SMPS and AMP1

[theAnonymous1]

I plan on using a 28-0-28 SMPS on three AMP1's and was wondering what the best way to get the "stabilized 50ma 5v" would be. The supply will be in a case with three XLR plugs, one for each individual amp, so the "solution" would need to come from the power feed into the amp.

Oh, and a couple dumb questions..... what is it even needed for, and does it need to be 5-0-5 or just a single supply?

[soongsc]

I'm thinking about doing something similar with the AMP2. It uses +5V. I wonder if just adding something like a LM78xx to bring a voltage down to 5V would do.

[theAnonymous1]

This little obstacle is the only thing holding me back from ordering three of them, so you can imagine how anxious I am to find an easy answer.

[theAnonymous1]

Well I just read the data sheet for the TA2022 evaluation board and it say it needs a +5v supply that isn't referenced to the main supply ground. Does that mean I'm SOL on taking the 5v off of the main supply?

[soongsc]

My AMP2 is not here yet, but the assembly instruction say as follows:

Audio signal sources and the 5V supply must be grounded to J2. This connector is in turn connected via an inductor bead to the star grounding point where the power supply is connected.

[theAnonymous1]

I guess I'll just get a 5v supply and figure out another way to put everything together. I really did like the idea of three separate amps with only a single XLR running to each one for power.

[sx881663]

Near the bottom is shown a simple LM317 derived voltage source that should solve your problem and allow you to keep your ELR connectors
Roger
http://www.41hz.com/downloads/TA2022.pdf

[theAnonymous1]

The only reference to a LM317 in the document I see is for an external VN10 supply that should be around 11v. Do I just adjust the 1.8k or 240 ohm resitor to get a lower voltage?

I'm sure this is probably something very simple for most, but I'm kind of new at this stuff so please forgive me.

[sx881663]

Sorry for the confusion, I didn't look into it deep enough. I have no idea what use their recommended circuit was for.
The LM317 input would be from the main + input, its ground should be the analog ground connected on the same connector where the 5V goes into the board. R1 = 240 ohm (out to adj), R2 = 720 ohm (adj to ground) for 5 volts. Wish I had an easy way to do a little drawing. Scanning and editing is way too much effort to get it small enough to be accepted for posting.
Roger

[soongsc]

Originally posted by theAnonymous1
The only reference to a LM317 in the document I see is for an external VN10 supply that should be around 11v. Do I just adjust the 1.8k or 240 ohm resitor to get a lower voltage?

I'm sure this is probably something very simple for most, but I'm kind of new at this stuff so please forgive me.

You could adjust the 1.8K part, I somehow recal the 240 is a pretty standard value there.

I think you could also use an LM7805 sort of device.

Check the maximum input voltages before you use them.