AT http:/www.kiwa.com/rxtips.html, A nice publication on
"Tips for Imporivng Receiver Performance"
Under the section "audio imporvements" it is suggested that
all of the ceramic capacitors ber rpelaced and polarised
electrolytics be replaced.

Has anyone made these mods and if so, do they really improve
the audio.

Given that everything else on the Kiwa site is topnotch,
I have to at elast think about this fairly inexpensive
upgrade.

His commnets on replacing the Si switching diodes in the 8ve
fitlers with PIN types is "spot on". In high signal situations,
this mod really helps reduce the distortion. I have ordered a
set of schottky do replace those Si diodes in the ceramic fitler
swithces.

I would love to buy an AOR AR7030+, I have a borrowed unit
that I will have to return to it's owner this weekend. But
until I can save $1500, I will have to live with what I
already have.

Terry

Terry - both of these suggestions are good ones. The best thing for
the audio caps are film capacitors and for the low signal levels cheap
mylar film will do just fine. The improvement is mostly on the high
end of the audio spectrum where the response characteristic of the
electrolytics is very poor. I'm not so sure you would notice too much
of a difference with changing out ceramic caps. The bandpass switching
diodes can be problematic under high signal levels if they are standard
PN diodes and this is noticible on the R-2000 in the 6 MHz range if the
stations on 49M are strong.

Frank

I wouldn't follow the advice regarding yanking out ceramic power supply
bypass capacitors and replacing them with polyester. Ceramic capacitors
have a low self (series) inductance and are chosen for that purpose. No
audio is in series with those bypass caps anyway.

This is a good write up on ESR/self inductance and how to measure it.
http://www.emcesd.com/tt020100.htm

Otherwise, the none of the suggestions on the Kiwa page will do any
harm and may do some good. Polystyrene caps are really about as good as
it gets, but they are huge. I use them in situations where leakage has
to be low.

To be honest, the Kiwa article is a bit dated. I'd suggest going for
Sanyo oscons on the power supply rails

wrote in message
oups.com...

AT http:/www.kiwa.com/rxtips.html, A nice publication on
"Tips for Imporivng Receiver Performance"
[snip]

Replacing the caps might give better audio, if the caps are causing a
noticable percentage of the distortion. Capacitors aren't perfectly linear
and those nonlineararities will cause distortion. Steve Bench has posted
tests of several caps:

http://members.aol.com/sbench102/caps.html

However, the Kiwa article doesn't mention detector distortion, which can be
a significant source of distortion, at least with diode detectors. The
subject of detector distortion has been beaten to death here and on other
forums. One post I seem to recall involved some simple mods to a common
diode detector which significantly reduced distortion but also reduced
output by about 3db.

The Kiwa article doesn't mention detector distortion but it does say:

"High definition speaker wire and gold plated connectors are recommended for
any remote speaker connection"

Cool! I just need to get some gold plated connectors and figure out what
"High definition speaker wire" might be, and my old S-40A will sound as good
as my SX-62!

Or, maybe not.

Frank Dresser

On Tue, 17 May 2005 15:06:49 GMT, "Frank Dresser"
wrote:


wrote in message
roups.com...

AT http:/www.kiwa.com/rxtips.html, A nice publication on
"Tips for Imporivng Receiver Performance"
[snip]

Replacing the caps might give better audio, if the caps are causing a
noticable percentage of the distortion. Capacitors aren't perfectly linear
and those nonlineararities will cause distortion. Steve Bench has posted
tests of several caps:

http://members.aol.com/sbench102/caps.html

The Kiwa article doesn't mention detector distortion but it does say:

"High definition speaker wire and gold plated connectors are recommended for
any remote speaker connection"

Cool! I just need to get some gold plated connectors and figure out what
"High definition speaker wire" might be, and my old S-40A will sound as good
as my SX-62!

Or, maybe not.

Frank Dresser


What the heck is ''high-definition speaker wire''? I usually run like
hell from such claims.

Frank Dresser wrote (in part):
Replacing the caps might give better audio, if the caps are causing a
noticable percentage of the distortion. Capacitors aren't perfectly
linear
and those nonlineararities will cause distortion. Steve Bench has
posted
tests of several caps:

http://members.aol.com/sbench102/caps.html

However, the Kiwa article doesn't mention detector distortion, which
can be
a significant source of distortion, at least with diode detectors. The
subject of detector distortion has been beaten to death here and on
other
forums. One post I seem to recall involved some simple mods to a
common
diode detector which significantly reduced distortion but also reduced
output by about 3db.

The Kiwa article doesn't mention detector distortion but it does say:

"High definition speaker wire and gold plated connectors are
recommended for any remote speaker connection"
----------------------------------------------
Thanks for the link showing capacitor distortion.
And I was wondering about detector distortion, and
the distortion caused by crappy audio power ICs.

I will have to wade through ancinet post looking for teh
thread on reducing detector distorion. That strikes me as
a good first step.

The one thing that made me ask quetions was the "high diffiniton...)
comment. That stuff has always reminded me of snake oil.

Terry

Caps 101:
http://my.execpc.com/~endlr/index.html

There are many flavors of ceramic capacitors. The C0G wouldn't show
such distortion.

If you ordered Schottky diodes, you ordered the wrong type. You need PIN
diodes. 1N5767s would do the trick.
It is worthwhile to change the audio coupling caps.

Pete
wrote in message
oups.com...
AT http:/www.kiwa.com/rxtips.html, A nice publication on
"Tips for Imporivng Receiver Performance"
Under the section "audio imporvements" it is suggested that
all of the ceramic capacitors ber rpelaced and polarised
electrolytics be replaced.

Has anyone made these mods and if so, do they really improve
the audio.

Given that everything else on the Kiwa site is topnotch,
I have to at elast think about this fairly inexpensive
upgrade.

His commnets on replacing the Si switching diodes in the 8ve
fitlers with PIN types is "spot on". In high signal situations,
this mod really helps reduce the distortion. I have ordered a
set of schottky do replace those Si diodes in the ceramic fitler
swithces.

I would love to buy an AOR AR7030+, I have a borrowed unit
that I will have to return to it's owner this weekend. But
until I can save $1500, I will have to live with what I
already have.

Terry

Tony Meloche wrote:


"High definition" speaker wire is jargonese for "heavy". Monster
Cable is excellent, but much heavier than it needs to be. Some of the
best audio engineers, while lauding Monster Cable, have also written
that the difference in performance between Monster Cable (12 gauge, if
memory serves) and 14 gauge wire is purely for late-night debates, not
anything truly hearable or usually, even measurable (to a significant
degree).



Another pet term of of super-audiophiles is "oxygen free cable".
Again - any improvement this makes is barely measurable wih lab
equipment, let alone audible.

All just another way to seperate the audiophool from their money.

In the dark ages when we used zip cord for speaker wire, upgrading to
Monster Cable was a good idea. The wire resistance can effect the
speaker damping. Beyond basic Monster cables, the improvement is
suspect at best..