In what ways are monoblocks better?

JohnR · « **on:** 2 Oct 2004, 01:15 am »

It's commonly said monoblocks are "better" but I was wondering if anyone has had an opportunity to listen to amps that are identical other than being a stereo or mono amp?

I thought about it and my only experience like that is with the Dynaco ST70 and MK IVs. The mk IV is the monoblock. I never did like the pair of Mk IVs I had whereas every ST70 has an "organic" quality to it. To be fair, these were vintage amps so it's hard to know what else was different about them.

Anyway does anyone have any comments?

PS. When I say "monoblock" I'm really thinking about separate power supplies. So a stereo amp with independent power supplies counts as a "monoblock" for my purposes

Vinnie R. · « **Reply #1 on:** 2 Oct 2004, 01:29 am »

Well, you can have "dual mono," where there are separate power supplies for each channel, but they still share the same ground. True monoblocks have separate power supplies AND separate grounds for each channel.

Carlman · « **Reply #2 on:** 2 Oct 2004, 02:08 am »

It's another level of separation. Just like why would you have a separate amp and preamp, having a separate amp for each channel theoretically isolates each channel better. Furthermore, there's less or no chance of one amp's signal distorting the other.

There's not many amps that are similar enough to make a comparison. I think some of Odyssey's amps might work for that but otherwise, it's all theoretical or speculative for the laymen to say what's 'better'.

However, it's one of those things that clearly have been researched and applied with good results... or it wouldn't be done.

JoshK · « **Reply #3 on:** 2 Oct 2004, 03:08 am »

no offense but I am pretty sure John understands the theoretical arguements for why monoblocks would be better (channel seperation, more power delivery capabilities assuming the two PS's were bigger than the one, etc) but I think he is asking for actual experience. As Carl says, their aren't too many amps out there that hold other things constant enough to tell. Odyssey is probably the best example here. Maybe ask Klaus off the record, his own thoughts on this.

mgalusha · « **Reply #4 on:** 2 Oct 2004, 04:27 am »

Comparing the stereo Odyssey's to the monos is not a good comparison as the monos are run in a bridged configuration and not really the same amp.

Probably the easiest way to do such a comparison would be with an identical pair of stereo amps. Use one channel of each for a monoblock and obviously one in normal stereo to compare it against. The idle channel should have very little effect on the driven channel unless they are pure Class A in which case the extra current draw might make a difference. They would effectively be monoblocks at this point.

JohnR · « **Reply #5 on:** 2 Oct 2004, 10:15 am »

Aha, good thinking Mike! Hm... or I guess if you had a "dual mono" amp you could join up the power supplies... hmmmmm....

I guess I was just wondering whether anyone out there had "apples and apples" thoughts based on listening. It would probably depend a lot on the amp, I expect. I'm sorta wondering how significant the improvements really are, especially if you have plenty of power reserve.

orthobiz · « **Reply #6 on:** 2 Oct 2004, 12:29 pm »

I don't have monoblocks, but in a stereo/multichannel world "monoblock" sounds positively retro-cool.

You can get insanely short speaker cables (at the expense of long interconnects, so who knows how much of an advantage?).

They look cool next to the speakers, like some kind of outboard motor powering things, far away from the rest of the centrally stacked equipment.

That's 3 advantages right there...

biz

Charles Calkins · « **Reply #7 on:** 2 Oct 2004, 02:24 pm »

JohnR:

My first jump into seperate components was the purchase of an Adcom system. Tuner,Preamp and one GF-555 amp. I did this about 18 years ago. Everything worked great much better than the receiver I had at that time. Well anyhow I kept on thinking about going with two mono amps. I got another GF-555 and bought more cables and speaker wires etc. I finally got the whole mess up and running and started listening. Sorry to say but I couldn't tell any difference. Sounded the same in stereo or mono. Five or so years later I made a big booboo and one of the amps blew a gizmo inside. While it was being repaired I listened in stereo. Sounded the same. Got the amp back from the repair shop,hooked it up. Started listening in mono and I still couldn't tell any difference. Since then I got a new system with guess what? two Nad 218THX amps in mono. Go figure!!

Cheers
Charlie

mgalusha · « **Reply #8 on:** 2 Oct 2004, 02:38 pm »

I have my Odyssey extreme monos configured so I can run them either as a stereo pair or as monos. I could connect them up in as described above and see but like Charlie I'd be suprised if there was little, if any difference.

Theoretical separation should be better but they are still being fed by whatever source and preamp and those are almost certainly sharing a power supply and chassis and associated capacitive coupling. Especially true if using a turntable as even a very good cartridge only has 50 or 60dB or separation.