Which power amp?

[Scott Andrew]

Ok, so I have the Pioneer 1014 matched up to a bi-amped pair of B&W 604's, with B&W 602 surrounds, a B&W LCR600 centre and a Dr HSU VTF-3 subwoofer. But the problem is I am not getting enough "punch me in the face" power from my mains. So I am thinking I need to get a separate 2 ch power amp for them but the problem is that I have no clue about simple power amps... any ideas? With a price tag that matches what i already have...

 

[tomd51]

Hi Scott;
I just suggested the following on another thread over at HTF:

For $180 shipped, the Behringer A500 Reference Studio Power Amplifier is a great deal for a 130w 2 (8 ohm mode) channel bridgeable amp. Even better in 4 ohm mode (180 watts @ 4 ohms @ 20Hz @ 0.056% THD).

This is one heck of a good amp for very little money. Here's a good writeup on it over at AH, give it a read...


This will give any sub $2000, pre-amp capable receiver a shot in the arm to power your mains. You can spend a bit more on a more powerful 2 channel amp, but you're likely to get any better performance and I can almost guarantee you won't find anything with this kind of performance at this price... -TD

 

[brendy]

Only thing I noticed was that all of the measurements are at one frequency and most with one channel driven.A more valid and meaningful method would be with both channels driven over 20hz to 20khz.

 

[tomd51]

There's other extensive test results here and over at AVS as well. Regardless, this is a pretty standard means of measurement for most amps as well as A/V receivers.

The general consensus of those that not only have performed testing on this but also own it is the price for performance of the Behringer is very impressive... -TD

 

[j_garcia]

Tom - 230w at 8 Ohms, not 130w Even if it "only" does 175-200w at 8 Ohms, it would be plenty for the 600s.

 

[WmAx]

Only thing I noticed was that all of the measurements are at one frequency and most with one channel driven.A more valid and meaningful method would be with both channels driven over 20hz to 20khz.

I wast transcribing the measurement graphs to text report. The actual graphs showed THD in detailed sweep plots. The measurements are absolutely meaningful, as I also gave the both channels driven maximum output at 1 percent THD. The measurement were not at one frequency. I selected 20 hz, 1000 hz and 20000 hz as the points to give THD data, since this encompasses the human hearing range(and would make obvious slew-limited/TIM distortion at 20khz if it was an issue). The difference in THD from one point to the next is essentially linear in change in the graphical plots of THD. The amplifier was tested into highly reactive loads(which almost no other place bothers to do, but it is a critical factor in performance with some speakers).

-Chris

 

[mike c]

so what is your budget? aside from the behringer, if you want brand name recognition - most people look at Rotel amps
you can choose from 130w x 2 RB1070, 200w x 2 RB1080, 380w x 2 RB1090, 500w x 2 RB1092
but like jgarcia said, 200w x 2 is plenty for the 600s - it's just that if I were in your position I prefer to buy the max I can so when (an off chance) I decide to change my speakers one day, my amp can still be used.

 

[tomd51]

Tom - 230w at 8 Ohms, not 130w Even if it "only" does 175-200w at 8 Ohms, it would be plenty for the 600s.

John;
I was going on my own 'rough' estimate of WmAx's findings in the link I referenced. In particular:

"120 watts @ 8 ohms @ 20Hz @ 0.030% THD+N, 1 channel driven"

I felt it safe to assume (I know, the bad word...) that it would achieve ~130w @ 8 ohms @ 20Hz well under 1.000% THD for both channels driven. Either way, 130Wx2 should be plenty for the 604s.

There are plenty solid 2 channel amps available without breaking the bank, but considering the price point of the Behringer, this amp's a fairly attractive solution...-TD

ps
Thanks to WmAx for clarifying Audio Critic Magazine's testing results and methods...

 

[eirepaul]

Don't forget about the used market. Good power amps are hard to abuse and generally are built pretty well. I picked up two great used Adcom power amps (one off e-bay and one off Audiogon) for half of what they retailed for. Both units were in mint condition. The Adcom GFA 555 II is a great 200w/ch stereo amp, built like a tank and can be had for around $400 or maybe less.

 

[tomd51]

Good point, eirepaul...

