The benefits of using a Power Amp

[stevee1966]

I don't really know much about this and haven't found too much on the net in terms of explanations so thought i'd throw the question out to the forum.

What are the benefits of using a Power amp in combination with an integrated amp, in comparison with just using an integrated amp on it's own. For the normal hi-fi user in the environment of their own home, and therefore maybe not the biggest of rooms etc, and maybe not the highest quality components, what does the addition of a Power amp add to the listening experience.

Thanks

 

[nopiano]

I've never tried it other than experimentally with something weird like the original NAD3020 into a Quad405, and the only significant benefit is more output.

I personally find pre and power only possibly worthwhile at several thousand GBP cost level, though one or two honourable exceptions may exist. As you can see I use a powerful integrated, which although aging, still shows many pre plus power combinations the way! So, consider me biased based on my own experience. There are too many opportunities for weaknesses, such as cabling and hum pick up, but it can be a tweakers delight.

 

[Kefref]

I too was considering adding a power amp, and nearly bought a used 8200s yesterday (but after spending about £900 recently thought i better not!)

Currently running ~ Marantz CD6005 + MAudio 410 Audio PC > Audiolab M-Dac > Audiolab 8000s > Audioquest FLX Slip 14/4 > Refurbished Kef 104/2's (Custom made Interconnects and 75ohm Coaxial Cables)

My thought was maybe the 104/2's would benefit from the additional juice from an 8000s or 8200s power amp?

Id be interested to hear some opinions.

 

[bluedroog]

Often there is little benefit as tweeters usually only account for about 5% of the amp load, with a three way speaker you'll feel more benefit. Also if the power amp is of a different brand you risk dis jointing the sound if they have a different sound signature. I'm not saying there is never any benefit and in some circumstances you can have great results, it just depends.

if you have mono power amps in parallel you'll get far better control but now we're talking about a whole other area and much more costly.

 

[abacus]

If your speakers have 2 sets of terminals with links between them, then another matching power amplifier will certainly have benefits as you can use it to bi-amp the speakers (Not to be confused with B- Wiring which has no proven benefits whatsoever) by using the power amplifier for the bass and the integrated for the treble. (It also has the advantage of relieving pressure on the integrated power supply, thus allowing more power and less interference for the integrated pre-amplifier)

The biggest benefits are had with lower priced amplification, as they will have less muscle and a less developed power supply than more expensive integrated amplifiers.

NOTE: for this to work the gain of the power amplifier must be the same as the integrated or an imbalance in the sound will occur. (Also note that some manufactures create a characteristic sound for their amplifiers, rather than being neutral, so it is best to stay within the same manufacture when combining amplifiers)

Hope this helps

Bill

 

[davedotco]

If your speakers have 2 sets of terminals with links between them, then another matching power amplifier will certainly have benefits as you can use it to bi-amp the speakers (Not to be confused with B- Wiring which has no proven benefits whatsoever) by using the power amplifier for the bass and the integrated for the treble. (It also has the advantage of relieving pressure on the integrated power supply, thus allowing more power and less interference for the integrated pre-amplifier)

The biggest benefits are had with lower priced amplification, as they will have less muscle and a less developed power supply than more expensive integrated amplifiers.

NOTE: for this to work the gain of the power amplifier must be the same as the integrated or an imbalance in the sound will occur. (Also note that some manufactures create a characteristic sound for their amplifiers, rather than being neutral, so it is best to stay within the same manufacture when combining amplifiers)

Hope this helps

Bill

From a practical point of view I have always found bi-amping to be much better in theory than in practice. Unless you increase the power of the bass amp considerably, I have found the improvement to be mostly illusory.

I accept that others have different views (Hi Bill..*give_rose*), I add my comments just for balance. In general I find differences in power amplifiers to be very small, if they are of comparable power and standard they tend to make very little difference, unlike pre-amps (or integrated) which is where, generally, any 'designer voicing' will take place.

 

[Kefref]

Apologies for hyjacking your thread, hope you dont mind me jumping in

So is it the case that the result of such an upgrade will very much depend on the type of speaker system used? A smaller 2 way for example is unlikely to benefit as it does not have as much of a power requirement where as a large 5 way speaker (like a set of kef reference series for example) may well benefit from the additional power available from the power amp.

Obviously the type of amp will have an influence as well.

Unfortunately I do not have the option of bi-wiring the 104/2's unless i change the crossovers which i dont want to do, so the addition of an Audiolab 8000p to the 8000s was being considered. An 8000s can be picked up 2nd hand for about £100-£150. These are all gain matched so would be a perfect addition.

But the question is whether i would hear any benefit...I would have thought any gains would be from the bottom end? Anyone else went down the same upgrade route?

 

[davedotco]

Apologies for hyjacking your thread, hope you dont mind me jumping in

So is it the case that the result of such an upgrade will very much depend on the type of speaker system used? A smaller 2 way for example is unlikely to benefit as it does not have as much of a power requirement where as a large 5 way speaker (like a set of kef reference series for example) may well benefit from the additional power available from the power amp.

Obviously the type of amp will have an influence as well.

Unfortunately I do not have the option of bi-wiring the 104/2's unless i change the crossovers which i dont want to do, so the addition of an Audiolab 8000p to the 8000s was being considered. An 8000s can be picked up 2nd hand for about £100-£150. These are all gain matched so would be a perfect addition.

