Thoughts on 2 channel amp for home theater?

bansheesho

What are your thoughts on adding a 2 channel amp to my 5.1 setup? This is my first venture into external amps. Would it sound weird to power the left and right channels with an external amp such as an adcom gfa-555 but leave the center and the rears to be powered by the receiver (keeping in mind that the receiver is a sc-25).

I mostly use this for HT, but do listen to music as well. Setup is in my signature. The goal is to tighten up the bass and improve the overall sound stage, depth, clarity, ect. Also just for fun and the experience of it.

snake1

Sounds like a good plan to start with. One of the main advantages (aside from the obvious) to putting your towers on an external amp is that you free up power in your AVR to use elsewhere like center and surrounds. It will not sound weird or unbalanced. Your question mirrors one of my main questions a few months back before I ventured toward external amplification. You'll probably love the results especially for music!

txcoastal1

Those Kef's are pretty efficient running 91db@8ohms and are having no problems being powered by the SC25 ICE amps. This is where "welcome to the rabbit hole" comes into play because if you are looking for particular changes there are dozens of configs that maybe related and not neccesarily an amp will fix. First of all I would work on room and positioning tweeks, examples: toe in, spikes or no spikes, reflections, etc., setting with the SC25 may help conciderably....start cheap and work your way out. Timber matching your rears would also be a start.

Continue with posting more details on your room setup and settings and maybe some pics

bansheesho

I did notice that the power recommendations were fairly low on the speakers when compared to some others (15-200w). My room is a nightmare for sound, and there isn't much I can do about it due to space constraints. I am not particularly unhappy with them.. I know they could sound better with a better room (its really not fair to them), but they sound nice even in a crappy situation.

If I can spend $250 and get some improvement and have some fun then it might be worth it

specd_out

I added a 2ch amp to my vsx-32. Best thing I ever did. Nice improvement for HT but a massive upgrade in the music department.

Face

txcoastal1 wrote: »

Those Kef's are pretty efficient running 91db@8ohms and are having no problems being powered by the SC25 ICE amps.

Being efficient doesn't mean they're easy to drive...it just means, they're efficient.

I measured the KEF Q900's frequency response in the farfield with DRA Labs' MLSSA system and a calibrated DPA 4006 microphone. The Q900's voltage sensitivity is specified as 91dB/2.83V/m. My estimate was slightly lower, at 90dB(B)/2.83V/m, but this is still usefully higher than average. The speaker's impedance is specified as 8 ohms, but as fig.1 shows, the impedance drops to 4 ohms in the top octaves and to below 4 ohms in the lower midrange, reaching a minimum value of 3.17 ohms at 160Hz. There is also a combination of 5 ohms magnitude and ?42? electrical phase angle at 80Hz, meaning that the KEF does need to be used with a good 4 ohm?rated amplifier or receiver.

http://www.stereophile.com/content/kef-q900-loudspeaker-measurements

txcoastal1

I stand corrected, but you may have to raise the budget for a decent 2 chnl amp

bansheesho

Yeah, I know $250 is chump change for an amp. I found an adcom gfa-555 locally that seems to be in good condition. I have also been keeping an eye out for carver amps in the $200-300 range. I understand that they are older amps and may need repair in the future.

I would prefer something like a parasound with a 12v trigger or a new emotiva, and maybe that is in the cards later on if I like what I hear. I am just interested in getting in the game at this point... test the waters.

Sherardp

I run a D-Sonic 1000S to my fronts and power the rest off a Sunfire TGA5200 with excellent results. I initially started with Outlaw M2200 Mono amps on my fronts, and they did very well for me also. Get into it, you will love separates.

Monster Jam

IMO - If your main usage is HT I would shoot for a 3-channel amp to run FL,FR,C and power all other channels with the receiver, or I would equally amplify all channels. Primary point being that the center channel in HT might be the most important channel to amplify.

playback

This is a great way to improve your setup , I got started on my journey to full blown separates with a Denon avr3200 ( They don't make em like that anymore) and an Parasound hca2003a and latter added Adcom gfa555 which I liked better on music at times for such an old amp, truly built to stand the test of time, go for it!

bthogan

Allow me to be the PITA who suggests getting a Parasound instead - 2 ch or multi. There's a bunch on ebay atm (both kinds). Just moved to one from an Adcom GFA-545, and the improvement (for music) was quite noticeable. Quite noticeable. Plus, they've got "THX Certified" stamped all over them. The Parasound HCA 1000A has a bit less power than the Adcom GFA-555, but it's got a lot of current, and can be had for $200-$250.

bansheesho

All suggestions are welcome... I am also looking at parasound, sunfire, emotiva, carver.... Just keeping my eyes open for a good deal on something in the 200-300 wpc range. Ideally it would be a 3-5 channel amp but if i can pick up a good 2 channel I will jump on it.

tonyb

http://chicago.craigslist.org/chc/ele/3385239430.html

The guy is a tad bit over the top in his description, but for 3 bones it's a decent amp.

EndersShadow

tonyb wrote: »

http://chicago.craigslist.org/chc/ele/3385239430.html

The guy is a tad bit over the top in his description, but for 3 bones it's a decent amp.

True but given the customized faceplate I would worry about what might have been added (or messed up on) to the internals

bansheesho

Hahaha.... It sounds like he snorted a few lines before he wrote that. I was looking into tfm-25, 35, 45, 55 (and their gaugeless counterparts) ... Nothing good in the area at this time.. there were some good ones a while back, but it just wasn't in the cards then.

bansheesho

Anyone know if you can bridge a Sunfire Cinema Grand (200wpc 8 ohm x 5 channels) into a 3 channel amp with 2 channels to each front speaker and 1 channel to the center?

Are these good sounding amps? I would assume that they would be similar to the carver tfm series amps... yes no? Also, anyone know how hard it is to change the bulb on the gauge?

EndersShadow

bansheesho wrote: »

Anyone know if you can bridge a Sunfire Cinema Grand (200wpc 8 ohm x 5 channels) into a 3 channel amp with 2 channels to each front speaker and 1 channel to the center?

Are these good sounding amps? I would assume that they would be similar to the carver tfm series amps... yes no? Also, anyone know how hard it is to change the bulb on the gauge?

Sunfire stuff is good and lots of folks here have them. In regards to changing out the bulb I think its decently easy if your handy. CarverAudio.com/Forums is where you want to go as I am sure they have instructions somewhere. Bunch of us from this forum frequent that one, so you'll probably have a link shortly.