Hi all,
I have built a TDA15454 DAC (NOS with passive I/V) with the battery PSU suggested by Kuei Yang Wang at post #21 in this thread:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=15551&highlight=
My question is whether the TDA1545 can be operated in piggy back mode, and if so, what changes to the Iref & Vref (or anything else) would be needed. Also, how many 1545 chips can be piggybacked?
Cheers,
Joe
I have built a TDA15454 DAC (NOS with passive I/V) with the battery PSU suggested by Kuei Yang Wang at post #21 in this thread:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=15551&highlight=
As for the TDA1545, just to put some cats among the pidgeons, I came across an interesting circuit from a French On-Line Mag, originated in the "dustcircle" of Pierre "Mr. MDI" Johannet for modding the Philips and Marantz Players using TDA1545 output Stages (Philips CD71X/72X and Marantz CD3X/4X) which I have attached.
You could use three "D-Cell" NIMH Batteries in this circuit, taking care to have a suitable "standby/float plus fast" charger which is simply disconnected when the Player is unmuted. Given the very low current Draw of this circuit you would likely get 2 - 3 Month battery life out of three non-rechargable high performance batteries, so completely omiting the charger and all may also be an option.
This would likely make for a VERY cost effective modification for the Philips and Marantz Players of this type, elimiating any active output Stage. Not shown in the Schematic are the Output Coupling Capacitors.
Oh, before I completely forgte, for adventerous souls, you could use a simple Silicon Diode (1N400X for example) string where each battery is replaced with three diodes as supply. Simply feed this diode string with a few 100mA current (from an LM317 connected as current source and a seperate mains supply) and things should work quite well to, you could even seek out adjustable references that can handle a few dozend mA and can supply 1.5 to 1.8V. In all cases I'd probably place one each BG NX-HiQ or Sanyo Os-Con on the Reference and Supply pin of the TDA1545 to ground.
An externally hosted image should be here but it was not working when we last tested it.
My question is whether the TDA1545 can be operated in piggy back mode, and if so, what changes to the Iref & Vref (or anything else) would be needed. Also, how many 1545 chips can be piggybacked?
Cheers,
Joe