NAP150X pseudo-monoblocks

You don't say what your speakers are and why you want to do this. It'll work but I'd question the value of doing this and the potential gains. I'd spend money at the front end if you're looking for more bang for your buck.

James

If you need more power replace the Nap 150 with a 200 (unfortunately a pre amp replacement will likely soon follow) or swap the whole combo for a supernait. 

If you want to try something that will make your system sound better and cost you nothing, take the flatcap off of the 122 - make it power the cd5x only (a source first boost). 

A half measure can be adding a power line on the 150 - it will help fill out the bass - it may be enough of a boost to keep you with your present system.          

Driving only one channel gives you the whole power supply behind it. The only draw back is the cost of the second power amp. Then it depends on speakers whether you can go active from there.

You will be better off going 200 on 122x and/or leaving the FC on the preamp. But don’t take anybody’s word, try and listen for yourself. 

Chag -

Whether there is benefit in  the proposal depends on the power supplies for the 150s, but certainly there is no reason for detriment to sound quality, and there could be an improvement, though given Naim’s attention to power supplies it might not br great.

Two additional options arise:

1) if your speakers are 2-way, and depending on the crossovers you could bi-amp:

a) with biwire type connectors you could easily passively biamp - i.e. connect one power amp channel to the bass connectors and the other to the tweeter connectors. Some people do this and claim an omprovement, though personally I expect the difference to be not  likely to be worth the extra cost ...unless you happen to have a spare amp. (If speakers are 3-way, you can do same but keep the mid and top connected together).

b) otherwise removing the crossovers could enable active bi-amping, but for that you’d need an active crossover between preamp and power amps.

2) inquire of Naim if it is possible to connect the 150’s channels in bridged mode, giving true monoblocks, each with greater power capability.

Regarding 2) I can tell you now, that would be a "no".

If you want to upgrade with another box then I would go with another Flatcap 2x - that way you can dedicate one to the NAC122x and one to the CD5x.  That will give a bigger lift than running a pair of NAP150x amps on just one channel.

How about sticking with the amp you’ve got and looking out for a good used CDX2!

ChrisSU posted:

How about sticking with the amp you’ve got and looking out for a good used CDX2!

That would lift the system even further, albeit at greater cost.

Richard Dane posted:

ChrisSU posted:

How about sticking with the amp you’ve got and looking out for a good used CDX2!

That would lift the system even further, albeit at greater cost.

I was just looking at the low prices used CD players fetch these days, and with a CD5X to sell, maybe it wouldn’t be so expensive?

Also, as the OP has a fairly balanced system just now, starting any upgrade process at the front end seems like a safer bet.