More than half my equipment is either used or refurbished allowing me a better product than I could afford new. I've had my Outlaw 755 (used) for over a year and a half and my HK PA2000 (refurb) for amost 3 years and they both work like a champ. Amps hold their value and rarely have problems... -TD

 

[WmAx]

John;
I was going on my own 'rough' estimate of WmAx's findings in the link I referenced. In particular:

"120 watts @ 8 ohms @ 20Hz @ 0.030% THD+N, 1 channel driven"

I felt it safe to assume (I know, the bad word...) that it would achieve ~130w @ 8 ohms @ 20Hz well under 1.000% THD for both channels driven. Either way, 130Wx2 should be plenty for the 604s.

There are plenty solid 2 channel amps available without breaking the bank, but considering the price point of the Behringer, this amp's a fairly attractive solution...-TD

Yes, it is safe to assume such, because the unit outputted 138 watts per channel with BOTH channels driven @ 8 ohms @ 1 percent THD.

Thanks to WmAx for clarifying your testing results and methods...

They were not my testing results, they were the results from The Audio Critic.

-Chris

 

[WmAx]

Don't forget about the used market. Good power amps are hard to abuse and generally are built pretty well. I picked up two great used Adcom power amps (one off e-bay and one off Audiogon) for half of what they retailed for. Both units were in mint condition. The Adcom GFA 555 II is a great 200w/ch stereo amp, built like a tank and can be had for around $400 or maybe less.

I don't know about the Mark II version of the GFA-555, but the original version was under-rated in power. At least 2 independent publications found that the unit actually output around 240-250 watts @ 8 ohms per channel when measured. I have used one to drive 2 ohm(actual nominal 2.8 ohms impedance calculated) subwoofers in a home theatre application and the unit did so perfectly, even at high continous SPL[as a torture test I played bass demo CDs for a period of time to see if the amp would overheat/shut down]. Seems to have no problem with low impedance loads.

-Chris

 

[tomd51]

Yes, it is safe to assume such, because the unit outputted 138 watts per channel with BOTH channels driven @ 8 ohms @ 1 percent THD.


They were not my testing results, they were the results from The Audio Critic.

-Chris

Thought it would be better to be more conservative on the ratings than overstate them.

Thanks again, Chris, I forgot you got these from Audio Critic, I've gotta correct that... -TD

 

[wire]

Don't forget about the used market. Good power amps are hard to abuse and generally are built pretty well. I picked up two great used Adcom power amps (one off e-bay and one off Audiogon) for half of what they retailed for. Both units were in mint condition. The Adcom GFA 555 II is a great 200w/ch stereo amp, built like a tank and can be had for around $400 or maybe less.

Great point .
There is some good stuff out there on the used market , for a good price and i agree Most amps are built like tanks . I have a Bryston 4b its age is 20 + years and had in for a check up just before the 20 year warrenty was up and the replaced the power switch and was givin a good bill of health ( this amp is a tank ) .
I picked up a Carver TFM 35 for $ 300 US off Audiogone and this is a great sounding amp 250 rms per channel ( high Current ) .

 

[biz97]

Great point .
There is some good stuff out there on the used market , for a good price and i agree Most amps are built like tanks . I have a Bryston 4b its age is 20 + years and had in for a check up just before the 20 year warrenty was up and the replaced the power switch and was givin a good bill of health ( this amp is a tank ) .
I picked up a Carver TFM 35 for $ 300 US off Audiogone and this is a great sounding amp 250 rms per channel ( high Current ) .

Wow, 20 years.... That IS a quality amp.... wish they still made stuff that lasted that long

 

[zildjian]

Wow, 20 years.... That IS a quality amp.... wish they still made stuff that lasted that long

Bryston still does, well... I can't prove one of their current amps will last 20 years cause we're not there yet, but they still have that 20 year warranty and their amps are excellent performers. They are a stand behind their product company if I ever saw one.

 

[BigGuy]

Big fan of the Bryston myself, My brand new 9BSST and SP1.7 Both have a 20year warrantee on them, transferable as well. For used, Bryston would be a great option due to their transferable warrantee! I'd agree that used amps are a good way to go to save some money, as long as your looking at good quality amps.. not so sure if i'd buy a Berhinger A500 with a 1 year warrantee used, considering their price new, lol. The Rotel 1077 that I tried out was also a very nice amp, but I liked the sound of the Bryston better (different price point though)

Brian