Class D power amps Rotel vs Bel Canto

CLIVEEDWARDS · 19-10-2009, 9:02 PM

I am interested in going down the Class D route and was looking at the Bel Canto ref 1000 and the Rotel 1092.
Both of these amps contain the same B&O ice power module but differ with power supplies and filters.
The Rotel is the cheaper option but how do these amps compare sound wise?

Roger Thornhill · 19-10-2009, 9:38 PM

''We'' all got hot under the collar at CD replay with Brick-Wall filters at the output to get rid of the 44.1kHz sampling frequency, now, Class D amps with, guess what, yes.........Brick-Wall filters at the output to get rid of the switching frequency noise are all the rage

I for one don't get it.

And yes, i have listened to (and scoped) a Susano, didn't like it, too much noise on the scope and the sound.........was 'digital' (?sorry!), didn't like it.

Welwynnick · 19-10-2009, 9:42 PM

Not the same as CD-type brick-wall filters at all. Class D amps run at 10 to 20x the analogue audio bandwidth so that they can have relatively gentle filters.

I'd expect the Rotel and the bel Canto to sound much the same.

The filtering is probably for EMC purposes.

Nick

ralphmalph · 20-10-2009, 9:47 AM

When I bought my Icepower amps with ASP1000 modules in I compared them to the Bel Cantos. We even opened them to compare and inside they were basically identical except for a ferrite core on the internal power leads.

They sounded the same as well. I did not compare a Rotel version another manufacturer, but I would also agree with the poster above I would say they would sound identical or 99% the same if the modules are the same.

Medrep1 · 20-10-2009, 11:09 AM

I wonder why Rotel moved away from the 1000ASP to the 500ASP in the 1575? Not even the 1572 uses the 500 ASP, I think its just the 500A's?

These would have probably been a much better supply for my speakers?

I'z von't more power!!!!

Welwynnick · 20-10-2009, 11:18 AM

The A suffix means amplifier only.
ASP means integrated power supply and amplifier.
An ASP module can drive one or two other "A" amplifiers.
The Rotel power amps seem to follow the NHT architecture:

5-channels: 2x500ASP + 3x500A
2-channels: 1x500ASP + 2x500A

I think this is what the 1572 does, but I seem to recall that some rotel class D amps did use Rotels power supplies instead.

nick

Medrep1 · 20-10-2009, 12:27 PM

I read somewhere, by someone, who has looked into this, literally, that the 1572 uses the 500A modules with a custom power supply?

The 1575 uses the config you suggested?

Would you think there be a difference in performance in either configuration?

Rotel are about to release their new £2k 12x100w amp, and speaking to them directly about this, they were very enthusiastic for me to try this for my front x3 speakers all being biamped, as opposed to extra 1572's for example???

Im intrigued to say the least.

UFN · 20-10-2009, 5:34 PM

The 500ASP and the 1000ASP models do sound quite different with (in my opinion, but confirmed by others as well) the 1000ASP being "cleaner" and more "hi-fi" and the 500ASP being slightly "warmer" and more "musical".

Disclaimer: I have worked for ICEpower (but don't any more and it wasn't in R&D) so my opinion on the differences are based on quite extensive listening but you may of course read as much bias into my opinion as you want

Nick: The configurations you describe is basically correct, but since the 500A and the 500ASP are different and don't sound the same building a stereo amp based on this combination isn't recommended. I believe NHT used 2 500A's and 1 500ASP with the ASP basically only acting as the power supply for the set up.

/U.

PS: I believe the only technical difference between the Rotel and the Bel Canto (at least the old version) is that the Rotel uses an op-amp based buffer at the input whereas the Bel Canto has the stock low(ish) 8k input impedance. The new version of the Bel Canto uses some buffer circuit at the input though I can't remember its configuration off the top of my head.

CLIVEEDWARDS · 20-10-2009, 8:22 PM

I figured they would both sound similar to each other so it would probably make sense to lean towards the cheaper Rotel.

I am currently bi-amping using an Arcam P7 into B&W 802D's, Would a class D amp with the extra power give me the sonic benefits over and above what I am using now.

Welwynnick · 20-10-2009, 8:31 PM

I have a P7 and an NHT P5 (500ASPs) and I've been comparing them for weeks.

I think you would gain some muscle and lose some musicality.

Difficult call.

Nick

Medrep1 · 21-10-2009, 7:19 AM

Im using the 1575 into 803D's, and its also running a HTM2D and 805S for rears for AV.

For stereo listening, the power limit seems endless and has an effortless presentation to it. The sound is very clean, and could be described as clinical to the more HIFI biased enthusiast. I have been trying various players over the past few months, and the amp just seems to let each spinners own character come through so easily, so I guess its doing what it should. Very neutral amp, possibly a touch bass lean, but extremely dynamic.

