Another variable is application. You have to choose the correct amplifier for whatever application you want.
For example, if I have a subwoofer array with a 1 ohm nominal
impedance I would not choose an entry level amplifier whether home or pro audio. I would choose the pro amplifier with 'bigger
hardware' which is not the entry level models.
What if I'm tri-amping or bi-amping where the tweeter is operating with it's own amplification. Does a simple dome tweeter need 'big hardware' to operate well? ........ no ...
You can use a lower powered amplifier. You can also use an entry level pro amp and get a great value for the money plus they have alot more headroom for the money.
Since someone brought up automobiles as a comparison. Again,
application is important. That Ferrari would be a nice car to have but it would not make a great towing vehicle. You won't be able
to tow horse trailer effectively so even though the Ferrari is great, it fails miserably in that application.
There is alot of testimonials in the home theater forums where pro amplifiers can sound pretty awesome.
Movie theaters also use pro amps and the sound quality from
the theater is more or less related to proper installation,
ie proper speakers for that application, room acoustics, and
connecting everything up correctly. The amplifier has less effect on the final sound as long as you get the correct power ratings
for the application.
For example, if I have a subwoofer array with a 1 ohm nominal
impedance I would not choose an entry level amplifier whether home or pro audio. I would choose the pro amplifier with 'bigger
hardware' which is not the entry level models.
What if I'm tri-amping or bi-amping where the tweeter is operating with it's own amplification. Does a simple dome tweeter need 'big hardware' to operate well? ........ no ...
You can use a lower powered amplifier. You can also use an entry level pro amp and get a great value for the money plus they have alot more headroom for the money.
Since someone brought up automobiles as a comparison. Again,
application is important. That Ferrari would be a nice car to have but it would not make a great towing vehicle. You won't be able
to tow horse trailer effectively so even though the Ferrari is great, it fails miserably in that application.
There is alot of testimonials in the home theater forums where pro amplifiers can sound pretty awesome.
Movie theaters also use pro amps and the sound quality from
the theater is more or less related to proper installation,
ie proper speakers for that application, room acoustics, and
connecting everything up correctly. The amplifier has less effect on the final sound as long as you get the correct power ratings
for the application.
As a general rule, the emphasis with pro-amps is on reliability, since they spend most of their time at close to full power. Reliability transcends most things, including sonics, and the protection circuitry in pro-amps is comprehensive and sonically intrusive. Waveform compression on peaks is common.
Many high end amps eschew protection in the name of sonics. This is possible because the environment is not demanding by comparison, particularly if the speaker has sensible impedance curves. The emphasis with high end is sonic quality, NOT reliability, and in consequence you can usually, though not always, expect a better sounding amplifier. Together with all the marketing hype, this makes for poorer bang for the buck, but there ain't nothin' for nuttin'........
Cheers,
Hugh
Many high end amps eschew protection in the name of sonics. This is possible because the environment is not demanding by comparison, particularly if the speaker has sensible impedance curves. The emphasis with high end is sonic quality, NOT reliability, and in consequence you can usually, though not always, expect a better sounding amplifier. Together with all the marketing hype, this makes for poorer bang for the buck, but there ain't nothin' for nuttin'........
Cheers,
Hugh
Hugh D. give a good answere to this question .
Only thing that I want to say is that nobody will push to limit a pro amplifier at home .
If we supose that somebody have an 2 x 600w good pro amplifier with all the protection enabled ( limiter , High pass filter etc. ) and will use them at only 10% of all power amount it is obviously that all protections will be usless and will don't have any sonic signature .
The pro amplifier will work better becouse at 10% of power or less the distorsion will be smaller . Only potential problems will be if somebody will use an 1000w amplifier at only 0,5w to drive an high SPL lodspeaker horn .
H.P.Filter will be a good thing ( 24 - 30 Hz - 2th order or more ) for the loudspeaker .
Many pro amplifiers have switching ( ON/OFF ) for Limiters and HP filters .
QSC is just an example .
So , why should anybody will spend the same amount of cash for an audiophile amplifier with only 10 - 20% power compared with a pro - amp if the both schematics topology are the same ?
Only thing that I want to say is that nobody will push to limit a pro amplifier at home .
If we supose that somebody have an 2 x 600w good pro amplifier with all the protection enabled ( limiter , High pass filter etc. ) and will use them at only 10% of all power amount it is obviously that all protections will be usless and will don't have any sonic signature .
The pro amplifier will work better becouse at 10% of power or less the distorsion will be smaller . Only potential problems will be if somebody will use an 1000w amplifier at only 0,5w to drive an high SPL lodspeaker horn .
H.P.Filter will be a good thing ( 24 - 30 Hz - 2th order or more ) for the loudspeaker .
Many pro amplifiers have switching ( ON/OFF ) for Limiters and HP filters .
