Log in
Register
Home
Forums
New posts
Search forums
What's new
New posts
New profile posts
Latest activity
News
Members
Current visitors
New profile posts
Search profile posts
Features
Log in
Register
Search
Search titles only
By:
Search titles only
By:
New posts
Search forums
Menu
Install the app
Install
Reply to thread
Home
Forums
Pro Audio
Product Reviews
Amp Tests (1 of 2)
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Message
<blockquote data-quote="Langston Holland" data-source="post: 31616" data-attributes="member: 171"><p>Amp Tests (2 of 2)</p><p></p><p><strong>The Players:</strong></p><p></p><p><u>Camco Vortex 6</u></p><p></p><p>Alluded to earlier, this is simply the best sounding professional amplifier I've ever heard. It's a class H design and somehow manages to reveal the most subtle details in high-end recordings with earphone clarity over (excellent) loudspeakers. To date I've yet to hear a class D variant (including the following amps) that can present the width and depth of a recording anywhere near as well. I have no idea why this is the case - no measurements I've ever made are conclusive. The flatter transfer function certainly doesn't hurt, but it's more than that. Full output at 120v 30 amps works perfectly, no need for the 208/240v model unless it’s more convenient for where you live.</p><p></p><p><u>QSC PL380</u></p><p></p><p>One of the best bang for the buck ratios on the planet. My (9) PL380's have been rock solid for several years. They are also one of the better sounding class D amps if you have to use one in the mid/high region. Like the Camco, full output at 120v 30 amps works perfectly, no need for the 208/240v model.</p><p></p><p><u>Powersoft K10</u></p><p></p><p>Oh my - this beast is ready for your welding rods and sine waves masquerading as music. One rack space of pure attitude - it's squirrel fans will go into overdrive if necessary, much like the old Crest 9001's, but this amp will just keep belting out continuous power unlike any amp I've ever come across. It also is solid on the Keele short-term tests. The amp is very well designed and feels as solid as it runs. Very logical layout and very efficient with power, will accept any voltage on earth and do sine waves all night long (trance, electronica, whatever). Optional DSP card available with FIR filtering, but not on the order of either the Crown HD or Lab PLM series. Quite good nevertheless - you can download the software for your PC and see if it fits your needs. Sound is much better than average for class D - about equal with the PL380, though a more forward sounding midrange. You obviously want 208/240v with this amp if you're going to use its full capacity.</p><p></p><p><u>Crown IT5000HD, IT9000HD and IT12000HD</u></p><p></p><p>The processing in these things simply rocks. Very steep and well-designed FIR filters, plenty of all-pass and parametric EQ filters. Nice average and peak limiter facilities. The software interface to the ITech amps is probably the best I've ever seen, Crown works very hard at this and releases updates frequently. I noticed earlier this year that the 2nd order all-pass filters weren't working and Crown had it fixed in less than a week - wow. It also made me wonder why I was the first to notice this since they’ve been out for a while... The software makes for very nice multiple amp management in larger company or install environments. The sound is greatly improved from my previous experience with the non-HD models. My guess is that it's due to the processing upgrade since the amps measure fairly similarly. I prefer the sound of the other amps in this test in the mid/highs when ignoring the processing, but you shouldn’t do that. I designed FIR filtered, flat-phase presets for Troy’s KF730’s to mimic what I’ve done with the Dolby Lake processor and was amazed at how good the net result was. The limiters sounded good too. I noticed a similar result when doing listening tests with the Lab PLM20000Q with internal processing vs. the FP14000 fed by a DLP. Interesting. Reliability reports are good with the HD series. The ITech's have always been good at making power and these amps are no exception, but it’s silly that they increased the numbers in their model numbers – output has not increased as far as I can tell. Though I don't report it here, short-term output into 2Ω’s will surprise you with either the older or newer ITech’s. You think this is a 4Ω only amp? Nope. It shows a similar increase in output into 2Ω’s that you see in typical amps as long as you don't ask it to do so for un-musically long periods of time. Still, voltage is king and is what SPL is made out of and you should stick to a nominal 4Ω’s regardless of amp IMO. The ITech’s play nicely with others due to worldwide voltage and PFC.