gafbass02 Posted August 30, 2011 Share Posted August 30, 2011 No problem dude, sorry the attachments didn't copy, I'm sure someone will fix that. I've no interest in buying a TC amp, but I've still followed this with some interest, as there's been a few times I've run across amps I felt didn't seem to match the ratings. Quote Link to comment Share on other sites More sharing options...
Musicman20 Posted August 30, 2011 Share Posted August 30, 2011 The general consensus is the 750 spec is a typo. We shall find out soon. Quote Link to comment Share on other sites More sharing options...
wateroftyne Posted August 30, 2011 Share Posted August 30, 2011 [quote name='Musicman20' post='1355979' date='Aug 30 2011, 09:33 AM']The general consensus is the 750 spec is a typo. We shall find out soon.[/quote] I really, really hope it is! Quote Link to comment Share on other sites More sharing options...
Musicman20 Posted August 30, 2011 Share Posted August 30, 2011 [quote name='wateroftyne' post='1355982' date='Aug 30 2011, 09:34 AM']I really, really hope it is![/quote] Otherwise, there would be no additional power, which doesnt make sense at all....we shall see! I do however understand Uffe's explanation given, and why they did it. It might seem odd, but as a few on talkbass mentioned, you can turn everything up full and nothing will clip...at all...just keep pushing. Quote Link to comment Share on other sites More sharing options...
wateroftyne Posted August 30, 2011 Share Posted August 30, 2011 (edited) [quote name='Musicman20' post='1355987' date='Aug 30 2011, 09:37 AM']Otherwise, there would be no additional power, which doesnt make sense at all....we shall see! I do however understand Uffe's explanation given, and why they did it. It might seem odd, but as a few on talkbass mentioned, you can turn everything up full and nothing will clip...at all...just keep pushing.[/quote] Y'see, that's the bit I struggle with. It doesn't feel like it pushes to me. It's like listening to a song on the radio - you can turn it up loud, and it'll get loud, but it doesn't punch. But that's TC's take on valve amps, I suppose. Edited August 30, 2011 by wateroftyne Quote Link to comment Share on other sites More sharing options...
51m0n Posted August 30, 2011 Share Posted August 30, 2011 (edited) [quote name='lojo' post='1355304' date='Aug 29 2011, 03:05 PM']Is there a way to really measure output at varying volume settings, if so , then one of the magazines should surely set up a test when reviewing and give some sort of rating or benchmark, which at least would allow you to compare across the board with a level benchmark As I said before whatever amp I use I always seem to end up with the dial in the same place anyhow[/quote] Yes. Take an anechoic chamber, a reference system measuring actual dB of sound, and test pink noise and frequency sweeps to accurately plot the volume at various frequncies and the slew rates etc over time of the entire rig. You could even work out THD from this. Personally I dont think most bassists are ready to try and take the output from the corresponding figures and try and work out if that would make it asny good on a gig. Edited August 30, 2011 by 51m0n Quote Link to comment Share on other sites More sharing options...
charic Posted August 30, 2011 Share Posted August 30, 2011 Very interesting read, having twiddled the multitude of settings on mine again I'm happy as a pig in dirty stuff again Quote Link to comment Share on other sites More sharing options...
stingrayPete1977 Posted August 30, 2011 Share Posted August 30, 2011 [quote name='Musicman20' post='1355987' date='Aug 30 2011, 09:37 AM']I do however understand Uffe's explanation given, and why they did it. It might seem odd, but as a few on talkbass mentioned, you can turn everything up full and nothing will clip...at all...just keep pushing.[/quote] To me it's like limiting a Nissan micra to 40mph then marketing it that it feels like it is never struggling for power, but its just that you can never get at it's weakest point. Quote Link to comment Share on other sites More sharing options...
