RB 1080 or 1075?

[shadow]

I am thinking of adding one of these amps to my 1056 to drive my front speakers (ML Aerius i and Cinema). I have participated in the threads in which the 1080 is favored over the 1070 stereo amp. However, since the center channel is the most important channel in HT or multi channel music, I would think having the additional amplification for the center would be preferred. There is a three channel Rotel amp on ebay now but it appears to be older. If I got the 1075, I would likely use it only for the front speakers and let the 1056 drive the two surrounds. Any opinions/advice?

[dermie999]

As I understand it (and this is what prompted me to go the 1080 plus 1075 route) the 1080 is a great 2 channel amp and so if you use it to drive your fronts then you will have great 2 channel music. The 1075 is a great HT amp so use it to drive your rears and centres. Works really well for me I get great music and great HT.

[shadow]

Well, as I pointed out, if I get the 1075 I will use it for the front three channels only. The 1080 may or may not be better than the 1075, but I question its utility if it cannot also amplify my center channel.

[aud19]

Are your speakers bi-wire/bi-amp capable? If so go for the 1075 and bi-amp your mains. Or go 7.1 Sounds like your more of a HT user as opposed to stereo anyways....right?

Jason

[audiofan]

Are your speakers bi-wire/bi-amp capable? If so go for the 1075 and bi-amp your mains. Or go 7.1 Sounds like your more of a HT user as opposed to stereo anyways....right?

Jason

aud19,
How do you bi-amp 1075? My buddy's speaker has biding-post and he has 1075 as well. I'm interested in learning how. Thanks.

[Aussie Geoff]

Bi-amping and Bi-wiring with the 1075

Audiofan,

Bi-amping the left and right speakers - Get two complete separate runs of speaker cable (identical is best to my ears). Connect one to earc pair of binding posts (e.g. Left and surround left). Run the cables to the same speaker. Remove the joiners pins / wires on the speakers between the two binding posts. Connect one pair of cables to the top pair of binding post (red to red, black to black). Do the same for the bottom pair. Repeat process for the right speaker

This will have used up 4 of the 5 channels of the 1075. You can bi wire the centre channel if you like which will help it sound more like it's bi-amped cousins. THis requires special cables with one set of bananna plugs on one end and 2 sets on the other - essentially two parallel runs of the same cable joined at one end. OR you can use two cable runs with spades one one end of one pair and bananna plugs on the rest, as you can connect the spades under the binding posts and the bananna plugs in the same binding post on the amplifier.

Geoff

[shadow]

Geoff, interesting option. Have you tried this in the past and if so, what was the difference in sound biamping over solo amp use? My center speaker has only one set of inputs so biwiring is not possible.

[Aussie Geoff]

Shadow,

Firstly, I forgot one really important point in my comments - how to split the source signal accross the two amps channels. You need a high end splitter, or "Y" cable (RCA -> RCA,RCA) from the Left channel preout of the the pre-procesor or receiver, to the Left Channel(s) input of the 1075. One RCA of the "Y" goes to the Left Main input of the 1075, the other RCA of the "Y" goes to the Left Surround input of the 1075. This will give you your two "amps" for the left main. Repeat this for the right channel.

Secondly, here is a INTERESTING THREAD about HTGuide member "Bing Fung"s journey to bi-amping his 1095 - the 1075's big brother... You will see he did it and loved it....

Geoff

[shadow]

Appreciate the link. Sounds like a good option to try. I noted in the past that some people who tried this type of passive biamping were not impressed with the results. I have had no such experience one way or the other. I hope to try it in the near future.

[Aussie Geoff]

Hi,

My sense is that a lot depends on the underlying quality of the speakers and whether they are truely made for bi-amping / bi-wiring (like the B&Ws) or whether they two binding posts est have been included more for marketing reasons than by sound quality design. Some speaker crossovers just don't work well bi-wired or bi-amped.

Geoff

[shadow]

I suspect my Martin Logans have the biwire ability for biamping. A classic tweak for these speakers has been the use of solid state amps on the woofer and tubes on the panels.

[Aussie Geoff]

Shadow,

I'd definitely try it then - as the panels in speakers like the martin logans tend to have way different impedence / inductance / capacitance characteristics with frequency that the enclosed cones in the bases. True bi-amping is likely to allow each amplifier to better track the changes in driver behaviour...

Let us all know how you go with it!