</p><p></p><p>If you push these amps to their limits, you're going to want to feed the 9000 and 12000 with 208/240v. At 120v even at 30 amps, both these amps "groan" when under load. That kind of vibration can't be good in the long run. At the 240v feed they got during my measurements, they were nearly silent other than fan noise, which can get up into the Crest 9001 range. The 5000 is happy with 120v 30 amps into anything that will ever happen in practice, though it did want 240v for continuous sine testing.</p><p></p><p><u>Lab Gruppen FP14000</u></p><p></p><p>I'm buying (4) of these as a result of these tests. Their output to size, weight, sonics, warranty and cost is a winner. These amps are not auto-ranging, you have to choose either 120v or 208/240v - the latter is the only thing that makes sense given the horsepower involved. This amp is all about allowing the peaks of music to get through without clipping as their testing method indicates. It has both hard (lows and subs) and soft (mids and highs) limiting available as well as several cool protection circuits with a light show on the front panel. I made all the pretty lights come on without letting the smoke out. Too bad they make you buy a thousand dollar gizmo to connect your PC to the amp to monitor its behavior - they should nix that thing and its cost and allow you to connect your computer directly to the amp(s). Maybe the smaller Labs sound better in the mid/highs, but this amp showed its class D heritage in my listening tests, which nixed my thought of replacing the Camco's with a Lab on the mid/highs. Still, this amp is probably the best sounding class D amp I've heard.</p><p></p><p><strong>Long-term Measurements:</strong></p><p></p><p>Though I expected this to be boring, I accidentally learned some interesting stuff here about design philosophy between the various manufacturers. All have made reasonable compromises in trying to skin the cat of high output without damaging itself or the stuff at the other end of the loudspeaker cable when operated by a bunch of lunatics.</p><p></p><p>Each of the below show a reference measurement of magnitude and phase at 50 watts and at about 1dB beyond their maximum output capability with both channels driven into 4Ω. Do not freak out about the max power traces, I could have backed off a hair and made them all pretty, but that wouldn’t have been very helpful, would it? Plus I would have missed out on the flames from some of the manufacturers – and what fun would that be? Actually, I learn from those as well and look forward to it. Be sure to read the caption at the bottom of each graphic for details.</p><p></p><p><u>Camco Vortex 6</u> (low level and 1dB beyond max)</p><p></p><p><img src="http://homepage.mac.com/soundscapes/PSW/AmpTests/STEPS_V6.PNG" alt="" class="fr-fic fr-dii fr-draggable " style="" /></p><p></p><p><u>QSC PL380</u> (low level and 1dB beyond max)</p><p></p><p><img src="http://homepage.mac.com/soundscapes/PSW/AmpTests/STEPS_PL380.PNG" alt="" class="fr-fic fr-dii fr-draggable " style="" /></p><p></p><p><u>Powersoft K10</u> (low level and max)</p><p></p><p><img src="http://homepage.mac.com/soundscapes/PSW/AmpTests/STEPS_K10.PNG" alt="" class="fr-fic fr-dii fr-draggable " style="" /></p><p></p><p><u>Lab Gruppen FP14000</u> (low level and 1dB beyond max)</p><p></p><p><img src="http://homepage.mac.com/soundscapes/PSW/AmpTests/STEPS_FP14000.PNG" alt="" class="fr-fic fr-dii fr-draggable " style="" /></p><p></p><p><u>Crown ITech HD</u> (low level)</p><p></p><p><img src="http://homepage.mac.com/soundscapes/PSW/AmpTests/STEPS_ITech.PNG" alt="" class="fr-fic fr-dii fr-draggable " style="" /></p><p></p><p><u>Crown ITech HD</u> (1dB beyond max)</p><p></p><p><img src="http://homepage.mac.com/soundscapes/PSW/AmpTests/STEPS_ITech_Max_+1dB.PNG" alt="" class="fr-fic fr-dii fr-draggable " style="" /></p><p></p><p><strong>Short-term Measurements:</strong></p><p></p><p>This is really interesting.</p><p></p><p>The following scope traces are from the FP14000 to demonstrate how I made these measurements. The scope is used to determine the point at which the shaped tone burst begins to deform and plotted with the input signal scaled to for reference. The red trace is the input signal and the blue trace is the output at the point where I judged it to be the maximum. I lost the 100Hz measurement like a dummy, and I’m too lazy to do the measurement again, but it’s immaterial. One thing you’ll notice is at the higher frequencies, the output trace is late to the party – a simple measurement of phase lag as predicted by the long-term STEPS trace. The scope's phase calculations agreed with STEPS. I think I’m getting the hang of this. <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="smilie smilie--sprite smilie--sprite1" alt=":)" title="Smile :)" loading="lazy" data-shortname=":)" /></p><p></p><p><u>FP14000 Shaped Tone Burst Measurements</u></p><p></p><p><img src="http://homepage.mac.com/soundscapes/PSW/AmpTests/FP14000_Scope.png" alt="" class="fr-fic fr-dii fr-draggable " style="" /></p><p></p><p>And now, ladies