[indus]

Hello.

I'm in the process of buying poweramps, with a view to going pre/pro. At the moment I have the 909 for left and right, and the less powerful 99 stereo biamping the centre.

The plan is to move the less powerful 99 stereo to the rears (or maybe move it to another room altogether)

That means I could either buy another 909 to biamp the centre, and buy monoblocs for L and R or leave the 909 for L and R and buy one monobloc for the centre.

Anyway, what I'm trying to ask is, would two monoblocs give me better stereo sound than one 909 firing the L and R? I now that would be the obvious claim, but is that true?

Thanks

[Mark.Yudkin]

Remember that the 909 is bridged to make the 909 mono, so you could even run three 909s as monoblocs (the 909 mono is simple "pre-bridged", but you can bridge it yourself).

[indus]

Originally Posted by Mark.Yudkin

Remember that the 909 is bridged to make the 909 mono, so you could even run three 909s as monoblocs (the 909 mono is simple "pre-bridged", but you can bridge it yourself).

Sorry Mark you've lost me. To some extent that's probably due to a lack of knowledge on my part but also confusion on nomenclature. The stereo amp is called a' 909' and the monobloc is called '99 mono'

Can you explain again what you are trying to say?

Thanks

[lbstyling]

you can turn the 909 into a mono amp.

[indus]

Originally Posted by lbstyling

you can turn the 909 into a mono amp.

Ok, but which is better for driving L and R channels?

1) One 909 stereo

2) Two 99 monoblocs

As I said, the marketing blurb claims the latter, but is that a reality?

Going back to the idea that the 909 can be used as a mono, WHY and HOW would one go down this route?

Thanks

[lbstyling]

as i havnt heard them in the described configurations -i couldnt say, -there are advantages to mono configuration that arnt available by sharing the transformer between 2 channels, so i would take a proper look at the bridging option, noise floor, crosstalk and available current can all potentialy improve by bridging.- i beleve thd can rise slightly though.

the conclusion wont be as simple as you realy want.

look at several factors to assist your choice -mainly the impedance sweep of the speakers and efficiency.

but ultimately your going to have to hear them both realy for the answer.

- i know, its not the answer you were looking for- but what can ya do a?

[indus]

Thanks, yes I appreciate there are often no easy answers in life! A couple more questions though

1) Are the potential benefits of monoblocs purely down to seperation of power supplies?

2) I'm not sure I really understand what bridging means. Would bridging mean using one stereo poweramp for each of the L and R channels? What would be the potential advantages of using 2 stereo amps bridged as opposed to 2 mono amps?

Thanks

[indus]

Actually forget that, I obviously have no clue what bridging means and need to go and do some reading!

[Mark.Yudkin]

Bridging is tieing the + from one channel to the - of the other channel to yield twice the power over the pair, but it needs manufacturer support to make it work without going up in smoke.

In theory the 909 should be a better quality amp (lower distortion) and using a pair as monoblocs may yield a pinch more. OTOH (I can't resist this) using Quad ESL speakers will achieve far greater performance improvements than anything you'll gain by tweaking the amplification and you'd be much better off looking into the speakers.

[indus]

Thanks Mark.

Unfortunately I don't have room for electrostatics even before considering cost. Also I've never seen a 5.1 system using esl, what does one use for a centre speaker?

[Mark.Yudkin]

Indeed, what does one use as a centre (see my sig)? Best bet is probably a Martin Logan Stage.

[dean999]

Originally Posted by Mark.Yudkin

Indeed, what does one use as a centre (see my sig)? Best bet is probably a Martin Logan Stage.

hi indus,

a centre is not essential, i run a 4.1 system.

ideally if funds allow and you are looking for more power, if you want to stick with quads, then use 4 monoblocks - 2 for the front left & 2 for the front right, effectively you will be biamping your fronts, i biamp mine and it is a serious step up in terms of realism, large 3d soundstage.

regards
dean

[indus]

Originally Posted by dean999

hi indus,

a centre is not essential, i run a 4.1 system.

ideally if funds allow and you are looking for more power, if you want to stick with quads, then use 4 monoblocks - 2 for the front left & 2 for the front right, effectively you will be biamping your fronts, i biamp mine and it is a serious step up in terms of realism, large 3d soundstage.

regards
dean

I'd like to think about biamping (with either 4 monoblocs or 2 x 909s) but I don't think I can without buying a quad 99 pream as well. The quad amps have an ampbus that allow daisy chaining but there needs to be a 99 pre in the chain.
I'm not really keen on spending £800 on the pre because I've heard its not that good