Guest bassman7755 Posted August 30, 2011 Share Posted August 30, 2011 (edited) [quote name='stingrayPete1977' post='1356666' date='Aug 30 2011, 06:43 PM']To me it's like limiting a Nissan micra to 40mph then marketing it that it feels like it is never struggling for power, but its just that you can never get at it's weakest point.[/quote] Thing is that these amp specs are measured at 1khz and doesn't really indicate how well the amp perform driving much lower frequencies. An amp might be rated at 500w 1khz but only deliver a fraction of that at say 50 hz - 60 hz so the RH450 might well significantly out perform such an amp especially for bass if it can still deliver 230w at these sorts of low frequencies. You get the same thing with hifi amps - alot of the boutique ones have comically low headline 1khz RMS ratings like 15 - 20w. The dilemma for the likes of TC electronics is that their target market (unlike the hifi buff crowd) isn't clued up enough to know how little the 1khz rating matters. The car analogy is a good one actually because people focus on HP ratings rather than torque across the most used rev ranges. Edited August 30, 2011 by bassman7755 Quote Link to comment Share on other sites More sharing options...
stevie Posted September 2, 2011 Share Posted September 2, 2011 (edited) "[This Audio Precision (”AP”) measurement shows a 1kHz sinus burst (20 ms) that have a peak value of 60V, corresponding to 42.42Vrms 450W RMS in 4 Ohm]" In that case, perhaps TC will rate this amplifier accordingly, at 450 watts PMPO (Peak Music Power Output) in future. To answer the original question - no, the RH450 is not a 236W head. The power output measured in the test was at 2.5% distortion into 1kHz. The accepted level of distortion for these measurements in most circles is 0.1% across the rated bandwidth. So the RH450 is probably not even a 200-watt amp. I'll bet my bottom dollar that the technical guys will have issued a disclaimer in writing to protect their backs when they heard that the product would be rated at 450 watts. My guess is that they are laughing up their sleeves now that the marketing experts have been caught with their pants down. Edited September 2, 2011 by stevie Quote Link to comment Share on other sites More sharing options...
wateroftyne Posted September 2, 2011 Share Posted September 2, 2011 Uffe's lack of response the RH750 question is a little odd, as well. If it had been a typo I would have thought he would nipped that in the bud right away. Quote Link to comment Share on other sites More sharing options...
51m0n Posted September 2, 2011 Share Posted September 2, 2011 See what we have here is a basic failure to disclose the truth. The truth is that due to its clever digital preamp processing it can ring a lot out perceived volume of the signal. There are several ways you can do this, you can bin any tricky frequencies likely to soak up a lot of power (that would be sub bass), you can compress and limit the signal before it leaves the pre and hits the power amp, you can have very clever control of the power section current too. Its all great and it definitely makes the most of the actual power of the device. There is one thing it does not do though, it does not change the wattage RMS rating of the head. Not a bit. So if you claim it to be more powerful than it really is, you are lying. And as our mummies told all of us, dont tell fibs because you will get caught, and at the very least look like a bunch of complete prats. Quote Link to comment Share on other sites More sharing options...
GreeneKing Posted September 2, 2011 Share Posted September 2, 2011 I've been reading through most of this thread and while I'm not at the moment a gigging bassist we do practice pretty damn loud (to compete with our lead guitarist) and I was never entirely at one with my RH and went back to LM. My thoughts aren't so much 'naughty TC lying' but wondering just how subjective or precise the measurement of wattage is. A question for the experts, how is wattage measured, obviously not by power consumed because there are efficiency factors to take into account? What I'm saying is, is it just TC who've been caught or are other manufacturers up to similar tricks to win buyers? Peter Quote Link to comment Share on other sites More sharing options...
Mr. Foxen Posted September 2, 2011 Share Posted September 2, 2011 Wattage is measured any way you like. TC conspicuously didn't say 'RMS' jsut gave another figure for 'peak' showing they weren't doing the usual trick, ala Behringer. For a real measurement you need watts RMS @ x% distortion @ y-z frequency range/a specific frequency. Quote Link to comment Share on other sites More sharing options...
alexclaber Posted September 2, 2011 Share Posted September 2, 2011 The normal way is with a scope to check for THD and then running a sine wave at set frequencies (the more the better) and seeing how many volts you can get out into a fixed load (4 or 8 ohms) before the %THD hits your spec limit. Then P=(V*V)/R A better way is to use a reactive load with capacitive and inductive components to test the amp at more challenging phase angles (when voltage and current aren't in unison), which could be done with a large bank of speakers (sufficient that they don't start exhibiting power compression which would change the value of R) or a reactive dummy load (measure some speakers and build a model with a load of resistors, inductors and capacitors). That's also silent which is a bonus. I'm looking forward to getting one of these test rigs built and getting a few amps on it - it'll be enlightening... Quote Link to comment Share on other sites More sharing options...
alexclaber Posted September 2, 2011 Share Posted September 2, 2011 There's also how long you run the test for - peak, burst and continuous reveal very different ratings! Quote Link to comment Share on other sites More sharing options...