But the question is whether i would hear any benefit...I would have thought any gains would be from the bottom end? Anyone else went down the same upgrade route?

Yes, many times.

The limitations with Audiolab amplifiers has always been the preamp section, the slightly dry, matter of fact style comes from there. The power amps are all ok, if you need the extra power the power amp might be worthwhile, debateable really.

Given the relatively low cost, buy a set and try it out. You will learn a lot from the 'hands on' experience, you can try single amp and bi-amp option, lots of fun.

 

[TatuHoo]

I had Nad 356 Bee and considered that I should try out how it would perform as a mere power amp. So I made my Marantz 1604 to be pre-amp to the left & right front channels. It added to the quality of sound clearly; Marantz was offering nice tweaks and NAD just doing what it dioes best, the main amplification.

Now I have Audiolab 8000q & 2 pcs Audiolab 8000M's. I have to say, the combo delivers fantastic sound. And Marantn 1604 uses this combo to drive front channels too. Very good and perfectly working solution.

cheers

 

[stevee1966]

my situation is the equipment i have in my signature, in a room 5m wide by 4m, so a listening position about 3m from my speakers.

Thinking of going down the route of Roksan M2 power amp to match my integrated one, to then bi-amp my speakers.

In the small room i use, would i hear an improvement ?

Planning to chat with Roksan at the Bristol show, though the cynic in me thinks they'll tell me anything if it gets them a sale.

 

[TrevC]

The only difference between a power amp and an integrated used at line level is the volume control and source switching is in the same box on an integrated. Can't see how that would matter. Biamping passively, ie no active crossover, is effectively turning two amplifiers into one, with no output power, or any other, advantages.

 

[TrevC]

my situation is the equipment i have in my signature, in a room 5m wide by 4m, so a listening position about 3m from my speakers.

Thinking of going down the route of Roksan M2 power amp to match my integrated one, to then bi-amp my speakers.

In the small room i use, would i hear an improvement ?

Planning to chat with Roksan at the Bristol show, though the cynic in me thinks they'll tell me anything if it gets them a sale.

No, it will make no difference except to your wallet. The maximum power available will be the same as one amplifier.

 

[SteveR750]

my situation is the equipment i have in my signature, in a room 5m wide by 4m, so a listening position about 3m from my speakers.

Thinking of going down the route of Roksan M2 power amp to match my integrated one, to then bi-amp my speakers.

In the small room i use, would i hear an improvement ?

Planning to chat with Roksan at the Bristol show, though the cynic in me thinks they'll tell me anything if it gets them a sale.

I couldn't really hear any benefit of bi-amping with an M2, certainly not worth the £700+ on a used one, let alone new. Bridging into twin mono blocs might be more interesting

 

[stevee1966]

So one amp connected to the speakers High Frequency and the second to the speakers Low Frequency will make no audible difference or give any benefit from the sharing of input power ???

 

[TrevC]

So one amp connected to the speakers High Frequency and the second to the speakers Low Frequency will make no audible difference or give any benefit from the sharing of input power ???

Correct. The output power available will be the same as one amp if both have the same wattage rating. If one has a lower rating, the maximum power available will be the same as that of the lower powered amp.

 

[davedotco]

So one amp connected to the speakers High Frequency and the second to the speakers Low Frequency will make no audible difference or give any benefit from the sharing of input power ???

Pretty much.

The 'sharing' of the power really does not do anything, given that, for an average two way, with a crossover in the 2-3khz region, pretty much all the power will be supplied by the bass amplifier anyway, this is simply to do with the energy distribution in music, only a couple of percent of the energy will come from frequencies higher than the crossover point.

Other than that, the arguement is similar to the one involving bi-wiring the 'science' behind the use of separate return paths for each driver doesn't really stand up and the superiority of bi-wiring has never been shown in a blind test, so you are down to subjective opinion only. Make up your own mind on that.

 

[matt49]

IMO there aren't that many circumstances where a separate power amp makes sense. Where it does make sense, it'll be because your speakers have specific needs. If your speakers are drastically short of power (and you already have a decent preamp or an integrated amp with pre-outs that doesn’t deliver enough power), then it can make sense to invest in a separate power amp. Otherwise I wouldn’t bother.

By way of an example, last year I switched to electrostatic speakers, and my amp simply wasn’t delivering the required voltage. I found an amp designed to drive ESLs, which, as it happens, is only available in the form of a power amp, not an integrated. It's turned out to be a huge step up.

But this is an extreme case. In most cases a decent integrated amp will be fine.

 

[stevee1966]

Thanks to all for your input and advise. Looks like i'll now be saving myself some money.

 

[jiggyjoe]

I would give the the bi-amp option a go with the rx6, The rx6 is wired a bit different from the norm.

The upper terminals feed both the tweeter and the upper mid bass driver, while the lower terminal feeds the lower bass driver.

When single amped the load seen by the amplifier is 4 ohms through the bass/lower mid region because the mid/bass units are working in parallel. If you bi-amp the rx6 the impedance minimum now raises to 8 ohms, because each amp channel is now only driving one mid/bass driver, making the speaker considerably easier to drive.