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Confusing tube compliment

sloober

sloober

Super Member
Just picked up a Blaupunkt Chicago Stereo console. Is a cute little thing. I opened the rear panel and there are indeed twin output transformers, and 3 drivers per side including electrostatic tweeters. But the tubes have me confused. I would have thought it was a single ended amp with a pair of output tubes. Here is what it has as per the rear panel markings.
EF89-Bugle Boy
EABC80
ECH81 -Valvo
EL84- Valvo
EL86-Bugle Boy
ECC85- Siemens
EM87 EYE TUBE

What is going on here?
 
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sloober said:
Just picked up a Blaupunkt Chicago Stereo console. Is a cute little thing. I opened the rear panel and there are indeed twin output transformers, and 3 drivers per side including electrostatic tweeters. But the tubes have me confused. I would have thought it was a single ended amp with a pair of output tubes. Here is what it has as per the rear panel markings.
EF89-Bugle Boy
EABC80
ECH81 -Valvo
EL84- Valvo
EL86-Bugle Boy
ECC85- Siemens
EM87 EYE TUBE

What is going on here?
Click to expand...

There's no ELL80 dual pentode output? That's what's in my stereo Blaupunkt.
 
I dunno, but the rear panel is pretty clear gloss black with gold lettering and diagram. I just checked and it appears to have all the same tubes installed. John
 
That's what I thought. But, one power transformer, 2 speaker transformers with leads going to each side. Stereo on the front. Connectors on rear for external R L speakers.
 
sloober said:
That's what I thought. But, one power transformer, 2 speaker transformers with leads going to each side. Stereo on the front. Connectors on rear for external R L speakers.
Click to expand...

Trace what the hot side of the output transformers go to.

Is there a second 6BQ5, with the legend missing the "X2" and that second EL84 is missing from the set, leaving an empty socket?

But seriously, hold all the tubes in your hand, read the printing on the glass. Count the sockets. Unless there is a separate amplified speaker cabinet or a solid-state final (which does happen on some German sets) then what you describe is not possible.
 
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I will have to see. I am bringing it up slowly. I did check the tubes by pulling them out.
Somehow, this is stereo. I will get photos up tomorrow night. Now we are both confused!
 
sloober said:
I will have to see. I am bringing it up slowly. I did check the tubes by pulling them out.
Somehow, this is stereo. I will get photos up tomorrow night. Now we are both confused!
Click to expand...

This is getting interesting. Please take pictures!

If the set is working, run it a bit and see what tubes get hottest - the power tubes.
 
Its up to 50v...dial light is on and tubes are getting warm. Eye tube is glowing. The ECL86 and EL84 are right next to each other and look similar. On the other german radio I have here, it is sililar, but only one tube in that location and one output transformer.
 
Isn't the EL-86 the other output tube? There was another German set on the tube forum recently with factory unmatched output tubes.

edit: now I see, it's an ECL-86 and melodymaster beat me to it.
 
That's a cheaper solution than my Blaupunkt. The ELL80 fetches $150 or more, it is rare rare. And inevitably one of mine fell off the bench and broke.
 
Scuzzer said:
Isn't the EL-86 the other output tube? There was another German set on the tube forum recently with factory unmatched output tubes.

edit: now I see, it's an ECL-86 and melodymaster beat me to it.
Click to expand...

Sloober said it was an EL86, (6CW5) which didn't make sense. It wasn't until he correctly said in Post #11 that it was an ECL86 that the answer popped up.. Numbers ARE important.
 
I am waiting for a box of caps for the Tonfunk rebuild. As long as this makes some sound, I will do the same. This has a circuit board on top of the output transformers to drive the electrostatic tweets. There is also another crossover board in the bottom of the cabinet for each channel.
 
Alas...the ECL86! does not light up...but getting great sound from the other side!

Tests OK and lights on the tester, so it's a dirty socket or something worse. It looks fixable I think. John
 
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