and gents… These numbers are per channel in stereo mode into 4Ω. They would have been higher at 2Ω, though voltage and the SPL from your loudspeakers would be lower. Chew on that. I hate this whole watts thing – just did it for the peanut gallery – next time it’s volts like God intended. <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="smilie smilie--sprite smilie--sprite1" alt=":)" title="Smile :)" loading="lazy" data-shortname=":)" /></p><p></p><p><u>The Data</u></p><p></p><p><img src="http://homepage.mac.com/soundscapes/PSW/AmpTests/Amp_Burst_Table.png" alt="" class="fr-fic fr-dii fr-draggable " style="" /></p><p></p><p><u>The Picture</u></p><p></p><p><img src="http://homepage.mac.com/soundscapes/PSW/AmpTests/Amp_Burst_Graph.png" alt="" class="fr-fic fr-dii fr-draggable " style="" /></p></blockquote><p></p>
[QUOTE="Langston Holland, post: 31616, member: 171"] Amp Tests (2 of 2) [B]The Players:[/B] [U]Camco Vortex 6[/U] Alluded to earlier, this is simply the best sounding professional amplifier I've ever heard. It's a class H design and somehow manages to reveal the most subtle details in high-end recordings with earphone clarity over (excellent) loudspeakers. To date I've yet to hear a class D variant (including the following amps) that can present the width and depth of a recording anywhere near as well. I have no idea why this is the case - no measurements I've ever made are conclusive. The flatter transfer function certainly doesn't hurt, but it's more than that. Full output at 120v 30 amps works perfectly, no need for the 208/240v model unless it’s more convenient for where you live. [U]QSC PL380[/U] One of the best bang for the buck ratios on the planet. My (9) PL380's have been rock solid for several years. They are also one of the better sounding class D amps if you have to use one in the mid/high region. Like the Camco, full output at 120v 30 amps works perfectly, no need for the 208/240v model. [U]Powersoft K10[/U] Oh my - this beast is ready for your welding rods and sine waves masquerading as music. One rack space of pure attitude - it's squirrel fans will go into overdrive if necessary, much like the old Crest 9001's, but this amp will just keep belting out continuous power unlike any amp I've ever come across. It also is solid on the Keele short-term tests. The amp is very well designed and feels as solid as it runs. Very logical layout and very efficient with power, will accept any voltage on earth and do sine waves all night long (trance, electronica, whatever). Optional DSP card available with FIR filtering, but not on the order of either the Crown HD or Lab PLM series. Quite good nevertheless - you can download the software for your PC and see if it fits your needs. Sound is much better than average for class D - about equal with the PL380, though a more forward sounding midrange. You obviously want 208/240v with this amp if you're going to use its full capacity. [U]Crown IT5000HD, IT9000HD and IT12000HD[/U] The processing in these things simply rocks. Very steep and well-designed FIR filters, plenty of all-pass and parametric EQ filters. Nice average and peak limiter facilities. The software interface to the ITech amps is probably the best I've ever seen, Crown works very hard at this and releases updates frequently. I noticed earlier this year that the 2nd order all-pass filters weren't working and Crown had it fixed in less than a week - wow. It also made me wonder why I was the first to notice this since they’ve been out for a while... The software makes for very nice multiple amp management in larger company or install environments. The sound is greatly improved from my previous experience with the non-HD models. My guess is that it's due to the processing upgrade since the amps measure fairly similarly. I prefer the sound of the other amps in this test in the mid/highs when ignoring the processing, but you shouldn’t do that. I designed FIR filtered, flat-phase presets for Troy’s KF730’s to mimic what I’ve done with the Dolby Lake processor and was amazed at how good the net result was. The limiters sounded good too. I noticed a similar result when doing listening tests with the Lab PLM20000Q with internal processing vs. the FP14000 fed by a DLP. Interesting. Reliability reports are good with the HD series. The ITech's have always been good at making power and these amps are no exception, but it’s silly that they increased the numbers in their model numbers – output has not increased as far as I can tell. Though I don't report it here, short-term output into 2Ω’s will surprise you with either the older or newer ITech’s. You think this is a 4Ω only amp? Nope. It shows a similar increase in output into 2Ω’s that you see in typical amps as long as you don't ask it to do so for un-musically long periods of time. Still, voltage is king and is what SPL is made out of and you should stick to a nominal 4Ω’s regardless of amp