[john61ct]

B&O ICEpower's 250A & 500A full-range modules are designed to work directly off DC inputs, tapping into the output rails fed by the rectification / SMPS power supplies integrated into ASP modules like 1000ASP.   

Same with the 1000A module, but unfortunately its frequency / power curve is not full range, only suitable for powering sub / woofers.

The only other ICEpower module that is designed to work off DC is the 200AC, at around 48v plus a little 12v . Setting that aside for now, really want to focus on building (or buying, or having built) a 2.1 amp, one of 1000A for a sub, plus two of 500As for stereo full range driving a pair of LS50's.

In googling around, I came across this, sorry will post the ref link when I get a chance later:

You can use DC power in on the ASPs if you want because the SMPS rectifies the AC line voltage, but your min. voltage would then be equal to 85VAC rectified or around 120VDC

I find this **very** exciting, since I have plenty of DC power / LI battery experience and gear, banks of many kWh, high-end DCDC converters etc,

Not at an EE level but good enough, for now I really don't need help there please, just with this audio stuff I be noobish.

I know lots of high-power server / telecom rectifier / PSUs designed for running off AC mains, can also accept high-voltage DC input instead, in fact 270-300Vdc is a bit of a standard now for the backbones of industrial and some military POL setups.

So, I infer from the above quote that the SMPS / rectifier built into the 1000ASP could be driven directly off 120+Vdc, and perhaps then in turn supply the two 500A units as well, not just the main power voltages but the + and - 12.8Vdc accessory / housekeeping circuits.

In addition to any ideas and informed commentary on the above, I'd appreciate any advice, links to sources etc on practical implementation. Recommendations as to a builder qualified to "just make it" for me would be fantastic, but to be honest I'd rather get some step by step mentoring, (paid of course) enabling me to learn, by doing it myself.

And yes, I will explore doing the same with nCore or even Purifi, but my budget is a bit tight, and TBH I suspect ICEpower's inferiorities will likely not be detectable to these old ears.

I hope you don't mind if I fill in some more details here, as I gather them from elsewhere, keep this thread growing as a KB repository on the topic, even if sometimes it seems I am talking to myself!

Thanks in advance for any feedback.

EDIT: cross-reference to my more general, but related first thread https://www.audiocircle.com/index.php?topic=170549.msg1805899#msg1805899

[john61ct]

A Series product page

https://icepower.dk/products/other/a-series

can be used on their own, powered by a linear power supply, or they can be powered by the hanger bus from the modules in the ASP series

That "linear" requirement seems odd, since I'm pretty sure the PSUs integrated into the ASP units are switched?

Perhaps this wording was selected just because most SMPS are just so bad?

In any case, my plan is batteries, can't really get more "linear" or cleaner than that, right?

I found that previous thread: https://www.diyaudio.com/forums/class-d/162508-icepower-500-1000asp-power-battery-dc-input.html

[janghell]

Icepower ASP modules can also be driven with DC. See this post; https://www.diyaudio.com/forums/class-d/162706-icepower-asp1000-tweaking-mods-upgrades-7.html
Here they are feeding 385v DC into the DC bus on the ASP modules.

[john61ct]

Wow that's very helpful, inspiring. The reference above mentioned a minimum of 120Vdc. If 385Vdc is hitting the max end, that is a heck of a tolerant spread.
270-370Vdc range is actually a pretty common backbone for distributed / POL systems in industrial and some military use cases.

Thanks for the link!

Icepower ASP modules can also be driven with DC. See this post; https://www.diyaudio.com/forums/class-d/162706-icepower-asp1000-tweaking-mods-upgrades-7.html
Here they are feeding 385v DC into the DC bus on the ASP modules.

[FullRangeMan]

Great, thanks for inform.
Seems perfect to drive FR drivers.
Any info on Battery use life?
Key Performance Parameters
Output Power per channel 1 % THD+N, 20 Hz – 20 kHz
250 W (2.7 Ω)
110 W (8 Ω)
Minimum load impedance    2 Ω
Maximum amplifier efficiency    –
Maximum total amp+psu efficiency    93 %
Supply voltage input    115-230 VAC
Peak output current    >25 A
Dynamic range    112 dB
Amplifier maximum output voltage per channel    –
Output referenced idle noise (A-weighted)    85 µV
THD+N 1W/1kHz    0.015 %

[Norman Tracy]

As a matter of safety please remember in electronics 48 volts DC is considered the threshold above which the danger of electrocution rises. Simplified above 48 VDC there is enough potential that if a conduction path across the human body occurs enough current can flow that fibrillation is more likely to occur. If you are new to DIY electronics and/or want to be more casual I suggest steering your plans to solutions running off 15 to 24 VDC that can yield 30 to 100 watts of audio power. Or the ICEpower 200AC designed to run off 47 VDC.

