[Elecraft] Yamaha CM500 Headset

[Don Wilhelm]

Jamie,

Without regard to what that ad states, the CM500 has an electret element 
- NOT a dynamic element.
I don't know about the Koss SB40, I could not find any reliable data, 
but they seem to be universally advertized as "computer headset" and 
since most if not all computer microphones are electret types, I suspect 
the SB40 is also electret type.

When you get yours, see if it works without bias - if so, it must be a 
dynamic type, but if it needs bias, it is an electret.

73,
Don W3FPR

On 2/18/2012 1:10 PM, Jaime P.Ullivarri wrote:
> Hello,
> I have a Yamaha CM500 and looks exactly as Koss SB40 but this one in EUis
> easy to get from Amazon and cheaper.
> Both headphones have the same characteristics 120 ohm, 96 dB etc. and both
> have Dynamic Mic.
> <http://www.shopping.com/xSBS-Koss-Koss-SB-40-Headset-ear-cup-Yamaha-Yamaha-CM500-Headset-with-Built-In-Microphone~PRDLT-21312157-30843141>
>
> Well I have ordered a Koss SB40 and will see.
> 73.
> Jaime, EA6NB.
>