Dual Mono / Monoblock - L/R Channel Separation


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I recently had an Atoll IN300 on home trial which from what I understand with it's 2 power supplies is in essence a Dual Mono setup which shares the same powerlead etc.

Something I immediately noticed was the width of soundstage and how seperated the left and right channels / speakers seemed and which is often a discussion point about Dual Mono / Monoblock setups, generally talked in a positive way.

I'll exagerate what I experienced so it's clear what I'm saying but normally the instruments more mixed to one side there's a certain amount of "Bleed" to the other side so the gap in between the speakers is "filled in" but this was very distinct from left to right and almost seemed a bit "weird" giving the impression there was an empty space in between.

I don't have ideal speaker placement as they're far wider apart than ideal but it almost sounded a bit strange , is this is what you'd normally expect with Dual Mono / Monoblock configs (doesn't happen with my stereo amp) or is it my speaker placement and how would more toe in would affect it (although they're nearly pointing directly at me anyway).

I should have experimented with that more when I had it but was reluctant as it'd taken me so long to get them sounding right for my curent setup, currently the speakers are 3.62m apart and 3.41m from my listening position.

I reiterate again, I've exagerated the effect but in comparison it does sound a bit strange and I'm not sure if I like it or not so interested to hear other peoples experience with similar setups.


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Nov 18, 2022
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Yeah I've got several amplifiers that I switch in and out of my system on a regular basis and yeah dual mono/ monoblock is huge when it comes to left to right separation.

I've got an older rega maia power amplifier I regularly use which I love, and if you remember correctly that thing has two transformers in it making it 100% dual mono. The only thing that would make it more dual mono would be if it had separate power cords for the left channel and the right channel, and in fact there are a few power amps on the market that have such a configuration.

I also have a restored set of dynaco Mark 2 tube monoblocks. Older no doubt but completely faultless sonically and even better when it comes to that separation of left and right.

Yeah you can expect a better stereo separation with either configuration because it allows the channels individually to have better isolation from one another and of course that prevents cross-contamination electrically.

If you're used to a more congealed sound then yes having this almost exaggerated left and right separation can be disquieting, but you do get used to it and honestly I couldn't go back To using a standard stereo amplifier.
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Feb 9, 2024
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I'll chime in sideways.. I recently upgraded from a Denon AVR (900 series) to an Audiolab 6000A. I'm a skeptic by nature so expected to return it (the other one was good enough, right?). Obviously I didn't! lol. But, one of the things that immediately struck me was the massively increased stereo separation. Like you said, at first it struck me as eerie. Like I had two stereos.

Now, my setup isn't even dual mono, or close to it, so your effect could possibly be much higher.. but what I wanted to say was "me too!" and, "I got over it". Maybe give it some time?
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that thing has two transformers in it making it 100% dual mono.

If you're used to a more congealed sound then yes having this almost exaggerated left and right separation can be disquieting

That's the configuration of the IN300 and as you say it just seemed disquieting as not used to it.

Maybe give it some time?

Problam is it was on a home demo and has now gone back, if I were to change for the amps other "better" qualities it's a big leap of faith as the change would cost quite a lot and then maybe more if I changed back again.


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The suggy I own is a dual mono based design missing the 2 transformers but still offers a massive sound stage. Offering exactly what you’re on about, there is very a much defined left and right but get the centre image locked and it’s an amazing experience.

But it also requires more careful alignment of distances from the front wall it’s far more noticeable it has to be just so. Or that could be just my ocd.

I personally love the dual mono design and couldn’t go back. Maybe one day I’ll get a 100% design but love the class A way of doing things at this moment in time.


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Thanks to all for the replies, if nothing else it's confirmed it's not me going mad and it seems whilst I'd have reservations about jumping in with both feet when I have some reservations and the cost involved, concsensus seems to be I'd get used to it.

I've had a slight change of circumstances this afternoon though, on my journey back from returning the amplifier to the dealer the other day my car developed some issues. and I just managed to limp home.
I heard from the garage late today the engine's completely ceased so unfortunately any available funds I may have had for this are now allocated towards a new car .... better find one with a decent stereo.

Cheers for the input though, much appreciated and I would say anyone looking for an amp in this price bracket I'd highly recommend adding one to your demo list, they really are brilliant amps.


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I was thinking about this more as you do when you wake up at 3.30 in the morning :confused: .... I think the separation is greater than you'd experience in real life and wonder if that's why I found it a little "strange" bordering on unnerving.

It's so distict from one side to the other, almost like there's a really wide wall in the middle seperating the 2.
If you were sitting in front of an orchestra / band, yes there's be a "weighting" of sound from one side to the other depending on where the instrument / amp was placed but the sound would still spill to the other side .... just at a marginally lower volume and probably not as pronounced as I experienced.

This may however be exaggerated by how far apart my speakers are.
Sorry to read about your car. I remember many years ago my wife’s Clio expired at 40,000 miles due to cam belt, but it was a devils job to get Renault to contribute.

FWIW I don’t believe the crosstalk between two channels is significant with any decent stereo amp and therefore monoblocks won’t make a meaningful difference. But speakers too far apart definitely will. Unless you’ve achieved a single spoken voice firmly in the middle, together with a head-sized image, then the speakers need aligning. I recognise that for lots of music, too far apart is quite appealing, but it isn’t ‘accurate’.
Dual mono makes no practical sense. The difference between a regular amplifier and dual mono can only be seen in the laboratory
A true dual mono amplifier should offer better stereo separation, which should be noticeable outside a laboratory. No crosstalk may not be noticeable as you state.
However, I don't see their benefits outway the difference in costs when versus a regular stereo amplifier.
Bigger benefits will only be achieved by using two monoblocks, in my opinion.
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Bigger benefits will only be achieved by using two monoblocks, in my opinion.
...and the more you look into those Fosi V3 Mono, the more appealing they look.

I think, due to cost around £160 each - and said by one (non-hype- type) reviewer to be at least as good as much more expensive monoblocks.

Feed them something with a variable output....and you could have more power and performance than any other £320 worth of power amp can provide.
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