Of course audio electronics professionals and DIYers often work above 48 VDC. We all chose a level of risk we are personally comfortable with. If you are a skier and headed onto a black diamond run I say "good luck and have a blast". As an electrical engineer I just want to highlight if you are considering stacking batteries up to voltages above 48 VDC be aware modern batteries can dump 10s and at times 100s of amps of current if shorted and need to be approached with care. Just as you should be careful if your project requires wiring up 120 VAC/60 Hz or 240 VAC/50 Hz.

[Jon L]

If you are new to DIY electronics and/or want to be more casual I suggest steering your plans to solutions running off 15 to 24 VDC that can yield 30 to 100 watts of audio power. Or the ICEpower 200AC designed to run off 47 VDC.

Good advice!

Also, reading comments about improvements using DC to power ICE on the DIY Audio thread, the improvements don't seem night-and-day and "omphf and power" can lean out unless really stout DC supplies are used, e.g. doubling up on DC supply.   

For example, to quote "noniaster":

"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."

[john61ct]

Seems perfect to drive FR drivers.

What are those, a kind of speaker?

> Any info on Battery use life?
Not sure what you are asking?

Of course how long you can play off a given battery pack depends on how loud, Ah capacity, many factors.

If you mean pack lifespan, in years or cycles, that depends on the chemistry type of battery, and how well you care for them, also many variables.

Not on topic here though, PM me if you want to discuss further.

[john61ct]

As a matter of safety please remember in electronics 48 volts DC is considered the threshold above which the danger of electrocution rises.

Yes always good to remind, thanks for your concern. I would like to refrain from discussion of the battery / power supply issues in this thread, except as regards what is specific to Audio and these specific 250A & 500A ICEpower modules.

Or even better, the ability to power a  ASP module directly from clean high-voltage DC input, and then power the 250A and/or 500A from the ASP as ICEpower intended and designed.

[john61ct]

All the ASP series have these auxiliary / utility busses

Vcc +12.8V @+0.8A, fused
Vss -12.8V @-0.8A, fused

The 1000ASP integrated rectifier / PSU puts out:
Vp1 120V @9A  (90 - 265V)
Vp2 80V @7A (same as 500ASP)

500ASP:
Vp1 50V @5.5A  (? range ? same as 250ASP)
Vp2 80V @7A (same as 1000ASP)

250ASP:
Vp1 50V @5.5A  (? range ? same as 500ASP)

So, it seems, **if** the ASP units can be fed high-voltage DC, bypassing their rectifiers, acting as DC-DC converters for the output of their various "hanger busses"

some of the possible combinations I'd be interested in for a 2.1 amp include:

one 1000ASP + two 500A
one 500ASP + two 500A
one 500ASP + two 250A
one 250ASP + two 250A

In reality I do not **know** if all these combinations would work?

Also, are there SQ advantages to any one set, compared to the others, other than watts/SPL?

I plan for the main pair to be KEF LS50s, no idea yet about the sub.

Portability, or at least "transportability" and robust for mobile use are critical, see the parent thread and my intro post for more context.

I would like to use the built-in input buffer, budget is "low without sacrificing much SQ", suggestions for a good quality case, wiring / connectors would also be appreciated.

I'm thinking Anderson PowerPole for the DC power inputs.

And again, I would really welcome leads on someone who could just put this together for me for a fee, or else I'm willing to DIY under supervision.

[john61ct]

bump?

[hifiamps]

Would like to see your battery setup.

The other thing about DC voltage at high levels is that you can get very beautiful and impressive plasma arcs, and as a result, fires can start. Lawsuits regarding the Tesla solar installations catching fire come to mind. Any with home roof solar units should watch the video.

https://youtu.be/S9a2oPCIMr0

At tube amp voltages around 500VDC, explosive vaporization occurs with large storage capacitors.

[hifiamps]

Just one more video. Higher voltage, more impressive plasma arc. Safety first.

https://youtu.be/ndHm12bNaDc?t=93

[john61ct]

So no information about, answers on what I'm actually asking?

Safety advice is fine, but that's all anyone has to say?

[hifiamps]

Pertaining to your post, the information on diyAudio on the OPS-U500-385 in the Jeff Rowland amp is the best I have seen on the subject. We know that's what Rowland is doing. I have the 500ASP and 125ASX2 (BTW, I can detect no problems with sound quality on these, but I haven't listened to the Hypex or others to directly compare. My experience is tube amps, and these sound similar in mids, but much better bass, highs barely not quite as clean as tubes.) , and have thoroughly read the data sheets and designer's manual for the 50ASX2. Looking at the block diagrams, there is input rectification and filtering then going to DC-DC converter. Should not be a problem. One thing to pay particular attention is the ratings on the auxiliary 12V or 24V supplies. Don't overload them. Follow the guidelines regarding in series resistors if you have large input capacitors tied to the auxiliary supplies. They are fused, but.... See the design manual and data sheets. I figured you would have these up and running on DC already. Are there any specific reservations that you have?

