Whatcha think about "pro" amps from Crown, QSC, etc?

[Chrispy]

Those, and remote 12 volt control are the types of features I was referring to earlier that home amplifiers have that pro amplifiers typically do not have.

My Crowns have a somewhat different type of remote turn on than consumer gear, but easily done diy or with a smart power strip or some other ways of resolving a minor issue.

 

[Newman]

I have used the Biamp MCA8050 power amp octets to drive DIY active horns for home stereo purposes. It’s an older AB design of modest technical numbers. I disabled the fans just in case (“go on ya bastard, I dare ya to blow up sending 1W peak to a horn”). But from the seat I could faintly hear hiss from the horns.

 

[Rednaxela]

So are these

Definitely!

 

[MakeMineVinyl]

My Crowns have a somewhat different type of remote turn on than consumer gear, but easily done diy or with a smart power strip or some other ways of resolving a minor issue.

But that's the point - buying a product which is suited to purpose from the start means you don't have to go through the trouble of rigging a DIY solution.

I might ask the question - why is a pro amplifier more suited for home use than a good amplifier specifically designed for the home? Can anybody answer this question?

 

[Qbd]

I don't think hiss with sensitive drivers is (or rather should be) an issue, for almost any amp.
Line level analog attenuation either built into the amp, or inserted physically with a padding device, into the line going to the amp, allows proper gain structure to kill hiss.
Also, many proamps have selectable gain/ input sensitivity.
There's simply no reason to not solve hiss problems... easily, ime ( i use high sens compression drivers)

But the hiss is inherent to the amp though, and if it isn’t coming from the input those things won’t help.

I have a Crown XLS 1502 that I’ve tried with my speakers, and that results in audible hiss at the listening position with my speakers (Ascendo Immersive Audio CCRM12P, 99 dB/1W), both when connected to my receiver and with the XLR input pins shorted.

The specs also indicate it should be the case. With an SNR of just >103 dB for the amp, and an output somewhere around above 120 dB at full power, it’s not surprising that the noise is somewhere around 20 dB at 1 m, and thus audible in a quiet room.

Of course in a noisy room, or even an event hall or concert venue where it’s really meant to be used this isn’t a problem.

 

[Willem]

They are attactive because
1 They tend to have a rather lower price.
2 The often have balanced inputs, Speakon connectors, high pass filters etc.

 

[rdenney]

But that's the point - buying a product which is suited to purpose from the start means you don't have to go through the trouble of rigging a DIY solution.

I might ask the question - why is a pro amplifier more suited for home use than a good amplifier specifically designed for the home? Can anybody answer this question?

They might be a lot cheaper in terms of dollars/watt. The affordable options for residential use tend to be a lot less powerful.

This has been significant for me before the rise of affordable high-power Class D options. Back in the deeps of time, my Spectro Acoustics amp died (I had already resuscitated it several times), and I replaced it with a lower-power amp that was lying around. It compressed--not really noticeable hard clipping but definitely shaving off the peaks. I bought a Samson Servo 500--a PA amp of modest expectation, Class AB. It restored the dynamics of the system with my inefficient Advents. I think I paid $200 brand new for that thing--even cheaper than the bottom-of-the-line Crown. I could not have bought a used home amp of similar power for that money, with any expectation of improved performance. I also came upon a Carver PM-300 commercial amp, and that was a general backup for me.

I replaced that with a used B&K Reference 125.2, which at least looked a lot better in the home environment. Did it sound better? Quiescent hiss was a bit less, but that's all I'd be able to say.

Rick "would rather have abundant power in a cheap commercial amp vs. clipping or compressing a smaller but better performing home amp" Denney

 

[MakeMineVinyl]

They are attactive because
1 They tend to have a rather lower price.
2 The often have balanced inputs, Speakon connectors, high pass filters etc.

I know that, however we make a home stereo power amplifier with both balanced inputs and Speakon outputs. Of course it can't compete on price, but since when were people here on ASR who value good SINAD so willing to chuck all that out the window to save a few bucks?

 

[rdenney]

I know that, however we make a home stereo power amplifier with both balanced inputs and Speakon outputs. Of course it can't compete on price, but since when were people here on ASR who value good SINAD so willing to chuck all that out the window to save a few bucks?

Well, me. My Buckeye NC502MP is (literally) the most expensive amp I have every purchased, though it is also the only new amp I have ever bought. I don't think anyone would think of the Buckeye as expensive for a high-performing 300-wpc amp.

Rick "The B&K amps were probably a bit more when new" Denney

 

[MakeMineVinyl]

Well, me. My Buckeye NC502MP is (literally) the most expensive amp I have every purchased, though it is also the only new amp I have ever bought. I don't think anyone would think of the Buckeye as expensive for a high-performing 300-wpc amp.

Rick "The B&K amps were probably a bit more when new" Denney

Class D has leveled the playing field tremendously and enabled high power to co-exist with reasonable cost. In my own case, I've solved the power amplifier power problem by having very efficient speakers, so the cost of the power amp is basically a non-issue since the speakers only need a few watts to create large SPL. Owners of something like a Klipsch could easily get by with 50 watts.

 

[Willem]

I thought the 300 euro (now about US$300) for the 2x250 watt Yamaha P2500s was a very good deal.

 

[gnarly]

I might ask the question - why is a pro amplifier more suited for home use than a good amplifier specifically designed for the home? Can anybody answer this question?

