Amp advice??

neilinnh

So I’ve been lurking/learning on the forum for a little while now and have been convinced of the need for a separate amp. I’m currently running a 5.0 system consisting of Polk RTiA7 fronts, CSiA6 center, and A3 surrounds. No SW because of SWMBO (she who must be obeyed). Running it out of a Marantz SR5002 (90 wpc) with the A7’s bi-amped. Also have a mid-grade Sony SACD, lower end Sony BD and 50”Samsung plasma.

I like the sound of the set up with caveats. The Marantz sometimes goes into protect mode (shut down) during louder movie sequences. I’m assuming this has a lot to due with not having a SW as it doesn’t happen with music which is 75% to 80% of my listening. So it’s not the end of the world but frustrating none the less. With music, I’m even happier with the setup except that I like it LOUD. Like feel it going through you loud and I can’t quite seem to get that power out of the Marantz.

So what to buy? I’m looking to buy used (ebay/audiogon) with a budget around $500. Could go a little more for the right reasons but really rather keep it under. I’m looking for something that would fit with my mostly music listening. A Sunfire would be my dream but they seem way out of my budget. Maybe a later upgrade. I’ve also seen a couple Marantz MM9000 that I thought would match well with my current Marantz. I know Marantz has a “musical” reputation, but I’m not sure if 5X140 wpc is going to cut it. Also concerned about the honesty in that number as its total power consumption is 400 watts.

Outlaw and Emotiva are in my range and at 200 wpc seem to have the power but some have said they’re a little harsh on the music side. But do I really need 200 wpc to drive the A7’s? I accept I’m not getting 180 wpc with my current bi-amped Marantz, but I’ve got to be getting 120-140 right? I see a lot of stuff in the 100 to 125 wpc range that fits my budget but I’m not sure that would be an upgrade. Am I right, am I wrong? Any advice and insights appreciated.

ps Also thinking that I want 5 channels as it would leave me with the option to bi-amp the A7's if necessary but would settle for a 3 channel if I was convinced it would do the job.

cstmar01

a 3 channel amp would beat out an AVR that is bi amp with no problem. You are also not doing a true "bi amp" as you are using the same power supply which in turn doesn't really do much.

I would say get a 3 channel amp and then run the surrounds off the AVR. You could also just go with a stereo amp and run the center and surrounds off the AVR as well, but normally its nice to do the front three.

The one thing I would say though is you are missing out on a lot by not having a sub. It makes a world of difference when doing movie playback and can also be good if doing a 2.1 system for music.

Personally I would say get a sub before getting an amp, however its up to you what you want to do.

NewHTguy

cstmar01 wrote: »

You could also just go with a stereo amp and run the center and surrounds off the AVR as well, but normally its nice to do the front three.

I'm doing this. For me it is the most economical way to have good stereo amplification in a double duty system. After all, it is the fronts that need the power, especially with no sub. I can't imagine your Marantz not having enough power for a large center and a couple of surrounds. Of course, if you find a good deal on a three channel, that's also a good option.

PrazVT

The RTi A7s have great bass once they're paired with a nice high current amp. I only listen to music w/ the A7s. The sub is only used for movies. And even then, I could live without it. So I think you'll be ok neilinnh.

With regards to wattage - Your receiver is never going to be putting 90w or 100w x 5. It'll be some fraction of that. So a nice high current 100w x 5 power amp is going to be better than a "100w x 7" receiver. That 100w is probably only when driving 2 speakers - and it's probably not high current.

ie. current more important than wattage.

I would think something like a Parasound HCA-1205A (140w x 5, 45 amps, ~$595 on Audiogon) would work

Or

a NAD 925 (125w x 5, $465 on Audiogon) would work as well.

Just my 2 cents.

neilinnh

So I'm having a little trouble getting my head around the watts vs. current thing. I get that most receivers share a power supply that is generally not high current but I guess I was under the impression that most if not all dedicated amps were high current. If this isn't the case how do I distinguish? Is this why the MM9000 Marantz amp is rated at 140 X 5 but only uses 400 watts of power?

I'm also very happy with the bass of the A7's even in movies. The bass capabilities is one of the reasons I went with them. It would just be great if my receiver didn't shut down every time there's an explosion

PrazVT

Here is a high level explanation

neilinnh

Thanks for that! Very enlightening.

tonyb

Very good video btw, we should incorporate that into a sticky somewhere.

jayman_1975

How about the Marantz monoblocks. MA500 i believe. My bro inlaw has 6 of them and they sound excellent. He was previously using his Marantz receiver to power everything but since he added the monos he can listen at louder levels without losing control of drivers.

PrazVT

Very good video btw, we should incorporate that into a sticky somewhere.

Yeah - I stumbled onto it when I was doing some Parasound googling. there are a few more, though not all as technically useful perhaps.

Gulfstrings

I think Spirit Sound had the 5 channel NAD T955 refurbed below $600 a couple weeks ago. New, they're $800. Very musical IMO with my setup, which is similar to yours.