Various PSU/case issues

[KeithC]

My power requirements for my main system are low as I use Lowther drivers @ 97db efficiency - in fact for some time I ran them connected directly to the headphone sockets of my soundcard & DAC1.

Sort of drifted into Class D looking for amplification without background noise (the curse of efficient speakers). Quite liked the Charlize bass, but not it's soundstage. Really liked UcD180 with single HG/100A psu, so upgraded to dual mono with additional HG/100A. Like the improved soundstage, but the overall sound seems somewhat colder. Could this be down to drawing minumal power from the psu?

Being a generous chap, I've just bought the wife a paiir of Quad C22s. These do require beefy amplification, so I have purchased a pair of Coldamp modules and smps. Coldamp shipped a linear supply in error, so now I will be able to compare smps & linear - once I get my hands on a suitable transformer. I'm thinking of getting a transformer at the bottom end of the voltage spec. with low power rating, or possibly using one of the Hypex 100As. Any obvious negative issues with this? Class D amps seem so much more sensitive to minor psu changes than the Class As I've tended to use in the past.

I typically box the mains side of amps I build and display the low voltage components. Not a problem in my office as the amps are more than 12 feet away from any other electronics, most of which is digital anyway. Supply DC for 400 watt amps is stretching the limits of 'low voltage' anyway.

The wife's amp will be close to a mess of TV equipment, so due to RFI ( and her lack of appreciation of the visual glory of a circuit board) I guess I'll have to enclose the whole. I have an enclosure on order (since March - that'll teach me to use a British supplier). Really looking forward to cutting holes in a steel backplate again. When I was a lad you could buy hole cutters for punching large orifices into valve chassis.

I assume that the Coldamp modules are somewhat more generous than the Hypex ones w.r.t RFI, on account of the on board large ferrite ring.

Not a lot of comment on Coldamp hits on Google - any ideas why?

[ssanmor]

We are a starting company and we are selling only from January. That's why you don't get too many hits in Google... but give us some time.
We have a demo setup with 5ch coldamps on a normal 19" box just by a TV and DVD set. No special cautions taken at all (ferrites, filters, etc) and no problems at all with RFI.

[KeithC]

Originally posted by ssanmor
We are a starting company and we are selling only from January. That's why you don't get too many hits in Google... but give us some time.

Good point - hadn't realised it was so recent (first half of year always seems subjectively >> second half, UcD dialogues started this time last year).

Excellent order turnround BTW, ordered Tuesday, delivered Friday

[kartino]

Hi Sergio, did you implement your posting at several years ago?

Best Regards,
Kartino

[ssanmor]

Sorry, don't understand your question very well

[classd4sure]

Originally posted by ssanmor
We are a starting company and we are selling only from January. That's why you don't get too many hits in Google... but give us some time.
We have a demo setup with 5ch coldamps on a normal 19" box just by a TV and DVD set. No special cautions taken at all (ferrites, filters, etc) and no problems at all with RFI.

Hi Sergio,

While I believe I understand your reasons for doing so, I can't help but think you'd get more traffic if you encouraged your customers to post here, good and bad. The public will get a good idea on the caliber of support offered, types of issues (minor etc) and how to solve them. This may scare some away, but it may also attract many others.

I think Kartino was asking if your product is the amp which you've worked on here in the forum awhile ago, I forget the name of the thread, but it is one of the oldest, biggest, and most interesting ones I think. A frontrunner at least.

Regards

[ssanmor]

Ah, ok, I thought he was talking about "posting service!"

We _do_ encourage our customers to post comments here, and they are usually good for us. In fact our support is one of the things they value the most, just ask any of them.

Yes, the design is somewhat based on that old schematic (triangle oscillator based synchronous design, IC mosfet driver, etc), although with many improvements. In fact we have never claimed to have invented a "totally different, innovative and definitive earthbreaking new technology". We didn't invent anything but small touches in that forum, and I got many ideas (and also contributed some) from it. The principles are well known, but the excellence is in the details.

Our goal was to develop a very flexible and rudged module with very good sound and performance, not a ultra-sub-mini-low THD performer. Sorry but we don't believe on single parameters as a measure of quality... and we think we have achieved that goals, judging by the experience of our customers.

In fact, some users here have compared our modules to "you-know-who" and "that-one-you-also-know" and we must say that they have withstand the comparison very well, to say the least. (and that's something to be very proud of, as the level of our competitors is very high).

[classd4sure]

Hi Sergio,

No one was saying you claimed to invent anything ... in fact it's actually refreshing to see an amp that didn't, if that is the case.

I have yet to hear anything bad about your modules, and you're right, definately something to be proud of, as the competition is fierce. Keep at it.

I know you support your users and I know they're content with the level of support which you offer them, and I know your support forums are private. It is the private thing... that bothers me.

Personally, when I'm interested in some new hardware, I do all kinds of research on it and the first and probably main thing I look for are the kinds of issues users have had with them, if they've been able to get them solved, and how they managed to do it.

By keeping your support forums of a private nature, you'd appear as a blank on the radar in such a search.

[ssanmor]

Thanks for the suggestions and encouraging.

However, our private support forums are only for OEMs, in fact it is not exactly a forum but an access to our own intranet. It is an special attention to big customers among others like reduced price samples, for eample. In the near future we plan to implement a public forum in our own servers, however.

But, what's the difference between our competition support and ours? The only difference I see is that apart from the comments in this forums, we have the private OEM support as well (I suppose they also have it, of course). In fact I don't see a difference. I am here for any question users may have. However, I recognize that I am not very inclined to appear too much in these public forums as someone can think I am taking advantage of them for commercial purposes.

In a nutsell, all this comes from the true fact that there are not many thousands of coldamp users to post comments, that's the ONLY reason why you cannot find much information of that kind. But I insist, let it some time...