Keith G wrote:
"Trevor Wilson" wrote in message
...

"andy" wrote in message
groups.com...

As yet another owner of a Pioneer DV-575A I am curious about what the
above modifications will achieve and why?

**Output muting, via the use of BJTs has always been a sonic disaster,
IME. A relay contributes no distortion, whilst in the O/C mode. The output
IC used, whilst adequate, is hardly state of the art. Output ICs in 1983
(ie: First generation) CD players were superior. In Philips derived
machines, that usually meant an NE5532/5534 chip. A fine chip, back then
and still a fine chip today. There are two, 220 Ohm resistors in series
with each O/P IC. These should be shorted (after replacing the ICs with a
more suitable device, of course). A 440 Ohm output impedance is pitifully
high. Additionally, it would be nice to organise a spilt rail power
supply, for the output IC. At present, it is powered by a single rail
supply, thus a large electrolytic coupling cap is required.

I suggest anyone who is interested, to compare the 575A to a decent,
contemporary CD (only) player, such as a Rotel RCD951 and report on any
differences.




All well and good Trevor, but like Andy says: 'why'...???

Don't see the point of buying a perfectly adequate budget player in the
first place and then spending *more* money on it.....???


All looks quite bizarre to me ... but ... for anyone interested HFW (Jan
2005, pp.34-7) has some details: change output capacitors to Black Gate
- "really helped the Pioneer achieve its true potential"; overblown bass
"tamed"; high frequency "astounding"; "life-like ... sound blossomed"
etc. - you get the picture.
:-)
Rob