pearl HELP!

[d to the g]

New sk289 installed, back up and running. Whew... it was tough not having my system in full effect the past 4 weeks.

Thanks for the help!!!

 

[h_a]

Honestly I've to say that this pearl is the first I've seen here on DIYAudio that has a blown 2SK389.

The discussion on AnalogAudio refers to another discussion on Audiomap where 1 guy also had a blown 2SK389.

I guess some thousand pearls are done up to today. So I cannot see a reason to deduce a general problem from these 2 cases. However this does not stop the rumor from spreading.

Cheers, Hannes

 

[Fox]

Hannes,

Besides Gerry (PVC at Analog Forum) and Shallbehealed there's me and that makes three (not two)

What could be the problem and could it be fixed by duplicating the source resistor (R25) of the dual JFET, as is suggested at AudioMap.de?

All the best,

Fox

 

[d to the g]

Fox;

Are you referring to the "improved Pearl" thread? My german is so rusty that about all I can make out is that they want to isolate the k170 and have a 50kHz frequency cutoff.

Doug

 

[Fox]

Doug,

No, I have read the modification you are referring to but somehow cannot find it anymore. I belief it was a major modification of the output stage. If you can come up with the hyperlink, please do ...

The modification I mentioned only involves that each halve of the JFET gets it own source resistor. After this modification the Pearl problems did not reappear again.

Again, what I would really like is an explanation as to why the Pearl output stage is prone to malfunctioning. Who of the members on this forum is experienced in this respect?

Best,

Fox