SDS-254 Amplifier

[magiccarpetride]

As some of you know, I am using Magnepan planar speakers, which are incredibly inefficient, power-and-current hungry beasts. Last year we had some discussions percolating around Behringer A500 power amp on the forum here, and how these may be a good choice for Magnepan speakers.

In the meantime, I've also stumbled upon this amp: http://classdaudio.com/index.php/sds-254.html

2 X 250W per channel into 4 Ohm (my Maggies are rated at 5 Ohm) -- now that's more like it! And for measly $235.00 (I've seen some very favorable feedback on the high degree of sound quality this amp can deliver:)

The only problem is, it's a kit, seems like it needs some assembly, and comes without the amp case. My question to the esteemed panel of experts here is: how much extra work is needed to put this amp into a workable state, and will I be able to accomplish the setup? Also, what do I do about the amp case, and can it even be tested without first setting it up in a case?

[Welder]

Alex, these might work well for you.
http://www.outlawaudio.com/products/2200.html

I have a mate with Quad 2905 and he uses these behind a Brinkman.

[Reid Malenfant]

If you are asking whether you'll be able to set the thing up yourself then the likely answer is no.

The amplifier looks like it could be tested as is. However there is no power supply so you'd need to find a rather large say 750VA or 1KVA transformer with the correct secondary AC voltages, a rather heavy duty bridge rectfier & at least a couple of large reservoir capacitors. Fuses, fuse holders etc etc. The list would get quite long by the time you actually want to case the thing up & i should imagine you'd be looking at triple that price by the time you are done, maybe more :doh:

[Techno Commander]

You can buy the complete kit (http://classdaudio.com/index.php/products/class-d-audio-kits/sds-254-kit.html) for only $310. Makes life a bit easier. :)

[Reid Malenfant]

:lolsign: Typical underated transformer & joke PSU capacitors, why not do the job properly in the first place :doh:

[Ali Tait]

Sure it's that underrated? This is a class d amp remember-very efficient.

[Reid Malenfant]

Even at say 85% efficiency 2 x 250W RMS would still need a transformer of at least 600VA rating innit :eyebrows: & that's at a minimum :rolleyes:

The amp may well be more efficient at lower powers but when getting close to full power it's not just switching losses that need to be taken into account, there are conduction losses of the mosfets & they only look like TO220 devices to me. As they get hotter transconductance falls & then conduction losses increase still further ;)

[Ali Tait]

Yebbut you are very unlikely to ever run it at full power in a living room.

[Reid Malenfant]

Oh i don't know :scratch: Maggies aren't exactly the most sensitive speakers i could think of ;)

[Ali Tait]

Yes indeed, but the power handling will be limited I would say, they are not rock speakers!

Don't get me wrong, I'm not disagreeing with what you said, but I reckon that PS would be ok for Maggies used in a living room.

[magiccarpetride]

Alex, these might work well for you.
http://www.outlawaudio.com/products/2200.html

I have a mate with Quad 2905 and he uses these behind a Brinkman.

Thanks for the link. I'm not sure about that one, and here is why: as far as I know, well designed power amp will deliver double wattage when you go from 8 Ohm to 4 Ohm. Most good amps I've seen do exactly that. The one you've suggested above isn't capable of doing that (it is rated at 200W into 8 Ohm, and only 300W into 4 Ohm), which makes me think that it may not be that solid of a design.

Maybe I'm mistaken on this. If so, please correct me.

[Welder]

I’m not an electronics engineer Alex so I’m not in a position to say any more than I’ve heard these powering Quads which aren’t the most efficient of speakers and they sounded fine in approximately 8m x 4.5m room at what I at least consider to be very loud :)

[magiccarpetride]

I’m not an electronics engineer Alex so I’m not in a position to say any more than I’ve heard these powering Quads which aren’t the most efficient of speakers and they sounded fine in approximately 8m x 4.5m room at what I at least consider to be very loud :)

In that case, for only $700 (providing that they're pleasantly musical as well), looks like a good deal.

Can you comment some more on the musicality of these monoblocks?

[magiccarpetride]

In that case, for only $700 (providing that they're pleasantly musical as well), looks like a good deal.

Can you comment some more on the musicality of these monoblocks?

Also, can someone comment on the side-by-side comparison between this amp and Emotiva XPA-2, which retails for $799 (http://emotiva.com/xpa2.shtm)?