IMO. The ITech’s play nicely with others due to worldwide voltage and PFC. If you push these amps to their limits, you're going to want to feed the 9000 and 12000 with 208/240v. At 120v even at 30 amps, both these amps "groan" when under load. That kind of vibration can't be good in the long run. At the 240v feed they got during my measurements, they were nearly silent other than fan noise, which can get up into the Crest 9001 range. The 5000 is happy with 120v 30 amps into anything that will ever happen in practice, though it did want 240v for continuous sine testing. [U]Lab Gruppen FP14000[/U] I'm buying (4) of these as a result of these tests. Their output to size, weight, sonics, warranty and cost is a winner. These amps are not auto-ranging, you have to choose either 120v or 208/240v - the latter is the only thing that makes sense given the horsepower involved. This amp is all about allowing the peaks of music to get through without clipping as their testing method indicates. It has both hard (lows and subs) and soft (mids and highs) limiting available as well as several cool protection circuits with a light show on the front panel. I made all the pretty lights come on without letting the smoke out. Too bad they make you buy a thousand dollar gizmo to connect your PC to the amp to monitor its behavior - they should nix that thing and its cost and allow you to connect your computer directly to the amp(s). Maybe the smaller Labs sound better in the mid/highs, but this amp showed its class D heritage in my listening tests, which nixed my thought of replacing the Camco's with a Lab on the mid/highs. Still, this amp is probably the best sounding class D amp I've heard. [B]Long-term Measurements:[/B] Though I expected this to be boring, I accidentally learned some interesting stuff here about design philosophy between the various manufacturers. All have made reasonable compromises in trying to skin the cat of high output without damaging itself or the stuff at the other end of the loudspeaker cable when operated by a bunch of lunatics. Each of the below show a reference measurement of magnitude and phase at 50 watts and at about 1dB beyond their maximum output capability with both channels driven into 4Ω. Do not freak out about the max power traces, I could have backed off a hair and made them all pretty, but that wouldn’t have been very helpful, would it? Plus I would have missed out on the flames from some of the manufacturers – and what fun would that be? Actually, I learn from those as well and look forward to it. Be sure to read the caption at the bottom of each graphic for details. [U]Camco Vortex 6[/U] (low level and 1dB beyond max) [IMG]http://homepage.mac.com/soundscapes/PSW/AmpTests/STEPS_V6.PNG[/IMG] [U]QSC PL380[/U] (low level and 1dB beyond max) [IMG]http://homepage.mac.com/soundscapes/PSW/AmpTests/STEPS_PL380.PNG[/IMG] [U]Powersoft K10[/U] (low level and max) [IMG]http://homepage.mac.com/soundscapes/PSW/AmpTests/STEPS_K10.PNG[/IMG] [U]Lab Gruppen FP14000[/U] (low level and 1dB beyond max) [IMG]http://homepage.mac.com/soundscapes/PSW/AmpTests/STEPS_FP14000.PNG[/IMG] [U]Crown ITech HD[/U] (low level) [IMG]http://homepage.mac.com/soundscapes/PSW/AmpTests/STEPS_ITech.PNG[/IMG] [U]Crown ITech HD[/U] (1dB beyond max) [IMG]http://homepage.mac.com/soundscapes/PSW/AmpTests/STEPS_ITech_Max_+1dB.PNG[/IMG] [B]Short-term Measurements:[/B] This is really interesting. The following scope traces are from the FP14000 to demonstrate how I made these measurements. The scope is used to determine the point at which the shaped tone burst begins to deform and plotted with the input signal scaled to for reference. The red trace is the input signal and the blue trace is the output at the point where I judged it to be the maximum. I lost the 100Hz measurement like a dummy, and I’m too lazy to do the measurement again, but it’s immaterial. One thing you’ll notice is at the higher frequencies, the output trace is late to the party – a simple measurement of phase lag as predicted by the long-term STEPS trace. The scope's phase calculations agreed with STEPS. I think I’m getting the hang of this. :) [U]FP14000 Shaped Tone Burst Measurements[/U] [IMG]http://homepage.mac.com/soundscapes/PSW/AmpTests/FP14000_Scope.png[/IMG] And now, ladies and gents… These numbers are per channel in stereo mode into 4Ω. They would have been higher at 2Ω, though voltage and the SPL from your loudspeakers would be lower. Chew on that. I hate this whole watts thing – just did it for the peanut gallery – next time it’s volts like God intended. :) [U]The Data[/U] [IMG]http://homepage.mac.com/soundscapes/PSW/AmpTests/Amp_Burst_Table.png[/IMG] [U]The Picture[/U] [IMG]http://homepage.mac.com/soundscapes/PSW/AmpTests/Amp_Burst_Graph.png[/IMG] [/QUOTE]
Insert quotes…
Verification
Post reply
Home
Forums
Pro Audio
Product Reviews
Amp Tests (1 of 2)
Top
Bottom
Sign-up
or
log in
to join the discussion today!