IcePower ASP1000 - Tweaking/Mods/Upgrades

I've just got my hands on a pair of ASP1000, and I would like to know what could I do to take the most of it.

I already know all the limitations these modules, and I'm also going to give a try with Hypex's UcD with SMPS and HxR, and maybe Coldfire.

Cheers,



It would be great if you tell me the limitations of the ASP1000 :scratch:, since I have done many test at that module, and I can tell its just GREAT module.


It sounds just great, lot of current, small size, rugged. simple design. and very smart design indeed.

It will be great to discuss.


Regards
 
Two "limitations" as far as I know:

- Both absolute bandwidth and power bandwidth is lower than newer designs (although updates have been made, the 1000ASP design is still more than 10 years old). Might not be an issue for all applications though.
- The module is fairly compact for the power levels it can produce, so thermal limitations need to be considered. However, this is unlikely to be a problem for a normal home application.

None of this necessarily affects the perceived sound quality of course :)

/U.
 
Two "limitations" as far as I know:

- Both absolute bandwidth and power bandwidth is lower than newer designs (although updates have been made, the 1000ASP design is still more than 10 years old). Might not be an issue for all applications though.
- The module is fairly compact for the power levels it can produce, so thermal limitations need to be considered. However, this is unlikely to be a problem for a normal home application.

None of this necessarily affects the perceived sound quality of course :)

/U.


Yes, I agree with the bandwidth, but thermal has no problems.

Also B&O Sold thousands all over the world, and that module is still wanted.

I am not sure if too many people can tell the difference in bandwidth through the ears. for example when they hear music.


Reminder, that module is used into the RCF powered speakers, + Many other commercial powered speakers. so

Regards
 
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I finally recieved my ops-u500-385b PFC modules from china. I have connected them to my 1000asp mono blocks, my 250asx2 amp and my dual 200asc amp. here is my finding!

200asc:
working, and seems to be an improvement, but i didnt spend much time testing this setup. i used the 200asc to test that i didnt blow up my 1000asps. I wanted to make sure, since i bought my PFCs used.

2x1000asp with one PFC:
Cleaner sound but at the same time it sound like the amps is missing some omphf and some power.

2x1000asp with 2 PFC:
Happily this setup does not have the lack of power noticed with the previous setup. At first i didn't experience much improvement the sound quality, so i was a little disappointed, but i left them connected to the amp. After listening to them for a week, i have changed my view. I'm not disappointed anymore, but instead I'm becoming pleased with the PFC. I experience the improvements as very subtle but very enjoyable. It is as if some noice (that couldnt be noticed before) now has disappeared. the total result is more clear sound, with new and delightfull details. over all i feel that the music become nicer to listen to.

250asx2:
The 250asx2 doesn't seem to work with the PFC. The amp is silent when the PFC connected and powered. When i unplug the power the amp starts to play for 10 seconds or so. It seems that the 250asx2 has a different power supply that doesn't work with the PFC.
 
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Something is bothering me about the PFC....What is everyone doing to the fuse on the 1000ASP using the PFC?

Its been a while since I looked at my 1000ASP, but remember there was a 120v / 240v fuse config option? Of course there was no 385v fuse option... drop it to 3 amp and place in the 240v fuse slot? 6.3A (standard on 240v) and 10A (standard on 120v) a bit too high with PCF?

If I see no real change in the PFC addition on ICEPower module, I guess I could always use the PFC for a tube amp - clean B+ of 385VDC would be good for a 6L6 or EL34 tube amp......in Class A sweetness!!! It would replace power trannys, rectifier, caps...and take up much less space...
 
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Using PFC with ICEPOWER 1000ASP modules is almost useless.

No idea how PFC will help the audio performance while the SMPS is regulated.

So, adding PFC to the 1000ASP is almost useless.

It will only help 100 ~ 240VAC auto switching. I also cannot tell the performance of LINE THD with that PFC, so your PFC might be a bad option at this stage.
 
Useless?? Damn, I just bought two of them....

Hello

Thats my own opinion, as the PFC major JOB is to regulate the voltage for the SMPS. and to increase efficiency of the whole design in a SMPS application.

and specially in the 1000ASP SMPS, is REGULATED, and even if you ran the module at 200VAC, the amplifier will perform the same, only thing it will draw more current.

So, the point is that the amplifier will operate either at 110VAC or 230VAC so the output voltage of the SMPS is going to be stable alll the time.


I still cannot see evidence of improved performance of AUDIO or anything else, from those who used PFC with the (1000ASP) module specially, and I am only talking about that module ONLY with PFC.

PFC is necessary in MOST of the SMPS applications, and its a MUST.

ICEPOWER engineers can tell if they needed a PFC or not, and it was a smart choice and smart trade off between cost of production and PFC.

and FYI a 1KW PFC wont be small at all.

Good luck
 
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LOL.

To my mind, Jeff Rowland is a solid amp designer who felt that adding the OPS PFC in front of the IcePower modules made enough of a difference to justify the cost and complexity. I haven't looked at his product info or any reviews, so I don't know what he stated as those reasons, but I don't doubt they were good ones and that he validated them with listening tests.

Given that and Arky's listening comments, it makes sense to pursue, just as it made sense for me to pursue the Bel Canto power supply front end to the same modules. I know that second path provided significant sonic gains to my ASP1000-based amps and was very worthwhile.

My 2 cents.

Greg in Mississippi
 
I had a visit of one of my skeptic friends the other night. He didnt believe that a PFC would make any changes to the music. After listening he changed his mind. There is an audible difference. without pfc the sound is more "like a wall hitting you" and with PFC is more "welldefinned sounds". My friend like the non-PFC sound better while i like the PFC sound. I guess its a matter of taste.
 
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An offer...

john65b,

Yes, I did, to the 6.3v specified for 240v operation. That is also what Bel Canto has on their upgraded version.

noniaster,

Your comments on your listening session where your friend ended up not liking the PFC pushed me to go find reviews on the JRDG 501 with the PFC. I only found one review where the PFC was also auditioned... here: Jeff Rowland Design Group 501 Monoblock Amplifier Reveiw | A Unique Audiophile Experience .

I found it very interesting that the reviewer was also ambivalent on the effects of the PFC.

Hmmm.

I then went back and checked the reviews for the Bel Canto Ref1000 upgrade. All were very positive, with impressions similar to mine... greater sense of dynamics and of extension at both ends with increased articulation.

I know I'm very happy with the results.

So I make an offer... If you contact me via email through my profile (not PM, my in-box is almost full) off this topic, and can convince me that you have an 1000ASP and can safely build and install the pre-module AC to DC conversion, I'll send you the schematic (poor, hand-drawn, but sufficient) and pix showing the setup. It's up to you to make it work... I did mine point-to-point, it is really a pretty simple circuit with a low parts count, but again, if you make a mistake in building it or don't test and install it carefully, you can have exploding caps, a dead module, or worse.

Greg in Mississippi
 
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I'll start feeding you info tonight. I need to dig out the schematic I drew... likely need to re-draw it, it was pretty rough. But see the Wikipedia link I put in my post #52... that is the basic circuit.

It's clearly not a PFC, really it is just performing the rectification and initial filtering off-board.... and as a good side-effect, adding a lot of energy storage to the power supply. Think of it as a slightly more sophisticated capacitor bank!

Greg in Mississippi