Bi amp NAP 155x

Sorry it is NAP 150x

The problem with your plan is that if it's successful, you're goung to be disappointed when you have revert to a single amp.....

"Can I use the second NAP 150x to bi-amp my existing system?"

I was asking the same question about using two NAP 150X in bi-amplification mode?

Can it be done?

If the speakers can be bi-wired/bi-amped then yes, it can be done. However, advantages are marginal and not as good as spending money elsewhere or a better amp. 

Understood. Thanks

BUT....using each as a pseudo-monoblock may well be a noticeable improvement....connect both amps to your Flatcap, but hook up only one set of speaker cables to each amp-one for the left channel and one for the right channel. This relieves the power transformer from having to juice both channels. This works quite well even with a NAP500 and does not compromise stability in any way. Driving all four channels (as in bi-amping) halves the input impedance seen by the flatcap and could introduce some frequency rolloff. 

Interesting! ... Have anyone tried this?

"Driving all four channels (as in bi-amping) halves the input impedance seen by the flatcap and could introduce some frequency rolloff" ... in this case would adding another FLATCAP help?

(just to understand a little bit more how the NAIM kit works)

Yes, It can be done and I have done it. I can't really tell the difference  however it is interesting to hear just how little  the tweeter adds relative to the woofer. You also need a second set of cables so it is pricey when you consider the cables and the second amp.

G

Bear in mind that George was referring to bi-amping using all 4 channels and not 'monoblocking' which requires no additional speaker wires and may just have an edge on biamping. Since Naka already has the extra power amp, he can try it out with a few minutes of effort and no additional expenditure. 

As Richard said, the benefits are marginal SQ wise. However, (and this is a big one) bi-amping does radically increase the number of speakers you can choose from. A pair that may be too much for a single 150 may be driven by 2x 150s. 

If you have enough power amps and intend to keep them then you might as well get the benefit from your choice of speaker that was not available to you before. There are plenty out there that really need more than a single 150 can deliver to really open up (such as much of the PMC Twenty range). A single more gutsy power amp may be better but use whatever advantage is at your disposal.

Hi All,

The pseudo-monoblock idea sounds great. Are you saying  I would use two NAP 150x's (lets call them the Left and the right 150x's) . Both connected to the Flatcap. The left speaker output from the left 150x  goes to the left speaker (with the right output  bare) and the right speaker output from the right 150x  goes to the right speaker (with the left output  bare) . In my case I would hace to re-install the jumper wires in the speakers and eliminate one set of speaker cables. Will this sound better than the traditional bi-amping that I have now?

The forcing of a stereo power amp into use as a monoblock seems like a good way to cause it to sound imbalanced after prolonged use and potentially render it unsuitable for regular use again in a worst case scenario.

The benefit also seems dubious. The unit is still being fed with both channels so it is not like there is any signal isolation that you would get from using a true monoblock unless you mondify the cabe going into each power amp which I don't recommend.

Would really stick with a single stereo power amp or biamp if you need the power for the speakers you intend to drive. 

I've tried using 2 250s as pseudomonoblocks, and had a couple friends use 2x500 in the same fashion. The 500's in particular gave a significant improvement that way.  The biggest advantage is splitting the demands  between two different power supplies (and transformers).  This is far, far more important that signal isolation (the L/R separation is probably no more than 25dB in music signal anyway). And George W. has all the gear already to try it out and make his own mind up. So, find the jumpers and give it a spin, and report back. I tell you what-it certainly won't sound worse than biamping. 

I would agree here a bit with Ron, I too have used a pair of NAP-250's(And currently, a pair of NAP-100's) as pseudo monoblocks, it can be a worthwhile option as stated above. Use what you have, and as Ron said, it certainly won't sound worse, at least I doubt it anyway.

I find it humorous how things like this can be knocked down so easily, yet the talks of suspending wire/cabling so it doesn't touch or cross precisely at the wrong points, or heaven help us, using another speaker cable other than NACA5, etc. is taken as gospel. As always, every one's mileage will differ as to certain benefits or not.

It is really exciting to know that pseudo-monoblocks is a possibility, but I think that I will try the bi-amplification mode first (with 2x NAP150X) simply because my Roksan Darius speakers (from the 90's ...remember them?) work better with one pair of cables for each driver.

For the bi-cabling I wiil need to some kind of "F" type termination with banana plugs (I'm using the Van Damme LC-OFC 6mm) because the 4mm plugs on the speakers (separate crossover) don't allow any sort of shunts.

George White posted:

Hi All,

The pseudo-monoblock idea sounds great. Are you saying  I would use two NAP 150x's (lets call them the Left and the right 150x's) . Both connected to the Flatcap. The left speaker output from the left 150x  goes to the left speaker (with the right output  bare) and the right speaker output from the right 150x  goes to the right speaker (with the left output  bare) . In my case I would hace to re-install the jumper wires in the speakers and eliminate one set of speaker cables. Will this sound better than the traditional bi-amping that I have now?

George,

what Naim amplifiers are you using in bi-amp configuration?

I am trying to figure out the way to connect two NAP150x to the Flatcap 2x (connected also by the NAC 122x using Power Out A).

Is it:

- Signal Out A for one NAP 150x ........ connecting the speakers Tweeters speaker's crossover_ left and right

- signal Out B for the other 150x........ connecting the speakers Bass speaker's crossover_left and right

Is this right?

My speakers really work best with bi-cabling or bi-amplification.

I wonder if can I still use the Power Out B and Signal Out D to juice my CD5x?

Thanks

Naka, on A you should have three Din4s that will give you stereo pre-outs. Use any two.

Richard Dane posted:

Naka, on A you should have three Din4s that will give you stereo pre-outs. Use any two.

Resuming:  SIGNAL OUT A is identical to SIGNAL OUT B and SIGNAL OUT C on the NAC122X? I can choose either one to connect to an NAIM amplifier?

And can I still use the Power Out B and Signal Out D to juice my CD5x? This will not over charge the FLATCAP 2X?

Yes, Signal Out A, B and C are all effectively the same, each one providing a stereo output.  Power Out B is just fine powering the analogue output stage of your CD5x.

Understood. Thanks Richard