Hypex UcD700HG amplifier

[xerxes]

The parts for the Hypex amps have arrived.


These are the parts for one mono amp, obviously I have two of everything to make a stereo pair of monoblock amps.

All I need to do now, is connect everything together and put it in a box.

[xerxes]

350 wpc into 8ohms, 700 into 4, 1,400 into 2. Plenty of ooomph!

[bullpup]

Xerxes,

I am intrigued, apart from heating your house with these what are you going to use them for i.e. do you have particularly difficult speakers to drive very loud or that require bags of control?

[leo]

You'll have fun with those!
The UCD's actually make great sounding amps, I've not tried the 700's but thinking of trying the UCD400HG's next, currently use a pair of highly modified UCD180's

[xerxes]

I am intrigued, apart from heating your house with these what are you going to use them for i.e. do you have particularly difficult speakers to drive very loud or that require bags of control?

The Hypex amps are class D, very efficient, so despite the power they apparently run very cool. I've got some whopping great heat sinks to mount them to anyway, so they should be fine. My speakers are a pair of Dynaudio 52SEs, which are quite difficult to drive and apparently sound better with more powerful amps; we shall see.

My current amp is 70 wpc and there is a sense that it is slightly over-stretched; if I really crank it up it gets very hot and the thremal protection has kicked in and the amp has cut out on a couple of occassions.

I'm still waiting to get hold of a few bits and bobs, but I should have them up and running by the end of the week. I'll be sure and let you know what I think when I have a listen. Based on the reviews I have fairly high expectations; hopefully I won't be dissapointed.

[PinkFloyd]

You're making me salivate Xerxes, it's been ages since I've DIY'ed anything that beefy.... keep us updated on the progress. To compliment your amp I may let loose with one of my loudspeaker designs and do a step by step online build...... loudspeakers are my forte and something I have never mentioned "online"

Mike.

[FritzS]

The parts for the Hypex amps have arrived.

I read about another good class D amp from Hubert Reith
www.hifiakademie.de/

pictures about
hifiakademie.de/?id=0.3&si=MTE4NTc4NDYyMC43NDgzfDE5My4xNjQuMTUuMzV8IA

Some german DIYs compared Class A/B power amps (incl. tube amps) with class D power amps and very impressed about the tube like sound of class D

I have no experience about class D - but I read some in german HiFi forums from the Reith amplifier. Personally I am sceptic about but can it cause surprise?

But I think "green" - in 10 years all power amps would be in class D and the audio signal path are pure digital

And all old, good analog - OPA's, tubes, etc. tombstoned!?

I opened a thread about class D in headphone amp
rockgrotto.proboards39.com/index.cgi?board=m&action=display&thread=1185704333

[leo]

I've heard quite a few classD amps, Nuforce,Tripath,ICE power etc, the UCD's was easily the best IMHO and had lots of potential.
I have a lot of respect for Bruno Putzeys
The modified UCD's I have are very neutral sounding, out of all my amps they sound the least coloured

[xerxes]

But I think "green" - in 10 years all power amps would be in class D and the audio signal path are pure digital

Class D isn't actually digital, I don't pretend to understand the technical details, but there is some information on the Hypex web site about how it works.

I don't think the Hypex design is particularly green, although the amplifier itself is very efficient, > 80%, it still uses a linear power supply with a 600VA transformer for the UcD700 amp. Some class D amps use switch mode power supplies, which should make them "greener":

B&O Icepower
Nuforce

However, neither the B&O modules nor are the Nuforce amps are available as a DIY option. There are quite a few manufacturers using the Icepower modules, Bel Canto, Rotel, Jeff Rowland and a few others. As far as I can tell, the manufacturers are simply putting the finished amp modules in a box, but the price of the finished amps varies wildly depending on which brand you choose. Some manufacturers claim that they have made some modifications to the modules, but I can't see them from the pictures I've come accross and I suspect that some manufacturers are charging and awful lot for a nice box. Even if some manufacturers were altering the boards, adding some better components etc. I can't see how they would add up to the price difference between some of the cheaper variants and the dearest.

Rotel RB-1091, $3,000.00 for a stereo pair.
Jeff Rowland Model 501, $6,700.00 for a stereo pair.

Both models use the B&O Icepower 1000ASP modules. The Jeff Rowland cases are beautifully made, milled from solid aliminium billets, but whether they are worth the extra $3,700.00 USD is another matter.

