Telefunken console

[Jeff Kempin]

I just inherited a Telefunken Concerto 5296 wk stereo. It was my grandmothers and I remember seeing this all the time as a kid. Now, 30 years after she died, I got it from my aunt who had it stored in her basement. Overall, the cabinet is in good shape. The finish on top is starting to crack a little, but otherwise, it's still solid. The radio is still there, but sadly the turntable is not. Neither is the hinge that held the lid open or the nameplate on the front. I have no idea where to find a replacement for these items, short of coming across another one looking to be parted out. If anyone has a lead on a turntable for this, let me know. This originally came with a TW504C model # turntable, but anything close to that would work, I assume.

I know these are not worth much, but to me, the sentimental value is off the charts. The radio works, but it has no antenna and the dials are a bit stiff and I don't want to force anything. I don't have any experience with tube sets, but if anyone can offer any advice on what to do to get it working properly again, it would be a great help. I've included pictures of the guts of the radio and it looks like a nest of wires and tubes, so I'm hesitant to touch anything.

I have done some research online and there isn't a whole lot about Telefunkens out there. I'm not afraid to handle old electronics, but I just don't have the knowledge on them.

Thanks in advance for your help.

 

[dshoaf]

Yep, these are tough decisions. I, too, was recently given a Blaupunkt console similar to yours. With the sentimental value far out-weighing eveything else, this is one of those rare moments when you can preserve some of the memories of your family into something tangible.

As for how to do this, there are some tube-amp basic priorities you'll need to observe, assuming that you want to actually get it running as a daily driver:

- The power supply must be able to operate safely.

- The electrolytic cap must be replaced. The electrolyte paste will dry up and caps with high voltage turn into resistors, generate heat, and in worse cases, will explode from the pressure created by the heat. They gotta go.

- Resistors will likely drift out of spec after you get it running. Be prepared to go back into it after a few months of daily use. Its normal but tedious to deal with.

- All operating voltage must be in spec for it to operate as it should.

- You'll need to plan on adapting the connections to something we use today.

Otherwise, it can be a lot of fun from a new-found hobby. All this, though, and you'll have something you can show your kids and grandkids about what it was like to live in the post-WWII era.

Cheers,

David

 

[Hull Rust]

Jeff, there is a lot of information out there on your Telefunken.

You'll need the SAMs for it.

Here:

https://www.samswebsite.com/en/photofact/search/index/samsid/634_13

Google search results:

https://www.google.com/?gws_rd=ssl#q=Telefunken+Concerto+5296wk

Best to have someone work on it who knows what they are doing. If you share where you are located there may be an AKer who can help you out. If not, there may be a local tech who can service it for you.

I'm sure more folks here will chime in with ideas.

Good luck, looks very cool.

 

[JURB]

"I know these are not worth much, but..."

That thing is solid f****ng gold. Not audio wise, antique wise. People are fimnally waking up and NOT sending this stuff to the dumpster. (or skip if you are across the pond)

THEY ARE NOT MAKING ANY MORE.

If youy are not in to electronics, learn SAFETY first if you decie to work on it yourself. Tube units have voltages that can electricute you. A solid state receiver on the other hand, you can let a five year old kid work opn it and not worry too much. The nly placew that'll killya is the AC mains. In a tube unit the source is usually over 100 volts at least, and with a power amp even more with some current behind it.

But if you are iunterested in doing it, get the priont and go ahead. Just be careful and let's not have your olady on here posting that you are dead.

One nice thing about tubes though, if you make a mistake and short saomething out it usually means nothing. Tubes and their circuitry are very forgiving.


Well there are exceptions, like 200 watt amps etc. that have REAL current behind them, but this ain't that.

