Having run a few integrated, stereo, and mono amps over the years, my best experience was with tube mono amps (Primaluna PL7), by a large margin. However, those tube amps were superior to anything else I ran, so is it the tubes, the mono, or the quality that really made my system boogie?
Fast forward a few years and kids and such have relegated the tubes to but a distant, sweet memory. I did manage to scrounge up a pair of Bel Canto Evo 200.2 bridgeable amps on the cheap since both were broken. One worked fine in stereo mode, so other was sent back to Bel Canto for a little love. The BC crew hooked me up, and I was lucky the tri-paths were still good (unobtanium now...). Swapped ’em out and sent the other back. The newly repaired unit sounded pretty much the same, not enough difference for me to notice.
It’s a pretty good amp, especially considering its 20 year old digital switching technology, but my system was dark, lifeless, and just generally not even close to my old mono tubes. Frustrating since the rest of the system is more or less the same.
Yesterday I got the second one back, and was like a kid in the candy store, excited to see what was waiting for me. I turned it on low and sat at my desk, not wanting to listen too much for an hour or two while the one channel warmed up from its deep slumber.
Well, I didn’t have to wait that long. After about 5 minutes my listening room began to fill with the punch I remembered from my mono days. Even at a low listening level the sound was ’jumping’ out of the speakers. Okay, time to listen.
Its hard to describe, but that effortless sound that could seemingly come from cutting the mass of the moving components in the speaker in half emanated forth like a freight train of power. Heavy metal saturated the room with concussive power, yet delicate music sprang forth from the blackness with a new found resolution, especially at lower volumes.
Paired with LS50s the stereo amp was always a pretty good at imaging, but the pair of monos noticeably sharpened up the edges, and made it easier to hear the difference between a natural soundstage and artificial stereo effects.
The character of the sound did not change when switching to mono. However the difference in presentation was dramatic. I really can’t explain it better than saying it felt like a dramatic increase in dynamic range.
Doubling power helps, of course, but my tube monos at half the power had it too...so I think its more than just a simple wattage number.
With my tube monos, I had feeling mono made a difference. But now that I’ve experienced back to back with similar equipment, I have no doubt. Mono amps just give a dramatically better presentation.
If I were to start from scratch tomorrow, and had the budget to do so...
All mono class D's, +/- 100 wrms. In the thousandths in the basic specs would be nice, but I don't expect 'bleeding edge' from what is still an emerging technology IMHO...
Why D's? I've owned 'cinderblock' mono blocks that required 'dead lifts' to move. I like the idea of 'lightweight' power, especially since my cardiologist told me to stay away from heavy lifting....*G*
Current amp is a basically a distribution AB with 6 - 2 channel amps, any and all capable of bridging. Run individual or from the line, each with variable level and pan. Run from 6 drivers to 24 with any combination I care to play with....
I'm big on 'flexibility; absolute perfection, not so much.
And then there's the 2 matrix that control What and How... ;)
There is a 'regular stereo' to keep peace with the spouse....*G* One of 2, actually...
I had a chance to buy two spectron fully speced out amps to drive a pair of ML CLX that required a lot of voltage at higher frequencies - I bought the first one to evaluate the performance and ran it on stereo for a few months - the previous owner said he would hold the second one for 60 days in case I wanted it ( these were an experimental build by the manufacturer with additional components and consecutive serial numbers - so if I wanted to add a 2nd one a year later - it would not be a match)
When I added the 2nd one in bridged mono configuration - it was one of the biggest improvements in the performance of my system I've ever experienced - no regrets
So with a direct comparison of the exact same amp - in stereo - vs - bridged mono - there is a huge improvement in noise floor and separation - and even though I listen at very moderate levels - the additional power available minimizes any distortion with loud transitions - and mounting the amps right beside each speaker has likely contributed ( at least on the coat of speaker cables )
Mono is the answer, if I can remember the question. I have a pair of Accuphase A-70's. These are true 60W Stereo full Class A , doubling all the to 1 ohm amps. 480W at 1 ohm stereo, 960W at 2 ohm bridged.
I almost bought the A-200 (100W mono) instead. I decided I would rather have the ability to HORZ./VERT. bi-amp and bridge. In the end my preference was BRIDGED.
Side note on how Accuphase does things. In their design, like the A-70 for example each cannel is basically is 2 amps in parallel. I said parallel not series ( bridging 60W becomes 240W, series ), buy running 2 amps this way main design gains are increased current, lower over all stress on amps per given output. Cost is the down side. These amps are a lot cooler to the touch than any other Pure Class A amps that I have come across.
