Would I gain much upgrading to a second amp?

[Greg86z28]

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I posted this on Audiokarma, but I figure the advice here could be even better.

Just curious if you think this is a "good move" or not. There is a McIntosh MC 7270 power amp for sale locally, and if I can get it for ~1500-1600 I might jump on it (it's severely overpriced at the moment). What I would do then is essentially have monoblocks (one 7270 on each channel). I'd be going from 1 power amp in stereo at 270W/channel to 1 amp on each channel in mono at 540W.

Would that be much of a gain over my current set up? For what it's worth, if I could get it for $1600, that would put me at about $2800 total into both 7270s. Maybe I'm pissing my money away at this point.

I'm currently set up with:
Speakers:
JBL L250 (upgrade to 250Tis in progress, need to build CC networks)
JBL B460

Cables:
Audioquest evergreen cables
DIY speaker cables using CAT5 cable

Pre/Power:
C32 Pre
MC 7270 Power (stereo, powering the 250s)
JBL Pro Amp 6260 (mono, powering the B460)

Source:
Rega table with RB300 tonearm (including Incognito rewire and Michell TecnoWeight)
Dynavector MC 10X5 cart
Sony CDP-650ESd (for occasional cd listening)



Thanks,

Greg

[Mr. Widget]

Maybe I'm pissing my money away at this point.

I'd put the money towards the 250Ti upgrade instead... you'll have a much greater sonic improvement.


Widget

[Greg86z28]

Thanks for the input widget. I guess I should note that my Ti upgrade is in progress, I already have the 044Ti/104Hs installed, I just need to build the CC networks. I think I was estimating ~$500 to do that?

[rusty jefferson]

My feeling is that bridging amplifiers on full range speakers tends to reduce performance by raising the noise floor. Bridging for passive subs, maybe, but not full range imho. Those speakers should be fine with 1 stereo amp of that power rating.

[SEAWOLF97]

I've run the 250Ti's on various amps from an 85wpc Denon receiver to an Adcom 200wpc to a BGW w/ 325 wpc.

all were acceptable, tho the sound improved with each application of extra power. At the current 325 level, I doubt that any extra quality would be realized from more power. IMHO.

They will scale up with quality sound ... louder than I can handle w/o breakup already.

[Greg86z28]

Ok. So maybe I'm better off saving my money and someday selling my current MC 7270 and upgrading to a better amp (like a MC 352 or something of the sort, doesn't have to be McIntosh)?

[Mr. Widget]

Ok. So maybe I'm better off saving my money and someday selling my current MC 7270 and upgrading to a better amp (like a MC 352 or something of the sort, doesn't have to be McIntosh)?

Widget

[Mr. Widget]

My feeling is that bridging amplifiers on full range speakers tends to reduce performance by raising the noise floor. Bridging for passive subs, maybe, but not full range imho. Those speakers should be fine with 1 stereo amp of that power rating.

+1 for most amps.


Widget

[dr_gallup]

If you are not too far down the road with the CC cross over, I would consider using an active cross over and bi-amping a better use of the two amps than bridging them. Active cross overs have quite a few benefits over passive.

[Mr. Widget]

Active cross overs have quite a few benefits over passive.

...and many potential negative side effects as well. It certainly is a possibility, but not one to be entered into lightly.


Widget

[Greg86z28]

I haven't even started to think about the crossovers yet. I haven't done enough research to even know what I want/need.

If bi-amping is the way to go, I should have maybe jumped on the MC7200 that was listed locally (which is a much better amp than the 7270) to run on the high end.

[Mannermusic]

...and many potential negative side effects as well. It certainly is a possibility, but not one to be entered into lightly.


Widget

+1. No magic.

[Ducatista47]

I seem to recall that Greg Timbers considered bi amping the 4345s very, very desirable but didn't mention it at all for the 250ti in the post comparing the two.

[honkytonkwillie]

A second amp is good for +6dB headroom.

I've not experienced noise floor issues running amps bridged, but somehow the dynamics seem to flatten or compress. (perhaps one is a symptom of the other?)

Sounds like you're already committed to the speaker upgrades, so a new amp, at worst, will delay completion.

If the two amps don't immediately impress, bi-amping and active crossovers would be the next move. Myself? I'd do it just to learn and have fun doing it. If it really ends up disappointment, the amp shouldn't be hard to unload again.

[Ian Mackenzie]

It might be worth seeing if you can try out some other power amps when the 250ti upgrade is complete.

In the past I have found the desire for more power is in fact a quest for hearing more detail.

Most consumer amps sound cleaner as you driver them harder up to a point.

However the dipping point is the onset of an increase in harmonic distortion of the loudspeaker.

I doubt the L250 is clean at 300+ watts.

So what if you could come up with an amp that delivers superior detail and transparency at low levels.

You could in theory use an active filter and bi amp with a nice tube amp on the tweeter.

Personally I think it's over engineering a simple solution with more electronics in a critical part of the audio spectrum.

Consider biamping with a simple passive high pass filter using a small value series capacitor on the high input impedance input of the tube amp at 1000 hertz to gently remove the mids and lows. While the internal high pass passive filter controls the crossover characteristic on the tweeter Some changes would be necessary to split out the tweeter high pass filter but this could be done temporarily while testing the proof of concept.


I expect this is a lower cost option than purchasing some 350 watt Pass labs mono blocks.