Debalancer Box power supply (THAT 1206)

[camshash]

After my last posts I decided to build my own stereo debalancer box with the THAT 1206 boards.

Can I wire the power supply to each board by simply jumping from one power supply to + and - terminal for each (refer to picture) or do I have to isolate the two?

 

[Brian Roth]

Looking at the pic, you need to wire up the boards with bipolar power. That requires three power supply wires per board:

+ VDC (typically +15V)
0V (aka "ground"/"common")
- VDC (typically -15V)

Bri

 

[camshash]

Thanks for the help, after looking at the 1206 specsheet it does require a +/-15v power supply. I have been looking feverishly and cannot find a power supply that outputs +/-15V at max 0.8A. I dont really want to mess with mains power at my current skill set and would prefer a plug and play option. Do you think I could use a 2A power supply (see picture) , or would the high current be a problem.

 

[PermO]

I've been wondering about the same thing as switchmode PSU's need a bit of a load on it.
They all come at 2A minimum, and two opamps are not really going to put a load on it.

 

[ccaudle]

What about a DC-DC converter? Do you have an AC-DC supply you already want to use, or are you still looking? You can get +/-12V or +/-15V DC-DC converters that take 5V input, 12V, 15V, etc. Whatever is convenient for you to use.
I'll look on Digikey and find some likely candidates.

 

[ccaudle]

Check this module, 12V DC input, +/-12V output, low leakage current, and Class B rated for radiated and conducted emissions.
MeanWell MDD01M DC-DC converter (at DigiKey)

 

[PermO]

That's a pretty handy device,... thanks, bookmarked that one.

 

[Bo Deadly]

Check this module, 12V DC input, +/-12V output, low leakage current, and Class B rated for radiated and conducted emissions.
MeanWell MDD01M DC-DC converter (at DigiKey)

Those really small ones are not very good. I fiddled with a +-15V one and found the supply would droop significantly with load. And the noise is not insignificant.

 

[ccaudle]

Those really small ones are not very good. I fiddled with a +-15V one and found the supply would droop significantly with load. And the noise is not insignificant.

Good points to note. Regarding the noise, a CLC filter on the output is probably in order. The output regulation isn't great, -10% from 10% load to full load, but in this case the load should be low and relatively constant. If it is a worry you can get a model with double the output current for only about 40 cents more, that will make the circuit current a smaller percentage of full load, which should reduce the output droop.
I think it would be fair to say this isn't a slam dunk suggestion, more of a $7 gamble that is probably OK, might have some problems.

 

[scott2000]

Saw these and mentioned them in the BM a while ago... only 400mA though

https://www.ebay.com/itm/1437073632...=1&mkrid=711-53200-19255-0&ufes_redirect=true

 

[Brian Roth]

Thanks for the help, after looking at the 1206 specsheet it does require a +/-15v power supply. I have been looking feverishly and cannot find a power supply that outputs +/-15V at max 0.8A. I dont really want to mess with mains power at my current skill set and would prefer a plug and play option. Do you think I could use a 2A power supply (see picture) , or would the high current be a problem.

Where did the 0.8A spec come from? According to THAT data:

http://thatcorp.com/1200-series_High_CMRR_Balanced_Line_Receiver_ICs.shtml
One chip typically draws 4.7 mA.

Bri

 

[camshash]

I am basing this off the datasheet attached to the Ingenius 1206 on sparkfuns website. It does say the max draw is 4.7ma. Under "supply current" is says max is 0.8A. I could be misinterpreting this tho

 

[Ricardus]

I have boards BTW for balancing and unbalancing that use the THAT chips if anyone is interested. Basically the same as the Sparkfun boards but DIY.

 

[Brian Roth]

@camshash In that spec sheet, Max supply current is 8.0 mA which is 0.008 Amps <g>.

Bri

 

[camshash]

Max supply current is 8.0 mA which is 0.008 Amps <g>.

I see. forgive me I'm relatively novice. But going back to the CAPI power supply I mentioned, it outputs +/-15V at 2A. Wouldn't it be fine to use this power supply since the boards will only draw as much current as they need since voltage is steady at 15V? It seems the other solutions may or may not add a significant amount of noise.

The power supply sparkfun used on their website (discontinued) is rated at 0.8A output Mean Well Dual Output Switching Power Supply (15VDC, -15VDC, 0.8A) - TOL-14101 - SparkFun Electronics

 

[Brian Roth]

I don't recall which CAPI unit you mentioned. A quick check through other posts didn't find it.

If it's a linear supply, a low current draw should not be a problem.

SMPS supplies often have a minimum spec.

Bri

 

[camshash]

Gotcha, I posted a screenshot of the label, here is the link Classic Audio Products, Inc.

 

[Brian Roth]

It's a SMPS and CAPI sez:

"The latest version of this SMPS is pretty well filtered internally however we do recommend additional filtering to optimize performance."

I don't want to set off a fire storm here on the forum, but I've had.....ahhhh....variable luck with SMPS supplies. Perhaps someone might chime in and suggest "additional filtering" for that CAPI.

Once again, folks here will likely flame me, but for projects like this, I prefer a linear supply.

I know you don't want to deal with AC mains wiring, and the linear supply kits require that.

Maybe someone can chime in here...

Once Upon A Time, Mouser (and probably others) sold Wallwarts and Linelumps which produced an AC output....IE, a transformer in a plastic box with all the Mains input enclosed. If we can find a pair of those, then PSU kits from JLM, etc. would relieve your worries.

This is likely to set off a flame storm, but I have my opinions re. SMPS versus linears.

Bri

 

[PermO]

I'm defenitely no expert on this, but as a starting hobbyist I'm with Brian.

For the reason that building a low power linear power supply with 78xx / 79xx is fairly simple compared to working with switchmode powersupplys wich for me add another layer of complexity I'd like to avoid.

I even wonder if a switchmode powersupply is more effective with energy consumption if only a few mA is needed ?

The PSU I build for my Rhodes preamp is very quiet (noise level sat below the treshold of my soundcard) and does not get warm at all, I think it's very effective. (I'm working on a circuit board design, but it's my first so that will take a while I guess)

Don't worry too much about mains power, you should always be carefull, but as long as you don't plug it in the socket it will be save to work on, it's a low voltage device, no big caps, no high voltages, no tubes.

You will be only connecting a switch, a fuse, and a transformer, all the other stuff is at the other end of the transformer.

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Flame storm mode;

I replaced the switchmode PSU that came with my Korg minilogue analog synthesizer for a DIY linear one (I allready build that and I was curious what would happen ? if anything would happen at all ?)

Well, that difference was huge !

Just opening the noise generator or a VCO I could allready hear it, the nasty hash was gone.

There's files on GS, the same preset running on linear and on switchmode PSU, it's pretty obvious wich is wich.

So...

 

[NOON]

Personally I'd get an AC output plug pack and use a board that can generate the 2 rails from that. Several options around, pretty sure JLM has a decent one.