Looking for new project - Suggestions

Anyone know where I can get 4 seeburg 309412 transistors for a TSA-10 Amp?

And do not tell me the Sticky above because no one has them.

I'm willing to bet Ron Rich will probably have some, but they are going to be fairly rare. Germanium power transistors have pretty much gone the way of the dodo bird.

Here's some substitution numbers you can look for, tho:

GE: GE-3
Delco: DS-503
Motorola: HEP 232
RCA: SK 3009
Sylvania: ECG104
Generic number: 2N457A

The Sylvania number crosses over to an NTE104. The RCA crosses to an NTE121. Both are listed as a PNP germanium power transistor. NTE still lists both, so maybe you'll have some luck finding some that way.

-Jim

FWIW: if I needed all four at this point my approach would be to mod the circuit to use a modern silicon transistor. I've done this in 1960's era RCA broadcast equipment when I worked at a co thta catered to stations here in NYC.

In the case of output transistors it is mainly a case of being sure the maximum spec's and basing are the same (the B & E) although these are easily enough changed. For amps the forward bias must be increased to make sure the devices are linear in their operating range. Otherwise you get a grainy distortion (called: crossover) in the output stages.

It took a while, but I found an old set of posts on this topic at the Jukebox list:
http://markmail.org/message/qczvrdzlavm ... te:results

Bear in-mind that this discussion is about a Wurlitzer amp which is has driver transformers. The Seeburg is direct coupled but this can make things a bit easier due to the presence of a bias pot. I have not done this on Seeburg amps since I'm currently only using one TSA series, but on old commercial P.A. amps subbing was straight-forward.

BTW: Seeburg used the same PNP germanium devices on all it's TSa series

Rob-NYC

Jim,
You would win that bet !
I have a few of the correct ones left--marked with the generic number, and a few subs, that are marked with a Japanese number.
Yes, I'll sell them--PM me if you wish to purchase--
Ron Rich

I own the USC1, USC2 and STD3 and they are all in the same room and are nice looking machines. The USC2 (Firestar) was my very first jukebox. Ron and the guys here and on the yahoo board really helped me along in getting my machines up to working condition. I had no prior experience with solid state jukes. We have the two USC's right next to each other, so they conform perfect together. The Sunstar is across the room facing those two. We have wallboxes connected to the two USC's. I will never sell my Firestar, it's my baby. The Bandshell (USC1) is the wifey's, full of tunes that aren't really my taste. The STD3 is loaded with the year-end Top 80 songs from 1974, a great pop music year. Good luck in your choice of machines to keep, but like I said, I love my USC2 !!

I really like the style of the USC-2 and could not pass up an almost complete SPS-2 for $70, both need a lot of work but winter is coming

At this point I am not sure what direction I should take. I could buy the Transistors for the TSA-10 and then find out something else is wrong. I have already re-capped it but I could always sell it for parts since many people can't or won't recap their own stuff and just find a TSA-10 in better condition.

I have a couple of spare TSA10 amps that need redone, but haven't gotten to them yet. Also have a couple of SHP3 amps and some DCC's. Oh, I'll get to them one day, just not right now. Five grandkids keep us pretty busy. Good luck on your projects, I have always enjoyed the challenge.