View Full Version : Blaupunkt "Chicago" stereo console - info please!


Sam Cogley
05-22-2009, 02:01 PM
I found one of these at a yard sale today for $5. No turntable, case has been exposed to a lot of moisture so it's crumbling, and no amp (unless it's hiding in the bottom of the tuner/pre assembly). The cabinet was terrible and my car isn't big enough to carry it, so I pulled the tuner/pre and cut apart the bottom of the case to salvage the drivers - 2 4x6 woofers, 2 3"-ish mids and 2 tweeters. Two of the tubes are American (one GE and one something else), the other three appear to be original but the logo has crumbled into illegibility on all three - it's some sort of "sunburst" design.

If anyone can point me in the direction of useful information or a schematic, I'd greatly appreciate it. I haven't decided if I want to build the tuner/pre into some sort of tube receiver or if I want to use the original drivers and build some sort of table-top radio.

Pictures will follow later this afternoon or over the weekend.

Sam Cogley
05-22-2009, 05:50 PM
It appears to use the same tuner/pre/amp assembly as the "Sultan" tabletop radio: http://www.mbzponton.org/n2awa/radio.html#Blaupunkt_Sultan The tube lists appear to be identical.

cademan
05-22-2009, 07:19 PM
and no amp (unless it's hiding in the bottom of the tuner/pre assembly).

If its the same chassis as the sultan, the amplifier circuit is part of the chassis, and the 6BQ5 is the amplifier output tube.

Sam Cogley
05-22-2009, 07:36 PM
If its the same chassis as the sultan, the amplifier circuit is part of the chassis, and the 6BQ5 is the amplifier output tube.

One output tube for two channels? Interesting. Would there be any way to bypass the output and install some RCA jacks? I'd like to use it as a tuner/pre for my Maggie 8802.

The chassis model number is 10103, if that helps anyone.

cademan
05-22-2009, 09:53 PM
We haven't seen any pictures yet, but from what you have described above, this is not a stereo (2 channel) unit. If the tube layout is the same as the sultan, it has one 6BQ5 output tube for two speakers in mono.

If yours is stereo, a schematic will tell you where you can tap into the preamp outs.

GordonW
05-23-2009, 07:48 AM
Sunburst logo on the tubes could be Valvo...

Regards,
Gordon.

Sam Cogley
05-25-2009, 02:12 AM
The cabinet and the buttons on the unit swear up and down that it's stereo. I'll get pictures up tomorrow - the weekend went crazy on me.

Gordon, you nailed it. I looked up the Valvo logo online, it's a perfect match for the unknown tubes.

g 22000
05-25-2009, 03:09 AM
I have a NordMende "Mikado" that uses a ELL 80 twin output tube. It is 2 EL 95's in 1 tube and it is about the size of a EL 84/6BQ5. Maybe that's what you have too?

Al.

Sam Cogley
05-25-2009, 07:01 PM
The output tube currently installed is a 6BQ5, but the unit swears that it's stereo - there is a "stereo" badge on what's left of the cabinet, there is a "stereo balance" knob on the unit, and two of the buttons say something about "stereo" on them.

Is there a good source for Blaupunkt manuals?

The speakers are connected to some lugs at the very bottom of the unit. My best guess is that the sockets directly above those lugs are also for speakers.

There is a DIN socket on the back of the unit, was that for the turntable? Is there any good way to convert that to RCA (or would it be possible to find an appropriate adapter)?

I have no idea what the brown socket by the model number label is. If anyone knows, please tell me.

What is the "P something" button next to the "AM" selector? It and the AM button have a "stereo" marking printed across them.

Are there any sites dealing in Blaupunkt schematics? I haven't been able to find anything yet.

Skuker
05-25-2009, 07:38 PM
Sam,

I have a Blaupunkt Phiiadelphia thats pretty similar. Looks like the tube layout is a little different but mine runs a SE 6BQ5 setup. Yours does look like its stereo. Don't know if the schematic for mine would help you but I could send you it if you think it would help.