[Reid Malenfant]

If the link worked, possibly ;)

[Welder]

You’re asking the wrong person Alex. Amplifiers shouldn’t be musical imo. They should just get a signal at one end and shove out a bigger one at the other end.
Prolly be better off talking to one of the valve kiddies, they like a bit of tone in their amps ;)
Sorry mate, I don’t do the “lush second harmonic with a huge soundstage velvet tones highly resolving gorgeous highs” bit.
I'm an engineer, not a Hi Fi rag writer :rolleyes:

[magiccarpetride]

If the link worked, possibly ;)

Sorry, the editor messed up by including the question mark. Here it is:

http://emotiva.com/xpa2.shtm

[Reid Malenfant]

Forgetting specifications for a minute the second amplifier looks like a monster :eyebrows: 1200VA transformer means it is fairly serious & the heatsinking is substantial as well as output transistor complement ;)

There are no specifications for the first amp you linked to so i'm naturally skewed towards amp 2 & it's specs look pretty decent. They give all sorts of interesting stuff on PDF files which most manufacturers don't tend to publish...

I'm not sure of the sensitivity of your Maggies, but if i remember right even the big ones are not that sensitive, smaller models can be as low as 82/3 Db/W 1M though they'll all handle quite a bit of power due to the open nature of the winding on the panel.

I can't tell you that the second amp is better as i can't listen to it. However if you ever like to turn up the volume a tad (:eyebrows:) then the second amp wins hands down. It has a much more powerful PSU & probably more output power than your Maggies can handle which is a good thing imo. Clipped amps don't sound nice, clean overload is kinder on speakers than square waves :cool:

That looks like a hell of a lot of power amp for the money! Pity they aren't over here at the same sort of price :rolleyes:

[Ali Tait]

That second amp looks great value from what I can see. How it sounds is another matter of course.

[magiccarpetride]

That second amp looks great value from what I can see. How it sounds is another matter of course.

Reviews of Emotiva XPA-2 are extremely favorable, although it seems like it can't stand shoulder to shoulder with more serious contenders (like, 5k+ power amps).

Feels like this amp is a champ in the brute brawn category, and loses a bit in the finesse compartment (not exactly grainless highs).

[Techno Commander]

There have been some good reviews of the Emotiva. Definitely punches above its weight. They also do a 230v version and ship internationally.

[magiccarpetride]

Forgetting specifications for a minute the second amplifier looks like a monster :eyebrows: 1200VA transformer means it is fairly serious & the heatsinking is substantial as well as output transistor complement ;)

There are no specifications for the first amp you linked to so i'm naturally skewed towards amp 2 & it's specs look pretty decent. They give all sorts of interesting stuff on PDF files which most manufacturers don't tend to publish...

I'm not sure of the sensitivity of your Maggies, but if i remember right even the big ones are not that sensitive, smaller models can be as low as 82/3 Db/W 1M though they'll all handle quite a bit of power due to the open nature of the winding on the panel.

I can't tell you that the second amp is better as i can't listen to it. However if you ever like to turn up the volume a tad (:eyebrows:) then the second amp wins hands down. It has a much more powerful PSU & probably more output power than your Maggies can handle which is a good thing imo. Clipped amps don't sound nice, clean overload is kinder on speakers than square waves :cool:

That looks like a hell of a lot of power amp for the money! Pity they aren't over here at the same sort of price :rolleyes:

Yes, my Maggies are rated at 83 Db/W 1M, which poses a challenge to my DPA 200s power amp. Maggie experts claim that these babies need minimum 200 wpc, even for low listening volumes.

Emotiva XPA-2, at $799, is not exactly your high end audiophile amp, but many reviews seem to give it a lot of credit for neutrality and truth-in-music reproduction. The only complaints seem to be regarding their lack of ability to plumb finer details of the soundstage, as well as small, but still noticeable presence of residual graininess in the highs.

[Reid Malenfant]

I guess just about any class AB or B amp can be tarred with the same brush Alex ;) They all exhibit crossover distortion to one extent or another :rolleyes: The fact that you haven't got a metal dome tweeter which would emphasise this could curry some favour ;)

[magiccarpetride]

I guess just about any class AB or B amp can be tarred with the same brush Alex ;) They all exhibit crossover distortion to one extent or another :rolleyes: The fact that you haven't got a metal dome tweeter which would emphasise this could curry some favour ;)

You mean Maggies could make the unavoidable graininess seem less harsh?