To compliment your amp I may let loose with one of my loudspeaker designs and do a step by step online build...... loudspeakers are my forte and something I have never mentioned "online".

There must be a pun in there somewhere about you keeping quiet about your loudspeakers.

I have thought about DIY speakers, I thought these Wilmslow Audio speakers looked nice. However, whenever I've bought audio stuff in the past, it's allways been the speakers that I've spent longest agonising over. Sources and amplifiers do have their own distinct sound of course, and do effect the overall sound, but not as much as speakers. It seems speakers can vary quite dramatically in their presentation and choosing a set is more to do with personal taste than selecting the most technically "accurate" speakers. Then there's the problem of room acoustics, a pair of speakers will sound great in one room, but completely wrong in another.

I haven't heard the Hypex amps, so I'm taking quite a gamble, about £1,400.00 worth, that I will actually like the noise they make when I've finished. Given the variability of speakers, I'm not so sure I'd be ready to gamble so much without hearing them.

[FritzS]

Class D isn't actually digital, I don't pretend to understand the technical details, but there is some information on the Hypex web site about how it works.

for those people who understand german - a good description how class D works
hifiakademie.de/?id=1.8&si=MTE4NTgwNjgzOC40MjczfDE5My4xNjQuMTUuMzV8IA

[southpaw]

xerxes said:

I haven't heard the Hypex amps, so I'm taking quite a gamble, about £1,400.00 worth,

That's some gamble! Hats off to you for being brave and I hope it works out for you Ive never bought any really expensive hifi item and been disapointed.

Best of luck!

[PinkFloyd]

You'll be blown away by the Wilmslow speakers Xerxes, I built a pair of their "vogue" floorstanders a few years ago and there was nothing in the Hi-Fi shops that could come anywhere close to them..... absolutely first class kits Wilmslow provide and all can be tweaked to your own preferences with damping, X-over components, room placement, tube traps, coconut hair, sheeps wool etc....

Shaun Williams designed the Wilmslow speakers, he had a bust up with them and sold his half of the company.... he now lives in Spain and runs www.williamshart.com/ Shaun REALLY knows how to design a speaker and I certainly wouldn't overlook his Seraph 2 www.williamshart.com/seraph.htm A lovely guy too

[PinkFloyd]

Further to my last post I've e-mailed Shaun and invited him over here, there are not many manufacturers I'd want to invite but Graham Slee and Shaun Williams are two of the nicest most down to earth guys I have ever come across in audioland. I definitely think it's time to incorporate a loudspeaker forum here with a sub forum specialising in DIY, no doubt about that.... it will be going up very soon........ I've got 8 sheets of 25mm MDF in the garage, time to make something out of it We can also discuss x-over design, veneering techniques, cabinet damping, labyrinth enclosures, ported enclosures, standing waves......... I can't wait!

[xerxes]

I wasn't really looking at speakers in this latest round of spendage and I'm pretty happy with the Dynaudios at the moment. However, I certainly won't rule out the DIY route for the speakers in the future given your ringing endorsement of Shaun Williams' speaker desigs.

After the amps, I think a new CD player is next on the shopping list: www.tentlabs.com/index.html. Once again, I haven't heard a TentLabs CD player, but given Guido Tents reputation for CD player design and modding knowledge, I reckon it would be a fairly safe bet. I'll have to save a few more pennies first though.

[bullpup]

All for this idea - I have a couple of 15" Tannoy dual concentrics looking for decent cabinets that don't look like they were designed pre-war and I am talking WW2 rather than Iraq or Falklands.

[leo]

admin said:

Further to my last post I've e-mailed Shaun and invited him over here, there are not many manufacturers I'd want to invite but Graham Slee and Shaun Williams are two of the nicest most down to earth guys I have ever come across in audioland. I definitely think it's time to incorporate a loudspeaker forum here with a sub forum specialising in DIY, no doubt about that.... it will be going up very soon........ I've got 8 sheets of 25mm MDF in the garage, time to make something out of it We can also discuss x-over design, veneering techniques, cabinet damping, labyrinth enclosures, ported enclosures, standing waves......... I can't wait!