Cheers,
Tony

http://i36.photobucket.com/albums/e25/Skuker/Scan002.jpg

cademan
05-25-2009, 08:11 PM
Sam, yours is stereo! I see two 6GW8 tubes (simular to a 6BQ5), and two speaker output transformers. The "P" is probably for "PHONO".

solidjackson
05-25-2009, 08:14 PM
I have a similar model with a liquor cabinet installed underneath. Even though the radio is no good anymore, The cabinet gets some use.

I'd replace the electrolytic filter caps. The caps failed on mine and burned out the transformer before I could turn it off. The tubes in it were a mix of Valvo (RF) and Siemens (output tubes). The speakers are Blaupunkt Supracoustic... they sound okay, but I haven't replaced the bipolar capacitors yet. If yours had a turntable at one time, it probably would have been a Perpetuum Ebner PE66 idler drive.

Those tone buttons on the front panel can get stuck if the springs get weak... it can be a real pain to get them to reset. The ECL82/6GW8 tube there is a combination triode/ power pentode similar to the EL84 so that's how it gets stereo.

Edit: Yeah, the DIN input was for the turntable. I was planning to wire up an adapter for RCA input before it went south.

cademan
05-25-2009, 08:23 PM
The ECL82/6GW8 tube there is a combination triode/ power pentode similar to the EL84 so that's how it gets stereo.


The european designation for the 6GW8, is actually a ECL86. If you look closely, it has two 6GW8 tubes. These are like the 6BM8 tube with a triode and pentode in the same envelope. The triode section is like one half of a 12AX7/12AU7 tube.

Sam Cogley
05-25-2009, 08:33 PM
Thanks for the info, guys! Cade, one output tube is a 6BQ5 (Westie) and the other is a 6GW8 (GE) - probably someone's idea of a "good enough" swap.

One little bit of annoying weirdness - there are two tuning needles, one driven by each knob (FM and AM/SW). The FM needle refuses to stay aligned properly, instead twisting the tuning string until it's pointed at the back of the case.

Anyone have an idea why the "P" and "AM" buttons say "stereo" across the two of them? I could see it on the "AM" and "FM" buttons if it was made during that aborted simulcast stereo idea, but the location of that marking seems bizzare.

I understand that the "Hi-Fi", "Solo" and "Sonor" buttons are tone controls, but what exactly do they do and what does each marking mean)?

Skuker, even though the tube layout looks a bit different, that Philadelphia schematic might point me in the right direction for some of my modifications. If you could scan it, it would be a great help.

Current ideas rattling around in my mind - build a small cabinet for the head unit and speakers with an RCA input for the TT along with a switch to use the internal amplifier and speakers, or my Maggie 8802 and external speakers. If I can figure out some way to wire it in, I have a tube FM MPX adapter salvaged from the same console that provided my 8802.

I think a complete recap is in order before I even attempt to turn it on.

Where did Blaupunkt fit into the hierarchy of European audio manufacturers in that era? Good, bad, middling or a mix thereof? I know they've built some nice car stereo equipment in the solid-state era, including factory equipment for Porsche.

I'll get a picture of the speakers up later tonight.

cademan
05-25-2009, 08:41 PM
Just so you know, the 6BQ5 and the 6GW8 are not inter-changeable. You need to find out which tube actually goes there before attempting to fire it up.

Tom Bavis
05-25-2009, 08:48 PM
I though that the tubes might be a clue, so I checked at Radiomusem.org. As bizzare as it may seem, Blaupunkt made 30 different models using both an EL84 (6BQ5) and an ECL86 (6GW8). There's no "Chicago" model listed - that name may have only been used in the US. If there's a model number, it will maybe cross to a Euro version.

Sam Cogley
05-25-2009, 08:48 PM
Hopefully it has some tube markings by the sockets. Would they have done something so odd as to use two different output tubes? (Edit: I guess Tom just answered that question. Weird.)

