I'd like to find (or build?) a 12v to 64v (I think 48-64v would work) PSU to run several Hypex UcD180 or 250 amplifier modules for a fancy car stereo install. I'd probably build two amps (4ch UcD 180 for 720W and 2ch UcD250 for 500W) so it might be easier to find 2 PSU's around 800W rather than one big 1300 watter. Any ideas on what might work? An off-the-shelf solution would be best, but I could build something if need be too. Thanks!
12vdc to 64vdc power supply?
- Thread starter jdurango
- Start date
Help Support GroupDIY Audio Forum:
Don't Hypex amps need bipolar (+/-) supply rails?
Just for the sake of simplicity, it might be simpler(?) to hunt down some ready-made car amps, and bypass / remove their own amp circuitry, only reusing the power supply, basically. More often than not, those have some form of full-bridge power supply, and bipolar rails to power the amplifiers.
Just for the sake of simplicity, it might be simpler(?) to hunt down some ready-made car amps, and bypass / remove their own amp circuitry, only reusing the power supply, basically. More often than not, those have some form of full-bridge power supply, and bipolar rails to power the amplifiers.
Yes, sorry to mention that should be bipolar PSU. That's actually an excellent idea. I think UcD modules will accept a pretty wide range of power, something like 50-64V. Is it likely that's the kind of output most car amp PSU's will provide? Bipolar?
Okay, that idea led me to this:
https://www.ebay.com/itm/274960510549?hash=item4004ec6e55:g:Q4kAAOSw-ZlcIdTq
Which would (in theory) be good enough for 2 UcD250's, but I'd really like to build one large 5 or 6 channel amp and have plenty of headroom/rating on these Chinese PSU's. Soooo, would it be possible to somehow wire 2 of these up in a way that they'd create a bipolar PSU?
https://www.amazon.com/ACEIRMC-Converter-Step-up-Constant-Electric/dp/B0923ZTZ5K/
https://www.ebay.com/itm/274960510549?hash=item4004ec6e55:g:Q4kAAOSw-ZlcIdTq
Which would (in theory) be good enough for 2 UcD250's, but I'd really like to build one large 5 or 6 channel amp and have plenty of headroom/rating on these Chinese PSU's. Soooo, would it be possible to somehow wire 2 of these up in a way that they'd create a bipolar PSU?
https://www.amazon.com/ACEIRMC-Converter-Step-up-Constant-Electric/dp/B0923ZTZ5K/
Wouldn't several smaller supplies be easier to locate (and optionally conceal) than one great big honking one? I'm thinking that would also allow for slightly thinner wiring (for the inputs at least). Especially with high power and low frequencies AND class-D, ideally you'd want to minimize the length of speaker wiring as well.
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Maybe, but these are also more expensive and rated lower. I'm a little worried about pushing one of these cheap Chinese PSU's to it's max, although this looks pretty well built....with a proper heatsink, I feel like it'd be fine. 3 stereo amps would also be more work to make each one, messier wiring, and might actually take up more overall floor space. But might be easier than trying to get bipolar +/- out of two non-linear PSU's. If they were linear/regulated, I feel like you could tie together xformer secondaries to create a common ground, then just take a POS from one module and a NEG from another. Not sure how it would work with these....what would be the COM GROUND reference point for the amp modules to the PSU's? Just regular frame/chassis ground of the vehicle? With 2 x 1500W PSU's, would I still end up with a single 1500W bipolar supply, or would it effectively yield a single 3000W supply? Sorry, I'm a n00b with this stuff.
Morel MW6 Hybrid and MT230 tweets. They're pretty power hungry. Just want to be able to get my $'s worth out of them, naw mean? 
A tech friend and top notch repair dude is telling me he's pretty sure from reading the OEM docs from Hypex that "As far as I can tell the Hypex works on a single supply that floats relative to the audio path, or the audio path floats relative to the supply, whichever way you want to look at it. It could be +60V and ground, or +30V / -30V, or ground and -60V. They just need to be 60V apart. There SHOULD be no connection whatsoever internally in the boost convertor between the supply voltage GND and the (-) output. Again, the DC supply from the boost convertor should be floating. So if we connect the floating DC supply to the floating DC inputs, the audio path and its ground should be totally isolated from it. I might be wrong, but that's how I'm reading the OEM doc for the Hypex."
Of course this is all way over my head, but he's a G, so I'm gunna say he's probably right. I'll prolly run it by Hypex to make sure.
