Vintage Bang & Olufsen stereo speakers restoration

I’ve been in need of an outlet to break up the days of working on startups and programming. As such, I’ve taken up the hobby of restoring vintage Bang and Olufsen stereos. It actually started out of necessity since one of my B&O stereos broke. Instead of sending it in for repair, I took it apart and fixed it. So began my latest hobby.

I’ve always loved the Beovox 4500 and Beolab 4500 speakers. They are one of the finest minimal designs which remind me of the paintings of Piet Mondrian. I found a pair in need of some serious restoration. Here are some pictures from the restoration project.

Here is a picture of one prior to restoration:

Stainless steel panel removed for measurements:

Speaker grille stripped:

New stainless steel panels fabricated:

Closeup of the new panel installed:

Finished restoration (prior to mounting on the wall):

  • eGoh Jun 9, 2012, 9:32 am

    Cliff,

    I finished restoring a pair of Pentas myself not long ago. I’ve been slow in posting the details but will get a post up soon. My recommendation is to unplug the speakers and stop using them, for now. 20 years is the upper limit for many of the components, especially the capacitors, in the amps (and the crossovers). If you keep using them, you’re going to blow out more components, including the transistors. I restored 2 completely fried amps and they were quite a challenge.

    If you want to keep using the speakers for the long term, consider a complete rebuild of the amps and crossovers in the speakers. It’s hard to find B&O specialists but I’d recommend finding someone who has worked on B&O stuff. Working on these amps is extremely cramped and requires a delicate touch. It’s not going to be inexpensive though. I think I spent a few hundred on parts and that’s without a shop’s markup and my labor was “free”. That said, these speakers are still some of the sweetest sounding speakers that B&O has ever made and well worth the restoration. If you haven’t done so already, you’ll need to re-foam the midrange drivers as well.

    You’re not going to find any new amps out there, and if you find any working old amps, they will likely need a rebuild as well in the near future. I’d stick with restoring what you have.

    Hope that helps and be on the lookout for my Penta restoration post.

    Cheers!

    Eric

  • Cliff Brozo Jun 9, 2012, 9:09 am

    I have a pair of B&O Penta 2 speakers, bought in November of 1992. The power light at the bottom of one goes yellow while it’s plugged in and not being played. However, it plays fine when it’s on. The other speaker light now stays red, plays for a few seconds and the sound cuts out. What can/should I do? I love the look and the sound, but I need them operating! I’d hate to have to go looking for new speakers. Can just the amps be replaced? How much? By whom? Thanks so much for helping.
    Cliff

  • eGoh Mar 28, 2012, 5:41 pm

    Althea,

    Sounds like Beolab 5000’s. Check out this page: http://www.beoworld.org/prod_details.asp?pid=369 You can also email me from my contact page and perhaps I can give you a hand.

    Cheers,

    Eric

  • Althea Mar 28, 2012, 5:13 pm

    I have a pair of B&O speakers similar to those above but they are 33.5 inches tall and 18 inches wide. I want to sell them along with the Beosystem 4500 Receiver, CD, Cassette, and remote.
    My problem is I don’t know what and can’t find the model number of the speakers – would you have any idea. I bought the system in 1989, it is in great shape just don’t have the space for it anymore.

    Please let me know

    Thanks

  • eGoh Mar 27, 2012, 6:46 am

    LG,

    This cloth was purchased from http://www.parts-express.com/ but you might also try a clothing fabric store. Hope that helps.

    Cheers,

    Eric

  • LG Mar 27, 2012, 6:18 am

    I believe you can achieve a very straight line by scoring the rear of the panel before it is bent/pressed.

    Does anyone know where to get a similar cloth for the frets?

  • eGoh Aug 26, 2011, 5:01 pm

    John, The stainless for these had some minor waviness from the same type of break. However, another batch of metal for a Penta restoration didn’t have any waviness. As such, I think the straightness from this type of break is inconsistent. To see how well the Penta metal came out, see this thread at the Beoworld forums:

    http://forum.beoworld.org/forums/p/38842/328867.aspx#328867

  • John Aug 26, 2011, 3:46 pm

    I was curious whether you were able to get a truly straight line on the bends. The local shops I used have hydraulic break presses, and they used this to put the bends in. The bends though were generally straight, but had some waves in the crease. Not good. Did you get good results like the factory pieces? What did you use to get those results, if you got good bends?

  • Lar Morgan Jun 1, 2011, 1:24 pm

    Thanks for the reply. Fortunately for me, the Penta’s look great. It is just the cd player that has gotten a bit scratched and dinged over the year.
    Larry

  • eGoh May 15, 2011, 1:12 pm

    It’s a bit hard to find the exact thickness. Most shops carry stainless that is a little thicker. In my opinion, that’s a good thing since it’s more dent resistant now. However, the thicker metal is harder to get a crisp bend to. So expect a bit more of a rounded bend, not the crisp line that B&O achieved.

    You can get it cut and bent at any metal fabrication shop. Most cities have one or two. I’m working with a local shop that does lots of stainless countertops, duct work, etc. They squeeze in my little jobs when they have extra time. If you do go to one, it’s best to bring the original sample pulled from the device. While you can give them a diagram, measurements might change if the metal thickness changes. It’s easiest to just have them match the inner dimensions of the sample. Obviously, you want the piece to reattach in the same manner.

    It’s quite a project, but anything vintage usually is. Keep checking back for a major Penta speaker restoration I’m working on.

  • Lar Morgan May 15, 2011, 11:51 am

    Eric, great looking job. I have a vintage B&O unit as well. The main restoration needed in replacing the stainless steel trim. Where did you fine the right thickness s.s. and get it cut to size? Thank you!