Anyone else notice the very unusual tuning arrangement? The dials read backwards from the highest frequency/amplitude to the lowest.

Tom, I'll see what I can find at Radiomuseum, though I don't have a membership there. I was there earlier today looking for info on the Heathkit OL-1 o-scope I bought today. After some searching, it appears that the 10103 chassis was also used in a "Verona" model.

cooljjay
05-25-2009, 09:02 PM
I am just going to tell you its not worth restoring or trying to make into a stand alone unit. This guys are complicated and are we sure its a 120v set and not 220v? if its still 220v you need a converter before you can do anything with it. What you do is sell the knobs on the bay and you'll get 5 times your money back. I had one that I just decided to toss out because the particleboard was getting everywhere, I sold the knobs a few tubes screws, light bulbs and made like 75$ of the chassis. I have a nice 220v set in the bedroom that needs a converter.

Sam Cogley
05-25-2009, 10:27 PM
Blaupunkt seemed to name their models appropriately to the intended market - a "Chicago" model would almost certainly be something intended to be sold in the US...and therefore 110v (and I know it's a Chicago, I still have the speaker baffle with the badges attached). As for the rest, it really isn't about value or effort - I want to do something crazy and entertaining that will look cool when I'm done. Trying to figure this out will give me the chance to learn more about the mighty vacuum tube.

cademan
05-25-2009, 10:48 PM
I have never seen a unit use both the 6BQ5 and the 6GW8, but tom could be right! That's why you, or someone here, needs to get ahold of a schematic. It certainly has piqued my curiosity!

I have always wanted a german grundig, but could never find one, and yes, I too, noticed how the frequency dial is reversed. Quite unique to us americans!

Sam Cogley
05-25-2009, 11:00 PM
I've been sent a schematic of a slightly later 42953 Blaupunkt chassis - sure enough, it uses an EL84 and an ECL86 as outputs. On that model, the triode side of the ECL86 feeds straight into the balance pot and the treble tone control.

I may have found a source for the 10103 schematic, I sent an email to a site selling one for that number in a "Verona" model.

Update: last night I cleaned some of the massive layer of dirt off of the circuit board. Sure enough, next to the output sockets are markings for an EL84 and ECL86.

BwanaJim
05-25-2009, 11:11 PM
I'm Jealous, I restore old travel trailers like Airstream, Curtis wright, Bolus and Kozy Koach, a unit like that would ROCK in one of my Restoration's.
Gott'a love the short wave!!!!!!!

levlhed
05-26-2009, 09:32 AM
I *just* took one of these apart this weekend. Inherited it from in-laws, but never did anything with it. I yanked it's guts for a friend of mine that does tube projects and put the (huge) cabinet out on the street for the dump truck guys.
Beautiful cabinet, but no room for it @ my house and no ambition/skills to make it work.
http://www.flickr.com/photos/81998277@N00/sets/72157617345234911/

Sam Cogley
05-29-2009, 01:52 AM
I finally heard back from the seller, the "Verona" model with the same chassis number is indeed a tube-type radio. I ordered the schematic, hopefully it's the same design in a different model box.

An interesting discovery - I started taking the speaker baffles apart so I could junk the old, trashed materials. The tweeters (marked LSH 85) looked rather unusual, so I ran them through Google - it turns out they're electrostats, made by Isophon!

http://www.audiocircuit.com/index.php?c=ISA&m=LSH-85

The page for the LSH 75 has more info: http://www.audiocircuit.com/index.php?c=ISA&m=LSH-75

The indicator problem has been fixed - I was able to get the string off of one tensioning pulley, after that I could take each side of the pointer off of the string separately and rotate the pointer on the string.

TheRed1
05-29-2009, 03:37 PM
I have a schematic of the New Yorker model from 1961 which was a two chassis model like yours was. It appears that the lone EL84 in the tuner was used in the FM AF amp/cathode follower stage. The amp section would have contained a further 4 EL84s used properly as output tubes - hence stereo.

