Hybrid Hypex UCD

[Ceibal]

5 channel hypex amplifier

was curious if any of you have listened to the ucd700's? Wondering if there is a quality difference in the sound and if so, how much? The THD performance is outstanding and compares well to the Parasound 5250 which I have been comparing these amps to. Any thoughts?

 

[tiefbassuebertr]

Hypex UCD400 schematic wanted

About
Hypex Electronics B.V.
for the UCD 400 (UCD400) I can download only the pdf files
http://www.hypex.nl/docs/UcD180400.pdf
and
http://www.hypex.nl/docs/UcD400HG_datasheet.pdf
but no schematic diagram.
Who know, where I get this and a detailled circuit description?

The circuit (see attachement) looks much more easy than that one from B&O/Sanyo ICEPOWER module about
http://www.diyaudio.com/forums/clas...ic-about-rev-engin-not-complete-finished.html
and
http://www.icepower.bang-olufsen.com/files/solutions/icepower200ac.pdf

 

[andyjevans]

The last post was in 2009, but I'm interested in this. I have Hypex UCD400 modules - I haven't set them up yet or made a power supply. But I'm interested in driving the output stage direct from a balanced transformer preceded by a tube stage.

Are there versions of this with the UCD400? Wondering how to change the board.

Andy

 

[Koifarm]

Hello Andy,

i do not know if it is already done but it is quit simple.
Locate the two coupling capacitors between de opampbufferstage and the powerstage, disconnect them and use this point as input. This will only work with asymmetrical input. So signal in is the removed point from capacitor en shield must be connected to ground.

Ronny

 

[zerokelvin99]

What a coincidence this thread is.

Just started developing (at work) a UCD180OEM / UCD400OEM DSP controlled amplifier (After frying the last 180 LP modules, oops!). Also being driven by the same Shanling as you!


Ronny, would you be so kind as to answer a few questions?

1. Have you compared the Hypex SMPS versus the Red rocks audio SMPS? We're currently interested in exploring other alternatives to the hypex, cost always beeing a priority

2. Re: The OEM vs standard module, have you had the chance to listen to both of these? If so, any difference in sound quality?

Thanks

I'll be watching this thread with great interest

 

[Koifarm]

1. Have you compared the Hypex SMPS versus the Red rocks audio SMPS? We're currently interested in exploring other alternatives to the hypex, cost always beeing a priority

2. Re: The OEM vs standard module, have you had the chance to listen to both of these? If so, any difference in sound quality?

yes, i have compared the two smps with the UCD400oem modules. They sounded the same so price is an important issue.

Another issue is the opamp input stage of the hypex oem and st modules, if you use the inputstage with its supply from the smps then the background is not so quit and the highs are not so steady as with a conventional powersupply.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

If you use your own inputstage with its own conventional powersupply with is easy with the OEM modules and the smps for the powerstage then the sound can be as the Hg modules with hxr. I tested this with several opamp and tube inputstages.

Ronny

 

[zerokelvin99]

Ronny, thanks for the insight. I take it you're referring to the aux (unregulated) voltage off the SMPS - I think my boss would have kittens if I tried using that for anything LOL. The SMPS and class D topology was a massive stretch in itself..

Glad to hear that the input buffer makes a difference. We actually specialise in class A phono stages so shouldn't be too hard to make . (+ linear PS and regs)

Keep up the good work, and never stop building

Cheers,

 

[bassetrox]

Hi andyjevans,

Wondering if you ever had any joy with the tube > tranny > class D project? I'm looking at a similar idea for an MI application. I'd be interested to know your tx specs etc.

Cheers,

Rowan

 

[andyjevans]

I haven't put the system together yet. I have UCD400 modules and haven't so far shelled out for a 500VA 40+40 transformer. I would have preferred to build with the UCD180, but that's not what I have!! A colleague used a 300VA 35+35 with the UCD400, and I may try that. I'll use a Lundahl interstage with a PP output - I have several I can try. I have several choices for the preceding valve stage - I will use directly heated tubes myself including the 26 which can be found on the "26 pre amp" thread which is very long and useful and to which I contributed. This isn't a MI kind of setup!! Actually I'm a bass player but don't gig anymore, so though I'd be interested in a MI solution it isn't urgent.

andy

 

[pieter t]

Andy,
Watch the input impedance of a naked UCD 400, it is 1k8 for + and - inputs referred to ground.
Your DHT + IT will not low impedance enough to drive the UCD well; you'd need a source impedance of some 100 ohms, preferably even lower.
It can be done well with IHT's like 6H30, 5687, but I know that's not your cup of tea.
With a 26 you would need an additional buffer.