QSC is just an example .
So , why should anybody will spend the same amount of cash for an audiophile amplifier with only 10 - 20% power compared with a pro - amp if the both schematics topology are the same ?
K-amps said:
Considering that the original poster said
The purpose of the amp is home hi fi. I also have a bunch of tube amps but I am a bit fed up with their heat/biasing/delicate nature.
I don't think there will be any 1 ohn loads.
/food for thought.
I'm able to drive a 1 ohm load with my ancient Adcom 555
in bridged mode. It's only rated for no less than 8 ohms.
How can I do it? I was driving a tweeter array which doesn't consume alot of power and the amplifier is still operating safely.
That said, I can drive 1 ohm loads with many amplifiers assuming they have no protection circuits that detect this condition and
turn off.
Application is key
Someone wondered why pro amplifiers have a better cost per
watt ratio that high end home amplfiiers?
Keep in mind the target market. In proaudio they use alot of
amplifiers to get the job done and nobody in the proaudio industry wants to spend $10,000 - $50,000 for a single amplifier.
Imagine the cost when you need alot of them. The prices are competitive for the hardware you purchase.
But in home audio where the user may only use one amplfier
and they always seem to be on an endless quest for perfection,
they can and do sell > $10,000 amplifiers because the market
demands it.
watt ratio that high end home amplfiiers?
Keep in mind the target market. In proaudio they use alot of
amplifiers to get the job done and nobody in the proaudio industry wants to spend $10,000 - $50,000 for a single amplifier.
Imagine the cost when you need alot of them. The prices are competitive for the hardware you purchase.
But in home audio where the user may only use one amplfier
and they always seem to be on an endless quest for perfection,
they can and do sell > $10,000 amplifiers because the market
demands it.
There is no substitute for having a listen with an open mind. I've heard very high end cost-no-object speakers and amp and the improvement over my "budget audiophile" system with modest amps is modest IMO. I've had a listen to some PA amps on my speakers just out of curiosity and I found the results very pleasing.
I've heard an Alesis, QSC and my own Behringer EP2500 (a class H amp) and I've found them all very listenable. The impressive thing about them is firstly the bass authority and secondly how relaxed they sound at high SPL.
Placebo effect comes into play here. You expect a high end impressive looking amp to sound better than a workhorse amp.
One amp that has got my attention is the Alesis RA500, which is a studio amp without a fan, very stylish and appears to be excellent value. I've heard some use it and ditch a preamp - just use the attenuators. It's really hard to believe they can put this thing together for this price.
It's amps like this that tend to make me think diy amps aren't worthwhile (from a cost vs performance point of view) unless:
* you are able to put together one cheap and simple (although I know a guy who spent more on a gainclone than a bought amp due to the case, terminals etc)
* you have the means to put together a VERY high end amp that's better than any of the "budget audiophile amps" like the Alesis, or NAD or Rotel ...
* you are making a "boutique" amp which is somehow very exotic and would be ultra expensive to buy - tube amps, class A or something that is a work of art
I've heard an Alesis, QSC and my own Behringer EP2500 (a class H amp) and I've found them all very listenable. The impressive thing about them is firstly the bass authority and secondly how relaxed they sound at high SPL.
Placebo effect comes into play here. You expect a high end impressive looking amp to sound better than a workhorse amp.
One amp that has got my attention is the Alesis RA500, which is a studio amp without a fan, very stylish and appears to be excellent value. I've heard some use it and ditch a preamp - just use the attenuators. It's really hard to believe they can put this thing together for this price.
It's amps like this that tend to make me think diy amps aren't worthwhile (from a cost vs performance point of view) unless:
* you are able to put together one cheap and simple (although I know a guy who spent more on a gainclone than a bought amp due to the case, terminals etc)
* you have the means to put together a VERY high end amp that's better than any of the "budget audiophile amps" like the Alesis, or NAD or Rotel ...
* you are making a "boutique" amp which is somehow very exotic and would be ultra expensive to buy - tube amps, class A or something that is a work of art
thanks Paul.
I have tried a number of different amps ranging from tube transformer, tube OTL, tube vintage, hubrids, and full solid state.
Every single one has its own pros and cons and more or less had anticipated results. The one which caught my attention though was a solid state design which I have assembled using good PSW techniques (bi-rectification, independent supplies, 80000 uf per rail etc) together with good ampslab modules. The amp was truly a killer and had much better sound quality and dynamics than what was expected for the total cost (ie 800 US approx). Overall, this has proved to become a magnificent amp surpassing almost all else i've owned or tried and in similar ranking (to my mind) to the krells and levinsons of this world. So with that in mind the 800 US dissipated was money worth spent. Now, I cannot compare that with any pro equipment since I never owned any but I guess for their cost the pro amps would be bargains but in absolute terms perhaps mediocre compared to the high end stuff.
