ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Beolit 600:
When I got it the speaker was locked, due to dislocated magnet. Dial-cord was missing. Dial was discoloured due to heavy corroded indicator balls. And some other minor flaws. Speaker was dis-assembled re glued. Dial was cleaned. New dial-cord attached. etc.An unexpected nostalgic and nice feeling, to listen to a transistor radio, when cooking. Haven't listened to a transistor radio for decades!
//Bo.A long list...
These are lovely elegant radios that look modern even today. I would rather have one of these than the Beosound 3. Easy to use and super sound. You did well to fix the speaker!
Peter
Beovox S80.2:
Refoaming bass drivers.
I had one for repair a few years back, with a bad output transistor.
It was Germanium, and I couldn't find a replacement, so I did a mod to convert the two output transistors to modern silicon units.
Menahem
Did you shim the drivers for the S80.2's or freehand? Looks like the dustcaps are untouched.
I picked some s80s last night and just ordered foams.
I have just finished a set of cx100s where 3 of four were done freehand, but the last one I had to redo with shimming - for some reason that one didn't want to sit right on its own:)
I used to shim, but doesn't do that so often anymore. Reason is that I fund the result better with other methods. On smaller speakers I often use the cloth-peg method. On bigger I apply a low frequency tone (80hz) and use the magnetic field a a help of centering.
I,m not saying this is best and what you should do but it works best for me. I've done at least 100+ individual drivers, all with good result.
Beovox M100:
Got this nice pair of M100 at a reasonable price. Cabinets and all drivers except the mid-range drivers are in good shape.
Mid-drivers refoaming
Dust-cover pegs needed repair Didn't get the stands, so I decided to make my own. I've got the measurement from Sonavor. Many thanks for that.Made some CAD drawings.Making the parts
To be continued...
Left to do, Welding, Painting & Surface treatment.
Very nice work Bo! Hopefully I'll soon get around refurbishing my M100s.
The drivers you refoamed are actually not mid-range drivers, they are 'dynamic filler drivers' according to B&O's own description. I have a BeoVox M100 brochure, where a description of the different elements of the M100s is to be found. It's in Danish, but that shouldn't be a problem for you to understand, so if you want me to, I could try and scan it later and send the PDF to you?
Keep up the good work! Exited to hear more from you!
/Dennis
Dennis: if you want me to, I could try and scan it later and send the PDF to you?
Dennis:Keep up the good work! Exited to hear more from you!
Wow! You've been busy. The project is coming along great.
-sonavor
Is this your personal shop? I wish mind had all of the equipment and was as clean and well-lit.
D
sonavor:Wow! You've been busy. The project is coming along great.
Doonesbury:Is this your personal shop?
Beomaster 8000:
Got this one for a while. Been hesitating to open it up. Its in nice cosmetic shape but got some faults- Volume control is not working.- One channel is dead when listening to FM radio- The unit goes into protection mode after a while. ½-30 minutes depending on speakers.
The one dead radio channel problem was isolated to the FM Inteface board.
It turned out to be an defect OP amp
A new and better one in place and the radio sings again!
The volume control was an easy fix. Dust in the optic sensor for the flywheel. Idle current & DC offset was adjusted according to the manual.Now it seem to work again. Still have to fix one segment in the volume display. Will run it with a couple of different speakers for some time to verify it is functioning properly
My intention is to use it together with my M100 speakers when they are ready.
Beovox M100 Stands, continuing:Welding time.Painting:Remaining is surface treatment of the upper parts (zinc plating).
Looks great Bo, excellent job. Did you put felt (vilt) under the stands? That doesn't look to good to be honest.
Brengen & Ophalen
Leslie:Looks great Bo, excellent job. Did you put felt (vilt) under the stands? That doesn't look to good to be honest. Brengen & Ophalen
Beovox M100 continued:
Got the upper part from surface treatment.
Lovely!
Very nice stands and speakers too. Good job BO!
But I am wondering what those little glasses in the background could be for?
Vintage Bang & Olufsen
the_o_master:But I am wondering what those little glasses in the background could be for?
Perfect job on the stands Bo, congrats
Collecting Vintage B&O is not a hobby, its a lifestyle.
Søren Mexico: Perfect job on the stands Bo, congrats
Thanks a lot.
If anyone else want to make their own I can provide the drawings.
Very nice, they look like mine :)
What I need is a pair of M100 speakers for my stands. Congratulations on a great job!
Thanks
sonavor:What I need is a pair of M100 speakers for my stands.
If I could build a pair of M100 speakers from scratch I would be famous :)
Time for recap. Ordered a cap kit from Dillen. Came with very good instruction as always.
Ready for operation
Opening up
These speaker are really well built and a pleasure to work with. Only negative is the weight which make them difficult to handle.
Excellent drivers
Crossover
Components replaced
Caps secured with hot-melt.
Reassembled and done.
And the result? Not much difference. I did one speaker at the time to be able to compare. The difference is subtile. Maybe a little less shrill, sounds a liitle more damped (in a positive way), an overall more controlled sound. Maybe some hours of "running in" will make more difference.
I did the same exercise as you did with several speaker systems (Penta's, RL140's and now 4x RL7000's which I 'm working on now) but the difference is minimum.
I have also recapped several other speakers, where the difference before and after has varied from huge to nothing. I guess it all depends on the conditions of the caps you replace. The conditions of the caps will vary depending on type, age, hours used, temperature and other environmental conditions. However in all cases it will be better (if not audible) and guarantee a longer life time with sound as specified if not better. So I still recommend a recap if the speakers are 20+ years.
Great work, BO!
Since I got some of the older speakers as well but cannot do recapping on my own and would not like to do them any harm, I was always intrigued by the question of how much racapping actually does good for the speakers. Obviously all Beolink 7000 need recapping at some stage. However, my Beogram 4000 does pretty well with the original caps even after more than 40 years. So what about Pentas and Beolab 5000s? Interesting that you report that recapping didn't have much of an effect soundwise with even much older speakers.
Greetings,
Kai
New capacitors make a substantial difference in lowering the stress levels encountered by the semiconductors.
In my BG4000 restoration, check these scope waveforms, showing ripple before and after cap replacement.
Click here
Even if you can't hear any difference, just because the appliance "works", doesn't mean that long-term damage is NOT being caused by continuing to use the old capacitors.
And we KNOW that old capacitors in B&O equipment are generally unreliable by now.
And my recent experience with classic Beovox 5000 speakers is also enlightening. Night and day, the caps were mostly shot, showing absurd values with rocketting ESRs and raised capacitance.
On my Beovox Monitor70 speakers, a re-cap made no difference at all, the caps still being up to specs.
Another classic device where old caps seem to last forever is the Beolab 5000 amplifier.
But I'd say yes, replace the old caps, it is good for the peace of mind, if anything.
Jacques
Old thread I know,
But I finally found the impedance of that M100 filler driver. Thanks!
Amazing work btw!
Charles