. What is the max power rating of your speakers, and would you want to future proof your selection by making it powerful enough for possible speaker upgrades in the future that might be able to handle more power?

I have no particular experience with amplifiers in your price and power range, but based on what I've read I'd certainly look at the offerings from Pass Labs, Plinius, and possibly Ayre if their lower priced models provide enough power.

-- Al
If I had monoblocks I'd put each near its speaker thus reducing the need for exotic speaker cabling. Even if you still thought that necessary the cable runs would be as cheap as possible. On the downside in such a scenario I'd want the monoblocks fully balanced so to use XLR cables on the longer interconnect runs.
If the particular stereo amp sounds like is not likely that his mono clone will sound any better.

Better channel seperation (cross-talk)
Better (lower) total harmonic distortion
Seperate power supply for each channel (not always the case tho.)
Mono-block designs are usually reserved for top shelf models or
statement designs.

If in fact , both amps (mono blocks and stereo) are using exactly the same parts and circuitry the differences will be not worth going nuts about.

In short
base your decision on quality of the component, setup requirements and most of all, your personal preferences.

As to recommending a particular amplifier..........
well , there is no easy answer to your question.

Forgot to finish off by saying one builder's stereo amp can cetainly sound better then another's monobloc amps. Impossible to answer that part of your question without knowing the specific amps in question.
These thoughts have been mentioned, but- I'd like to agree: Having two separate power supplies, and being able to place the amps much closer to the speakers(shorter cables) are two big advantages to using mono blocks. One would only need balanced interconnects if the system were in a high RFI/EMI environment, and then only if the interconnects needed to be fairly long.
Thank you for all your responses. To clarify further my speakers are rated 20 watts to 500 watts. I am considering the Pass Labs INT 150 versus their XA 60.5 monoblocks, which I know complicates things because it is an integrated amp. It is appealing to me becuase it has the new XA.5 technologies in it as best I understand. But the downside is that I really like my current AH preamp. I am not yet aware of a high quality stereo amp in the price range mentioned new or used that I should be considering.
I am further uncertain about wattage - as best I understand if the 60 class A will drive the speakers loudly enough, then is it necessarily true that other things being equal that 200 watts class A would be better sounding?
My feeling is that neither the 60W amp nor the 150W integrated are powerful enough, considering the 500W capability of your speakers, your very large room dimensions, and your interest in music that has wide dynamic range.

If I were you I would try to audition one of the higher powered X.5 (class A/B) amps, as your target selection, and compare its sound with the XA200.5 (pure class A), which I suspect is well out of your price range. Assess how much difference, if any, you can perceive between the sliding class A/B design and the pure class A. I suspect it may be small enough that you will feel comfortable choosing one of the X.5 amps, which provide more watts/dollar, as well as functioning less like space heaters.

To answer your specific question, no I don't think that a 200W pure class A amp is necessarily better sounding than a similarly designed 60W pure class A amp, other than, of course, on high volume peaks that approach or exceed the power rating of the smaller amp.

-- Al
What speakers and pre amp do you have in mind???
I would select monoblocks from the choices given so far;keep speaker cables shorter;maybe even use balanced cables if the option exists as longer runs from the pre amp would now be possible if you can not locate the pre amp close to the amps.
I believe the Pass INT 150 is based on the Pass X150.5 (or X150)amp and the new Pass XP-10 preamp, not the XA.5 amp. As such it switches from class A to AB. There are some very positive reviews out there. I own the XA100.5 monoblocks and think they are great, so I'm biased. If you have the budget, I would choose monoblocks for the reasons stated above.

I think Audiofeil is a dealer and made a rather provacative statement above. Perhaps he can comment further.
A compromise is a "Dual Mono" Stereo amp on one chassy. In the most extreme case you would have 2 power cords showing the two amps share only the case. The advantage of this approach is that it gives better separation while saving on cost of another case , etc. My MF NuVista has three power leads from the power supply, one for each channel of the power amp and a shared one for the preamp. You cannot use this approach to put the amps next to the speakers but it has some real world advantages. But be warned, what constitutes "Dual Mono " differs not only by company but by individual model within the same company. For example , MF has called "Dual Mono " both amps which have separate power transformers for each channel and ones that have separate windings on the same transformer. A case could be made for either but they are not the same.
You can purchase TRL M225 monoblock amps brand new for only $5500. They put out close to 300 watts per amp and I have not heard better. The TRL stereo amp, no longer being made, beat the new $7500 CJ Hybrid (ET250S) amp by a good margin when I heard them both side by side this weekend in my friends home.

The new monoblock amps from TRL are a big step up from the old stereo amp so that should give you a good idea on how good they are.

I am confident you will find the m225 amps as good as it gets regardless of $$$$. They sound great with a nice tube pre like your AH.
>>Perhaps he can comment further.<<


Reputable companies such as Pass, Art Audio, Atma-Sphere, Bel Canto, Mastersound etc. etc. do not use cheaper parts in their stereo amps as compared to their monoblocks.

However for somebody to state categorically:

>>They normally have better bits and pieces inside of them as compared to their stereo counterpart<<

is BS as I noted.

My statement is hardly provocative.

Dealer disclaimer.
Many mono's do have better power supplies & transformers etc. They are "overbuilt" to a higher level if you will.
Going from the Aragon 8008BB to either of the Pass models you mentioned with the VR4 Sr's might be disappointing in the bass and dynamics but would sound more refined in the mids and highs.

The problem is the $8K budget for monoblocks. It can be done but you might have to get used or go to some of the class D amps for similar grunt as the Aragon. You could run dual Plinius SA-102's, in bridged/balanced mode for 400W/ch for about $3K each used, except you'll probably want a preamp with balanced outputs.
Responding to comments and questions:
Rleff - I am planning to use my Audio Horizons 2.0nB preamp in balanced mode and connect to Von Schweikert VR4Sr's by biwiring.

Peterayer - I heard the XA100.5's in a friends system a few weeks ago and they started this search for better amplification. They sounded (as part a a great system and room) incredible. Congratulations on your choice. I am trying to approach that sound a a bit lower the price. Best I understand from reviews the INT 150 was designed to function much like the XA.5's for the first watts

Grannyring - thank for recommending the TRL's. I will check them out. Have you heard them compared to Pass?

almarg - Great suggestion - I have been concerned with energy use,cost and heat with the class A, but am hearing from reviews that the XA.5 are a very significant improvement. Does make sense to see if I can to hear the difference in my system.

I thank everyone else as well for their input.
How about VAC amps.
They do sound right with your speakers.

Another consideration might be the DAC Cherry amp which is awesome for the bottom but a bit sterile at the least to my taste.

Pass is a great amp but unfortunately I haven't got a chance to hear it with VR4Sr so I can't say hey or ney. Nice amp tho.
The TRL amps are single ended only. I have not heard a Pass Amp and understand they are quite good.
Just for closure feedback. Thank you everyone for your comments they were very helpful. I decided to go with mono's, the Nuforce Reference 9V2SE's which seemed at a great price used. Had them a week and so far so excellent. I am getting great controlled, tuneful bass, good balance accross the spectrum and sparkling highs. So I am happy to now sit back and enjoy the music. Well - plan to do a little tweak in terms of vibration control and perhaps power conditioning. Happy Holidays
Nice to see a closure to a thread. I wish more were like that.
If you want XA.5 amplification, INT30A makes much more sense than INT150.
Hey Kzhtoo,

A tad late don't ya think?? ;o)
Haha..yeah. Just noticed the dates. I found this thread with the search function. :) I guess, INT30A wasn't even out at the time of this discussion.