Geoff

[aud19]

Wow, you got lot's of help since I was here :lol: Geoff rules eh!? Good luck with the bi-amping :T Especially if you go the "true bi-amping" route :drool:

Jason

[ds22030]

I have bi-amped my Polk LSi15 in the manner suggested by Geoff using the 1075. It did make an audible difference for the better....try it, I think you will like it. For pure stereo music, the opinion appears to be that 1080 will do better....but like you said, you lose the center channel amp. Also, you may want to use the little block splitters rather than a cable Y splitter. I have found that my setup is sensitive to cable selection so the more variation I can remove, the better.

[Bonster]

1080 and 1075

This topic is very appropriate for my needs. I'm leaning toward the 1075 in bi-amp'd config to drive my CM4's and center channel. I'll research the y-cable vs. block splitter as I don't know about the latter...

My questions are surrounding the following:

Current:
My system is heading toward 5.1 w/ Rotel RSX-1055 CM4's (mains), LCR 600 S3 (center) and DM 600 S3's (rear)... sub will be added soon.

I know I need an amp for the CM4's... 1075 will give me bi-amp potential on fronts and center...

If I want to add an amp for a second room (outside or downstairs) how do I daisy-chain the amps? I know I have the preouts for the 1075 from the 1055 but how would I go about adding the second room amp? I'm looking at adding the 1050/80 for the second room and using the RSS-900 to switch speakers.

Sorry if this is off topic...

Thanks,

Don

[JDH]

Can't you use the Zone 2 out feature of the 1055?

[hery]

Bonster
I agree with JDH on using Zone 2 out, I have a 1055 with a 1050 amp and speaker selector box with three pairs of speakers in three separate rooms. I'm also reading on closely since I'm planning on adding a 1075 to my HT 5.1 set-up which has CM 4's, CMC and CM 2's, pretty similar set ups.

[Bonster]

expansion plans...

Thanks for all the insight. The light is finally coming on... zone 2 is a pre-out AND can be reassigned to be powered by one of the internal amps in the 1055.

My options are very much in line with the numerous threads being posted for expansion:

1055 + 2 channel amp ie RB10x0 & redirect internal 1055 mains for Z2
or
1055 + 5 channel amp ie RMB 10x5 & redirect internal 1055 mains for Z2
or
1055 + 3(+) channel amp RMB 1048/1066 / or older RB99x models & redirect internal 1055 mains for Z2

Now that I understand the reassignment via redirect it makes sense.

JDH - glad to see someone else has tackled the multiple speaker issue via RSS (?) ... I've read about the IR repeaters and this is yet another path I'll eventually head down.

Bottom line is I've stepped into a very flexible HT/Music system. Just need to digest the upgrade-itis, take it step by step and be happy!

I'll get the RB-1080 next for powering CM4's
Next get the RMB-1075 for HT ... options for 6.1 or 7.1 and Z2 are all availabie with these additional amps.
Then move to the RSP-1068 and move the 1055 off to another room.

All in due time...

Thanks to Andrew and Jason for help on this as well via PM's.

15 years in high tech and it took a brick to hit me to get this stuff :E

Cheers,

Bonster

[audiofan]

Shadow,

Firstly, I forgot one really important point in my comments - how to split the source signal accross the two amps channels. You need a high end splitter, or "Y" cable (RCA -> RCA,RCA) from the Left channel preout of the the pre-procesor or receiver, to the Left Channel(s) input of the 1075. One RCA of the "Y" goes to the Left Main input of the 1075, the other RCA of the "Y" goes to the Left Surround input of the 1075. This will give you your two "amps" for the left main. Repeat this for the right channel.

Secondly, here is a INTERESTING THREAD about HTGuide member "Bing Fung"s journey to bi-amping his 1095 - the 1075's big brother... You will see he did it and loved it....

Geoff

Does it apply to Center Channel (bi-wired) as you mention above?
let say 1075 has 5 pair of speaker output. 2 pair( for example, Front Left and Surround Left) to Front Left Speaker with upper/lower binding post. Another pair to the FR and SR.

How about connect from receiver pre-out to 1075? Any picture drawing would be greatly appreciated. Please forgive for my slow understanding.

thanks.

[Andrew Pratt]

I'm pretty sure you can't redirect the 1055's internal amps to power zone 2...or is my memory failing me again?

[Scherr]

I know that you can redirect the main amps of the 1056 to the second zone, but I don't think that you can do that with the 1055.

Scott

[aud19]

Ooooh maybe not... Bonster check in you 's setup menu if 2nd zone is an option for the redirect or just rears. Andrew might be right that's it's only on the 1056....

Jason

[Eiffel]

Unfortunately, 2nd zone redirection is NOT an option with the RSX-1055 (I didn't know it is possible with the newer unit)

[aud19]

That sucks... Sorry guys. Looks like you'll have to use channels from the 1075 or buy a sperate amp etc for second zone Still do 7.1 though if you want...

Jason