I guess nobody has removed the plastic. In any case, I figured it out. The plastic just slides off of the heatsink. It does need a firm tap to get it to move. I used a scrap piece of wood to protect the plastic and a mallet to get it out.

Keep the pictures coming, good luck!

OK guys, here is a quick update. The crossovers are finished. I don't recommend upgrading to polypropylene caps unless you like playing capacitor tetris. Everything fits and it sounds wonderful, but what a pain. 

Here is a picture of a stripped crossover:

 

 

Rebuilding crossovers:

 

 

Foam stripped:

 

 

Re-foaming in progress:

 

 

Fixing display boards:

 

 

Naked Pentas working as passive speakers right now:

 

 

You, sir, are a steely-eyed missile man.  Well done.

I've recently played some Tetris with crossover rebuilds myself and can sympathize.

Thanks, but I still have a long way to go. I'm polishing scratches out of plastic and starting to re-skin the speakers today.

The amps are pretty fried but I have most of the parts so I'm going to get to them as time allows. I don't have new potentiometers for the amps and I'm thinking it might be smart to change them out while everything is apart.

I'm dreading repainting the gray plastic since that's not my forte, but I definitely want to see them in satin black.

Here is another quick update after the weekend. New stainless installed (protective white plastic hasn't been removed yet...in case you've ever wondered what white pentas would look like) and grills recovered.

 

Looks great! Can you make a close up of the rear to see how the bending is done?

Leslie, I'll definitely post up some more pictures soon.

BTW, if anyone needs to repair the copper trim (bad chip or scratch), Testors Copper (#1151) is a pretty good match. It's available at most hobby stores in the USA.

http://www.testors.com/products/136006

The amps are giving me a headache...too bad I need to finish them to stand these speakers up.

Hi Egoh,

Did some "refurbishment" on a Penta 1 myself a while ago.

The grey plastic side panels of the Beolabs has been painted into glossy black and a later Penta 2 pair I did, mirror finished SS panels has been placed.

Can't wait for your next pictures

OK, I made some progress during my lunch break from working.

One amp is fully functional. I've also tested the displays and one works prefectly. The other one doesn't light up the yellow volume and source LEDs. It looks like IC4 was a victim of the heat from when the voltage regulator blew. I'm torn though - I like the look of the display without these LEDs, so I don't know whether to fix this one, or disable the other display.

On another note, anyone know anything about setting the bias? The manual says to set 30mV without load and while the amp is "cold." How cold do they mean? How many minutes after startup? At start, I'm at 22mV....rises to 27mV after 1 min., then 30mv after 2 min., 31mV at 3min. I found another thread where someone said to check after 5min. Could really use some guidance before I button this amp back up.

Thanks!

Here are a few photos of the blown amps:

Bulging caps:

Fried transistors and melted resistor:

Unsoldered from the excessive heat:

Fabricated new fuse board:

Three fixed amps: re-capped, all new transistors, new trimmers, cleaned, and waiting for refinished plastic trim.

WAIT! Three....they multiplied. Hehe :) Actually I found another blown amp on eBay and fixed it in case I needed a spare. I'm thinking of fabricating a "Penta" subwoofer and using the extra amp.

Rich's Corollary of Murphy's Law states now that you have a spare on hand, you'll never need it!

egoh:

I'm thinking of fabricating a "Penta" subwoofer and using the extra amp.

Take a look at THIS THREAD re: Cona -not sure what happened to the project?

P.S. And a belated and long overdue welcome to BeoWorld from me -your project is impressive! Well done!

You shouldn't have posted that Jaff! I was already thinking of giving my Conas their own monoblock!

Seeing those pentas in white got me thinking too..................

So many projects I need to do....

 

Well done! Keep up the excellnt work!

Rich:

Rich's Corollary of Murphy's Law states now that you have a spare on hand, you'll never need it!

Untill the day after you give it away or sell it

 

Thanks for the warm welcome burantek! And thanks for the link to that thread...however, I think that project might be more fun to fabricate.

Design parameters would be to blend with the Pentas, utilize the beolab 150 - modified with active crossover and combine both channels, trimmed with stainless, and probably a 10" driver. We'll see...

Evan, the protective plastic wrap in white doesn't look too bad. Although, I'd have to see the speakers standing up to really tell. I'll try to get a picture before I remove all the film for you.

Prepping and painting plastic.

The satin black came out great, but the reflective nature of the satin picks up surrounding colors. If I were to do it again, I'd do flat black to de-emphasize the plastic parts of the speakers.

For Evan - "white" pentas (really just the protective film for the stainless)

r

 

 

Completed (mostly) Twins:

I'm waiting on a part from my local B&O dealer so I can install the final amp trim piece:

Lock for Lid 3024066 (which has been updated to part #3034003) 

The Twins are back!

It was gorgeousness and gorgeousity, O my brothers!

Just spectacular results.

But...but...but...how do they sound?!?!

Thanks Rich, they sound fantastic. Better than I remember when I auditioned a new pair back in 1990, but we all know sound memory isn't very good. My wife and I were worried we'd upset the neighbors as we were really "enjoying" them until about 11PM last night.

It's been very rewarding seeing them go from such a sad state to almost like new. The only remnants of their prior abuse are 1 top cap has a couple of dents, the bases have some blemishes from the underside (I polished the heck out of the top with Novus and got most of the superficial damage out), and the small trim on the back of one has a few dents. I found all the parts (or could have fabricated them) to make them 100% but they would have lost their character. I like the story these speakers tell and the blemishes have to be pointed out in any case.

Egoh, you are an absolute craftsman. Those are beautiful looking Pentas!

I also appreciate you taking the time to snap some pics of them dressed in white, looks like they have some real potential! Thanks!

Way to go!

Evan:

Egoh, you are an absolute craftsman. Those are beautiful looking Pentas!

Evan said it, my compliments, an electro-mecanical show piece that gives the rest of us an example to work by

Brilliant job! Great to see there are still people who rather do a "little" work than part out or junk stuff that isn't "salesworthy".

...and I do like them in white