Hi,
if I have 2 amps that require single positive power input, can I feed them with a single dual output SMPS like this one: https://connexelectronic.com/product/smps600rxe/ and just invert the connection to the second amp? Or does the supply need to provide isolated outputs?
Thanks!
if I have 2 amps that require single positive power input, can I feed them with a single dual output SMPS like this one: https://connexelectronic.com/product/smps600rxe/ and just invert the connection to the second amp? Or does the supply need to provide isolated outputs?
Thanks!
They say "All outputs are isolated from each other, and they are well suited
to be connected in any configuration required" so you should be able to
connect them in series if desired. You may want to verify your intended
use with the mfr.
Well, the secondary outputs are isolated, the main output has a common 0V so not isolated.
The way I see it is that the two loads are in series so they should get half the total voltage if resistance is equal. The only thing I'm not sure about is if I should be connecting the 0V to the amps or not.
The way I see it is that the two loads are in series so they should get half the total voltage if resistance is equal. The only thing I'm not sure about is if I should be connecting the 0V to the amps or not.
Hi Wealas,
Please make a drawing of what you're planning to do, as asked by Scottjoplin.
Regarding the power requirements: a single TPA3255 needs more than 7,5A according to the specs I find at Bangood, that's close to 400VA.
Two will draw more than the 600VA powersupply can deliver, so full power for both amps won't be available.
If you haven't purchased the powersupply yet, I'd get a seperate one for each amp.
Regards, Jan.
Please make a drawing of what you're planning to do, as asked by Scottjoplin.
Regarding the power requirements: a single TPA3255 needs more than 7,5A according to the specs I find at Bangood, that's close to 400VA.
Two will draw more than the 600VA powersupply can deliver, so full power for both amps won't be available.
If you haven't purchased the powersupply yet, I'd get a seperate one for each amp.
Regards, Jan.
I'll never run the amps full power - I do live in an apartment and my speakers can't handle that much power anyway so power requirements are fine. Attached is a schematic of the two possible ways I can think of to connect the amps and power supply, not sure if that's what you're asking for.
Thanks!
Thanks!
Attachments
Yes, amps do take balanced input. I have not bought the supply yet, checking if it's possible first 
It's just that the 600rxe is the most advanced and quiet of the offerings but they only come in dual output. I guess I can ask the manufacturer if I can just put a load on the positive output and get two of them - seems like a waste.
It's just that the 600rxe is the most advanced and quiet of the offerings but they only come in dual output. I guess I can ask the manufacturer if I can just put a load on the positive output and get two of them - seems like a waste.
The danger is surely if audio screening is connected to amp -ve?
And also any sensing or control you might add.
If so then joining screens together (perhaps through connected equipment) will short the amp 2 supply. You would need to ensure this was never possible.
SMPS300RS would seem to have single main supply (one per amp for full power).
Or contact Connex for their recommendations.
And also any sensing or control you might add.
If so then joining screens together (perhaps through connected equipment) will short the amp 2 supply. You would need to ensure this was never possible.
SMPS300RS would seem to have single main supply (one per amp for full power).
Or contact Connex for their recommendations.
NO, you can NOT.
As described, the main output is a split supply, you can choose between +/-45 to +/-72V but that does not change the main problem that the main output bis: +V ... 0/ground ... -V.
See:
So he has:
a) ONE "differential", I think they mean "split" and description confirms it :
b) ONE "differential", I think they mean "split" and description confirms it :
c) ONE (single) 24V
A/B/C are separated between them but all 3 wires in any "differential/split" supply are galvanically connected.
So you can connect one amplifier from o/ground to +V but you CAN NOT connect theother from -V to Ground , even if "inverting connections" becaiuse now its own +V will be Ground but its ground will be -V ... how will you send signal to it?
The second "ground" will be 45 to 72V DC below ground, the moment you join both grounds more than sparks will fly, think an arc welder instead , destroying everything, and even IF you used a transformer to separate grounds , the second amp will have a very dirty ground ..... if at all.
