Replacing 100KAX2 with 100KBX2

svkr2k

Member
2011-12-17 2:07 pm
Hi all,

I have a Kenwood Amplifier KA-32. The volume potentiometer in the amplifier is not working as expected even after lot of cleaning. So, I have decided to replace it with a new one.

The old potentiometer is : 100KBX2 - linear, stereo
The new potentiometer that I have is : 100KAX2 - logarithmic, stereo.

Is it okay to replace the linear pot with a log pot?

Please advice.
Thanks !
 
hi svkr2k
You have already the LOG -version, which will fit. But, as I remember, the old pot has a kontact
at about 50% to do a loudnes. Kenwood did this to make a lin-pot to log-pot and for loudnes.
The log-pot You already got has mybe a poor bal. at low volume and - with the loudnes-kontakt
the input-impedance of the vol-pot is about 50k ohm. Go on solder.....
 

svkr2k

Member
2011-12-17 2:07 pm
Replacing 100KBX2 with 100KAX2 (updated title)

Hi all,
i noticed an error in the title of this thread.

Carification: The pot originally in the amplifier is 100KBX2, which is linear (i hope).

The new pot that I've purchased is 100KAX2, which is log I think.

hope this clarifies.


So ... if i have the log pot instead of linear pot, what would happen?
Hi ingo50, could you please clarify your comment about the pot... sorry, I'm not an expert ...

Thanks,
Raj.
 

Ian Finch

Member
Paid Member
2010-04-11 4:22 am
Coffs Harbour, NSW
......Carification: The pot originally in the amplifier is 100KBX2, which is linear (i hope)......
No, read the replies - volume controls should be Log.
Linear pots are for tone controls, if fitted.

There can be a few types of logarithmic taper pots and this may be be just choosing between two of them. - as with a loudness tap.
However, if you can't see "log" or "audio taper" specified in the catalogue, don't buy it.
 
Last edited:

Ian Finch

Member
Paid Member
2010-04-11 4:22 am
Coffs Harbour, NSW

Ian Finch

Member
Paid Member
2010-04-11 4:22 am
Coffs Harbour, NSW
Am I correct in thinking that A and B for log and lin (or vice versa) swapped over at some point in the past?
I think the Japanese took the "law" into their own hands as far back as the 1960s when it was cussed about a lot in repair shops. Today, every Asian manufacturer has their own version of Japanese convention with only general adherance to those practices. Industrial part manufacturers still seem to keep faith, but then they don't really play in our league with suitable audio replacement parts.

Just for the fun of it, both A & B suffix codes are log. law here but the letters seem only to refer to the connection variations. :scratch1:
 
I have a stereo amplifier which had the same problem with the volume potentiometer. It has also the same reference 100KBX2, also four connections and has even another feature that I like very much: in the back of the double potentiometer and also connected to the spindle, it has a gear which has its teeth engaged in a sphere pressed against them making the "clic-clic-clic" feeling when one turns the potentiometer. The potentiometer was not working properly as in most off the travel there was no sound; sometimes the sound came but was in positions where the volume was too loud. Therefore, was impossible to select a proper volume.


Following the suggestion in the beginning of this thread, I applied on the inside of it (from two openings that it have in its case) a little of contact cleaner (Philips contact cleaner 390CCS), turned several times the spindle to the left and then to the right and allow some time to dry. After that, I tried the amplifier and the potentiometer was now working properly!!!