jalejos - Please do not insert very large file photos inline in your posts. I have resized and attached them.Read this thread.
http://www.diyaudio.com/forums/everything-else/183084-pictures-why-not-attach-them.html
To revive this thread again, I finally got a chance to examine a Ref1000MkII power supply closely.
It is a switchable rectifier voltage doubler circuit as I linked to above. Output to the IcePower module is 340VDC. It does seem to reduce the noise fed back into the AC lines a bit, but definitely does not eliminate it.
The additional components I could not identify appear to be related to inrush surge reduction.
I'll try to provide more details this weekend, but if one wanted to build the circuit linked above with appropriately-rated components, you'd be on the right track.
Greg in Mississippi
It is a switchable rectifier voltage doubler circuit as I linked to above. Output to the IcePower module is 340VDC. It does seem to reduce the noise fed back into the AC lines a bit, but definitely does not eliminate it.
The additional components I could not identify appear to be related to inrush surge reduction.
I'll try to provide more details this weekend, but if one wanted to build the circuit linked above with appropriately-rated components, you'd be on the right track.
Greg in Mississippi
First of all, anyone contemplating trying to duplicate the Bel Canto Ref1000 MkII Pre-SMPS linear supply needs to be aware of the dangers of working with a setup like this.
1. It is a power supply with no transformer. It has rectifiers directly connected to the AC line. It can kill you easily!
2. It has substantial energy storage. Even unplugged, it can kill you easily until the bleeder resistors bring the voltage down.
3. It is directly connected to the input of the B&O amp module. Connect it when it is not working right or connect it with the wrong polarity or connect it when it is not fully discharged or connect it with the voltage set wrong on the amp and you will have a smoking boat anchor.
Having said all that, due to concerns about liability, I have decided not to publish full details here.
Here is a bit more detail to what I had said in my previous posts. With this, a knowledgable DIY'er can duplicate this supply upgrade. What I said in Post #59 above is correct. The additions to the voltage doubler circuit from Wikipedia are:
- A transient surge suppressor across the output of the diode bridge
- An inrush current-limiting resistor at the input to the positive side of the capacitors
Greg in Mississippi
P.S. I assume that the bulk of the $1000/amp cost of the upgrade is in the metalwork. I just ordered all the parts I need to build these supplies for my 4 IcePower-based amps for about $130 USD. This does not include a circuit-board, I'll do it point-to-point, but still you should be able to add 4 boards and still keep it under $200!
1. It is a power supply with no transformer. It has rectifiers directly connected to the AC line. It can kill you easily!
2. It has substantial energy storage. Even unplugged, it can kill you easily until the bleeder resistors bring the voltage down.
3. It is directly connected to the input of the B&O amp module. Connect it when it is not working right or connect it with the wrong polarity or connect it when it is not fully discharged or connect it with the voltage set wrong on the amp and you will have a smoking boat anchor.
Having said all that, due to concerns about liability, I have decided not to publish full details here.
Here is a bit more detail to what I had said in my previous posts. With this, a knowledgable DIY'er can duplicate this supply upgrade. What I said in Post #59 above is correct. The additions to the voltage doubler circuit from Wikipedia are:
- A transient surge suppressor across the output of the diode bridge
- An inrush current-limiting resistor at the input to the positive side of the capacitors
Greg in Mississippi
P.S. I assume that the bulk of the $1000/amp cost of the upgrade is in the metalwork. I just ordered all the parts I need to build these supplies for my 4 IcePower-based amps for about $130 USD. This does not include a circuit-board, I'll do it point-to-point, but still you should be able to add 4 boards and still keep it under $200!
Hi. I was looking to attach 2x OPS-U-500-385 module to my pair of JRDG 201 amplifiers, thinking is just the same as Rowland PFC module, just without fancy machined housing. But was really concerned about your notice of polarity. I was under impression that switching supply of IcePower modules is irrelevant to polarity if powered with DC.
I agree that polarity of connection SHOULD not matter due to the bridge rectifier input. Sorry for mis-stating this.