 

[Jeff Kempin]

I downloaded the SAM for it and I did google it and read a lot of the hits I got, but I know I need to do more. This isn't necessarily going to be a daily driver type of unit, but I would like to have everything work and to try to put it back to the way it originally was. I can tune the radio in on some stronger stations and the speakers all sound okay.
Stereo repair isn't my hobby, but I'm mechanically inclined and I can figure stuff out if I'm pointed in the right direction. Obviously, I'm going to have to remove the unit from the chassis to work on it, because there is no room in there to see or work on it properly.
I'm from Oak Lawn, IL which is a suburb on the southwest side of Chicago. If anyone is local, I'd be happy to hear from you.

This will be an ongoing project that will take time. Thank you all for your responses so far.

 

[RWood]

I agree it's worth putting effort into this console but it will be a challenging 'first project'. If you could put it on hold until you've done some easier work (Magnavox console / Zenith / RCA / Motorola or the like) then you'll hone your skills a bit by the time you are ready for the Tele.

I've done two Telefunkens, both stereo receivers from consoles. Both came out really well and the owners use them daily. A few things I will add:

-take as many digital pics as you can, then take some more from every angle. This includes before you remove it from the cabinet, and the various connectors. Trust me, you will not remember how it was hooked up! Set aside a dedicated folder or thumb drive for the pics, and put the best ones out on a sharing site like photobucket for when you need to ask questions here.

- The electrolytic caps in the power supply all need to be redone, as David said. These are usually 100uF and 50uF caps in a can, coming from the rectifier with a large dropping resistor between them. Caps are much smaller now so your options will include mounting the new ones on terminal strips below deck, restuffing the existing cans, or buying replacement cans. This last option is the most expensive.

-There are other electrolytics in the crossover/tone compensation network which do not necessarily need to be replaced. They see low voltage and if they leak they won't damage anything. These are the ones that are between the output transformers and the speaker connectors. Often 160uF or 100uF or so.

- the rectifier should be replaced with a modern silicon full wave bridge. Easy to do and they take up far less space than the existing 'tubular unit'. I have a good pic of one of the ones I did, if you need it.

- the paper coupling caps should, ideally, all get replaced, value-for-value, with modern film caps. Thankfully, all the values are easily and inexpensively obtained. This is probably the most daunting task, though, since the way these chassis were built - in layers - some of the caps are now buried under other components. If you want to start with just a few of these, do the final couplers that go to the grids of the power tubes. These are critical because they block dc voltage from the input of the power tubes and enable them to be biased correctly.

The remaining electrolytics (one or two in the power supply and especially the one from the power tubes to ground) should be replaced. The 'bypass caps' from the power tubes can be difficult to access but it is critical that they be done.

That is it in a nutshell as far as the main rework. Yes, checking resistor values is good but I've found that the carbon film resistors in a lot of these units are still okay. Testing and replacing tubes might be needed, but it's amazing how well these things run on marginally good tubes.

You mention that you are mechanically inclined, so that is a big plus. If you also have a mind for troubleshooting, that helps. Willing to learn how to read a schematic? Almost a prerequisite, at least as far as understanding what does what in the circuits. But you can learn as you go, because most of the above is replacing what was in there with new stuff of the same value.

Let us know what you decide to do, and how we can help.


RWood

 

[Jeff Kempin]

That was very informative. Thank you! I'll post my progress. I have a lot of OT at work, so it will be awhile. Stay tuned.

 

[Jeff Kempin]

Okay, I have finally removed the chassis from the cabinet of my Concerto. I have posted some pics. I'm just looking to restore this thing back to full working condition. I haven't cleaned it yet, so I know it looks dirty. I just wanted to show you what it looked like straight out of the cabinet. THere aren't a whole lot of paper capacitors on this thing, at least not on top. THere are more on the bottom side, and I plan on replacing them all. The flat silver case on the bottom is the rectifier, according to the SAM, and that will get replaced also. Is there anything else I need to do? In the second picture, there are a
several small paper caps going around what looks like a dial or small switch. Do those need replacing, as they look kind of hard to get to.