I have tried a number of different amps ranging from tube transformer, tube OTL, tube vintage, hubrids, and full solid state.
Every single one has its own pros and cons and more or less had anticipated results. The one which caught my attention though was a solid state design which I have assembled using good PSW techniques (bi-rectification, independent supplies, 80000 uf per rail etc) together with good ampslab modules. The amp was truly a killer and had much better sound quality and dynamics than what was expected for the total cost (ie 800 US approx). Overall, this has proved to become a magnificent amp surpassing almost all else i've owned or tried and in similar ranking (to my mind) to the krells and levinsons of this world. So with that in mind the 800 US dissipated was money worth spent. Now, I cannot compare that with any pro equipment since I never owned any but I guess for their cost the pro amps would be bargains but in absolute terms perhaps mediocre compared to the high end stuff.
That can be a bit dangerous ... when you hear what you expect to hear it's a bit hard to know if you actually heard it or you just heard your expectations!
That would depend on the use. I recall reading some comments by Lynn Olsen on his articles on his TL design that solid state for bass and tubes for the rest is a good match.
PA amps impress me with their bass. I got together with some guys who frequent this forum and we did a comparison of a plate amp / sub and the crown K1. We were all a bit surprised how much more authority the Crown had.
I also like to have clipping indicators.
I must say I'm keen to hear some tube amps, I haven't really had the chance to listen to any that I can recall.
paul,
Tubes, except OTLs add some colouration to the sound which makes it more attractive and warmer to the ear hence their demand. I am not yet convinced that tubes offer a better sound reproduction than transistors...
PS I am very much impressed with your projects. Any good speaker/subwoofer kits you have come across?
Tubes, except OTLs add some colouration to the sound which makes it more attractive and warmer to the ear hence their demand. I am not yet convinced that tubes offer a better sound reproduction than transistors...
PS I am very much impressed with your projects. Any good speaker/subwoofer kits you have come across?
Making these general criticsms as well as responding to them is tricky. Since any design requires compromise and weighing of priorities, it is certainly true that the designer of unit that is to be lugged around the world by a gang of roadies has no choice to give survivability a higher priority than would be the case in a unit designed for home use. Some measured spec may well suffer particularly from the action of protection circuitry, but whether this results in any thing audiblle by all but a very few ifs another mater.
Home equipment, even high-end home use equipment, is subject to compromise as well but of a different sort. Visual appearance is a very big concern - if you going to ask a price in the thousands the product MUST NOT look like a Pioneer or Realistic. Given a fixed budget, the cost of 1 inch aluminum plate and blue LEDs has to be subtraced from something else! High-end designers can also face compromises brought about by the lates fad in specmanship. One is was power ratings, then THD, then damping factor -- today it impossible to have a good enough slew rate. The common theme is that there is an essential competative need to make "your product" different from all the others and this requires compromise and trade-offs.that may or may not impact cost and audible performance.
This is just the sort of statement that closes people's minds to other alternatives that may in fact be sonically equivalent, for less cost or with other improvements as well. You start as a newbie on this site, and after a whole lot of slightly more experienced diyers tell you things like this, after a while you end up saying the same things.
But have you done a fair apples to apples comparison? A blind AB test?
Rarely is this the thing that has been done that lead to the conclusion. As Sam has pointed out, neither PA nor hifi amps are built with fidelity alone as the sole aim. If money were no object, then I'd say a hifi amp should sound better, however, for a given power output requirement if quite high, with low impedance, a hifi amp could quite possibly sound equivalent for quite a bit less. For bass or subwoofers it would most likely sound better. PA is a competitive market free with an absense of hifi voodoo (which can put up the price a lot).
One thing that is overlooked often with things such as CDs, DVDs, preamps and amplifiers, is that they are almost never the weak links in the chain. The recording, the speakers and the room have far more serious weaknesses. IMO it's not worth considering anything beyond the standard of Rotel amps unless you have both high end comercial cost-no-object type speakers (ie AU $10,000 and above) and a dedicated listening room with acoustic treatment done right.
I say start with the big things first!
If you were a world leading expert, an audio guru with a crossover typology named after you or something equivalent, some of us might say "well that settles it, HE thinks xyz so it must be right!" But since we're mostly all amateurs here, fellow experimenters, you might elaborate on that a little!
Using a pro-amplifier in a home setting is reasonable but it’s useful to understand what you are getting before putting down the cash.
A pro-amplifier design as mentioned previously may have different goals then what your home setting is looking for. Beware that some pro-amplifiers use capacitive output to the speakers to eliminate complex DC detection circuitry and expensive output relays in the event of the amplifier ‘railing’ when it blows. While the large capacitors are within the feedback loop may people claim to hear the large electrolytic within the audio path. Second, many pro-amplifiers use an IC front end instead of a carefully tuned discrete front end for a number of reasons. While this difference may not matter in your particular home setting, it’s useful to listen to the amplifier you chose to verify it meets your needs using ‘home’ speakers and audio sources.
