Dangers of using a Pro Audio amp at home

[70salesguy]

Compare, investigate and listen!

I think what is missing in this talk of pro-vs home based gear is the sound.
Although I have noticed that some pro-gear fails to mention it's power bandwidth when saying it will deliver "700 wpc @ 8 ohms", while most decent home audio gear mentions their wpc from 20-20000. So this wpc rating can be miss leading.
I don't think the careful design and attention detail in circuitry in some home audio amps is for show, it's to achieve a certain sound, or design philosophy (High slew rates/fast rise times-etc) and in some instances lower other types of audible distortions other than THD, such as IMD, etc.

http://www.crownaudio.com/pdf/legacy/k1073-4.pdf

Check out the specs on this "Pro" amp, which is quite popular among many members here!

Of course, not every "Pro" amp has this kind of specs. It is certainly true that some may well be lacking in some aspect that wouldn't make them as musically pleasing.

Just have to read the specs as well as doing some investigation for yourself.

I use PS-400s and as far as I'm concerned, they compare to any of the "High-dollar Boutique-Brand" power amplifiers!

 

[Mchaz]

True, pro amps are cheaper, but to think that snobbery is the only reason for high end gear is to forget one thing: nothing evolves in pro audio gear. New technologies are not exploited, circuit designs or topologies. Pro gear is built simple, strong and to last, with sonics afterward. Listening environments are different and any distortion in the pro gear is easily overlooked by crowd noise, adult beverages...

Really, no innovations? Have you ever taken a look at the following?
Crown XTi
QSC PLX

 

[automojo]

The PS-400 looks like a nice amp-good distortion/s/n specs, and it gets close to doubling it's 8 ohm spec into 4 ohms-the sign of a good power supply.
I can't attest to the sound, as I've never heard one-obviously a few here seem to like it.
As far as having too much power, I think you can never really have too much power, unless to like dropping a tonearm on a lp at 3/4 plus volume etc, or your totally deaf, or grank the bass/loudness control to max at full volume-etc.
Your speakers are likely to be damaged by too little power-i.e. clipping than by the potential power reserves.
Again specs only tell half the story, as how they sound is important as well. How they blend into your system.

 

[similost]

i thought i saw a Tapco in your signature, although it's a different model. i guess i'm going to have to keep going to 2RU/3RU pro amp therapy to get over my big iron addiction actually, i was JUST about to by a Crown K2 when the PC5002Ms came into my life, and i haven't wanted for much since. the situation might present itself again, though, ya never know. and there are quite a few infinity folk running QSC, which has certainly got me thinking.

I've been very impressed with my tapco.. lots-o-power, very clean sound.. very quiet fan, a HUGE tranny in it.. amp weighs in at 48 lbs... and you sure can't beat the new prices on them..

 

[similost]

OK.. so pro amps have poor specs.. let's see how many home amps with these kinda specs..

Tapco Juice J-1400 Power Amplifier Specifications:

* Continuous Sine Wave Average Output Power per channel, both channels driven, 20 Hz to 20 kHz
* 2 ohms: 800 W
* 4 ohms: 450 W
* 8 ohms: 310 W

Bridged Mono Operation, 20 Hz to 20 kHz
* 4 ohms: 1400 W
* 8 ohms: 900 W

Power Bandwidth: -5 Hz to 50 kHz (+0, -3 dB)
* Frequency Response: -25 Hz to 25 kHz (+0, -1 dB)
* Distortion: THD and SMPTE IMD; 20 Hz to 20 kHz < 0.03% @ 8 ohms
* Signal-to-Noise Ration: > 100 dB below rated power into 4 ohms
* Channel Separation: > 90 dB @ 1 kHz
* Damping Factor: > 300 @ 1 kHz and below
* Input Impedance: 20 kOhms balanced; 10 kOhms unbalanced
* Input Sensitivity: 1.15 V (+3.4 dBu) for rated power into 4 ohms
* Gain: 32 dB
* Maximum Input Level: 9.75 Vrms (+22 dBu)
* Turn On Delay: 2.5 seconds
* Subsonic Filter: 9 dB @ 30 Hz
* Topology: Class AB
* Cooling: Dual variable-speed fans with back to front airflow
* Indicators: Channels A and B, SIG (Signal Present), OL (Overload), Power

Current Consumption
* Idle: 0.5 A
* Musical Program @ 8-1/2: 5.1 A
* Musical Program @ 4-1/2: 6.7 A
* Musical Program @ 2-1/2: 10.6 A

 

[MoreBeer]

That Tapco amp is only $299 new. I bet it clips often and well below rated output. Your Altec's are commercial PA style speakers and can tolerate it. Most audiophile speakers can't.