The connection used by Bel Canto on their pre-rectification upgrade has the positive connected to the pin closest to the center of the board, the negative to the pin in the middle of the power connector, and the ground to the pin on the outside edge of the board. You can see this in the pictures I posted above and the pictures from the reviews of the upgraded units.
I used this when I did my upgrade as I know it works.
I hope this helps!
Greg in Mississippi
P.S. Please let us know what differences the OPS modules make!
The connection used by Bel Canto on their pre-rectification upgrade has the positive connected to the pin closest to the center of the board, the negative to the pin in the middle of the power connector, and the ground to the pin on the outside edge of the board. You can see this in the pictures I posted above and the pictures from the reviews of the upgraded units.
I used this when I did my upgrade as I know it works.
I hope this helps!
Greg in Mississippi
P.S. Please let us know what differences the OPS modules make!
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Modules and case just arrived. Have put them together and checked - both modules working with about 375 volts output, without load. Now thinking how to deal with output connectors: have to be fool-proof hence Neutrick proprietary round powercons make sense, rather than just usual IEC outlet.
All done.
Huge improvement - highly recommended mod. Image on my Sony APM-6 is just as at ESL speakers.
Huge improvement - highly recommended mod. Image on my Sony APM-6 is just as at ESL speakers.
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An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
I also think about building a DYI PC-1.
Arky, where did you buy the modules?
I can only find the OPS-U-500-385B on Ebay, not the OPS-U-500-385C
Will 2 x 1000asp benefit from 2 x OPS-U-500-385C or is one just as good? I can see that Jeff Rowland has a splitter cable so one PC-1 can supply 2 x mono amps.
Arky, where did you buy the modules?
I can only find the OPS-U-500-385B on Ebay, not the OPS-U-500-385C
Will 2 x 1000asp benefit from 2 x OPS-U-500-385C or is one just as good? I can see that Jeff Rowland has a splitter cable so one PC-1 can supply 2 x mono amps.
The guy on ebay from Indonesia who's selling these - just drop him a message that you need 385C and he will select the module for you. Initially he sent me one B and one C, then I purchased additional one from him and asked that I need "C"-type exactly. He's well aware of the thing, just message him. Wattage-wise it's obvious 1kw IcePower will overload 500w OPS module - so at least dedicated one for each channel, or just search for OPS-U-700.
I also noticed that OPS require heatsinks. Now truing to figure how to fit them to chassis, maybe it's worth having bigger case with solid aluminum floor and use thermopaste. In real life my box with two modules gets warm. Not hot, but I never use my Jeffs at over 20% power.
thanks for your reply! I contacted the indonesian guy, but he didn't have any any ops-u-500-385c or ops-u-700-385, only the ops-u-500-385c. Im thinking off just buying the ops-u-500-385c, since the other ones seems impossible to get hold off.
How does the ops-u-500-385b sound? how does they compare to the ops-u-500-385c?
How does the ops-u-500-385b sound? how does they compare to the ops-u-500-385c?
Really I found no difference in sound, both B and C revisions gives similar, but huge impact on micro-details, clarity, presence and stereo image. And, to my ears, neither affect to the timbres and tonal balance. And this is reasonable outcome: speaking in natural terms - the only thing that OPS module does is converting AC to DC using PWM (where 50Hz sine is upscaled x1000 times or even more), being the perfect mains filter with comparable effect to sine re-generators for conventional power supplies with trafos.
Great thread; I'm currently building an amp following this setup. I've got the ASP1000 and the OPS-U-500-385B supply. The arrangement seems a little lean...400W at 120V input for a 1000W amp...I'm not sure how I missed that part. What experience have people had running this arrangement?
Also I want to make sure I've got this correct before power up: I have OPS + output tied to ASP1000 L input, and OPS - output tied to ASP1000 N input. Is that correct, or is it immaterial?
Also I want to make sure I've got this correct before power up: I have OPS + output tied to ASP1000 L input, and OPS - output tied to ASP1000 N input. Is that correct, or is it immaterial?
There's a bridge rectifier on the PSU input of the ASP, so polarity should not matter.
/U.