[Reid Malenfant]

Less than a metal dome tweeter which will ring like a cow bell, yes...

Frankly i doubt the amps are that bad in all honesty, they look well set out construction wise & considering the power output don't look under specified from the pics available..

[Ali Tait]

Yes, my Maggies are rated at 83 Db/W 1M, which poses a challenge to my DPA 200s power amp. Maggie experts claim that these babies need minimum 200 wpc, even for low listening volumes.

Emotiva XPA-2, at $799, is not exactly your high end audiophile amp, but many reviews seem to give it a lot of credit for neutrality and truth-in-music reproduction. The only complaints seem to be regarding their lack of ability to plumb finer details of the soundstage, as well as small, but still noticeable presence of residual graininess in the highs.

83dB is low, but IMHO the load the speaker presents is the more important bit as to how an amp will sound with them. Do you know the max power handling of the Maggies?

You say the reviews of that amp says it loses a little to 5k+ amps. Sounds like a bloody bargain to me!

[magiccarpetride]

Forgetting specifications for a minute the second amplifier looks like a monster :eyebrows: 1200VA transformer means it is fairly serious & the heatsinking is substantial as well as output transistor complement ;)

There are no specifications for the first amp you linked to so i'm naturally skewed towards amp 2 & it's specs look pretty decent. They give all sorts of interesting stuff on PDF files which most manufacturers don't tend to publish...

I'm not sure of the sensitivity of your Maggies, but if i remember right even the big ones are not that sensitive, smaller models can be as low as 82/3 Db/W 1M though they'll all handle quite a bit of power due to the open nature of the winding on the panel.

I can't tell you that the second amp is better as i can't listen to it. However if you ever like to turn up the volume a tad (:eyebrows:) then the second amp wins hands down. It has a much more powerful PSU & probably more output power than your Maggies can handle which is a good thing imo. Clipped amps don't sound nice, clean overload is kinder on speakers than square waves :cool:

That looks like a hell of a lot of power amp for the money! Pity they aren't over here at the same sort of price :rolleyes:

It turned out that it's hellishly difficult to order Emotiva XPA-2. I placed myself on the waiting list, but haven't heard back from the seller.

In the meantime, what do you guys think about Yamaha P7000S? (http://www.americanmusical.com/Item--i-YAM-P7000S-LIST)

It reportedly offers 750 WPC into 8 Ohms (1,100 WPC into 4 Ohms). This one seems much easier to purchase (while being a bit less expensive), so I'm wondering at this point should I sit and wait for the seller to eventually get back to me with the PO for Emotiva, or should I go instead with Yamaha P7000S?

[Techno Commander]

The Yamaha is a PA amp so will definitely loose some refinement compared to the Emotiva. You will also have to put up with fan noise and making new interconnects (either jack or XLR).

[magiccarpetride]

The Yamaha is a PA amp so will definitely loose some refinement compared to the Emotiva. You will also have to put up with fan noise and making new interconnects (either jack or XLR).

Thanks, I wasn't aware of these hurdles. Definitely pushes me into fishing for Emotiva. (at least, the good news seems to be that Emotiva is quite popular, as they still don't know when will the next ordering/shipping cycle commence).

[Techno Commander]

I would rather have the Emotiva over the Yamaha.

[magiccarpetride]

I would rather have the Emotiva over the Yamaha.

Me too! It's just that I am being really challenged for days now trying to find ways to purchase it. There's been recent offers on the buy-and-sell online boards, but Emotiva seems to sell in a matter of minutes:(

[Welder]

I’m going to make a recommendation Alex :doh:
As I understand it you listen to a lot of pop and rock and some classical.
I suggest you consider a valve amp (John recommending a valve amp, Christ, he must be ill :eek:)
In fact, I suggest you check this out
http://www.morningstaraudio.com/shop/item.asp?itemid=7
It is one of the few affordable valve amps I’ve heard that perform as well as the solid state at the price range.
Whether it will be able to drive your Maggies is something you would have to check.