 

[blackfly]

It seems many people here have not heard about some of the truly high-end pro audio companies and what is involved in their designs. I would suggest you do some research before knocking pro stuff. You may also not realize that there are a good many studios in this world running Krell amps in the control room. It works both ways.

Bryston got their start in pro gear and then switched to supply both. But this is rare. Most pro gear is designed for pro use where esthetics are secondary and the understanding that reliability and functionality are first and foremost, not sonics or esthetics. Fact.

The esthetics of a unit, whatever it be, is VERY important to the overall sound you get. If you dislike the looks of a component chances are you are not going to think it sounds the best. Psychology works both ways too. Pro audio gear is never reviewed in mags, especially high end mags, so to get info takes more work and sourcing.

Pro amps are not going to damage gear but home use is definitely not its first intent and is designed as such.

 

[blackfly]

Similost: specmanship is long dead, but since you bring it up.....

The use of pure sine waves for power testing is VERY different than music which has peaks that can ask for the use of headroom, which is a far more telling spec.

And ANY amp SHOULD NOT HAVE A SUBSONIC FILTER THAT IS 9db at 30Hz. This is horrible and does NOT QUALIFY for hifi, by any measure. Contrary to popular belief there is content this low and the amp should amplify it. No sub amp for sure. No home amp maker would supply such, and if it did it would be SUB SONIC, below 20Hz. Not above it.

 

[similost]

There is a switch for that subsonic filter. I run it in the off position. It is not a constant filter on the amp.

I use this amp as a sub amp for my Peaveys. I can drive this amp into clipping as indicated by clip lights, but if I do, you have no desire to be in the room... TO get it to that point it's way too loud..

Ya'll can keep knocking pro gear all you want.. but there have been many people that have heard my system and have been very impressed.. and I like it, and that's all that matters... you want to only use home consumer gear, more power to you. It leave more for those of us with open minds..

 

[Goodwill_HiFi]

The danger of pro amplifiers range from cancer caused from high power microwaves emitted from the amplifiers, or deadly fumes emitted from the circuit boards killing you in your sleep. It's just not worth it when there are so many high quality home stereo amplifiers available.

Is that a joke?

 

[Ender]

I read it that way... assuming author was hoping he could scare you away from buying item so he could.

 

[automojo]

I think you could also draw a similarity betwwen one person prefering tube gear vs solid state.
I love the midrange a good tube amp gives, but they lack the clean solid bass of a ss amp, so I lean towards solid state amps. My H/K PA2400 runs a bit of a higher bias, so it gives it a bit of tube sound, without the weak bass. My H/K Signature 1.5 runs a more normal bias- and thus sounds a bit more neutral. I like the sound of both, and have tried to match the assocaited equipment of each system to maximum their pluses, and minimize any negatives.
I do think specs can be misleading-as they don't say anything how a amp will SOUND, except it may play very loud-loud isn't the measure of a good sound system IMHO.
I think a powerful amp with plenty of reserves is a very good starting point for a nice well rounded sound sytem, but merley throwing out specs (particulairly sine wave power output) says little of how it sounds, or it's potential with other asscoiated equipment.
Those of us who lived through the power war's of the 70's (especially car audio-and the "civic center mega sales") find gear that tries to only sell it self on specs-well call us, or me for one -skeptical.
Having said this-I'm sure your gear sounds fine- I have no problem with one enjoying pro gear, and /or huge VOT speakers. However, arguing pro vs consumer gear makes little since in the end, because of the wide ranging preferences each of us has. Just because you like it, doesn't necessitate the need to convince someone their gear is superior, or inferior to someone else's (a popular 70's sales gimmick)
If one size fit all-it would be convenient perhaps-but mighty boring. And there would be little use for this sight as well.
Enjoy!

 

[similost]

good post automojo.. and yeah.. I wasn't even gonna start up about my pa tube amps...

