Axiom Home Page Forums General Discussion Technical Questions Connecting Hifi system to HT system

Hello everyone
I need your opinion on connecting two receivers to the same amp.
Basically, I need to connect two systems to the same amplifier and front speakers.

I have a yamaha Rx-v3800 receiver, a Rotel Rc-1070 pre-amplifier, a rotel Rb-1070 stereo amplifier and a rotel Rcd-1072.
As or now, my M80s are connected to the Rb-1070

The Front speaker Preout of the Yamaha are connected to the AUX input of my rotel pre-amp.

The pre-amp output is connected to the Rotel stereo amp.
The cd player is connected to the CD input of the pre-amp.

This way, when I want to use the front speakers with the yamaha receiver, I set the rotel pre-amp to AUX and when I need the speakers for the cd player, I simply set it to CD.

The rotel pre-amp input can handle up to 5 volts before they being to saturate but I was told my method of connecting everything together would not insure Unity gain. I'm not sure what is meant by unity gain and I was wondering if you guys had better ideas on how to connect everything together.

Thanks

I think an important question here is why?

Because intially, I was going to connect my m60s to my HT receiver and get m80s for my other system but I ended up upgrading my m6os for the 80s and the yamaha receiver can't handle the 4ohms load. So I need to use my stereo amp for the m80s.

When I bought the rotel cd player, the Rotel rep told me that going through the yamaha pass-through would alter the signal. So i was told to switch the interconnects to the Rotel amp input between the rotel pre-amp and yamaha receiver depending on if I wanted to listen to cds or watch movies. It wasn't a great solution so I tried to connect everything together until I get new speakers,new amp and separate both systems again.

Have you tried the yamaha with the m80's? Are you sure that it can't handle the 4 ohm load?

Sounds like the Rotel rep was trying to sell you more Rotel gear. Was he specific on how the Yamaha would alter the signal?

Use the Yamaha by itself and the Rotel gear by itself.

yeah, I tried the m80s with the yamaha and it shuts down after a few minutes at medium volume.

I was told by the Rotel people that I could connect the L & R preouts of the Yamaha to the aux inputs of the RC-1070 and my amp to the “Tape 2” output of the RC-1070. Then by setting the “RECORD” selector to “AUX” I would then be able to select any source on the Yamaha and have the signal passed through the preamp.

In the end I might just retire my pre-amp until I get a new set of speakers.

I wonder if there is something wrong with the 3800 as there are others using the same receiver with M80s and no issues, but this is the reason why Axiom doesn't recommend Yamaha with M80s.

I agree with St. Patguy here... the Yamaha's not going to alter the signal unless you use a surround mode or something.

Couldn't you use the Rotel amp for the mains from the Yamaha pre-outs?

I can't see the Yamaha noticeably degrading the signal from the CD player.

I think the Rotel pre-amp is surplus. Or, sell it and the Yamaha and get an integrated multi-channel processor solution.

yes, the pre-amp is surplus but I already had it before. I bought the rotel stereo amp to power the m80s because my older rotel amp was busted. I liked how the rotel gear sounded together so I figured I could try and save myself from buying new speakers for now by combining the two.

I contacted Yamaha's tech support before buying the m80s and they told me that although the rx-v3800 would support 4ohm speakers, they couldnt guarantee it would work with all speakers. Takes a little longer to shut down when watching movies, but when I put in cds like "Olé by John coltrane" or Cachaito lopez (cuban bass player) it takes about 4-5 minutes before the yamaha shuts itself off.

Should have bought a Denon

Thats another story. I needed to change my yamaha rx-v1400 without "anybody" noticing

I do agree with everyone else about using the Yamaha as a pre pro with the Rotel amp, I bet it will sound great.

If you changed the setting for the speaker impendence try it back at 8ohm. If you haven't then you could always try changing it to 6 or 4. I think it is on page 33 of the manual where it says you can use 4ohm speakers... Good luck.

This is your best option.

Al, as you can tell from some of the replies, it's rather puzzling why all this is necessary. The bottom line, not going into lab tests and user reports which have been linked before, is that the 3800 has a very powerful amplifier, including output into 4ohms, and even lesser units(including Yamahas)have been driving 4ohm speakers more demanding than the M80s(which are a relatively easy 4ohm load because of above-average sensitivity and relatively flat impedance)to more than "medium" listening levels. Note what Graeme(Hay)pointed out about the impedance setting and be sure that ventilation is adequate. Also, it might be worthwhile to carefully redo the wiring to the M80s in case a loose strand might be causing an intermittant short due to sound vibrations. Of course there's also the possibility that your particular unit is defective.

Be that all as it may, although it wouldn't solve the 3800 mystery, the simplest immediate solution would be, as already suggested, to use the 3800 front channel pre-outs to drive the Rb-1070.

Thanks for all the answers guys.

I did redo all the wiring not so long ago with 10-gauge 5T00UP blue jean speaker cables. And I did set the Yamaha receiver to 4 ohms. I will try to have someone look at it, but even better I'll try and see if I couldnt try another rx-v3800 with my m80s.

I don't think you want to change the Yamaha switch to 4ohms, as your reducing its available power. Most AVR's with a 4, 6, or 8 selection switch are best left on 8, at least that is my understading from JohnK and others on this forum.

I agree with Randy--you hardly ever want to switch it to 4 ohms.

I would say this is the cheapest option, but the best option is to sell all that bloody gear and condense it to a single usable receiver or other combinations thereof, but eliminating the mess.

Certainly cash is a limiter, but places like Audiogon, eBay or Canuck Audio Mart tend to have pretty good sale turnarounds. I'm still astonished at what some people pay for items on eBay.

It isn't likely that it's the total cause of the problem, but yes, despite the direction in the manual that the 6ohm impedance setting should be used with 4ohm front speakers, don't do it. This reduces the maximum voltage that the power supply section of the receiver can output and, following Ohm's Law, this likewise reduces the maximum current and power capability. This can cut the maximum power capacity in half. This is a UL mandated safety feature that should never actually be used.