Harry Lavo wrote:

"Kalman Rubinson" wrote in message
news:EoRUb.107438$U%5.553285@attbi_s03...
On Fri, 06 Feb 2004 04:21:59 GMT, chung wrote:

Can you provide some examples of worthwhile mods?

Nothing recent since I have not done any or much DIY in the last 10
years. However, I can recall one example.

In the old AA DITB, all the chips, digital and analog, were fed with
+/-5V. The chip mfrs spec sheets for the output opamps showed a
substantial rise in THD with such a reduced PS voltage, especially
since the DITB output at 0dB is +/-2V. Changing the Vregs so that the
available voltages were +/-5V and +/-12V and fed to the appropriate
pins, I was able to realize and measure a significant reduction in THD
on the analog outputs. I also added larger output caps and heatsinks
on all the chips. (Of course, they would have gotten even warmer at
the higher PS voltage had they not been heatsinked.)

I think that AA's decision to use the same +/-5V supplies for
everything was based on (1) reduced parts inventory and (2) an earlier
choice for the analog opamps. Nonetheless, the results were an
improvement compared to a stock DITB.

Kal


To Chung's original question.

The mod's being done on SACD and DVD-A players generally involve
substituting a clock module, substituting better sounding opamps in the
outpout circuits, and upgrading the output capacitors to BlackGates. The
owners swear by them. I haven't heard them, or a before and after
comparison. Perhaps after my five year SONY warranty runs out I'll consider
it.

Harry

The original question was whether there are any examples of worthwhile
mods, as far as Kal knows. I know what modders have been doing.