GreeneKing Posted September 2, 2011 Share Posted September 2, 2011 Thank you. I suspect that TC aren't the only company gilding the lilly Quote Link to comment Share on other sites More sharing options...
Musicman20 Posted September 2, 2011 Share Posted September 2, 2011 I really wouldn't read too much into raw specs. As much as I agree they could have advertised it better, the amp does outperform most other micros eg the LM3 and F500. I don't know how it does it, but none of us, or the talkbass posters, know exactly what's going on with the APM. If you want a massively wide clean amp with massive headroom, the RH isn't for you. It's all about the low mids, and a tube like feel. Whatever the rating, it's a very powerful amp. Quote Link to comment Share on other sites More sharing options...
BB2000 Posted September 2, 2011 Share Posted September 2, 2011 [quote name='GreeneKing' post='1360430' date='Sep 2 2011, 09:19 PM']Thank you. I suspect that TC aren't the only company gilding the lilly[/quote] Of course they aren't. The rating for most of the musical instrument class-D amplifiers are at distortion levels in the 10's %, and no bass/guitar amp will be able to be driven continuously at it's rated output. Amps designed for industrial use will usually be rated for continuous operation at their rated power (which itself will be stated at a particular THD). I believe some PA amplifiers also have realistic ratings. Quote Link to comment Share on other sites More sharing options...
stingrayPete1977 Posted September 2, 2011 Share Posted September 2, 2011 [quote name='GreeneKing' post='1360430' date='Sep 2 2011, 09:19 PM']Thank you. I suspect that TC aren't the only company gilding the lilly[/quote] Well mm20 reckons that Genz amps always come up short, if you take into account the TC is only hitting 236 where does that leave the 600watt GB? That said maybe the TC has been pinching some Hz from the user that the GB hasn't giving the wrong impression and that would also explain why some TC users felt something lacking? I wouldn't be surprised if gb are being sneaky too but as I have said before I won't be defending their company, why would I? Many of the class D amps use the same bang and ollufson output amp too although as we have seen here it depends what happens before it gets there too. Quote Link to comment Share on other sites More sharing options...
Musicman20 Posted September 2, 2011 Share Posted September 2, 2011 Wot mentioned the tone, but not one person said it didn't whump. Strange effect, isn't it? Bring an article out that may not even be 100% accurate, and suddenly people worry about wattage! Quote Link to comment Share on other sites More sharing options...
wateroftyne Posted September 2, 2011 Share Posted September 2, 2011 [quote name='Musicman20' post='1360453' date='Sep 2 2011, 09:38 PM']Wot mentioned the tone, but not one person said it didn't whump. Strange effect, isn't it? Bring an article out that may not even be 100% accurate, and suddenly people worry about wattage![/quote] It didn't whump. It totally didn't whump. Quote Link to comment Share on other sites More sharing options...
stingrayPete1977 Posted September 2, 2011 Share Posted September 2, 2011 My comment isn't based only on bass chat members (and I've never been on talk bass) I'm talking about other people I know in the real world that felt something was missing, none of them are currently class D users now. Quote Link to comment Share on other sites More sharing options...
GreeneKing Posted September 2, 2011 Share Posted September 2, 2011 [quote name='wateroftyne' post='1360463' date='Sep 2 2011, 09:47 PM']It didn't whump. It totally didn't whump.[/quote] Quote Link to comment Share on other sites More sharing options...
Musicman20 Posted September 2, 2011 Share Posted September 2, 2011 [quote name='wateroftyne' post='1360463' date='Sep 2 2011, 09:47 PM']It didn't whump. It totally didn't whump.[/quote] That is the first real volume issue I've ever heard of, and the rest came from non-owners who haven't even tried it so I don't count them. Did you compare it to the Walkabout? I know of a few owners that said the RH450 had a lot more headroom. I think the best qualified comparison I can give is the RH750 vs STL900, and I can honestly say they both have a lot going for them. The bass is too much sometimes on the STL900 and the 750 has more mids/cuts better, but on overall volume, extremely similar. Quote Link to comment Share on other sites More sharing options...
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