Your Opinion on offloading channels from Yamaha Z7 to AMC Power Amp

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AllenG

441 posts

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#55603 6-Jan-2010 21:11

Hi.

As per my previous thread I've just ordered a Yamaha Z7 reciever to replace my RX-V2500. I was using an 5 x 100W AMC 5100 poweramp to drive the Zone2 speakers and offload the front three channels from the 2500. Do you think this would be a good or bad move with the Z9, or should I offload the surround backs instead?

Yamaha z7, Boston VR2 (LR), Boston VRC (C), Energy RCR (SL & SR), Boston 4HD5 (SBL & R) Yamaha SW200 Sub. Phillips CD650, Sony DVP S735D, TViX M6500A, Oppo BDP83 (on order) Panasonic PT-AE700

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Welcome my Son, Welcome to the machine...
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Yamaha z7, Boston VR2 (LR), Boston VRC (C), Energy RCR (SL & SR), Boston HD5 (SBL & R) Velodyn SPL1200 ultra. Phillips CD650, Sony DVP S735D, TViX M6500A, Oppo BDP83, Panasonic PT-AE700, 120" Fixed screen.

Batman

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#287611 6-Jan-2010 22:38

i think your FLAGSHIP receiver will cope just fine! seems though the speakers are a bit undermatched - coz they're the tyres of a car - the final link. if you wanna use those amps - use them for the front 3 i'd say, but there's no need to

AllenG

441 posts

Ultimate Geek

#287627 6-Jan-2010 23:18

Cheers Joker97.

Which speakers are you referring to? all of them? I know the HD5s will be in for replacement next.

I don't have the budget for $20K speakers.

I'll try the yami driving everything, I just thought I'd get better "All Channels Driven" power levels by offloading some channels?

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#287635 6-Jan-2010 23:43

well i guess you're right - any 'better' speakers will need a mortgage in new zealand! but if you want my opinion, the weak link is your sub. if you really want good (not just loud but effective) bass get 2 identical subs that'll go down to at least the low 20's Hz esp if you have a large room (1 is ok for small/medium rooms). [i actually am doing a half educated guess as nowhere does it list the freq response of your sub on google - but 100W can't possibly generate that much deepness??]

unless you're going to max out your volume (well i dont know, perhaps you really have a HUGE theatrical room) the Z7 is not going to clip. but the 4 surround speakers dont produce sound all the time you see. the center speaker produces 70% of movie sounds.

AllenG

441 posts

Ultimate Geek

#287675 7-Jan-2010 08:51

Thanks.

I have detailed my room in another thread asking for opinion on my choice of Energy RCR surrounds here. http://www.audioenz.co.nz/forums/showthread.php?t=9537

The room is 6m long by 4m wide x 2.5m ceiling, so only a medium size.

The sub is 16 yrs old, and the frequency response is 20Hz to 160 Hz (-10db). -3db specs not listed.

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#287695 7-Jan-2010 09:37

sounds like your sub is okay, and more importantly, there is no way (unless a deaf man arrives and all the neighbours have left town!) your amp will even be remotely stressed! the Z7 is very highly capable!

my biased opinion against preamps is that when there are multiple connections, you have multiple chances of 'losing' sound signals unless you have near-perfect interconnects. but if you don't believe in interconnects and you really want to use the AMC - you're more than welcome to, esp if you believe they will sound better. again, use it for the front 3.

regarding zone 2, you might find it is 'easier to control' those speakers i guess, if you have a separate amp. but if you're going to run 7.1 on the home theatre you WILL need the separate amp for zone 2 wouldnt you?

mailmarshall

349 posts

Ultimate Geek

#287873 7-Jan-2010 19:41

Hi AllenG

Unless I am missing something you don't really need the second amp. As I mentioned I have the z7 as well and with the second zone setup for outside speakers. I use the second remote to that came with the system for controlling volume etc.

You will love the z7. Its my one hub for all gadgets (wii, xbox,dvd etc) and it outputs to my tv and projector. I dont have have a Bluray player but would love that OPPO one.

AllenG

441 posts

Ultimate Geek

#287948 7-Jan-2010 22:50

Hi Joker/Mailmarshall.

I will use the Z7 for all 7 channels in a 7.1 setup. I will still need two channels of the AMC for Zone 2.

Heres some history that explains why I have the AMC Poweramp.

1987 or so, built my own 150W mosfet stereo amp from ETI or Electronics Australia design. Masked up and printed own circuit boards. Used same J49, K134 Hitachi mosfets as the high-end NZ amps of the time, also had custom wound 500VA Toroidal transformer and seperate +/- 55V DC rails for each channel with a 22000uF cap for each rail (4x)

1994 bought Yamaha A1000 Prologic Reciever, Used stereo amp with A1000 to even up power across all 5 channels.

1999 Toroid in stereo amp shat it's self as did rewound transformer after short time. Added AMC Dolby Digital Decoder and 5 Ch AMC Poweramp to A1000 to get DD.

2005 upgraded to RX-V2500, still using AMC for 3 front channels and 2 x zone 2 channels.

2010 Z7 and AMC relegated to Zone 2!!!

Below are links to a couple of pics of the homebuilt amp that I cant bear to get rid of. Just needs a new power transformer.

Pic1, Pic2

Regards, Allen.