Hm, I thought that +V, 0 and -V denote the electric potential of those connectors. And since voltage is the potential difference between two points I would get 45V when measuring between +V and 0, I will also get 45V if I measure between 0 and -V and I will get 90V if I measure between +V and -V. In the second case -V has lower potential than 0 so I should have a current flow.
If you look at the schematic for another of their power supplies http://connexelectronic.com/wp-content/uploads/2017/09/SMPS300R.pdf it shows that the 0 is simply one end of the secondary windings in the transformer and -V and 0 are connected by a winding.
If you look at the schematic for another of their power supplies http://connexelectronic.com/wp-content/uploads/2017/09/SMPS300R.pdf it shows that the 0 is simply one end of the secondary windings in the transformer and -V and 0 are connected by a winding.
SMPS300R is available single & dual output.
The manual schematic shows the dual output version.
Delete the -ve output and you have the single output schematic.
Two completely independent circuits could indeed be powered as you suggest.
We are concerned that in real life, when connecting the amps to your source equipment they are no longer independent and something will make a very expensive and potentially dangerous BANG!
The manual schematic shows the dual output version.
Delete the -ve output and you have the single output schematic.
Two completely independent circuits could indeed be powered as you suggest.
We are concerned that in real life, when connecting the amps to your source equipment they are no longer independent and something will make a very expensive and potentially dangerous BANG!
Isn't your amp going to want a Gnd that's approx mid-point between the V+ and V- rails of the power supply? If Connex doesn't offer a +/- 25V supply with fewer auxiliary voltages to distract, look around the internet a little more. There should be plenty of choices since this is a very common use, especially in audio.
Neither of your drawings showed both amps paralleled on one supply. (Somebody check me -- am I opening too big a can of snakes?) I would think that would be the most cost-effective solution.
Regards, Rick
Neither of your drawings showed both amps paralleled on one supply. (Somebody check me -- am I opening too big a can of snakes?) I would think that would be the most cost-effective solution.
Regards, Rick
Actually, the reason for my question is not about cost savings, it's actually about using the best possible SMPS I can find available for purchase. The 600rxe seems to be the only SMPS I can find that targets audio applications with input and output filtering and uses modern switching technologies on top of great efficiency. The 600rs seems to be a step down with less filtering and I'll use two of those since they are single voltage output.
As for using just one half of the output, I've seen a number of datasheets for other supplies that state that no load on one rail changes the supply performance. There is no mention of that for the 600rxe so I guess I could have asked the manufacturer.
There was another thread here recently about finding the best and quietest SMPS for audio and there wasn't even a single suggestion, just discussion around the merrits of the various topologies.
I've read people claim that the supply is not that important for class D but also read plenty of people claim improved amp sound with better power cords and power conditioning. For me, that simply means that the supply is not doing good enough job of producing clean and stable power. So I'm looking for the best performing SMPS to check for myself. I'd rather spend few hundred dollars more on an SMPS than thousands on cables and conditioners.
As for using just one half of the output, I've seen a number of datasheets for other supplies that state that no load on one rail changes the supply performance. There is no mention of that for the 600rxe so I guess I could have asked the manufacturer.
There was another thread here recently about finding the best and quietest SMPS for audio and there wasn't even a single suggestion, just discussion around the merrits of the various topologies.
I've read people claim that the supply is not that important for class D but also read plenty of people claim improved amp sound with better power cords and power conditioning. For me, that simply means that the supply is not doing good enough job of producing clean and stable power. So I'm looking for the best performing SMPS to check for myself. I'd rather spend few hundred dollars more on an SMPS than thousands on cables and conditioners.
Ok, then buy 2 of them, one for each.
Use just a +V to Gnd output from one to feed the first amplifier, and a +V to Gnd output from the other to feed the second one.
Both supplies end up being joined by the Gnd connection, which you NEED because input grounds will also be joined by cable screening or simply at the sound source which as a common ground for both channel outputs.
Use just a +V to Gnd output from one to feed the first amplifier, and a +V to Gnd output from the other to feed the second one.
Both supplies end up being joined by the Gnd connection, which you NEED because input grounds will also be joined by cable screening or simply at the sound source which as a common ground for both channel outputs.
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