Past projects: Old ICEpower Amps…

I’ve built quite a few ICEpower amplifiers over the years, but many of them were built and sold before I started this blog. Recently I actually saw an amp for sale that I am pretty sure I built and so I started looking to see if I had any pictures of these amplifiers. Mostly I don’t, but I did manage to find a few:

The first amp is a small amp based on a 200ASC-module with a 200AC hanger. Unlike the ASP and A-series, the amplifier sections on the AC/ASC are the same so it is possible to build a (deceptively compact) stereo amplifier this way. I used this amplifier in my office system before I eventually replaced it with the B1/125ASX combo.

The second amp is a full-size amp based on 2 pcs. 1000ASP-modules. At the time, this was intended to be my own reference amp, but firstly I preferred the sound of the 500ASPs I were using before and secondly I got a very good offer on it so I decided to sell it soon afterwards.

The last amp is a three-channel model with a single 500ASP and a pair of 200AC hangers. The amplifier I used for a couple of years to power the center and rear channels. As the front amplifier I had two stereo amplifiers with dual 500ASPs wired in bi-amp mode, which made for a very compact surround system with plenty of power – around 3kW into 4Ohms – on tap :D. I eventually sold all these amps and started using the 6-channel 50ASX instead.

Project files: ICEpower Linear PSU

What is it?
The project files for the linear ICEpower PSU board I showed here. The first version of this board concept was made around 10 years ago, but as I didn’t have any boards left over I updated the design and cleaned it up a bit in the process.
The basis of this is once again the GP-PSUs shown here and the same file that I also used in a triple-configuration here. I have simply added a single high-power rail with a rectifier, two main caps and the usual decoupling + discharge LED – absolutely nothing fancy 🙂

How big are the boards?
This is the “XL”-version for 35mm main caps and the board measures 4.4” x 3.45” (app. 112 x 88 mm.).

What is the status of the boards?
The design is called v2.0 as it is based on a previous idea. It’s been prototyped and I see no mechanical or electrical issues.

Does it use any special/expensive/hard-to-find parts?
Not really, unless you choose to go overboard with expensive boutique parts, such as premium capacitors and fast rectifiers for the low-voltage supply (which I kinda did…).

Anything else I need to know?

  • The board should work with the ICEpower 200AC/300AC and the 250A modules which require around a 50VDC Vp voltage. For the 500A and 1000A modules you might need to check and modify the board files to get enough high-voltage clearance for the higher supply voltages used (nominal 80VDC/120VDC respectively)
  • The high-power supply uses a pair of snap-in capacitors up to 35mm in diameter and a GBU-type rectifier (available up to 25A). The low-voltage supply uses 22mm snap-in or 18/16mm standard radial caps with 1N540x or similar rectifiers.
  • Due to the rectifier setup on the low voltage supply, it is possible to use it with both single (voltage-doubled) and dual AC connections. In that case you should connect the transformer to one side of the AC-connector and you need only fit the required pair of diodes (either DA/DB or DX/DY), although of course there is no harm in mounting both pairs.
  • If you have space, I would recommend that you run “dual-mono” with separate power supplies for each channel, mainly to ensure that there is a good amount of capacitance on the high-power rail. If, like me, you still want one box and avoid a true mono-block design, then the high-power rail can use separate windings on the same transformer and the low-voltage transformers can be separate or shared between the channels. The sharing can of course be done either as parallel-connected dual rectifiers or as separate voltage-doubled circuits with each board using one transformer winding (honestly not sure what would be better here 🙂 ).

Download design files here

Related information:
Note: Always read the “intro post” for additional important information about my designs.

Read the ICEpower module datasheets carefully as well (and, if you can get your hands on them, the Designer’s Manuals as well).

Note: For once, I do actually have some spare boards left as I only needed the pair and I had to order 10 pcs. As you can see, they are green, HASL-plated and made with 2 oz. copper. If you are interested in boards, drop me a line.

ICEpower 200AC Amplifier

A while ago I realised I still had a single pair of ICEpower 200AC modules left over as well as a suitable transformer – and why miss an obvious opportunity to make another power amplifier I don’t really need? 😀

The 200AC module is exactly the same amplifier section as the better-known ICEpower 200ASC only without the onboard power supply. The 200AC board is very compact at app. 55 x 107 mm per channel but will still put out over 200W into 4 ohms and because I had the transformer available I opted for a linear power supply. The transformer is a custom one I got from ebay (I think) with a 32VAC winding and a single 12VAC winding. This makes it perfect for the ICEpower modules as the dual-rail low-voltage supply can easily be generated via a voltage doubler. The main power rail is a bit lower power than I might have wished for (160VA), but not overly so, and the transformer is made by what I consider a quality manufacturer so it should be OK. 160VA is still more than 1/3 of the peak power which should work as a rule of thumb (yes, I know it is a bit more more complex than that but a good starting point as far as I am concerned).

The power supply board is a variation/update of a design I first made nearly ten years ago (when I started building with the ICEpower modules) and quite simple. I will publish the board files shortly as it might be useful for other users of the ICEpower AC-series and A-series modules without switching PSUs. I’ve used a dual-mono setup with separate PSUs mainly to be able to add a bit more capacitance to the mail supply rail (2 x 10000uF per channel) which shouldn’t hurt. The capacitors are very audiophile-approved “Gold Tune” types from Nichicon, not because I think it is audible per se, but because I like the look (yes I know, I shouldn’t admit to such things :D)

Apart from the amplifier boards and the power supplies I have added fuses on both the primary and the secondary sides of the transformer via a couple of my supporting PCBs. The secondary-side fuse board is the one I published here and the primary side fuse board is somewhere in the pipeline :). Obviously using these boards aren’t strictly required, but I wanted the fuses in the amp and especially the secondary-side board also makes for much neater wiring than would otherwise be possible for me to achieve.

I also wanted this amp to be fairly compact and unfortunately that took a few bits of custom metal work to achieve, namely a mounting plate for the modules and PSUs, another for the transformer and a small one for the primary fuse board (not fitted yet in the picture below). That obviously pushes the cost up a bit, but fortunately I have decided to ignore that part 😉

The back panel sketch is done and will be included in my next order with Schaeffer/FPX. Still to do is a front panel and some wiring, although I might actually hold off doing the front panel until later. That way I can match the looks of this power amp to an as-yet unspecified DAC/preamp/whatever to make a matching set 😀