[illuminetics]

I'm considering building two mono amps based on the Hypex UcD700 modules.  For the P/S, I'm on the fence between the UcD700 Power Supply and the SMPS1200A700. Can any of you shed some (sonic) light on these options?  Also - would the soft start be a good option with the linear supply?

Any guidance is appreciated.

Thanks!

[Currently, my desktop audio is based on iMac > Class D Audio SDS-254, and/or an Ampbox with the 41 Hz amp.
Main system is based on ARC VM200 tube amps.]

[FloridaBear]

I'm considering building two mono amps based on the Hypex UcD700 modules.  For the P/S, I'm on the fence between the UcD700 Power Supply and the SMPS1200A700. Can any of you shed some (sonic) light on these options?  Also - would the soft start be a good option with the linear supply?

Any guidance is appreciated.

Thanks!

[Currently, my desktop audio is based on iMac > Class D Audio SDS-254, and/or an Ampbox with the 41 Hz amp.
Main system is based on ARC VM200 tube amps.]

As far as the SMPS supplies, depending on speaker impedance, you may be able to drive both UcD 700's on one of the 1200A700 supplies (the UcD700 is rated at 360W into 8 ohms, so even the SMPS 700 is likely good for two UcD 700s if you have 8 ohm speakers; the 1200 would be good down to at least 5-6 ohms; for 4 ohm speakers I'd probably go with 2 SMPS 700s).

Can't really comment on sonic differences between linear and these SMPSs. Soft start is a good idea for linear from what I've read.

[jeffber]

I'm fortunate to have access to a large quantity of unregulated linear power supplies, some of which are already built into monoblock style chassis. I am interested in hearing if anyone has actually built an NC400-based amp using an unregulated linear supply. Since the NC400 has excellent PSRR, the lack of regulation should not be a big issue in terms of sound quality, especially if I'm driving speakers with 6 Ohms minimum impedance. Any comments? I have seen several comments about linear supplies, but so far no posts with direct experience.

The chassis' shown in the picture have 2x300VA toroids each at 40V RMS. They put out about +/-60V DC unloaded. It will be a bit shy on power under heavy load, but it's the fastest way for me to get a taste of the NC400's sound when it arrives in the mail this month. I plan to build a little standalone regulated supply for the housekeeping, or at least temporarily power it from a lab supply. Depending on results I may upgrade to a larger supply or even the SMPS if there's too much sag on my little monoblocks.

[Folsom]

Jeffber PLZ let us know how it sounds. I am very curious. While the smps units measure well and all there is something to be said for immediacy of power.

The stock power of hypex units looks inappropriate for good sound to me. I like linear power supply sound, but I have to say smps's can sound good with some conditioning (hypex has some) and proper capacitance use (not value).

The linear you have would perform better with multiple caps, not just two big ones. Are you certain 300va is short? I can't check, hypex website and iphones are incompatible it seems.

[jtwrace]

The stock power of hypex units looks inappropriate for good sound to me.

Are you kidding me?  You can look at a power supply (along with objective measurements) and know if it will sound good?  So this approach is fine for you so you're good if someone looks at your units and thinks the same? 

[Folsom]

I don't really understand what you are getting at. They look like they got room for improvement to me. I think a stronger body to the sounds might be achievable with a change in power design.

Most things measure well, some, like hypex, very well. But that doesn't fully define sound. ( in fact it is kinda hard to care about them, I have Horn Shoppe speakers, and don't care about the response graph because the sound is great )

Personally I prefer the ears do all the talking. Which is what lead me to conclude that what some people do not believe the hypex units are achieving is something to do with power.

[Julf]

I think a stronger body to the sounds might be achievable with a change in power design.

What kind of changes are you suggesting?

[Folsom]

Well I'd love to just know what kind of change in sound a linear has, but with the smps I am going to start spouting the same old boring more caps story. No one is going to think much of it in theory, but the payoff of what is delivered may be a very interesting story. I can't explain it yet how power can make that oh so subtle difference that we don't notice when measuring, but it seems to. The response of multiple caps seems key. That's part of the bypass cap approach too, but rather varying in size, the number of (good) caps seems more important. I'm fairly certain it'd be easy to do this between modules, and only if one smps is used per channel. Ideally they'd be attached closer but I don't think it's an option.

It worked on the output caps 

Now for a linear that's very different. But honestly with a change in capacitance use I've found smps's to be just great.

[Folsom]

The suspense!

[Cobra2]

Nothing like a good linear PSU
2 x 42V - 1500VA Trafo & 80 000 + uF  (mono-block)



Arne K

[teflonmats]

Hello every one.

This is my first comment here,,I'm not god at righting in English,,
But I have been trying some small things on N-core and try ed Audiopower smps and bypassing
with different caps and it definitely changes the sound of the N-core as in my opinion,,, 
always the ps will do.
I have experienced what salis audio are talking about many times.
So building à god linear ps would be interesting,,.

Mats.

[Julf]

honestly with a change in capacitance use I've found smps's to be just great.

So what you are saying is that Bruno got his design wrong?