TDA1541 NOS DAC direct battery powered

Is it possible to design direct battery powered tda1541 dac without any voltage regulator?

Using nimh or lipo batteries it could be possible to obtain the +-5V and -15V...
the max ratings of the datasheet are +-7v and -17v

It seems that lead acid batteries are not good, having noise, but nimh and lipo are quieter than the best mains psu.

Any experience? any advice?

Vill the voltage variance from fully loaded and empty battery move the vorking point of the TDA1541? I envisage to use the MK-8 design of ECdesign
http://www.diyaudio.com/forums/digi...ding-ultimate-nos-dac-using-tda1541a-401.html
 

patrykvel

Member
2011-04-09 10:47 pm
regulators have feedback loop, poor transient characteristic etc...
So You should try a discrete regulator without any feedback, condesators and resistors. Simplest zener diode with bipolar buffer on output is what You need. :) Zener noise will be filtered on the decoupling caps so it's not a big deal.
http://electriciantraining.tpub.com/14179/img/14179_210_2.jpg
Instead of resistor in R1, use a jfet(BF245B), G and S pin of jfet should be connected to zener diode.
 
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Eldam

Banned
2012-09-13 12:25 am
France
Hi,

Had some CD players (TDA1545 & 1541 & 1543) with battery (dac and I/V stages).

The gain is not great and sometimes is not.

You need two baterries for a battery phantom power supply for the I/V stage, lot of 1 uF saving caps in series to have a huge power capacity quality for tanscient, some normals big caps with low esr. It's expensive.

As voltage change with the load of the battery, I think you need regulators. Another problem is the I/V stage... most of the times you need more than 12 V... it adds complexity.

IMHO and experience, the design can be better with times spent on a good regulator and a long and carefull choices of capacitors. In fact you will ear more difference with playing with caps that playing with battery vs discret powersupply.

that just my own opinion. Not an expert but spent some times on this subject with more than 20 cd players (Marantz, Philips, TEAC, SONY, TOSHIBA, Kenwood, AIWA) with trying to improve DAC and I/V stage powersupply and sound signature. I'm still very surprised today seeing good designers making the bad choices abouts caps in relation to their position in the design...

You can try for the DAC some little ears'amp battery;;; but most of the times with the same stable voltage, the cap make the difference and have to be choosen in regads to the global sound of your DAC or CDplayer... it's a set up. A Nichicon FC can be better than a Panasonic SEPC near the DAC, but sometimes it's not ! The purple Sanyo Os con give incredible result because smoother (not avialable today), and Black Gate BGNX alone have a good "mate" sound but horrible harscheness alone...mixed with a good sepc value will be amazing...and so on.
 
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