For movies powering all speakers, it will do so with ease, way way above reference level, with a x over at 60hz to mains and 80hz for the rest. Anything lower mind you above SPL ref level and the amp will clip at the most dynamic moments, but this is very loud and as you can appreciate the 800's are gutsy speakers.

I have tried biamping the 803D's with the 1575, and I wasnt too sure for stereo. It seemed to give the high end a very forced presentation, extremely detailed to the point of being possibly a bit uncomfortable? There appeared to be more bass though, and possibly more controlled/tighter?

Biamping for movies was fun, although I could only run the front three, so not really a fair test and it was quite a while between cable set up/changes.

For the money I dont think there is much to touch them for their effortless and neutral performance. For you with 802D's and im assuming dedicated hifi 2channel guy, hmmm? I'd be inclined save a little more and partner the 802's with what they deserve?

CLIVEEDWARDS · 22-10-2009, 7:53 PM

Thanks for the replies , I think I will need to get a home demo if I can find a shop who has the Rotel.( A bit naughty as I intend to buy second hand though.)
By the way there was a typo in my last post. I actually have 803D's and not the 802D's ,if only!!

Medrep1 · 22-10-2009, 9:16 PM

I'd definitely get an audition. Hand on heart if I had to choose again I'd pick what ive got now.

Im not quite sure how much more id have to spend to gain a 'significant' improvement, and whether frankly I would want to spend that amount.

The set ups ive heard in the last 12 months, including 2 major shows, from modest to high end, have all performed admirably, and the differences from midrange to high end havent exactly been night and day either. In fact, being brutally honest, blind tested I'd probably struggle to tell whether it was a 3k set up or a 20k set up.

lbstyling · 23-10-2009, 3:33 PM

it might be of interest-that ive been busy...

maby you need a closer look at my latest toy....

thats a standard AA battery for size reference.

2 x 100rms @4 ohms- they now do a 4 x 100 as well.

- its about £40 delivered...

this was £26. delivered.

tahirti3 · 24-10-2009, 6:44 AM

please post your findings regarding this module.does it only need a power supply to get going? what type of connector does it use for power and can you advise on which power supply would be suitable.
thanks

Ianfromnotts · 24-10-2009, 7:08 AM

That sure looks an interesting module, cant see it listed on the Sure web site -

Audio Amplifier Boards_Audio Amplifier and other Audio Boards_RF and Audio, Video Equipments_Sure Electronics' Webstore

where did you source it from?

lbstyling · 24-10-2009, 12:07 PM

Quote:

Originally Posted by tahirti3

please post your findings regarding this module.does it only need a power supply to get going? what type of connector does it use for power and can you advise on which power supply would be suitable.
thanks

well, i bought it after looking into the whole class t thing for the last 6 months . the idea was that if they are as good as some say-then i could try tri-amping my stereo speakers for the improvement in sound ive experienced by tri-amping with my parasound halo.
i know the improvement in the sound i experienced wasnt due to the increase in power put into the speakers, because of various tests and other aspects i wont go into here- so i thought the tripath amps may provide adequate power.

i looked into them for some time, and decided the 41hz amps would be a good choice-but its alot of money to just try a new tecnology-epecially as previous experience has taught me that reviews and opinions of people on the web are far too often just plain wrong. (heavily modded lite audio dac-ah)

so i saw this on the bay and took a stab at it for evaluation of the tech (all tripath amps are very similar in design-this is because the amp is effectively all inside the chip- the board is just to supply and regulate)

ive only had time to run it at 12v (battery pictured-14.2v actually) which means at the 8ohm load my speakers present-im only delivering somthing like 15w at low distortion.

connected to higher efficiency speakers(92db@1w, benign load), this amp will deliver a surprising sound.

it pains me to say it but its better than the halo into these speakers at up to 90db at 1m.

the sound becomes brittle if pushed much above this.

into the lower efficiency speakers (85db@1w) -in my room they just wont go loud enough before the amp loses its quality to give it a fair evaluation.

but-the amp will take up to a 32v (ish) supply.-so i will try again with the second battery attached soon and let you know.

the good news is that the 41hz amps go up to 1200w per channel-(if you supply the voltage).

i was thinking of getting the amp 15-ps myself.

please remember that im using a battery for this, and that using a linear or switching supply may change the sound quite allot from mine-i have the switching supply coming from sure in a month or so (27v) so will keep ppl updated on what difference it makes.

-im inclined to think it wont make much difference to the overall sound because of the brick wall filter-however it will be interesting to see how it effects the transient performance because the battery setup has a verually infinate supply with 200amps avalible and a nearly 0m/s rise time.

for those who are interested-this is the same chip you will find in the naim n-vi Naim Audio n-Vi