A tech friend and top notch repair dude is telling me he's pretty sure from reading the OEM docs from Hypex that "As far as I can tell the Hypex works on a single supply that floats relative to the audio path, or the audio path floats relative to the supply, whichever way you want to look at it. It could be +60V and ground, or +30V / -30V, or ground and -60V. They just need to be 60V apart. There SHOULD be no connection whatsoever internally in the boost convertor between the supply voltage GND and the (-) output. Again, the DC supply from the boost convertor should be floating. So if we connect the floating DC supply to the floating DC inputs, the audio path and its ground should be totally isolated from it. I might be wrong, but that's how I'm reading the OEM doc for the Hypex."
Of course this is all way over my head, but he's a G, so I'm gunna say he's probably right. I'll prolly run it by Hypex to make sure.
I'm reasonably sure your audio source ("head"?) IS referenced to the car chassis "ground", so you're gonna have to keep that in mind.
True, the amps themselves rarely (if ever) care where "ground" is relative to their supply rails, but the input / signal ground is a different story.
UCD250LP datasheet says, under the pinout:
"Note 1: Pin 6,12 and 14 are physically connected to the same potential ( ground )." That is, the power supply ground pin and the speaker "cold" output.
The schematic (plus some bells & whistles "should" be quite similar to the original patented design:
http://www.handsontec.com/pdf_files/UM10155_2_Discrete_ClassD_Amp.pdf
But the Hypex units have balanced inputs. On the other hand, we can't know if and/or what parts of the circuitry may or may not be referenced to "ground" (ie. the midpoint between the positive and negative supply rail), and whether that relies on the existence of a bipolar supply, or there's a mid-supply-rail-divider on board.
True, the amps themselves rarely (if ever) care where "ground" is relative to their supply rails, but the input / signal ground is a different story.
UCD250LP datasheet says, under the pinout:
"Note 1: Pin 6,12 and 14 are physically connected to the same potential ( ground )." That is, the power supply ground pin and the speaker "cold" output.
The schematic (plus some bells & whistles "should" be quite similar to the original patented design:
http://www.handsontec.com/pdf_files/UM10155_2_Discrete_ClassD_Amp.pdf
But the Hypex units have balanced inputs. On the other hand, we can't know if and/or what parts of the circuitry may or may not be referenced to "ground" (ie. the midpoint between the positive and negative supply rail), and whether that relies on the existence of a bipolar supply, or there's a mid-supply-rail-divider on board.
There's a diagram that shows you can connect both halves in series, resulting in a single 60V/8A source.
That is a good indication that the two halves are floating.
That means that you can connect two of those to produce a bipolar +/-60V source.
That doesn't really help the OP, since he requires a 12V-input power supply, for a car audio application. If you had bothered to read the first line from the first post, that is...
In your question about wiring 2 "of these" up to create a bipolar supply, is the antecedent to "these" the original eBay link, or the Amazon link? If you are asking about the supply at the Amazon link, the description states "non-isolated boost power supply module." The phrase "non-isolated" indicates that the output return and input return (aka "ground") are tied together, so you can't wire two in series.
Have you looked at the specifications of the two amp modules you mentioned? The UcD250 gets higher output power than the UcD180 by using power supply rails higher than the maximum allowed for a UcD180.
You also did not mention how you are going to generate the second rail needed for the UcD250 (Vdr, 15V above the negative power rail).
The UcD250 also does not have a buffered input, and the input impedance is too low to connect most sources directly, so you would need to build an input buffer for those channels as well.
If you want to run everything from a single power supply you should just make all modules UcD180, there is no advantage from having some of the channels be UcD250.
So many questions, ha! Okay, here goes:
1. My tech buddy is saying a single rail supply should work for UcD250 as long as it's at least 60V. "As far as I can tell the Hypex works on a single supply that floats relative to the audio path, or the audio path floats relative to the supply, whichever way you want to look at it. It could be +60V and ground, or +30V / -30V, or ground and -60V. They just need to be 60V apart. There SHOULD be no connection whatsoever internally in the boost convertor between the supply voltage GND and the (-) output. Again, the DC supply from the boost convertor should be floating. So if we connect the floating DC supply to the floating DC inputs, the audio path and its ground should be totally isolated from it. I might be wrong, but that's how I'm reading the OEM doc for the Hypex."
Does this appear to be accurate?
2. The UcD180 would be about maxed out driving these drivers and I like having headroom on amps. Also, I'd rather just deal with one module type and circuit. Also, I can get the UcD250's pretty cheap.
