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[Michael 'Bink' Knowles]

photo by Brian Thomas

Okay folks, I blocked out a couple of free days over Memorial Day weekend and have been grappling with the large amount of data from the Amp Shootout. I've cobbled together and squeezed some of it down to a juicy bit I hope you'll appreciate, especially after waiting so long.

Here's an Excel spreadsheet of all the measured amplifiers' power levels relative to frequency and distortion. I tested each amplifier's power output with both channels working into a pair of 4 Ohm loads and fed with a series of pure sinewaves at 20Hz, 1kHz, and 20kHz. Each frequency ramped quickly up in discrete steps from -10dBu to... well, to a lot of signal. Too much, in some instances. All power measurements on the main composite results page are at 1% THD+N, to set a level playing field. Some amplifiers put out more power before reaching 1% THD+N, and the higher number was used. For many amps, there was a sizable jump up from clean power (less than 1%) to distorted (greater than 1%) and my analyzer programming wasn't good enough to catch the exact 1% figure. In these cases, the highest 'clean' power rating will fall somewhere between 'before 1%' and 'after 1%' and will be a little higher than on my main condensed list. For further clarification, you'll be able to look at the complete power results for these 3 frequencies by clicking on the link to a specific amplifier's chart.

You'll notice that only half the amps were tested at 'sagging' 96v AC power. There was not enough time for all the amps!

Here's the main results sheet with a condensed digest of 1% THD+N figures:
     http://www.roaddog.com/bink/data/AmpShootout_20-20k_results. xls

Here are the individual amp spreadsheets with 20Hz, 1kHz and 20kHz results. Many thanks to Dave Stevens for hosting the info:
http://www.roaddog.com/bink/data/AB 1590B 20-20k.xls
http://www.roaddog.com/bink/data/Apogee CA8000 20-20k.xls
http://www.roaddog.com/bink/data/Ashly MFA8000 20-20k.xls
http://www.roaddog.com/bink/data/Bogen M600 20-20k.xls
http://www.roaddog.com/bink/data/Carver ZR1600 20-20k.xls
http://www.roaddog.com/bink/data/Carvin DCM2500 20-20k.xls
http://www.roaddog.com/bink/data/Chevin A3000 20-20k.xls
http://www.roaddog.com/bink/data/Crest 8001 20-20k.xls
http://www.roaddog.com/bink/data/Crest 8002 20-20k.xls
http://www.roaddog.com/bink/data/Crest 9200 20-20k.xls
http://www.roaddog.com/bink/data/Crown CE4000 20-20k.xls
http://www.roaddog.com/bink/data/Crown K2 20-20k.xls
http://www.roaddog.com/bink/data/Crown MA3600VZ 20Hz.xls
http://www.roaddog.com/bink/data/EV CP3000S 20-20k.xls
http://www.roaddog.com/bink/data/EV P3000 20-20k.xls
http://www.roaddog.com/bink/data/Hafler SR2800 20-20k.xls
http://www.roaddog.com/bink/data/InterM H4200 20-20k.xls
http://www.roaddog.com/bink/data/InterM P3200 20-20k.xls
http://www.roaddog.com/bink/data/Lab.gruppen fP6400 20-20k.xls
http://www.roaddog.com/bink/data/Nady SPA2400 20-20k.xls
http://www.roaddog.com/bink/data/Peavey CS3000H 20-20k.xls
http://www.roaddog.com/bink/data/Peavey GPS3500 20-20k.xls
http://www.roaddog.com/bink/data/Phase Linear 700B 20-1k.xls
http://www.roaddog.com/bink/data/Power Pod P1200 20-100.xls
http://www.roaddog.com/bink/data/Powersoft DIGAM 7000 20-20k.xls
http://www.roaddog.com/bink/data/QSC MX3000a 20-20k.xls
http://www.roaddog.com/bink/data/QSC PL6ii 20-20k.xls
http://www.roaddog.com/bink/data/QSC PL6PFC 20-20k.xls
http://www.roaddog.com/bink/data/QSC PL9PFC 20-20k.xls
http://www.roaddog.com/bink/data/QSC PLX1602 20-20k.xls
http://www.roaddog.com/bink/data/QSC USA1310 20-20k.xls
http://www.roaddog.com/bink/data/RAM BUX34 20-20k.xls
http://www.roaddog.com/bink/data/Stewart World21 20-20k.xls
http://www.roaddog.com/bink/data/Tapco J2500 20-20k.xls
http://www.roaddog.com/bink/data/Yamaha PC4800N 20-20k.xls
http://www.roaddog.com/bink/data/Yorkville A44 20-20k.xls
http://www.roaddog.com/bink/data/Yorkville AP6040 20-20k.xls

Now to fold all this (and more) into a website and mount it. It's back to the digital grinding wheel for me...

-Bink
--
Michael 'Bink' Knowles
www.binkster.net

[dpaton]

Awesome. Simply awesome.

Thanks again for putting together the event.

-dave

[Robert Lunceford]

Hi Bink, This is an impressive amount of work and data. I enjoy reading your posts and replies. When there is a topic with numerous replies I always look for yours as I know that it will be informative and to the point.
To boil down the amp shoot-out........
If you were to personally stock just one amp to cover all needs, knowing what you know now, which amp would you choose?
Please consider performance, weight, rack spaces, and cost.
Thanks,
Robert L
http://authentic-audio.com

[John Roberts {JR}]

Three cheers for Bink..      

