Hi & Modding Sure Elec. 2x100 with 36v350w SMPS

[DennisF]

Hi there,

Not so very long ago I ventured into the world of DIY audio; starting with modifying a V-DAC and finding out that my amp suddenly has become an "issue" (that was right after the speakers changed ). A long story short -and about a month later in time- I find myself here and reading up on more electronics then I actually bargained for . So after a couple of weeks of voyurism I'd like to say hello to you, the form dwellers!

In order to start my adventures in DIY amp land, I decided to start simple and buy a Sure Elec. 2x100 amp with a 36v 350w SMPS they advertise. I intend to tune that back to 32v and thus get the "optimal" performance for the setup as found in some threads around here. Later on (and depending on performance, I tend to go either towards Hypex or down the
Solid state route).

But first I want to start tweaking the Sure 2x100 and that's when the problems start. Because after reading up a LOT on this forum (and about a dozen often-cited suppliers) I find that either I need to REALLY dive into electronics to get a full grasp of what I'm doing or don't fiddle too much at all and buy better a kit.

In order to get this resolved I'd like the resident experts (and yes, there are a lot of you lurking around here...) to come up with a couple of "easy" solutions for people like me: interested but no expert. I can read resistance colouring but I can't design low-pass filters, I can solder but I have no clue about mosfet problems with caps on SMPS

And with that I'd like to introduce the main issue I'm facing right now: additional performance and filtering:

Obviously it should not be hard to place a larger capacitor bank after a SMPS to get more power if the going gets though (this is in-line with possible updating of modules later on as the 100w8Ohm output has a horrible THD), however there also are quite a few horror stories around about problems with sound (losing mids) and "pumping" (afaik storing voltage and thus blowing the amps). I've read up quite a bit (http://www.tnt-audio.com/clinica/ssps2_e.html stands out) but am still at a loss on how to exactly design and build this, can I simply assume it's the same as class A aplification? By looking at modules from Conexx. I can see they have simple designs but will that work on what I have? And so how about filtering? Ow did I mention I'm even more clueless about the voltage pumping and draining?

Thanks!

[DennisF]

Dear all,

Actually is another thing I'm looking for, which is available as a module from various vendors, but I could not find them here are DIY instructions...

Slowstart module
This probably will have some linkage with the power supply question above, but I've read somewhere the SMPS don't like the massive current required to fill the caps. So a simpel slow start circuit is high on the list as well.