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Pavlov
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Two amps connected to same speakers

Is it possible(safe, advisable) to have the same set of speakers being alternately driven by two different amps. Let's say I want a stereo system(integrated amp) and a surround system(A/V receiver) to share the same set of front speakers could I have a set of wires running from each amp directly connected, (without a switchbox)to the speakers and simply toggle back and forth(movie/music) using a universal remote?

Kal Rubinson
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Re: Two amps connected to same speakers

Bad idea. The output stage of one is likely to shunt the output of the other, even if the former is not powered up. If it is, the shunting is certain. Get a switch or an amp with a HT bypass.

Kal

Pavlov
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Re: Two amps connected to same speakers

I was afraid so. What type of sound improvement could I expect by connecting a good quality stereo amp to my Yamaha RX-V1500 receiver to drive my fronts. It would still be using the Yamaha's pre stage wouldn't it? I'm not very familiar with these types of setups. I'd like to keep the Yamaha for surround/switching purposes but want better sound for stereo music.

Kal Rubinson
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Re: Two amps connected to same speakers


Quote:
I was afraid so. What type of sound improvement could I expect by connecting a good quality stereo amp to my Yamaha RX-V1500 receiver to drive my fronts. It would still be using the Yamaha's pre stage wouldn't it? I'm not very familiar with these types of setups. I'd like to keep the Yamaha for surround/switching purposes but want better sound for stereo music.

Adding an amp to your receiver might work but it depends how critical you are and how disparate in quality your stereo equipment and your HT are.

The switch is the easiest thing. A preamp with HT bypass is the ideal.

Kal

Pavlov
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Re: Two amps connected to same speakers

The switch is the easiest thing. A preamp with HT bypass is the ideal.
Kal


My first plan was to sell my HT receiver and get a Rotel RA-1062 integrated stereo amp - period. Then I thought maybe there is a way I could integrate the Rotel into my present HT system. Forgive my ignorance but, at this point, I still don't understand what I need to keep, what I need to get and most of all how to set everything up.

Kal Rubinson
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Re: Two amps connected to same speakers

OK. Get a switch. Then you can decide whether you want to upgrade any of the components in either the stereo or the HT system. If you do, that will determine the configuration needed.

Kal

Scooter123
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Re: Two amps connected to same speakers

Actually, it may be possible to keep your Yamaha and integrate a second amp into the system fairly easily. I did a google searh on your reciever and the one review that I read indicated that the Yamaha has pre-outs for adding a second and third zone. So, what you would do is buy a second amplifier (not an integrated, just a straight amp) and connect it to your Yamaha using the zone 2 pre-outs. The big question is whether it will be possible to balance the volume of your stereo pair with the rest of your system. For that, you'll have to read your owners manual and see if it's an option to adust ratio of the sound level of the second zone relative to the main surround system.

If you can do that, it's quite simple to wire it up. Get a set of interconnects, hook them to the zone 2 pre-outs on the Yamaha and run the other into to the amplifier in connections. Then connect your stereo pair of peakers to the second amplifier and your in business. Then all you have to do is figure out which buttons to push on your remote to get everything operating the way you want it to (as in zones one and two on, source to x for a movie or zone one off, zone two on, source to CD).

I don't know if Rotel makes a straight amp. If they don't, I would suggest you look into the NAD C272. My HT seteup is pure stereo, as in, I have my integrated amp connected to my TV sources. It's an NAD C372 and all I can say is "golly that sounds good".

Concerning using the Yamaha as a pre-amp, I wouldn't worry too much about that. Yamaha also makes many very good musical insturments and I think you can trust that their pre-amp is probably pretty darn good.

Pavlov
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Re: Two amps connected to same speakers

I dug this up...seems like it might be a solution. I'm trying to visualize as I'm still not clear about having two pre-amps...which one would control the volume, etc?

"I'm using an NAD C162/C272 separate pre-amp/amp combo (150W X 2) combined with a Yamaha RX-V1600 receiver and Energy RC-Series speakers for my "hybrid" HT/Audio system. I have things wired such that the Yamaha FRONT pre-outs are connected to the C162 pre-amp ("AUX" inputs), then thru the C272 amp, which drive my Energy RC-30 fronts. My Sony DVP-NS90V "universal" player's (2-channel) analog output's are connected to the C162 pre-amp ("CD" inputs). The Sony DVP-NS90V digital coax audio output, and 5.1 analog multi-channel pre-outs, are connected to the Yamaha receiver inputs, respectively.
This way, I can switch the NAD pre-amp for "CD" to listen to 2-channel audio, exclusively, thru the NAD pre-amp/amp combo, to the Energy RC-30 fronts. For watching DVD movies, or playing DVD-A's, I power-ON the Yamaha receiver, switch the NAD pre-amp for "AUX", and I get nice high-quality surround sound (thru combination of NAD and Yamaha amps). For SACD's, I only switch the Yamaha receiver for "MULTI-CHANNEL INP", and audio is played thru combination of NAD and Yamaha amps.
Seems "messy" but actually functions very nice and clean, easy to "switch" from one format to another, all, to get the best of both worlds."

Scooter123
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Re: Two amps connected to same speakers

First, I must say that I do NOT know enough about the specific voltage levels of the various inputs available to say whether this scheme is safe. However, I do know enough about what goes on concerning inputs to point out the potential areas that could cause a problem. I see two potential problems with employing this type of connection scheme.

First, there is noise. In this scheme your passing the source signal thru 2 seperate pre-amplifiers. I suspect that this will cause an increase in noise. Maybe not enough to matter but it's also possible that you may start hearing police radios or cell phone signals in the background of your music.

The second is that you may risk overloading the input stage on that second pre-amplifier. I cannot say for sure if that will happen because I do not know if Line Level inputs are designed for the same level of signal voltage as an Amplifier Input. If they are, using this scheme is perfectly safe. However, if Amplifier Inputs are designed for a higher signal voltage than a Line Level input then using a pre-out to feed a Line Level input could result in your overdriving the input. Which could result in a very nasty sound due to clipping or damage to the second pre-amplifier.

Those are the reasons why I recomended using your pre out taps to feed a second amplifier directly without any intervening second pre-amplifier. Less noise and no risk of overloading the inputs because pre-outs are designed to feed directly into an amplifier. The only problem with doing this is that your only way to "match" the sound levels of the 2 amplifers is either by using a "fader" built into your primary pre-amplifier or by "getting lucky". BTW, the chances of "getting lucky" are probably pretty good because amplifier inputs should be designed to a "standard" level, which means any variation in input sensitivity should be pretty small. I also think that it's fairly likely that your Yamaha already has a "fader" for the Zone 2 and 3 outputs so dig out that manual and check.

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