 

[Jeff Kempin]

Here are a few more. The multiplex FM adapter does not match what is on the SAM, but after opening it, it looks pretty clean. I don't think I need to do anything to it.
As for the tubes, how can I tell what is good and what is bad. Just plug it in and see what lights up? They are all original but they can't all still be good, right?

 

[Omegaman]

I have this Telefunken changer available. It is a TW501 and it works very well

Also has the Telefunken badge

PM me if interested

http://www.audiokarma.org/forums/showthread.php?t=612183

 

[s-petersen]

Here are a few more. The multiplex FM adapter does not match what is on the SAM, but after opening it, it looks pretty clean. I don't think I need to do anything to it.
As for the tubes, how can I tell what is good and what is bad. Just plug it in and see what lights up? They are all original but they can't all still be good, right?

The tubes will likely be fine,The can cap and orange electrolytics should be replaced

 

[s-petersen]

Okay, I have finally removed the chassis from the cabinet of my Concerto. I have posted some pics. I'm just looking to restore this thing back to full working condition. I haven't cleaned it yet, so I know it looks dirty. I just wanted to show you what it looked like straight out of the cabinet. THere aren't a whole lot of paper capacitors on this thing, at least not on top. THere are more on the bottom side, and I plan on replacing them all. The flat silver case on the bottom is the rectifier, according to the SAM, and that will get replaced also. Is there anything else I need to do? In the second picture, there are a
several small paper caps going around what looks like a dial or small switch. Do those need replacing, as they look kind of hard to get to.

The red and yellow plastic covered caps are electrolytics,and should be replaced.

 

[Jeff Kempin]

The flat orange round ones too? The yellow metal caps?

 

[toxcrusadr]

Any caps wrapped in cardboard or wax-coated paper, definitely replace. The yellow metal one I see looks like an electrolytic (has +/- on it) so it should be replaced.

The flat, round orange ones are mica insulated and will not drift and fail. Also they are in the tuning circuits (very low capacitance, pf) and changing them will require a complete realignment, which is bad enough for AM and nearly impossible for FM w/o fancy gear. So leave those.

This can't be a Telefunken, the dial cord rigging is way to simple.

 

[Jeff Kempin]

Im sorry for the dumb questions. I'm new to this so I'm relying on the knowledge of this board. I'll be making a list of caps to order and will start cleaning it.

 

[Son-of-Vere]

Some of those crispy resistors should be checked/replaced.

 

[Jeff Kempin]

I'm trying to place an order for new caps and electrolytics and I'm having a hard time finding exact match replacements for some of them. So my question is: is it more important to match the capacitance or the voltage? If I need a cap with a .01 capacitance and a 250 volt rating and all I can find from a vendor are with a higher voltage, will that be acceptable? The voltage rating just means that is the maximim it can safely handle, correct? So if I put a .01, 500V cap in there, that just means that it can handle the higher voltage, not that that's what is actually going through it, right?

I expected some problems with trying to match new caps with 50+ year old ones, but for every one I can find, there are 2-3 that I can't. I want to keep it as close as possible, naturally, but what is my leeway?

 

[Dandy]

For the caps, get as close as possible on value (uF, pF or whatever) and same or higher on voltage.

 

[Panamafred]

Are you using mouser.com? I was pretty lucky with finding all of the right values, you can sort out just radial capacitors and then further narrow it down by their UF value and then find proper voltage.

Over in my thread I was informed that 50uf can be switched to 47 uf, that may help. I know they standardized values after our consoles were built... big fun! It took me a few hours to put my list together as well.

Good luck!

 

[Jeff Kempin]

Ok, that'll make it easier. So far, I have 6 electrolytic and 24 regular caps to replace, plus the rectifier and a resistor plus a new power cord. So it's gonna be a big order. I haven't even dug into the rf adaptor or the can on the multiplex adaptor, but this will give me a good start. One thing at a time, you know?

Thanks guys!