 

[andyjevans]

Hello Pieter,

Indeed, I'll have to end up with a low impedence balanced signal. It could be done with some Mosfets - I have some Exicon ECX08N16-Z which I haven't used yet - not too familiar with solid state. This would require a different interstage maybe, though I have Londahl LL1671/PP which may work. Otherwise maybe 2a3 with a small stepdown. Or 4P1L with a larger stepdown like 4.1:1. That would give 5v out for 2v in and an output impedence of around 100 ohms. I could use a pair with a LL1660/18mA and have SE in and PP out.

What would you suggest? I am indeed thinking two stages like 26 into a driver stage.

andy

 

[andyjevans]

I've put together a power supply with a 300VA 35+35v toroid which I hope will supply either a UcD180 or a UcD400. About +-50v output - don't need much watts in a small room.

But I have the first version of the UcD400 - Ver1.0. This has a layout similar to the current UcD400ST shown below. The OEM version layout koifarm is using to remove the two caps is a different one - is this the UcD180 OEM? On mine removing the caps would be a nightmare, since there are lots of surface mount small parts underneath. So I'll have to leave it intact.

So a question about the hybrid version - which of these commercial modules can be used easily? On the HG versions there are a couple of red caps by the input - are these the ones to remove or what? Help please! I'm thinking UcD180 if I have to buy another couple of modules, but which version?

First picture is my original UcD400 Ver1.0, then current models

 

[Koifarm]

Andy, the first picture on page 1, 1 reply, you see the UCD180st. This board has the easiest access to the coppling capacitors.

An externally hosted image should be here but it was not working when we last tested it.

Ronny

 

[Koifarm]

If you like to use a tubebuffer and not a inputtransformer, see below.

An externally hosted image should be here but it was not working when we last tested it.

See here for more details, http://www.diyaudio.com/forums/tubes-valves/206415-6n16-12x-preamp-srpp-cathode-follower-printed-circuit-board-design.html

Regarding the inputimpedance of the unbufferred UCD180st the "+" input has 10k impedance to ground and the "-" input has 1k8 impedance to ground. This makes to use a unbufferred UCD more difficult to use with symmetrical input. I use unbufferred UCD only with asymmetrical input.

Ronny

 

[andyjevans]

Thanks for that - looks like the UcD18o is the way to go. I was told, however, that right now the UcD400OEM is a generation ahead (some of the nCore technology) of the UcD180OEM, which will come out in a later updated version. There's also the UcD250LPOEM which you might have considered.

http://www.hypex.nl/docs/UcD250LPOEM_datasheet.pdf

Andy

 

[KBK]

yes, i have compared the two smps with the UCD400oem modules. They sounded the same so price is an important issue.

Another issue is the opamp input stage of the hypex oem and st modules, if you use the inputstage with its supply from the smps then the background is not so quit and the highs are not so steady as with a conventional powersupply.

An externally hosted image should be here but it was not working when we last tested it.

If you use your own inputstage with its own conventional powersupply with is easy with the OEM modules and the smps for the powerstage then the sound can be as the Hg modules with hxr. I tested this with several opamp and tube inputstages.

Ronny

question:

Where did you get the R-core transformer from?

 

[Koifarm]

The R Core transformer came with the housing with i used. This was a defect amplifier. But R Core transformers are sold on Ebay.

transformer r core | eBay

And here:

Audio Catalog

 

[dude2010]

Can someone post pics on how EXACTLY to route, going from unbalanced DAC into the naked balanced UcD 180st with the bufferstage bypassed.
Thanks.

 

[Koifarm]

An externally hosted image should be here but it was not working when we last tested it.

Just connect sheilding of the dacout to the white and copperwire on the ucdboard as in the picture above. And connect signal from dacout to the redwire on the ucdboard.

 

[dude2010]

Just a regular unbal. to bal. - Are you completely sure? It dosn't need a capasitor??