 

[rifftrax]

The esthetics of a unit, whatever it be, is VERY important to the overall sound you get. If you dislike the looks of a component chances are you are not going to think it sounds the best. Psychology works both ways too.

This is true but only to a certain point. I've had some really lovely looking pieces of equipment that I just had to admit sounded like poo at a certain point.

I have some pieces of kit that look like poo that rock as well. I've learned to get past the whole "look" thing.

 

[whoaru99]

I own Audio Research, Levinson, Yamaha, et al, but my QSCs get used by far the most. I know there is at least one dissenting opinion, but I'm confident they wouldn't be embarassed by many, if any.

I'm going to venture a guess that most people dissing pro amps haven't used a decent one in their system, or else prefer tubes over SS, etc. That's great though. Leaves more (relative) bargains for the rest of us.

 

[Hendrix416]

The PS-400 looks like a nice amp-good distortion/s/n specs, and it gets close to doubling it's 8 ohm spec into 4 ohms-the sign of a good power supply.
I can't attest to the sound, as I've never heard one-obviously a few here seem to like it.
As far as having too much power, I think you can never really have too much power, unless to like dropping a tonearm on a lp at 3/4 plus volume etc, or your totally deaf, or grank the bass/loudness control to max at full volume-etc.
Your speakers are likely to be damaged by too little power-i.e. clipping than by the potential power reserves.
Again specs only tell half the story, as how they sound is important as well. How they blend into your system.

K, so what you are saying that it's better to power your speakers with higher wattage amps than lower wattage amps. Would you agree that I could buy a QSC PLX1104 to run my Realistic Optimus 1000s, set the gains mid way, set my EQ to flat and not worry about blowing my speakers (unless I play something like Woofer Cooker with the bass up all the way)?

 

[whoaru99]

...Would you agree that I could buy a QSC PLX1104 to run my Realistic Optimus 1000s, set the gains mid way, set my EQ to flat and not worry about blowing my speakers (unless I play something like Woofer Cooker with the bass up all the way)?

No, no guarantees. The gain controls do not indicate/limit power output, they merely scale the output to input ratio (gain). Meaning, you can get just as much power out of the amp with the gain knob at "5" as you can at "10", if you put in enough input signal voltage (5 and 10 only used to indicate relative level, actual markings are likely different).

The ultimate factor with any amp and speaker combination is the operator has to be attentive and understand what is going on with the system, then manage it properly.

 

[whoaru99]

Similost: specmanship is long dead, but since you bring it up.....

The use of pure sine waves for power testing is VERY different than music which has peaks that can ask for the use of headroom, which is a far more telling spec.

And ANY amp SHOULD NOT HAVE A SUBSONIC FILTER THAT IS 9db at 30Hz. This is horrible and does NOT QUALIFY for hifi, by any measure. Contrary to popular belief there is content this low and the amp should amplify it. No sub amp for sure. No home amp maker would supply such, and if it did it would be SUB SONIC, below 20Hz. Not above it.

The high pass filters in pro amps are intentionally put there, and generally are switchable on/off. They are there to protect pro audio speakers from low frequency content below the box/port tuning frequency.

And, actually, sine waves are a much more demanding test on an amp than music in terms of power output, durability, etc. The average power of music is only about 1/8 of the peak level (some variance with genre, recording compression, etc). Sine waves are much more demanding than that. This is why many amps, even big McIntosh, get hot and shut down with sine wave testing at 1/3 power, yet will run all day at "full power" with music, barely getting warm in the process.

 

[Spikedart]

connecting balanced to unbalanced

Could anyone explain to me the dangers of using a pro audio amp with a home setup? Someone said that voltage could be an issue? Can anyone clarify this for me?

This resource helped me A LOT. I had a Crown CT-810 hooked into vintage Nikko equipment and this made it work. http://www.rane.com/note110.html

Yes, it sounded very good.

 

[JoeESP9]

On a solid state amp running a higher bias means that it runs in class A longer. Any SS amp runs in Class A up to a point. A higher bias rases the wattage at which it switches to Class A/B. Most of the time amps are loafing and only producing a couple of watts. Those couple of watts you are hearing as smoother/better sound are Class A watts. This is what Class A power sounds like. Yes, it is kind of tube like. Yeah, that's why pure Class A amps are popular.