Lightweight amps - clarity in power ratings

[wateroftyne]

Actually, I'm getting my wires crossed. I don't think the TC uses the B&O module.

The RH750 is 267w, I think...?

[stingrayPete1977]

I think the TC 450's turned out to be 256 watts the 750's quite a bit more. Thats why I wondered about the modules as someone would of made that link earlier.

[wateroftyne]

[quote name='stingrayPete1977' timestamp='1346491506' post='1789790']
I think the TC 450's turned out to be 256 watts the 750's quite a bit more. Thats why I wondered about the modules as someone would of made that link earlier.
[/quote]

No - I think the 750 still came in at under 300w.

[stingrayPete1977]

Blimey

[Musky]

[quote name='wateroftyne' timestamp='1346491551' post='1789792']
No - I think the 750 still came in at under 300w.
[/quote]
Yeah. Weirdly the long term output of both the 450 and 750 is 236w RMS, even though the voltage swing and burst output on the 750 is greater than the 450.

Edited September 1, 2012 by Musky

[brensabre79]

TC use some kind of limiting compressor in their output stage to give the impression of a much louder amp. It squashes the signal, reducing the dynamic range but then so does a driven valve amp. So I think their model numbers are misleading but they are trying to say "this is as loud as a 450w or 750w amp" in terms of percieved loudness as opposed to measured loudness.

The Class D thing has been around a long time but has never been practical due to the way switching power supply works. What B&O have done is develop a power supply mode that makes Class D technology useable i the real world. There is more info on the website I linked earlier, I was just trying to simplify the point as its not really the topic under discussion here, and my knowledge is vague. I was told by someone in the business that the majority of class D amps use the B&O ICE power technology, or have licensed it. They do do custom OEM models not shown on their website, but to all intents and purposes its the same stuff.

[chris_b]

If your ears are telling you that an amp is loud enough then who cares what the spec sheet says.

[wateroftyne]

[quote name='chris_b' timestamp='1346498153' post='1789888']
If your ears are telling you that an amp is loud enough then who cares what the spec sheet says.
[/quote]

This is true, but of course it's only useful if you can physically try before you buy.

It would also be nice to be able to guage how much of the 'loudness' is achieved via clever compression & signal processing.

[Lozz196]

Well I`ve had a fair few Class D amps, Ampeg PF-500, Orange Terror, TC Classic 450, GK MB500 & MB Fusion 500. All have been loud, with the Ampeg being the quietest, and the Orange being by far the loudest (thought the GKs not too far behind). I`ve gone back to the Ampeg however, as I prefer the tone from this amp, plus it has enough juice for me. Irrespective of actual/claimed wattage, those are the important things, however, agree, it`s not fair if you buy a supposed 500 watt amp, and find it`s not loud enough. An amp of 500 actual watts should never need to be used at anywhere near full power.

[bertbass]

TC RH 450, http://vpub.boyd-printing.com/publication/?i=76122, from pages 52 - 3. and ORANGE TERROR BASS 500, from pages 74 - 75.

[stingrayPete1977]

Really unless someone comes up with a standard test its all nonsense

[Mr. Foxen]

The only lesson here is that watts mean nothing.

[wateroftyne]

[quote name='Mr. Foxen' timestamp='1346503380' post='1789981']
The only lesson here is that watts mean nothing.
[/quote]

...unless you're a marketing department.

[dincz]

[quote name='Mr. Foxen' timestamp='1346503380' post='1789981']
The only lesson here is that watts mean nothing.
[/quote]

If you don't know the measurement method/conditions then yes, they mean nothing.

[stingrayPete1977]

[quote name='dincz' timestamp='1346504374' post='1789993']
If you don't know the measurement method/conditions then yes, they mean nothing.
[/quote]
And even if you do they might just double them

[Mr. Foxen]

[quote name='dincz' timestamp='1346504374' post='1789993']
If you don't know the measurement method/conditions then yes, they mean nothing.
[/quote]

And you intend to use them under exactly those conditions.

[Musicman20]

[quote name='stingrayPete1977' timestamp='1346500870' post='1789946']
Really unless someone comes up with a standard test its all nonsense
[/quote]

None of these 'tests' performed by any of the mags or experts are official tests. They are merely their way of attempting to gauge the watts. Which leads me to ignore them now.

In the real world outside forums, the RH750 completely slays. So did the RH450.

There are plenty of traditional amps that have also 'struggled' to hit their wattage. Eg:

Mesa 400+ (ridiculously expensive, huge, and heavy)
Ampeg SVT Pro 3 (not my cup of tea at all, and needs to be maxxed out on the gain and master to keep up with amps in the same category that are barely ticking over).

Personally, I don't care about wattage. My Orange AD200b could smash down walls, but it depends what you want it for. I've given up on caring about the advantages and disadvantages of neo/ceramic class D/tube/SMPS, etc.

Play what you like, for the right reasons. If it sound great and has good quality aftercare (eg like Genz) then stick with it.

Edited September 1, 2012 by Musicman20

[Merton]

[quote name='Musicman20' timestamp='1346508664' post='1790051']


None of these 'tests' performed by any of the mags or experts are official tests. They are merely their way of attempting to gauge the watts. Which leads me to ignore them now.

In the real world outside forums, the RH750 completely slays. So did the RH450.

There are plenty of traditional amps that have also 'struggled' to hit their wattage. Eg:

Mesa 400+ (ridiculously expensive, huge, and heavy)
Ampeg SVT Pro 3 (not my cup of tea at all, and needs to be maxxed out on the gain and master to keep up with amps in the same category that are barely ticking over).

Personally, I don't care about wattage. My Orange AD200b could smash down walls, but it depends what you want it for. I've given up on caring about the advantages and disadvantages of neo/ceramic class D/tube/SMPS, etc.

Play what you like, for the right reasons. If it sound great and has good quality aftercare (eg like Genz) then stick with it.
[/quote]

All of this

[dincz]

[quote name='Mr. Foxen' timestamp='1346505185' post='1790006']
And you intend to use them under exactly those conditions.
[/quote]

Even if you don't, using a standardised power measurement method (and they do exist) would provide a basis for comparison. The unfortunate truth is that many manufacturers use peak or burst measurements but don't state the time period or distortion level.

[Mr. Foxen]

Still wouldn't be a comparison that relates to practice though. That is why the number's game exists.

[fretmeister]

I have a couple of little amps, Shuttle 9.2 supposedly 900w and a TC RH750 and whatever the accurate power ratings are they are brutally loud, in fact I'd say if I got to over half on the volume and I'm not using PA then I'm a knobhead.

[bremen]

[quote name='brensabre79' timestamp='1346488371' post='1789742']
I find it amusing in the Class D world that all the manufacturers have different claims as to the watts. They all use the same power section because Class D technology is patented and owned by B&O. If you open the amp up you will usually see the B&O ICE module in there separated from the rest. They are all pretty much the same.
[/quote]

first I've heard it, are you sure? anyway, its definitely not the case that all class d amps use the same output module, whether or not class d is patented.

the op's measured power figures are odd too. halving load impedance on a perfect amp will double the power; on a real world amplifier it will produce somewhat less than double the power.

[Mr. Foxen]

It is the coupling between SMPS and class d output stage that made for the lightweight amp revolution. Power supply is pretty important to wattage figures, along with heatsinking, its a pretty major determining factor to maximums.

[nottswarwick]

All I know is that when my ABM 500 comes back to me it will be pumping out big fat old school analogue watts he he he

[3below]

It is the age old caveat emptor, try before you buy, and try in anger at gig volumes. Then again 4 x KT88 or 6 x EL34 has never disappointed me over the years. YMMV.