That would be nice Mike, my speakers still need veneering

[xerxes]

Finally got the Hypex amps up and running, pictures and info here: www.tdsf.co.uk/Audio/Hypex.shtml

[Deleted]

Xerxes
Nice looking amplifier. However, I doubt that I will ever go the Class D route. Chopping up a nice quality analogue signal, that may already been digitised and reconstructed by a CD player for playback, then doing the same again , goes against the grain with me.
It seems to me , that if they can't even get most CD recordings at a high quality, why stuff them up even further? I realise, that one day the politicians will force all this kind of stuff on us,but I am in no hurry to follow blindly.
However, purely on "bang for buck" grounds they are interesting. I shudder to think what your average car audio f'wit could do to shatter the neighbourhood's peace using this technology.
SandyK

[xerxes]

The D in Class D doesn't actually stand for Digital, it's a missconception, it's just the next in the series, Class A, B, C, D rtc., there's a long explanation at Hypex, that I don't understand.

Whatever the technology, these are very sweet sounding amps, the highs are crystal clear, without a hint of "digital glare" even when using a digital source, for example, cymbals sound right, without being splashy or tizzy.

I've only had them a short while and I need to listen to them longer to really get to grips with the sound and they seem to be opening up a bit with use. But already the sound is very nice and completely un-tiring, even on some harsh, over-bright recordings that with my previous amp would have had me reaching for the off switch after a few minutes.

[leo]

My UCD's have embarrassed a lot of ClassA and A/B types when comparing, a few of the non believers was quite shocked when they heard it

en.wikipedia.org/wiki/Switching_amplifier

[Deleted]

I don't care how they phrase the wording of how they work. They are still chopping the signal in such a fashion, that filtering is needed to correctly reconstitute the analogue signal. Isn't that basically what every CD player does ? Some just oversample, so the "dots" to be filled in aren't so far apart. Don't forget that many Class A and Class AB amplifiers are very mediocre. Some people even think the original JLH Class A amplifier is great. It isn't. It is a very mediocre performer by today's standards, although it was way ahead of the game when first designed. I am willing to bet , that if Graham ever put his mind into designing an analogue power amplifier, using his latest techniques, that it would eat most current Class D amplifiers for breakfast.

SandyK

[leo]

sandyk said:

I don't care how they phrase the wording of how they work. They are still chopping the signal in such a fashion, that filtering is needed to correctly reconstitute the analogue signal. Isn't that basically what every CD player does ? Some just oversample, so the "dots" to be filled in aren't so far apart. Don't forget that many Class A and Class AB amplifiers are very mediocre. Some people even think the original JLH Class A amplifier is great. It isn't. It is a very mediocre performer by today's standards, although it was way ahead of the game when first designed. I am willing to bet , that if Graham ever put his mind into designing an analogue power amplifier, using his latest techniques, that it would eat most current Class D amplifiers for breakfast.

SandyK

Maybe but I can assure the UCD's are very good amps with a few mods, I;ve compared mine against a Krell 500i and the results was very interesting

I built the JLH classA and a Mosfet power follwer, not bad for cheap and simple but are toys compared to the UCD's, I'm not biased towards any amp and just rate any I find sound best.
I will admit there are a lot of average to poor sounding classD amps, I've heard Nuforce, Belcanto, various Tripath and ICE power based and IMO the UCD's was the best
Once I get round to building the SC classA I'll compare it, if its better than the UCD it will be my new reference amp
All the other diy amps I've tried so far that was hyped remain boxed up gathering dust

[Deleted]

Leo
I mentioned previously that my friend's modified SC ULD was compared with a Krell feeding AU$50,000 B and W speakers, and the Krell, in comparison had a very mediocre soundstage,compared to the modded SC ULD into Infinity speakers worth around 1/6 the price of the B and Ws.
Many DIY designs are overhyped. You have to start with a proven design and build on it's strengths. Douglas Self's low distortion designs make good building blocks. Much of the secrets into making most decent amplifiers sound better, involve clean regulated power for the front end of the amplifier. Even a simple capacitance multiplier can make a worthwhile improvement, and is easily implemented.
SandyK

[leo]

Amazing how poor the Krells sound for the price although people still seem to be buying them.
The NCC200 mono's I have uses VBE's now supplying the VAS which cleaned things up a bit

Never been a big fan of the Nautilus range of B&W's, they always lacked in the highs to my ears.
Bloody great big things too

[Deleted]

Rich man's toys !