JR

[Michael 'Bink' Knowles]

Robert L wrote on Wed, 02 June 2004 20:44

If you were to personally stock just one amp to cover all needs, knowing what you know now, which amp would you choose? Please consider performance, weight, rack spaces, and cost.

That's quite a tall order, Robert.

I'd be tempted to go with light weight as the first factor and AC power efficieny as the second. But the dollar figure will weigh in very, very heavily!

Another factor I would use to select an amp would be serviceability and support. For me, a foreign-built model might possibly feel like it's at the tail end of a long supply chain. I would give extra allowance for a local brand instead, especially if the local people were on their game.

Yet another factor for me would be the acoustic noise of the amp fans. Enough of my gigs incorporate quietly intense listening (classical, jazz, folk, world, spoken) in a smallish hall which makes me lean toward a naturally quiet fan system. The Crown Macrotechs, for instance, are virtual tornados, while the QSC PL 6.0 models are fairly quiet.

I sure like an amp's ability to flex with variations in AC power supply and still deliver the goods. That's a big plus. The amps that have power-correcting supply circuitry will score big with me.

Finally, if the amplifier can take a high level of input and not go into protective shutdown, it is more idiot-proof. If the amp is able to hold further increases in input level at bay and yield low distortion figures and steady power output then it's a winner. I won't have to recone very much at all with an amp like this.

There's no one right answer. There's no one clear winner of the Amp Shootout. Your concept of what combination of factors is important to you will help you determine the amplifier that best fits your gigs.

Cheers -

-Bink

[Michael 'Bink' Knowles]

Thanks, JR, but I'm all too aware of the shortcomings of my venture out into audio measurement world. Too many of my tests appear flawed to me in retrospect and, of course, there wasn't enough time to complete the ambitious undertaking. I'd love to go back and redo a few of the tests with secondary verification such as a multichannel hard disk recorder taking down both input and output signals for reference. Smaartlive's spectrograms and transfers would have been helpful here and there. And a few basic thermal and AC efficiency tests would have rounded out the collection very nicely.

The only thing good I can say about the Amp Shootout tests that I spanked together is that all the amplifiers were tarred with the same brush. If a test of mine is flawed, every amp has to deal with it the same way.

By the way, I got terrific help from LABster Charlie Fox on the AP test sequences but ultimately, it was me deciding on what tests to run and how to tailor them for my situation. I made plenty of newbie mistakes, I'm sure of it.

Glad to hear you got back safely from your big Bay To Breakers race! I hope you had a good time chugging up Hayes Hill...  

-Bink

[Michael 'Bink' Knowles]

Dave Paton, Bink and Evan Miller wire up a PL 9.0.     Photo by Brian Thomas.

You're welcome, Dave. Thanks for throwing down in such a big way with your participation.

Did you ever write up your view of the weekend?

-Bink

[Ray Abbitt]

Bink wrote on Wed, 02 June 2004 22:28

Thanks, JR, but I'm all too aware of the shortcomings of my venture out into audio measurement world. Too many of my tests appear flawed to me in retrospect and, of course, there wasn't enough time to complete the ambitious undertaking.

Don't sell yourself short. A lot was learned by everybody there. Maybe all of the tests didn't get run, but I think there was enough of a sample taken to draw some pretty good conclusions. Your comments on how you would chose an amp say a lot--the fact that you don't come out and point at any particular brand and that you don't mention the sound say an awful lot.  It is kind of interesting that the factors you pick fit the same ones I do. (I know, this doesn't fit in with my buying E&W amps--but if I hadn't met Mark at the shootout, I wouldn't even consider them due to the limited support options.)

It was really nice to meet some of the people from here, and perhaps that was as valuable as the test results. Maybe we need to just have a get together every few months to learn what works (or doesn't) for everybody else.

Anyway, thanks again for all your efforts, and next time (if there is a next time) count me in.

-ray

[Dave Howden]

Bink,
Thank you for the hard work!
To have all of this information measures and presented in public the way you have is almost unheard of!

Best Regards,

[John Roberts {JR}]

Bink wrote on Thu, 03 June 2004 00:28

Thanks, JR, but I'm all too aware of the shortcomings of my venture out into audio measurement world. Too many of my tests appear flawed to me in retrospect and, of course, there wasn't enough time to complete the ambitious undertaking. I'd love to go back and redo a few of the tests with secondary verification such as a multichannel hard disk recorder taking down both input and output signals for reference. Smaartlive's spectrograms and transfers would have been helpful here and there. And a few basic thermal and AC efficiency tests would have rounded out the collection very nicely. The only thing good I can say about the Amp Shootout tests that I spanked together is that all the amplifiers were tarred with the same brush. If a test of mine is flawed, every amp has to deal with it the same way. By the way, I got terrific help from LABster Charlie Fox on the AP test sequences but ultimately, it was me deciding on what tests to run and how to tailor them for my situation. I made plenty of newbie mistakes, I'm sure of it. Glad to hear you got back safely from your big Bay To Breakers race! I hope you had a good time chugging up Hayes Hill...   -Bink

I thought your tests demonstrated how similar amplifiers were, one of my common arguments, so I am pleased. Applying consistent tests is very important.

I was surprised to find so few people actually running up Hayes. It seemed like I ran the whole hill at a 45' angle, zigzagging around people to pass them. I don't consider myself a fast runner but I did beat 57,000 to the finish line that day.  

My visit to the bay area was a success.

JR

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