I'm searching for a replacement balance pot for an old Harman Kardon amp -
a PM645. It's an Alps 50k MN series - these are the type where the first
half of the travel doesn't effect the level but the second half does (in
other words no attenuation to either channel at the central indent), so a
special for balance use. Other Japanese amps of the period used them too.
The mechanical construction is standard dual gang 17mm body type with 6mm
shaft, and as it's PCB mounting a direct replacement would be nice.

The HK part number is 5113-50399122, but HK say they have no spares for
this amp. Alps don't appear to list this pot either. And I'm worn out
Googling. ;-)

--
*Many hamsters only blink one eye at a time *

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote:

I'm searching for a replacement balance pot for an old Harman Kardon amp -
a PM645. It's an Alps 50k MN series - these are the type where the first
half of the travel doesn't effect the level but the second half does (in
other words no attenuation to either channel at the central indent), so a
special for balance use. Other Japanese amps of the period used them too.
The mechanical construction is standard dual gang 17mm body type with 6mm
shaft, and as it's PCB mounting a direct replacement would be nice.

The HK part number is 5113-50399122, but HK say they have no spares for
this amp. Alps don't appear to list this pot either. And I'm worn out
Googling. ;-)

If you can get the right type of log-antilog that'll do just as well nearly.
Failing that try 'slugging'a linear pot with a couple of resistors to bend the
law.

Graham

In article , Eeyore
wrote:


"Dave Plowman (News)" wrote:

I'm searching for a replacement balance pot for an old Harman Kardon
amp - a PM645. It's an Alps 50k MN series - these are the type where
the first half of the travel doesn't effect the level but the second
half does (in other words no attenuation to either channel at the
central indent), so a special for balance use. Other Japanese amps of
the period used them too. The mechanical construction is standard dual
gang 17mm body type with 6mm shaft, and as it's PCB mounting a direct
replacement would be nice.

The HK part number is 5113-50399122, but HK say they have no spares
for this amp. Alps don't appear to list this pot either. And I'm worn
out Googling. ;-)

If you can get the right type of log-antilog that'll do just as well
nearly.

These also are becoming hard to find - at least with my normal suppliers.
Especially with the proviso I'd like an identical one physically due to
the mounting arrangements.

Failing that try 'slugging'a linear pot with a couple of
resistors to bend the law.

Yes I'd thought of that as I have suitable linear pots 'in stock'.
However, both these approaches reduce the overall gain of the chain.

Graham

--
*Why is the word abbreviation so long?

Dave Plowman London SW
To e-mail, change noise into sound.

On Mon, 26 Feb 2007 18:40:39 +0000 (GMT), "Dave Plowman (News)"
wrote:

I'm searching for a replacement balance pot for an old Harman Kardon
amp -
a PM645. It's an Alps 50k MN series - these are the type where the
first
half of the travel doesn't effect the level but the second half does
(in
other words no attenuation to either channel at the central indent),
so a
special for balance use. Other Japanese amps of the period used them
too.
The mechanical construction is standard dual gang 17mm body type with
6mm
shaft, and as it's PCB mounting a direct replacement would be nice.

The HK part number is 5113-50399122, but HK say they have no spares
for
this amp. Alps don't appear to list this pot either. And I'm worn out
Googling. ;-)


You might find somethiong on Ebay.

Eg. Noble used to make an equivalent of the Alps Black Beauty or Blue
Velvet pots. Try this link
http://cgi.ebay.com/50-KOhm-Noble-au...QQcmdZViewItem