RSX-972 as a Pre-Amp

[ALLAN H]

Hi there,

I currently have an RSX-972 running my HT set up.
H/ever I still have an RC-970BX pre-amp and two RB-970BX p/amps running my stereo and driving the front speakers in bi-amped, bi-wired set-up.
The RSX-972 runs my centre, rears & sub. The fronts are run through the RC/RB set up via RCA's frm the RSX-972 Front Outputs.

I've recently replaced my Marantz CD63SE player and Toshiba SD1200 DVD with a Denon 2200 multi-format. (great pic & DVD-A & SACD sound but CD is average)

Since my CD L&R analogue outputs on the Denon are connected directly to the RC-970, I can't hook up DVD-A/SACD in multi-channel format w/out running both the RSX-972 and RC-970 at the same time. In effect as 2 pre-amps, and can't "balance" the sound.

Question is, if I remove the RC-970 from the sytem can I run both the RB-970 p/amps directly frm the RSX-972?

As far as I can see the RSX-972 has only 1 set of L&R Front outputs.

Or, can I run one RB-970 frm the Front L&R outputs and then the other RB-970 from the Rear L&R Outputs on the RSX-972? Are they matched sonically?

My front speakers are Mission 753f's whc have a 6ohm impedence so I can't run the p/amps in bridged mono as ths halves the impdence to 3ohm and so is below the RSX-972's min requirements of 4ohms.

Any suggestions? Can ths be done? Or do I need to remove my RSX-972, RC-970, RB-970 set up and start again with a different pre/power set up?

Thanks fr any advice in advance.
Cheers.

[Andrew Pratt]

If you wanted to run both power amps off the one unit you'd simply need to purchase a RCA "Y" splitter to give you two RCA outs that you'd then connect your cables to and run each to the amps. The rear outs are not what you'd want to use as those are for the two surround speakers...just purchase a splitter to plug into the front left and right RCA out and you'll be fine. Radio Shack will have what you need or you can purchase higher quality ones if you like.

My front speakers are Mission 753f's whc have a 6ohm impedence so I can't run the p/amps in bridged mono as ths halves the impdence to 3ohm and so is below the RSX-972's min requirements of 4ohms.

Sure you can. The power amp will still see 6 ohms as the load from the speakers hasn't changed at all so they should be ok bridged which would be easier then running them in a bi amp/bi wire configuration. Just keep an eye on the amps to see how hot they're running in the bridged mode but from what you've posted above it should work just fine.

[ALLAN H]

Hi Andrew,

Thanks very much for the reply and appreciate the advice on the Y splitter cables.

The equivalent to Radio Shack in NZ is Dick Smith Electronics. They have such splitters but the quality looks a bit cheap & nasty.
Having forked out fr some decent Nordost interconnects I wouldn't want anything inferior getting in the way, if you get my drift. I'll try and search around fr some decent quality ones.

Thanks fr the Bridging comments. I've tried ths a few years ago when I got the Mission speakers and burn't out one of the p/amps. The advise I got at the time was it was due to running in Bridged mode and to change to a bi-amp set-up. That was the Rotel dealers advice.
I'll give it another crack and keep a close eye on the amps.

Ths is a great site and I've only found it a week ago despite being a proud Rotelian fr the past 9yrs. Keep up the good work!
When I grow up I want the RSP1098/RMS1095 combination!

Cheers/Allan H

[Andrew Pratt]

If those mission speakers were a 4 ohm load I could see why the amps weren't happy in bridged mode... in this case though with an 8 ohm load they should be fine. They will run a little warmer but just keep and eye on them and if they don't get too hot you should be ok.

As for the splitters see if you can find any solid metal ones so that you won't have any signal loss from a skinny patch cord between the RCA's

[ALLAN H]

The Missions hv a 6ohm load, so it's probably a bit borderline depending how loud I want to go.

I'll hv a hunt around fr the solid metal splitters.

Cheers/Allan

[Andrew Pratt]

You're right 6 ohms could be pushing it a bit esp if they dip well below that at some points as well (the 6 ohm rating is only an average not a hard value as resistance is frequency dependant)