3. As far as buffer, that might be an issue with the 250's, not sure. I'll be feeding these modules with a MiniDSP Harmony 8x12 amp/DSP that can either output speaker level (up to 40W @ 4 ohms) or be switched to line level out (I'm guessing consumer -10dB? Not certain....some kind of line level). Would this require a buffer?
4. If I go the UcD180 route, I'd probably just do two 4-ch units, use one to feed mids-tweets up front and one in bridged mode (2ch) to drive each coil of a 500W @ 4ohm DVC sub. I understand this might be less ideal than using one higher powered amp driving both coils in parallel (level matching issues).
Watcha think on all this? Thanks fellas!
1. My tech buddy is saying a single rail supply should work for UcD250 as long as it's at least 60V. "As far as I can tell the Hypex works on a single supply that floats relative to the audio path, or the audio path floats relative to the supply, whichever way you want to look at it. It could be +60V and ground, or +30V / -30V, or ground and -60V. They just need to be 60V apart. There SHOULD be no connection whatsoever internally in the boost convertor between the supply voltage GND and the (-) output. Again, the DC supply from the boost convertor should be floating. So if we connect the floating DC supply to the floating DC inputs, the audio path and its ground should be totally isolated from it. I might be wrong, but that's how I'm reading the OEM doc for the Hypex."
Does this appear to be accurate?
2. The UcD180 would be about maxed out driving these drivers and I like having headroom on amps. Also, I'd rather just deal with one module type and circuit. Also, I can get the UcD250's pretty cheap.
3. As far as buffer, that might be an issue with the 250's, not sure. I'll be feeding these modules with a MiniDSP Harmony 8x12 amp/DSP that can either output speaker level (up to 40W @ 4 ohms) or be switched to line level out (I'm guessing consumer -10dB? Not certain....some kind of line level). Would this require a buffer?
4. If I go the UcD180 route, I'd probably just do two 4-ch units, use one to feed mids-tweets up front and one in bridged mode (2ch) to drive each coil of a 500W @ 4ohm DVC sub. I understand this might be less ideal than using one higher powered amp driving both coils in parallel (level matching issues).
Watcha think on all this? Thanks fellas!
Is the implication here that you do not have enough confidence to read through the datasheet yourself? The datasheet very plainly says that all the specifications are with +64V and -64V power supplies (i.e. 128V across the supplies, not 60V as your friend seemed to be saying).
The idle current specification for positive and negative rails is different, which could not be the case if there was no internal connection to a separate ground (i.e. if a single rail with no ground in the middle would work, all current going in through one supply would have to go out through the other, so the idle current could never be different between positive and negative supply).
There are also separate overvoltage detection trips for positive and negative supply rails, which necessarily implies that there is some mid-point reference that each rail is measured against.
I don't know why your friend thinks that there is no required reference to ground for both supplies, but that does not match the clear language in the datasheet.
What is the driver impedance and sensitivity, and what SPL are you trying to achieve? How did you determine whether 180W would or wouldn't be enough power?
Fair enough, using one type of module is often the simplest approach.
Interesting question. The Harmony manual or datasheet doesn't give details on output impedance or minimum input impedance for a line level connection, but the pins are the same for speaker or line connection, which might mean that the same driver is used for both. If that is the case the 1.8k input impedance of the UcD250 would be no problem.
The max output is 5V, which would be +16 dBu or +14 dBV. Balanced output, which actually is a nice match for the UcD inputs.
The UcD250 datasheet indicates that you need 6.8V input to reach maximum output, so if you actually need that power then you would need a buffer stage to provide a little gain. 5V is only 3dB lower than 6.8V, so either an input buffer with 3dB gain, or just live with a maximum output of 180W instead of 250W.
Since the UcD180 already has a buffer it only needs 1.3V to reach maximum power.
I doubt that there would be any noticable difference between driving the coils separately or putting them in parallel and driving with one high power amp. Separate amps might actually be better, it is pretty hard on an amp driving a 2 Ohm load. As long as the amps are driven by the same signal the outputs will track very closely.
I don't know how well using two separate modules in bridged mode would work. That probably would work OK, but you really need more than 360W driving the sub inside a car? What is the sensitivity in the enclosure you have planned?
You might not end up getting any more power in bridged mode anyway with 4 Ohm voice coils, the maximum current output may become the limiting factor. It could potentially allow running at lower power supply voltages if that is convenient for some other reason, or it could allow hitting the max power output without needing an input buffer. I would ask Hypex whether they have any concerns about bridging two modules to be sure, though.