[Ali Tait]

Yeah, who are you and what have you done with John?? :lol:

[Welder]

Yeah, I know Ali, but what can I tell you (hope Ali will still talk to me :eyebrows:)
Alex has got those bloody Maggies waving about from what I gather. Electrostatics and planer speakers aren’t noted for their system tolerance, too analytical and not enough bass to offset any glassiness in treble and midrange.
One of the advantages of full range sealed box speakers; you can tune them. You cant do anything with stats and panels.
Now it seems he’s thinking of sticking an overpowered solid state power amp in front of them that from what I can gather is pretty unforgiving :eek:
Then of course he has a digital source and not like my mates ULN8 which you can tune with filters :(
Add to that he seems particularly critical of compression and harsh recordings………well, its just a recipe for disaster imo :mental:
He either needs to unload the Maggies or accept their shortfalls and work the front end to compensate. All just my opinion of course ;)

[Ali Tait]

Actually that's pretty good advice I think mate.

[magiccarpetride]

Yeah, I know Ali, but what can I tell you (hope Ali will still talk to me :eyebrows:)
Alex has got those bloody Maggies waving about from what I gather. Electrostatics and planer speakers aren’t noted for their system tolerance, too analytical and not enough bass to offset any glassiness in treble and midrange.
One of the advantages of full range sealed box speakers; you can tune them. You cant do anything with stats and panels.
Now it seems he’s thinking of sticking an overpowered solid state power amp in front of them that from what I can gather is pretty unforgiving :eek:
Then of course he has a digital source and not like my mates ULN8 which you can tune with filters :(
Add to that he seems particularly critical of compression and harsh recordings………well, its just a recipe for disaster imo :mental:
He either needs to unload the Maggies or accept their shortfalls and work the front end to compensate. All just my opinion of course ;)

Thanks inmate, that's a great advice.

Allow me to take this opportunity to explain where I'm coming from when it comes to building an audio system: I prefer 'production' to 'reproduction'. What I mean by that is that I'm not keen on having an audio system that will editorialize while the music is playing. I've heard many such systems, and some of those are breathtakingly brilliant. It's like having a Nobel Prize Literature winner provide a running commentary on what's going on at the moment. The editorial effort may be a piece of art in itself (and as a matter of fact, some of the ultra high end systems I've heard are matchless in that respect -- a case in point would be my recent experience with auditioning Focus Maestro Utopia speakers).

However, I'm not interested in pursuing that goal. I don't need a brilliant editor sitting in the chair next to me, commenting and sugar coating the sound that's pouring out of my audio system. I need absolute truth in music, brutal honesty, warts and all. This is the reason I'm staying with Maggies, because of all the speakers I've heard so far, they tend to editorialize the least.

In short, I'm not interested in euphonics, in sugarcoating the harshly produced recordings, etc.

[magiccarpetride]

There have been some good reviews of the Emotiva. Definitely punches above its weight. They also do a 230v version and ship internationally.

I'm seriously considering buying Emotiva, but at this time would only be able to justify the purchase if I sell my DPA separates. Which would leave me without a pre amp.

Would you guys have any recommendations on a decent pre amp that could take the signal from Caiman into Emotiva XPA-2?

[Alex_UK]

I'm seriously considering buying Emotiva, but at this time would only be able to justify the purchase if I sell my DPA separates. Which would leave me without a pre amp.

Would you guys have any recommendations on a decent pre amp that could take the signal from Caiman into Emotiva XPA-2?

Have you tried the Caiman's variable output direct into the power amp? Not sure what "best possible" analogue sources you have in addition to the digital ones through the Caiman, or if you could live without remote (assume your current pre has a remote?) - but "cutting out the middle man" might just bring about an improvement - whether it would be night and day, I'm not sure... ;)

[magiccarpetride]

Have you tried the Caiman's variable output direct into the power amp? Not sure what "best possible" analogue sources you have in addition to the digital ones through the Caiman, or if you could live without remote (assume your current pre has a remote?) - but "cutting out the middle man" might just bring about an improvement - whether it would be night and day, I'm not sure... ;)

Yes, I've tried it, but with my current setup, I must crank the Caiman's preamp all the way up to 3 o'clock to get the same volume I'm getting from my DPA pre amp at 9-ish o'clock.

Other than that, couldn't detect any differences in the sound quality. Both with and without my DPA pre amp, the sound remains the same. It's just that with the Caiman, it can't really go loud.

[Techno Commander]

It's just that with the Caiman, it can't really go loud.

That would probably change with a monster power amp though.