ELL80's from Lorenz & ITT?

[Ziradog]

My Fisher Allegro system X19 amp came with mostly Fisher-branded tubes, but one ELL80 output tube was branded Lorenz & the other was branded ITT. Both say Made In Germany & the look very similar. I know Lorenz was a real tube company, did ITT make tubes in Germany or are these rebranded? Are Lorenz or ITT tubes generally good sounding?

Fleabay shows tubes made (or at least branded by) RCA, Brimar, Valvo, Sylvania, Telefunken, etc. Most are also of German manufacture. So, if I decide to go looking for a matched set, and suggestions? This is a pretty low-end amp so I don't want to break the bank but I would like to give it a decent set of matched tubes at some point.

Thanks!

 

[sKiZo]

Both good tubes ... Lorenz was acquired by ITT eventually, so I suppose you could call them a matched set ... <G>

Those might even be original to the set ... Fisher was known to mix and match with what was in stock at build time.

 

[jaymanaa]

Yes, I agree, and they seem to last forever, or at least in Fisher's hybrid designs that used this tube to drive the germanium output devices via inter-stage transformers did. I thought they were almost all gone, as there was no sub, and no modern manufacturer ever picked them up (maybe because they don't wear out). You can also search 6HU8 which is the American number for this really cool tube.

 

[buglegirl]

Hiya,

Essentially two EL95's in a single bottle. A pretty cool and hard to find tube.

They do last a long time and you could run them a bit "Cooler" on the bias to save life.

Frannie

 

[sKiZo]

Took a quick peek around, and although maybe rare, they don't seem to be all that expensive either. Not much demand I guess ...

 

[jaymanaa]

About 35 each last time I checked and more for fancy ones. There's a pair in BT for 70 bucks I think. No Afill.

 

[kvflyer]

About 35 each last time I checked and more for fancy ones. There's a pair in BT for 70 bucks I think. No Afill.

Interesting. I have most audio tubes but not these. Maybe I should add them to the inventory. Who know, maybe one of these Fishers will show up here. NOT!

Cheers Mate!

 

[larryderouin]

I've got 2 Custom Electra hybrid chassis' and 1 Futura hybrid Chassis (1 console each from 65). with about 8-10 spare tubes all from FISHER's. 3 are FISHER Branded, and the rest Lorenz and ITT with a Valvo thrown in for good measure. Plus a quad of Zenith branded which look like ITT's. They all sound very much the same. The FISHER Branded have the same plate structure as the ITT's IIRC. All show low (below minimum's) on emissions, but testing for GM all rate about 80%. You can make an adapter to run 2 EL-95's instead of the 6HU8/ELL80. I've got a picture of one somewhere, but haven't done anything about it yet.

 

[jaymanaa]

I've got 2 Custom Electra hybrid chassis' and 1 Futura hybrid Chassis (1 console each from 65). with about 8-10 spare tubes all from FISHER's. 3 are FISHER Branded, and the rest Lorenz and ITT with a Valvo thrown in for good measure. Plus a quad of Zenith branded which look like ITT's. They all sound very much the same. The FISHER Branded have the same plate structure as the ITT's IIRC. All show low (below minimum's) on emissions, but testing for GM all rate about 80%. You can make an adapter to run 2 EL-95's instead of the 6HU8/ELL80. I've got a picture of one somewhere, but haven't done anything about it yet.

Those things made some serious power for the day, 120watts per IIRC. That was the one with adjustable emitter resistors. Problem was, they blew up sometimes, and when they did, they took that interstage TX which is now unobtainable I'm sure. I have a few of them stashed away, they are great sounding amps IMHO. I'm going to figure out how to change the devices to silicon which I think will keep them from blowing up. Germanium was famous for being leaky wasn't it?

 

[larryderouin]

Leaky and sensitive to voltage changes. Go over to the FISHER Forum and search FRED SOOP's posts. He's got a couple of 600-T's that he's doing a complete re-design and build on. He outlined on one or more posts how to change them over to Silicon, along with BIAS circuit changes. Luckily mine are all running well right now. Not 120Watts. Maybe 50W IHF total for the 49A (4 transistors) and 65 for the 59A (8 transistors).

The problem was the pots were trash from the Git go. Which is why FISHER switched to the 1n2326 temp compensating diode and had units brought in to the shops and retrofitted. I've seen a lot of the amps and have yetto find one with the 4 pots on it. I run mine once a week abuout 8 hours to keep the caps up and run off the humidity inside. Put some good speakers on them and they really shine.