Here are some of the things I like about proamps vs consumer; traits I expect from a proamp that can be hard to find in consumer amps

* balanced inputs
* line level inputs for proaudio (+4 dBu)
* variable gain settings / input sensitivity
* analogue level attenuation pots
* built in clip limiters (invaluable imo)
* instant off muting (no home audio bleed down)
* much better AC line noise/spike protection
* generally capable of driving lower impedance loads
* bridgeable
* considerably more wattage for the buck

with DSP added to proamps:
* output limiters for both RMS and peak voltage
* xovers, EQs, delays, gains, polarity, some with FIR filters
* presets
* real time amp monitoring over Ethernet or USB
* often with audio over Ethernet

with DSP amps and real time software control programs
* ability to make control screens for laptops, tablets and phone
* control screens than contain volume, presets and virtually any parameter or group of parameters

 

[MakeMineVinyl]

Here are some of the things I like about proamps vs consumer; traits I expect from a proamp that can be hard to find in consumer amps

* balanced inputs
* line level inputs for proaudio (+4 dBu)
* variable gain settings / input sensitivity
* analogue level attenuation pots
* built in clip limiters (invaluable imo)
* instant off muting (no home audio bleed down)
* much better AC line noise/spike protection
* generally capable of driving lower impedance loads
* bridgeable
* considerably more wattage for the buck

with DSP added to proamps:
* output limiters for both RMS and peak voltage
* xovers, EQs, delays, gains, polarity, some with FIR filters
* presets
* real time amp monitoring over Ethernet or USB
* often with audio over Ethernet

with DSP amps and real time software control programs
* ability to make control screens for laptops, tablets and phone
* control screens than contain volume, presets and virtually any parameter or group of parameters

But surely a typical home user doesn't need the vast majority of those features, especially if they're using a preamp / AVR with DSP built in. If somebody needs those features like you do, obviously they need a pro amp.

People have different needs, obviously - my needs are vastly different than yours - but to my mind unless financially constrained, directing the average audio shopper to a pro amp rather than a home amplifier is misguided.

By the way, we make both professional cinema power amplifiers and the cinema DSP processors to drive them. The combination has all the features you outline above.

 

[gnarly]

But the hiss is inherent to the amp though, and if it isn’t coming from the input those things won’t help.

I have a Crown XLS 1502 that I’ve tried with my speakers, and that results in audible hiss at the listening position with my speakers (Ascendo Immersive Audio CCRM12P, 99 dB/1W), both when connected to my receiver and with the XLR input pins shorted.

The specs also indicate it should be the case. With an SNR of just >103 dB for the amp, and an output somewhere around above 120 dB at full power, it’s not surprising that the noise is somewhere around 20 dB at 1 m, and thus audible in a quiet room.

If you have hiss with shorted inputs, I agree, problem is with the amp.

I see the XLS 1502 is a DSP amp. My bet is the cause of the hiss is the dsp, not the analog gain stage.

Is there a way to bypass the AD/DA conversion on an analog input? If so, I imagine hiss will disappear (99 dB/1w is not all that sensitive).
If hiss doesn't disappear with DSP bypassed, I'd put one on these line level attenuators in place, and get the line level as hot as possible without clipping, before feeding the amp. https://www.amazon.com/Audio-Technica-AT8202-Adjustable-In-line-Attenuator/dp/B000ZLX2TU

Good ole gain staging has always bailed me out of hiss problems (using 118dB/1w CDs)

That said, if you truly have a goal of being below 20dB @1m, well, God bless your good ears and quiet environment, sincerely
At only 2m, it's already down to 14 dB !

 

[MakeMineVinyl]

Good ole gain staging has always bailed me out of hiss problems (using 118dB/1w CDs)

That's certainly an option to reduce hiss with efficient speakers. My speakers are not quite as efficient as yours (107dB/w) but to reduce hiss to inaudible levels, I supply all the voltage gain in the preamp and the HF horn's power amplifier is literally unity voltage gain. The HF power amplifier is only 2.5 watts, a benefit so that under no circumstances can I destroy the HF diaphragms.

 

[Qbd]

If you have hiss with shorted inputs, I agree, problem is with the amp.

I see the XLS 1502 is a DSP amp. My bet is the cause of the hiss is the dsp, not the analog gain stage.

I’m fairly sure it’s not possible to bypass the DSP, and yeah that may well be the source.

 

[JeremyFife]

This is interesting, and opening up a whole new world of options and confusion

I expect to need a new Power Amp soon (Topping TPA5 away for repair - don't ask, that's for a different thread) and was looking at an Audiophonics Ncore (MPA-S250NC). I don't need all that power but I also want to avoid clipping. I'm in the UK and the price of around 450 EUR seems pretty good.

But now, pro amps like Behringer A800, or the Yamaha P3500 or a Crown sounds as if they have more than enough power, good enough specs and the promise of real reliability ... for much less money. Don't need DSP or anything clever - just balanced inputs and > 100W at 8ohm

I suspect that my objections are just down to prejudice ... I've got to get over that

 

[Chr1]

Second hand Class A/B pro amps can be had pretty cheaply now if you look, as PA companies are selling them to be replaced with lighter Class D. I got 4 Crown Macro-Tech 1200s for £180, collection only on Ebay a couple of years back. Two pairs in flight cases in great condition. Pretty good value for highly regarded amps, I reckon.

 

[JeremyFife]

Second hand Class A/B pro amps can be had pretty cheaply now if you look, as PA companies are selling them to be replaced with lighter Class D. I got 4 Crown Macro-Tech 1200s for £180, collection only on Ebay a couple of years back. Two pairs in flight cases in great condition. Pretty good value for highly regarded amps, I reckon.

Thanks... I'm going to do some research (but, man those are *ugly* ). Lots to learn, just how I like it

 

[mhardy6647]

Built "Missionary Tough".