A pro-amplifier design as mentioned previously may have different goals then what your home setting is looking for. Beware that some pro-amplifiers use capacitive output to the speakers to eliminate complex DC detection circuitry and expensive output relays in the event of the amplifier ‘railing’ when it blows. While the large capacitors are within the feedback loop may people claim to hear the large electrolytic within the audio path. Second, many pro-amplifiers use an IC front end instead of a carefully tuned discrete front end for a number of reasons. While this difference may not matter in your particular home setting, it’s useful to listen to the amplifier you chose to verify it meets your needs using ‘home’ speakers and audio sources.
Actually, a number of pricey home audio amps use IC's this way. Carver/Sunfire is the one that first comes to mind but there are others. In fact there are some home-audio units aimed at the high-end/audiophile segment where the whole thing is just an IC! Thus I doubt discrete vs. IC is a meanigful distinction between pro- and home- audio amplifiers.
As for capcitively coupled outputs, my impression is that that's pretty much buggy-whip technology that is rarely used by any new pruduct desiogns. Besides a cap that is big enough to be reasonably "clean" sonicly and handle the power levels of many/most tiouring amps is physically quite large and most likely costs more than the DC protection circuitry it substitutes for.
Take a look at QCS, and some Altec gear [I am sure there are others]? You will see 2 nasty large capacitors on the outputs for each channel [none to large either ~4700uF].
To see the effect of the capacitors, pretend to put DC into the base of the output transistors and see what will happen to the ‘output’. You will find that the charge on the output caps will discharge and over time the output will no longer be energized. I would not call this gear ‘buggy whip’ either, they are pretty current designs and used by many venues and are definitely considered ‘pro-amps’.
As for IC op-amps being used by main stream ‘home’ amplifiers all I can say is ‘whatever works for you’. I personally don’t care for using a general purpose op-amp as the front-end in a design due to the lack of tuning that I can do. After all, I even use one of those ‘IC front end’ amplifiers periodically [Phase Linear 400 II]. But I still prefer the sound of the Heath AA-1800 discrete front-end.
I realize that some ‘high-end’ home amplifiers use standard power op-amps, again I hope it works for them and they are successful. I built a few of the power op-amp amplifiers using Nationals products and find them OK but somewhat limiting when it comes to power capability [assuming I don’t want to bridge/ parallel the power op-amps]. Plus they seem a little touchy driving large capacitive loads since the power IC’s don’t let the designer adjust some of the internal capacitance(s) to help stabilize the circuit better. But that’s another thread…
To see the effect of the capacitors, pretend to put DC into the base of the output transistors and see what will happen to the ‘output’. You will find that the charge on the output caps will discharge and over time the output will no longer be energized. I would not call this gear ‘buggy whip’ either, they are pretty current designs and used by many venues and are definitely considered ‘pro-amps’.
As for IC op-amps being used by main stream ‘home’ amplifiers all I can say is ‘whatever works for you’. I personally don’t care for using a general purpose op-amp as the front-end in a design due to the lack of tuning that I can do. After all, I even use one of those ‘IC front end’ amplifiers periodically [Phase Linear 400 II]. But I still prefer the sound of the Heath AA-1800 discrete front-end.
I realize that some ‘high-end’ home amplifiers use standard power op-amps, again I hope it works for them and they are successful. I built a few of the power op-amp amplifiers using Nationals products and find them OK but somewhat limiting when it comes to power capability [assuming I don’t want to bridge/ parallel the power op-amps]. Plus they seem a little touchy driving large capacitive loads since the power IC’s don’t let the designer adjust some of the internal capacitance(s) to help stabilize the circuit better. But that’s another thread…
Those caps on what you think is the output of the QSC amp may not be what you think. From what I can gather, some of their amps use a different topology to the usual and those caps are actually part of the PSU. May be called grounded emitter or grounded base toplogy. I've seen it referenced with regard to QSC on this forum a few times, I'm sure a search will turn it up.
Yes but;
With DIY you can use second hand components and components you already have. The effective cost of these components is often $0.00.
The amp that I am building at the moment will cost way under $100 AUS ($75.00 US).
But it takes longer (rewinding transformers, cutting heatsinks and cases etc.) to do.
The end result (for me anyway) is greater satisfaction by achieving quite a lot for very little cost.
Cheers
With DIY you can use second hand components and components you already have. The effective cost of these components is often $0.00.
The amp that I am building at the moment will cost way under $100 AUS ($75.00 US).
But it takes longer (rewinding transformers, cutting heatsinks and cases etc.) to do.
The end result (for me anyway) is greater satisfaction by achieving quite a lot for very little cost.
Cheers
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