010309 tube?

[Axtman]

Anybody sean/heard of an 010309 tube? It is a special design 6550 tube. I am working on a Fender 300PS amp and there is a note on the schematic.

[The Dude]

I think the 010309 is an old Tung Sol version of the 6550. What is the note on the schematic?

[Axtman]

Here is the schematic. PS300 Schematic.pdf

[Chuck H]

Those tubes probably existed for a few months. Like the Yamaha Styrofoam trapezoidal speaker in the Fender Bantam Bass. From what I've just read in a few places the Fender PS amps were the most popular avenue for them. Some even speculated they were developed just for that purpose. Which I doubt, but maybe? Anyway... I wouldn't hold out for an NOS set anytime soon.

[Enzo]

I doubt Fender had custom tubes made. 010309 just looks like the Fender part number. Like their drive transformer is 010491 and OT is 011251. I tend to doubt there were tubes marked with it. Selected tubes usually just means someone sat at a tester and checked tubes all day. Looking for who knows what, low noise? Higher gain? Something else? Another note says 700 volts can exist in this circuit, so there is another test there. For some reason they may have specified a certain brand, or specified certain brands it should NOT be.

Just my opinion.

Yamaha had a number of oddly shaped styro speakers. They used them in console home organs. Also in some cabs. They could cram several into one cab and have greater cone area than just using round speakers. I had a dead one in my shop for years. It was a large oval speaker with one "corner" folded inwards. Think like an acoustic guitar, and fold one corner inward it becomes a cutaway acoustic. Sorta. Anyway, that cutout area made room for the expression pedal in some model organ. Our organ guy needed to replace one. He called Yamaha and they sold us the last one they had. I kept the baddie for show and tell. I also ran into those on the old Yamaha rotating speaker cab.

[g1]

A special design 6550 is still a 6550. So I put much more weight on the 'selected' aspect. And I would think selected for the 700V Enzo mentioned.
Someone elsewhere speculated that there could have been patent issues going on at the time and the (short lived) special part # may have been a work-around for the tube manufacturer. Sounds plausible to me.

[Enzo]

Just recalling a Peavey IC. If I recall, it was a CA3094 or something. For use in a power amp they had tested and selected for voltage tolerance. SO the same identical IC had two different Peavey part numbers.

[nevetslab]

I've never seen that PS300 amp before or the schematic. I like the interstage drive xfmr with the 6V6GT driving that primary to push the quad selected 6550 power tubes. Interesting draw of old school and present-day thinking.

[Chuck H]

I've never seen that PS300 amp before or the schematic. I like the interstage drive xfmr with the 6V6GT driving that primary to push the quad selected 6550 power tubes. Interesting draw of old school and present-day thinking.

So interesting to note that Fender was making this beast from about 1970 for a couple of years. Some say they were too far ahead of the curve on this one.