[Kenwood] Headphone impedance

[ken.d.brown at hawaiiantel.net]

Hi all,

     I have a new TS-590SG which I really like. I find the headphone 
volume, relative to the speaker volume, to be lacking. In other words 
when I put the cans on I always have to turn up the AF gain to get the 
audio level up to the same as had been coming out of the speaker. I'm 
using a Kenwood SP-43 speaker. I'm using some Koss QZ-99 headphones, but 
they don't have the original drivers in them. The original drivers 
failed and I put some in that claim to be 30 Ohm impedance. I see on the 
schematic that the headphone jack has 120 Ohm resistors in series with 
each of the hot (tip and ring) leads. So I presume that I would get the 
highest audio power delivered to the headphones if they were about 120 
Ohms. I have tried to find specifications for Kenwood communications 
headset to no avail yet. I wonder if they are 120 Ohms? Can someone tell 
me what Kenwood's headphones impedance spec is? Or what kind of phones 
do you use with your TS-590 or other Kenwood HF rig?

Thanks,

Ken N6KB