[anishbenji]

I need a linear power supply for the porta corda. I don't have transport right now, and the nearest Radio shack is too far too walk to it. What is the part number of the power supply, so that I can order it from the Radio shack website.... or is there a better place to get one from?
Anish

 

[tangent]

So far as I can tell, Radio Shack doesn't carry linear power supplies.

By the way, "linear" is not the same thing as "regulated". If it's "regulated" but not "linear", it's probably a switch-mode power supply. All the regulated supplies RS sells are SMPSes, as far as I can tell. That said, I'm using one of their SMPSes right now, to good effect. Sure it isn't ideal, but the noise is "only" 120 mV max (I've seen it as low as 80) and it doesn't seem to affect the sound of my DIY amps vs. a battery supply.

If you really want linear in a "wall wart" form factor, go to DigiKey or Newark and look up Elpac's WM series. They'll cost in the $30-50 range, vs. the $20 you'll pay for an SMPS from RS. I've got one coming that I'll be trying out soon.

 

[anishbenji]

thanks alot tangent. I'll check out the digikey and newark websites.

 

[anishbenji]

They don't seem to have what i want. I need about 24-28V and about 1-3A (i think). Can anyone with a porta corda correct me if i'm wrong?
Anish

 

[jedai]

anishbenji, 1-3A powersupply is way too excessive for porta corda which only consumes average 10mA on 9V battery according to Jan. Even if the corda consumes somewhat more for higher supply voltage, that's still excessive; one tenth of it should be more than enough in my opinion.

 

[RMSzero]

24 to 84 watts in a solid state headphone amp . . . I think that's a bit excessive. In particular, where are you using that amount of current?

 

[taoster]

ive got a 24V 1Amp regulated powertech supply to run my porta corda @home. The porta corda will accept it quite happily.

 

[tangent]

It isn't a matter of "accepting" that much power, taoster. A 1 amp power supply doesn't actually supply 1 amp to whatever it's plugged into, unless the device actually draws that much power. That spec only means the power supply can supply 1 amp if needed without overheating. If you get a microammeter and test your amp under load, I'll bet you're still only using 10-20 mA.

EDIT1: That should be "milliammeter".

As for voltage, the PC is based on LM6172 opamps, which will tolerate up to +/-15VDC (30V p-p).

EDIT2: They should sound better when given more than the 9V supplied by the battery, especially with high-impedance headphones.

 

[taoster]

that's true.. i dont expect the PC to be drawing that power. that said, its hard to found a linear regulated supply producing anything less than 1 amp at that voltage.

 

[anishbenji]

toaster, tangent...
Thanks for the information. I'll start looking for lower rated power supplies (about 100mA). toaster, where did you get that powertech amp from?
Anish

 

[Ctn]

From Jaycar

www.jaycar.com.au

 

[Joe Bloggs]

My power supply can give 3 amps and weighs about 3 tons