Surprise, surprise!

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Hi,
while tidying up my stashes today I surprisingly came across the devices shown in the pic. These are 16 pc. of 2SK135 and 18 pc. of 2SJ50 and were given to me by an Austrian friend in return for doing some favour to him about three decades ago. I've been searching for them since many years and yet was desperate to have lost them during one of many moves in the recent past.
Due to the screw marks around the holes, they're not new, but have been pulled instead.
Of course never in my remaining life I'll need sixteen pairs of those ancient Hitachi LATFETs, so I'm intending to sell most of them. Prior to this I'd like to examine them in order to avoid selling defective parts. But how to? What are the most important parameters, and how do I measure them?
Best egards!
 

Attachments

  • 20200715_163920_kl.jpg
    20200715_163920_kl.jpg
    99.9 KB · Views: 314
Last edited:
Hi,
which Hafler amplifiers did you refer to? Are there any schematics available?
I've built a pair of ELEKTOR Crescendo amps about 35 years ago, which is still running. They needed service only once in their lifetime when my son overloaded them by connecting too many loudspeakers to them. Consequently, a pair of those power devices was blown in one channel. As I've bought in toto six pairs before I began the built, i.e. I had two spare pairs, I could replace the defective pair and the amp went on running as if nothing had happened. So I now have seventeen pairs plus two 2SJ50's.
Best regards!
 
Last edited:
I've been snapping up the Semetec (or Exicon) equivalent lateral mosfets in TO-3, as I stil have a lot of heat sinks around drilled for TO-3.

One possible project is revamping an old 70's Kenwood receiver. I want the outside looks with the satisfying analog tuning and cool lights, but I feel things can be improved with the preamp and power amp stages. I have no intention of messing with the RF section, though.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.