UCDs with SMPS

[angchuck]

There is a smattering of information pertaining to UCD's and SMPS on this forum. I recently burnt my UCD modules due to supply problems (i had diode failure with no fuse on the rails) and would like to get back into the game using SMPS. They worked pretty well with my gainclones but i would need new more power smps for the Ucd's. Before i invest in this path.....

Does anyone tried SMPS as compared to linear unregulated supplies? I know hypex is providing OEM users with this option of smps. It does seem corherent to use SMPS with PWM.. something like "Alternative Energy" going on now.

Would Bruno or anyone care to comment?

Chuck.

[proengin]

I have been playing with Coldamp's SPS80 SMPS with my UcD400 AD modules from their initial production run in the last couple weeks. Results are very positive - I couldn't hear any beating noises. I am going to try to use their AUX +/-12V to regulate the AD8260. I will post more results later.

[Bgt]

am also waiting for the smps's from coldamp, the small 1, the 400w.
Want to try 2 seps. on the coldamps and ucd's.

[ssanmor]

I have eventually found here a reference to our coldamp SPS80 power supply and its use with UcD400, so I would like to point out some things...
After a long testing phase, we decided to make a first production run and offer them only to OEMs/distributors. Given the excellent acceptance they are having, we are now in the middle of a bigger production run, so we are going to offer them to particulars in a month more or less, as soon as we start receiving them from the manufacturer.
These supplies are specifically designed to operate with our BP4078 modules (which, by the way, now include bigger mosfets in order to allow much bigger output current and operate to larger power levels safely). We are soon offering a synchronization board that allows synchronization of up to 4 BP4078 modules with a SPS80 PSU, lowering the noise floor and ensuring whistle-free operation.

We have not tested the supplies with other modules such as ZAP-Pulse or Hypex ones, although reports from our customers are very good with these. In fact the supply can be easily modified to reduce output voltage down to +/-30V, so they should be suitable for UcD180 too, although, I repeat, we have not tested that.

Best regards,
Sergio Sanchez
www.coldamp.com

[Pierre]

Nice to see that the coldamp SMPS is available at last!

Hey, proengin, could you post more comments about how it works? What modules have you tried with the SPS80? Hypex, coldamp, ZAPPulse...?
What are your impressions so far? The photos look superb.

I just can wait to order some of them ;-)

[proengin]

I am running the SPS80 and UcD400AD combo in 4 monoblock config. Have been busy in the last couple weeks so not much listening. But I can tell you the dynamic of music is much better than HG linear supply (modded with 2 x 10KuF Jensen caps) and UcD400 combo. The most important of all - no audiable beating noise as most of us are concerned about.

I am busy in designing 4 small chassis as their permanent home. Will also make provision to install BP4078 amp modules for comparison.

[Pierre]

Could you post some photos to see your cabling, etc?
Wait to hear the BP4078's, I was shocked with their performance (and that was with an old linear power supply, can't wait to try them with the SPS80!).

[proengin]

Hi Pierre,

Please email me to discuss performance of BP4078.

Thanks

Patrick

[angchuck]

Thanks for the information on these smps. How far away is the quality of a generic smps like meanwell and corsel from these audiophile smps?

Not that i am a nuforce basher, but they apparently use generic smps in their amps.

I was looking at the ripple current noise specs, not much differences. Perhaps its not an indicative stat.

Chuck

[ssanmor]

There is an important difference between coldamp SPS80 and other general purpose switching power supplies: capacitance reservoir. For audio, it is very important to have a good reserve of energy for fast and deep current demands, and loading is also very variable.
Usually, SMPS have a few hundreds of uF at the ouptut because they are designed for quite constant loads. Our supply, on the other hand, has 6600uF per rail plus more than 3000uF at the primary side.

You can't simply add capacitance at the output of a general purpose SMPS in general, as the feedback loop may become unstable due to the added phase shift and oscillate (you really don't want that ).
Our SMPS has regulation but all the capacitance is taken into account at the time of designing the feedback loop, so it is very estable and no additional caps are needed.

There are other differences, such as the possibility of being synchronized between several supplies and with out class-D modules.

Best regards,
Sergio