48v dual voltage and the IRS2092

[mattinpdx]

Greetings,

So I think I already know the answer to my question, but I thought I would confirm.

I bought one of the IRS2092 dual voltage boards off of ebay: Assembled IRS2092 Mono Amplifier Board DC Power Supply 350W | eBay

I also bought a 350w 48v power supply. The specs on the listing say that the operating voltage is DC + -55V, but the board says "45v-65v". When I measured the output of the power supply I was indeed getting +- 48v.

When I hooked up the board, I'm reading more like +- 24v on the positive and negative board inputs.

So I am thinking that the problem is that I didn't account for +48v to -48v which would mean I actually need ~96v. OR the board is incorrect and I actually do need +-55v and I am actually 7 to 10 volts shy.

Are either of those correct or am I way off base?

Thank you for helping out a n00b.

 

[gpapag]

Hello matin
Welcome to diyaudio.com!

The amplifier requires a dual (symmetrical) power supply that outputs +xx and –xx DC Volts in respect to the center 0V rail.
I am afraid that the power supply you bought is a single supply +xxDCV in respect to it’s 0V rail.

George

 

[mattinpdx]

Hmm... I thought the power supply I bought was dual symmetrical.

https://www.amazon.com/gp/product/B005CLBZRO

 

[DPH]

48 VCT at 7.3 A would give you the 350 W rating. My bet is that you're getting +/- 24 under load.

 

[mattinpdx]

That's sort of what I was thinking since I was seeing +-48v before I hooked up the board.

So I suppose my next question is how I should proceed?

Do I just need a higher wattage power supply?

 

[gpapag]

mattin
This PSU is single ended.
The marking is +V and -V simply because the outputs are DC floating.
48Vx7.3A=350W.
(2x48)x7.3A would make 700W

Sanity check:
Play this amplifier at low levels. Measure the supply rails. Such an amplifier working at 2-3Watts can not load a 350W PSU to the extend of halving it’s output.

George

 

[nigelwright7557]

You need a supply that is -48v - 0v - +48v
Or two supplies that are 0v - 48v in series.

 

[mattinpdx]

Ok, thanks for all the replies.

So would it be insane to buy a second psu (like the first) and wire the +vcc of the first psu and the -vcc of the second psu to the amp, or will I still see the same voltage drop? Or am I just stuck buying a 700w power supply? Thanks for all the help.

 

[mattinpdx]

Going back over all the replies, the answer sticks out like a sore thumb. George (gpapag) was right from the get go. Sorry for being so thick headed. Now to dig through the site looking for the most cost effective SMPS threads.

Thanks again for everybody's help!

 

[steveeboy]

you probably want to check the abeltec 53v smps which is available right now on ebay for like $25. look for that thread.

 

[Wiggle8]

I have built an L15D irs2092 based amp and used two 48V supplies (meanwell NES-350-48) wired in series with the PGND connected in the middle of the series. I am currently troubleshooting a ground loop (my RCAs accidentally contacted enclosure ground which I did not want) but otherwise seems to work just fine. Make sure if you do this you adjust both supplies to an equal voltage before connecting the amplifier modules.