Lambda C-480M DC regulated power supply.

[Fictitiousfreedom]

Hello my amp obsessed friends, i recently had a friend give me a bunch of cool stuff his engineer grandpa had collected over the years. Among these cool things were a Gibson Vanguard that was found in the dump, an old signal generator, something he says is a long organ chassis but i dont know for sure, it is covered with small transformers and was full of molded blue caps that still seem very functional, a bag of tubes, and this lambda power supply. The tubes were mostly tesla 12AX7s and unmarked what look like 12ax7s. The power supply has 4 RCA blackplate 12AX7s and 5 RCA 6L6GBs, all but one of the 6L6s still test good and sound good but one started to catch fire from the dead spiders and dust that had fallen down into the broken key socket.

My question is, before i start digging in to this for those crazy transformers is it worth it to try and get it working? As much as it pains me to dissect and recycle old works of art i do it regularly because stuff is so expensive now that its the only way i can build anything, id prefer to use all new stuff.

Ive never seen anything like this thing. I have lots of pics but i haven't opened it up at all. The schematic is on the back.

Thanks!

[maxkracht]

I wouldn't feel too bad about scrapping the old stuff if you aren't going to use it in its current form. It's way too easy to collect more junk than you will ever get around to fixing, best to focus on the things you enjoy.

[Phil_S]

I'm a big fan of repurposing stuff like this. You received Telefunken 12AX7s and some RCA, too. If they still have life, these are a true find. (You said "Tesla" but I think you meant Telefunken.)

I'd restore the Gibson if it's doable. As for the power supply, if it's something you want to have and think you will use, why not restore it? IMO, a good project is a good project. In some measure, the journey counts more than the result. YMMV.

[Fictitiousfreedom]

I'm a big fan of repurposing stuff like this. You received Telefunken 12AX7s and some RCA, too. If they still have life, these are a true find. (You said "Tesla" but I think you meant Telefunken.)

I'd restore the Gibson if it's doable. As for the power supply, if it's something you want to have and think you will use, why not restore it? IMO, a good project is a good project. In some measure, the journey counts more than the result. YMMV.

You are exactly right about the Telefunken, they as well as all of the RCAs seem to work great! I had inserted the 6L6GBs, the Telefunkens, the RCA’s, and a handful of the Blue Molded caps from the organ into my already gnarly SLO 40 wattish build and it sounded great, the only thing i didn't leave in it were the 6L6s. I like your attitude. I also wouldn't mind having a regulated 200VDC power supply to test circuits. My friends grandfather got it from a military auction and it may still fire right up. All the fuses are good, the tubes test good ect. I just want to learn more before opening it up.

The Gibson ive already started restoration on. Im making a really accurate layout of it before and then after i change some things but its taking awhile. I also cant get the rectifier tube to not immediately melt down if i turn it on without a limiter. It’s sad to replace all of the cool old CCs but i think that may be next. I already replaced all the filter caps and screen resisters, replaced all of the shielded wire, the heater wiring, the power switching circuit, and any of the Astrons. That will be another thread in the future.

Thanks for your response!

[Stevem]

EI tubes use to be made in the Tesla factory if I am not mistaken.

A very high percentage of them where microphonic from day one out of the box, but they also had very high gain.

I still have a few that I only use in my non combo non high gain amps for recording at times.

I think JJ is now making tubes on most of that old Tesla production machines that where not lost in the Bosina war.

[Fictitiousfreedom]

EI tubes use to be made in the Tesla factory if I am not mistaken.

A very high percentage of them where microphonic from day one out of the box, but they also had very high gain.

I still have a few that I only use in my non combo non high gain amps for recording at times.

I think JJ is now making tubes on most of that old Tesla production machines that where not lost in the Bosina war.

Interesting, thanks for the info. It just honestly amazes me that these tubes all work being as old as they are. The 12ax7 RCAs are possible the best sounding Ive heard, at least in my somewhat limited experience. The fact that the 6l6s work well is even more surprising to me, although the metal can scared me away from them. I had them in my TOS and i heard a little crackle so i tapped the tube with my finger and i immediately felt that scary current tickling feeling in my hand. I took them out immediately, i assume they must need grounded or something but until i dig more on that they can hang out on my shelf with the 1000000 other old tubes people keep giving me.

[didit]

… so i tapped the tube with my finger and i immediately felt that scary current tickling feeling in my hand. I took them out immediately, i assume they must need grounded or something but until i dig more on that they can hang out on my shelf with the 1000000 other old tubes people keep giving me.

Tie pin one to chassis ground all will be fine.

Best ..

[Fictitiousfreedom]

… so i tapped the tube with my finger and i immediately felt that scary current tickling feeling in my hand. I took them out immediately, i assume they must need grounded or something but until i dig more on that they can hang out on my shelf with the 1000000 other old tubes people keep giving me.

Tie pin one to chassis ground all will be fine.

Best ..

Thank you!!!