This product may well be as close to the amp " erik_squires " says you can not find. Well, for under lets say $100K, just saying.
Any how, I would say this if you go stereo, get something bridgeable to keep your options open. If you have the funds down the road, yes in my opinion there are gains to be had in power and presentation, etc.
As for Thiel on the whole I would agree but once you have reached the Top of the Line, you can still take it further. This is the nature of upgrading, there is always another step. Perfection is unattainable, nothing is the best. Is trying to reach perfection a waste of money, well that is a question of ones values is it not.
Well, just like ( dlcockrum ) said, that ( stringreen ) above nailed it, and I agree. stringreen, that was a very good answer, and now I'm going to put something in and see if I can nail it as good as stringreen.
This is something that I have kept in my notes for many years and I thought I share it with everybody since it's perfect for this discussion.
From the old "Audio magazine" ( February 1991 issue, page 74, The late and great speaker designer Jim Thiel of Thiel speakers wrote "speakers will sound better with one very good amp than with two lesser amps". He also went on to say that your speakers should always be used with the best stereo amp that can be afforded rather than splitting the available money between two amps.
I think this is one of the very best pieces of advice a stereo manufacturer can give a customer and I agree. A really good $10,000 dollar retail price amp should always be able to beat a pair of mono blocks that retail at $5000 dollars each, basically. This is just my opinion as well.
By the way, I never owned Thiel speakers, but I always liked them.
If you have difficult to drive speakers, or just want to have the absolutely most solid amplifier possible that is the way to go. You aren't going to find a 200 W class A amplifier that goes down to 1 Ohm (1600W) in a single chassis, the power supply and heat sink requirements are monstrous.
But better...... meh.
In a HT that I could afford to live in however, I’d be looking at the ATI or NAD digital amplifiers based on Hypex modules. Smaller and more compact units are much more attractive to me these days.
You coud use two sterao amps bi wired if you are worried about seperation. I have used both but not for years. Krell was the last. It is easier to lift the monos!
Dave, yes I'm very happy with the MA500 monoblocks as I use them for home theater, one for rear left, one for rear right, and one for center channel. I think separates is the best when it comes to home theater.
Topology isn’t always the big deal with some amps, say tube amps for
example. There are tube monos running sE only. Very nice ones.
There
is a very good argument which paralelles this thread…. Fully
differentially balanced or single ended designs, which is best?
Cost
no object (C.N.O.) builds of either SE or XLR amps should have the
balanced amps doubling the costs of the SE amps provided both amps were
made . of identical parts as the XLR amps use effectively a twin SE
arrangement or twice the parts list essentially..
I can point to a number of issues that belie this comment:
Topology is actually a huge deal with many amps, especially tube amps. I've been trying to see how I might have misinterpreted your comment but I don't see how.
A cost no object (or even on a budget) balanced amp does not cost twice that of single-ended circuitry nor does it have twice the parts- that is a very common myth! I don't have to look very far to prove that out- most of our amps cost **less** than single-ended amps despite having greater power and performance (and yes they are full balanced and differential). Part of the reason for that is we don't have to pay for an output transformer, but even if we did, output transformers for push-pull amps are easier to build and thus less expensive.
I notice you use Marantz MA500 amps. I have them. Very nice but not quite an assault on the best of the best (stereo, mono, or bridged) to qualify making such a broad statement.
Glad you are happy with them though and can see why. Really. :)
If I was an amp designer I would only consider integrated and mono block separates. Why be somewhere in the middle? Same approach as audiophile - couple of more integrated upgrades and monos after that, funds permitting. The only exception that I would make would be for Gryphon if I wanted it because even used and quite old they are too expensive.
I don’t think amp makers will make amps which have everything their mono blocks have in their 2 ch amps. Not even in their dual mono single box setups. In fact there are a lot of ‘mono’ amps which are merely ‘bridged’ stereo amps, even if dual mono on one chassis. It’s a cost effective idea.
As such, within that brand, there would be no reason for buying their monos… apart from a slim chance the monos had greater power output, but then they would not be the same as their 2 ch counterparts yet again.
Its all about $$$$. Topology isn’t always the big deal with some amps, say tube amps for example. There are tube monos running sE only. Very nice ones.
There is a very good argument which paralelles this thread…. Fully differentially balanced or single ended designs, which is best?