The tube compliment of the New Yorker's tuner is: ECC85, EF89 (2), ECH81, EABC80 and the EL84. It does not have an EM84 as listed in the old add you linked to.

Sam Cogley
05-30-2009, 10:13 AM
Red, as I discovered during the back-and-forth in this thread, it's a single-chassis model with two SE output tubes - EL84 and ECL86. Once I have the schematic in hand, I intend to wire in RCA outputs so I can use it to drive my 8802 amp. The speakers in the cabinet were connected directly to the tuner/pre/amp unit.

With a bit of luck I can complete the stereo wiring by installing an old tube MPX adapter I have laying around...

Sam Cogley
05-30-2009, 01:03 PM
Sam,

I have a Blaupunkt Phiiadelphia thats pretty similar. Looks like the tube layout is a little different but mine runs a SE 6BQ5 setup. Yours does look like its stereo. Don't know if the schematic for mine would help you but I could send you it if you think it would help.

Cheers,
Tony

http://i36.photobucket.com/albums/e25/Skuker/Scan002.jpg

Based on your picture here, and what I've found on a schematic for yet another Blaupunkt that solidjackson sent my way, I've concluded that the DIN plug is for a tape loop and the weird-looking DIN-sized thing is for the turntable. I have no idea where I might acquire one of those plugs, I'd probably be better off trying to find another female DIN to replace the odd socket. I'll get this thing figured out, somehow...

The Philadelphia has two EL84s, and it seems to have another tube taking the place of the triode side of the ECL86. Maybe a more sensible if less compact layout.

persil
05-30-2009, 02:57 PM
Based on your picture here, and what I've found on a schematic for yet another Blaupunkt that solidjackson sent my way, I've concluded that the DIN plug is for a tape loop and the weird-looking DIN-sized thing is for the turntable. I have no idea where I might acquire one of those plugs, I'd probably be better off trying to find another female DIN to replace the odd socket. I'll get this thing figured out, somehow...

The Philadelphia has two EL84s, and it seems to have another tube taking the place of the triode side of the ECL86. Maybe a more sensible if less compact layout.

Those din plugs are available in the uk from "Maplin" That plug was standard in Europe for Phono input.
Blaupunkt products are very common in the UK, same chassis - different cabinates, it seems us brits wanted a combined "radiogram" cocktail cabinate. (we drink a lot!).
The elecrostactic tweeters were common in the better hifi units in the 60s in Europe.

Sam Cogley
05-30-2009, 08:20 PM
I haven't had any luck finding that weird DIN phono connector on their site. I wonder if there is a US source for them - if I have to pay $20 to ship a $5 connector, I might as well just replace the weird socket with a regular 5-pin DIN socket.

The good news is that the 2-pin DIN speaker plugs seem to be readily available over here.

goraman
05-30-2009, 09:38 PM
Also looks like the wireing is Italian ,Spegetti that is.

Sam Cogley
05-31-2009, 11:50 AM
Most of that ugly wiring is where I cut the speaker, antenna and power cords to get the head out of the cabinet. The pieces are still hanging there.

Sam Cogley
06-23-2009, 12:45 PM
I have a thread in the "Digital Docs" forum looking for the schematic. I know it exists in the Sam's folders, their webpage has it available, though the $15 shipping is insane.

steerpike2
09-08-2009, 07:44 PM
The matter of the STEREO markings on the buttons: Since the tuner itself isn't stereo (unless of the type where one channel on FM, one on AM), maybe it has something to do with switching the phono input between stereo and mono?

Or - another thought - maybe it was meant to take an outboard FM MPX decoder, linked through one of those unknown sockets on the back? Pushing the two buttons would retrieve audio from that socket instead of the internal discriminator.

That plug you are looking for ISN'T a DIN plug. It's similar, but not compatible. Right now the name of them escapes me, I have not seen them sold anywhere except occasional NOS.

I have a few 60's tuners that go high frequency on the left, low on the right.

It's very pretty - would look great if tidied up and put in a handsome cabinet!