[john61ct]

Thanks for your reply, good to know my inferences are correct and my goal i not just possible, but apparently pretty straightforward.

However I do not have any experience with component level electronics, have not done DIY stuff, really would like to just have modules case wiring etc drop shipped to someone with experience and receive a nice completed unit I could plug in and play.

Failing that, I'll figure stuff out with help, but right now forget capacitors resistors etc, I have no idea.

Battery banks, power supplies, DC converters etc those I have a handle on.

Note I am hoping to avoid feeding the amp 385Vdc, when 80V or 50Vdc direct will do, those levels are bog standard for example with bikes.

I'm ooking at the 500A since it has no PSU at all. But I guess I could buy a 500ASP, reverse engineer the interconnect voltages to get the right supplies to the right terminals on the 500A, and then sell the ASP on.

Or, if I do end up building a 120S battery pack to get 385V, then I guess I just need to know which terminals to attach the positive and negative to.

[hifiamps]

Looking at the 500A data sheet, ratings for the input power supply Vp are min 42VDC max 80VDC typical 75VDC and absolute maximum 85VDC. You are good with either 50 or 80VDC. Just make sure you are well below 85VDC under all conditions. So the quoted output power into 4 ohms is 500W with Vp = 75VDC. Lower voltages would get lower power output. Polarity is very important on the 500A with positive supply voltage connect to pins 3 and 4 (Vp) and ground connected to pins 7 and 8 (PGND) of the 8 pin power connector. It is likely protected against reverse polarity, but not certain of that. Speaker output is from pins 1,2 and the other lead is 5,6. If you power up the amp, be sure you have a speaker connected (expendable at first, 4 or 8 ohm). You will need leads, if you don't already have them, and it's just easier to buy them from Parts Express https://www.parts-express.com/icepower-6277424-power-speaker-wiring-harness-for-500a--326-120 power/speaker harness and https://www.parts-express.com/icepower-6277456-signal-wiring-harness-for-500a-1000a--326-122 for the signal harness even though you can likely remove all of the wires except for the input. The JST connectors are otherwise difficult to procure and fit to the wires (need an expensive crimping tool). Before you buy the cables from Parts Express, call support and hit them up for info. For the signal input, if you have single ended (RCA), you connect pins 3 (signal ground) and 6 (V- inverted input) with a jumper on the RCA and feed signal into pin 5 (center pin on RCA plug). I do this on my 500ASP, so it should work on the 500A. If you have balanced input (XLR), then connect appropriate +/- to pins 5 and 6 and ground is pin 3. These are the wires in the shielding. All the other unused wires can be removed (use a small flat screw driver or carefully with a sharp knife to lift up on the locking tab) and pull the unused wires out. 

Not sure if there is a YouTube video on constructing this particular amp, but there are on the 125ASX2. Watch and learn. This would be about the easiest diy audio amp project you can get. The modules are rugged and highly protected, just don't exceed maximum values and mind polarities. You need to solder an RCA jack to the input wire, but that's it. Very easy. Someone could do it for you and it would take two minutes. Not sure what type of connectors you use for the battery.

Some additional info here in review and questions.
https://www.parts-express.com/icepower-500a-class-d-audio-amplifier-module-1-x-500w--326-200

[hifiamps]

The 500A is designed to be used with either the 500ASP or 1000ASP, so any other application is likely not covered by the warranty. Parts Express support will likely not discuss any other applications. It has undervoltage protection, no mention of overvoltage protection.

Looking more at the data sheet, you do need to supply +/- 12VDC. It also looks like you may need an external transistor circuit (maybe just a switch to ground) to control the mute and standby lines. There needs to be a delay at startup and prior to shutdown, and this likely prevents pops or thumps when connecting/disconnecting the main power. Normally the 500ASP or 1000ASP provide these signals. Getting a bit more complicated. You may not need to do anything with these lines. I don't mess with these on my 500ASP, just switch the main AC line. No pops or thumps.

One last thing to mention with these amps is that the speaker outputs are floating, and you should never connect a ground to the speaker connections. See the note bottom page 14 in the 50 ASX2 designer's manual. "Loudspeakers may short the voice coil to the basket during heavy load resulting in damage to the module due to the short to ground." So for example in a car application, you must insure that the loudspeaker mounting is electrically insulated from the common ground or chassis of the car.

[hifiamps]

I think it's somewhat of a trailblazing effort here. Adequately fuse the modules. The safest approach would be to monitor diyAudio or the internet to see if anyone else powers their Icepower modules with batteries.