Cost no object (C.N.O.) builds of either SE or XLR amps should have the balanced amps doubling the costs of the SE amps provided both amps were made . of identical parts as the XLR amps use effectively a twin SE arrangement or twice the parts list essentially..
Power supplys are where most all upgrades, mods, performance enhancements begin despite the device, but especially with amplifiers. Stereo amps run nearly the gamut dual mono 2 ch amps run but their power sups as previously said already get upgraded… pretty often in a dual stereo amp.
If kept within the brand, Monos, worth their salt in design, build and topology are generally going to on paper at least out perform the other two amp entries.
However, there are some stereo amps sitting on one chassis which cost way more than some other brand’s mono blocks. Way more!! Way better sounding too.
It all comes down to $$$. That and preffs. If on the short list, I’ll opt for monos every time, provided…. Performance is better, the added costs are part and parcel their requirements for gaining that added edge. Albeit, wires, platforms, power cords, etc..
Size and space are considerations too. I’ve owned dual mono amps that are quite the monsters to move about the house, or even just a few feet from there to here and mono blocks that were far lighter and easier to rearrange physically.
All that said, recent Integrated amps from some very upscale amp makers seem to be making a great argument for themselves in terms of ‘voice’, synergy, and simplicity.
Mono block amps indeed do not have to be in the mix for a system to sound great and perform exceptionally well.
What are the advantages of a loudspeaker system with a 16 ohm nominal rating???
All amps have less distortion driving 16 ohms as opposed to 8 or 4. Tube amps in particular will not only have less distortion, but (if transformer-coupled) will play with wider bandwidth and slightly more power because the output transformer is more efficient.
With our amps (which have no output transformer), there is less heat and power draw from the wall; the smaller amps we make (M-60 and S-30) also make more power.
Finally, the speaker cables have far less impact on the sound and you can run them longer lengths.
I prefer separate monoblocks but each has its sonic merits. After building both push-pull and SE amps, some of which have been very similar in design and build except one being monoblocks and the other a single-chassis stereo amp, I reached a tentative conclusion--- the main differences I could hear were actually in imaging and soundstage characteristics. The stereo amp seems to have greater image density in the middle of the soundstage and less extension to the extreme sides. The monoblocks have a bigger soundstage with greater extension on each side but images are not as precisely fixed in space in the middle. Overall I prefer the monoblock presentation but I can see how someone else might prefer the stereo. I say "tentative" because it is really difficult to be sure what you are hearing is due to the monoblock vs. stereo chassis and not some other issue, but that's what I have heard on a couple occasions when I was able to make such a comparison.
The thing is you have to qualify any answers with 'all other things being equal'.
If you do that then monoblocks are the clear winner. One advantage is you can place them by the speakers and keep your speaker cables short. This can really help with definition and impact, particularly if you have 4 ohm speakers. But my speakers are 16 ohms and I find that short speaker cables help them out too.
Obviously, comparing a $500 monoblock with a $3000 stereo amp (say Rotel vs Parasound). The Parasound is going to win. I took this question to ask about amp topology. Not which amp actually sounded better.
Say you have a monoblock amp and a stereo amp with all the same component quality, driver circuit design, output devices, power supply capacitors, etc. If the stereo amp uses a shared power supply, then the monoblock is going to sound better. It may still sound better even if the monoblock is single ended. If the monoblock is fully balanced/differentially, it will beat the stereo amp (as long as the it is properly designed for balanced topology -- some amp circuits do not bridge/mono well).
I should also point out, despite the amps I used having relatively poor channel separation, using them in mono or stereo didn't make a really big noticeable difference.
Eventually I used one for pure surround, so I could turn it on/off by trigger and save the electrical costs.
Yup, agree with Erik. Monoblocks have completely separate power supplies, whereas most stereo amplifiers used a single shared power supply. However, some stereo amps are described as "dual-mono", which are actually two amplifier channels with two completely separate power supplies and transformers (just mounted in the same case). Some stereo amps have a pseudo dual-mono design where you still have a shared transformer, but the left/right power supplies use different secondary windings from that transformer.
Also, monoblocks are usually, but not always, a fully balanced/differential design (i.e. push/pull). Some stereo amplifiers are balanced/differential, but 90% of the stuff out there is still single-ended.
You must have a verified phone number and physical address in order to post in the Audiogon Forums. Please return to Audiogon.com and complete this step. If you have any questions please contact Support.
