The Workbench

Re: S40 Refurb Project

Step1 — Sat, 11 Sep 2010 13:10:40 GMT

would like to see the results of that wood repair! The 2400 is a lovely recieiver still got to recap mine, sound is a little muffled....

Re: S40 Refurb Project

Rich — Sat, 11 Sep 2010 10:45:22 GMT

Last night I received a new arrival from Ebay: A $25 Beomaster 2400.

Oh. My. God. It's not in pristine cosmetic shape, but all the lamps burn bright, there is no flaw in the sound, all sliders are noiseless and work. Switches all seem to work. I haven't hooked up a phonograph or line level source (yet), but the tuner works perfectly.

The refurbed S40s now have a temporary home providing radio playback in the garage while I recap/relamp my other Beomaster 2400.

$25. What a steal!

(PS - Klipsch kg2's make nice stands for the Beovox S40s!)

Re: S40 Refurb Project

Rich — Thu, 26 Aug 2010 09:52:40 GMT

The Solen caps are 400V.

Thanks so much for the procedure for fixing the gouge!

Re: S40 Refurb Project

yachadm — Thu, 26 Aug 2010 09:36:14 GMT

Rich,

Very nice!

The Solen caps are also my first choice for crossover rebuilds, in the budget price range. Did you choose the 450Volt version?

Remember - you can always correct your mistakes on the #1 woofer when the foam fails in another 20 years - then you won't feel so bad ;-).

To patch up dents in the B&O woodwork, I ask my friendly neighborhood carpenter for a small packet of wood dye coloring powder (Rosewood-Palisander), and mix that in to a bit of fine wood filler (from Home Depot), and couple of drops of Elmer's wood-glue (to make the mix VERY tough).

Apply it in the gouge, leveling it with a chisel, and work quickly before the glue dries hard. The colour matches great, and it won't chip!

After it's dry, sand it gently with fine Water-paper (without the water) to a shiny consistency - it will be tough because of the added glue. Apply some teak oil, and it will be indistinguishable from the surrounding area.

Menahem

Re: S40 Refurb Project

Rich — Tue, 24 Aug 2010 16:00:38 GMT

What wonderful timing - the UPS man brought my new copy of Dark Side of the Moon today.

This is my first 180 gram LP. These things are hefty.

Gonna play Dark Side with the S40s then swap them out for the S45-2s and play it again!

Re: S40 Refurb Project

Evan — Tue, 24 Aug 2010 12:15:04 GMT

Rich:

I had a pair of T-120s back in '85. Those things were bullet proof. We tried to destroy them and failed! I had a mixing board in the audio path and someone blew a whistle into a microphone. There was some kind of protection in those T-120s - you could see light glowing inside the cabinet through the bass reflex port when you blew the whistle!

Way hay!

I believe mine are from 84, spot on. They survived a direct hit from my earlier youth as they were my first Hi-Fi speakers, originally they were my father's. They were replaced by some JBL Northridge E80s once the foam rings on the woofers went. Thankfully my Dad has let me keep them for later repair, but I'm not sure for how much longer! I like them too much to part with them!

I will have to investigate this protection circuit buisiness, too.

Re: S40 Refurb Project

Rich — Tue, 24 Aug 2010 10:38:32 GMT

I had a pair of T-120s back in '85. Those things were bullet proof. We tried to destroy them and failed! I had a mixing board in the audio path and someone blew a whistle into a microphone. There was some kind of protection in those T-120s - you could see light glowing inside the cabinet through the bass reflex port when you blew the whistle!

Anyway, this past Sunday I picked up some vinyl from my Friendly Local Used Record Store:

Rolling Stones Dirty Work

Eagles Hotel California

Jethro Tull Thick as a Brick

Robert Plant Principle of Moments

All appeared near mint, and all turned out to be except the Eagles (very good instead, just a little static; but it did have a poster of the band I didn't know existed - Henley wasn't even recognizable!).

So I listened to the "new old" records on Sunday with the S45-2s and now I'm just finishing listening to the lot with this:

B&O RX-2 w/ MMC4 (rebuild by Bennie) -> NAD 7175PE -> S40 refurb

These are a very pleasing pair of speakers.

I will have to take up Evan's request for a comparison to the S45-2s. Maybe after I finish rebuilding my Beomaster 2400 that's sitting in pieces in the garage.

Re: S40 Refurb Project

Evan — Mon, 23 Aug 2010 21:46:32 GMT

Rich:

Fun project. And I learned a lot.

These threads are all very interesting and inspirational.

Once I gain the courage to try a woofer re-foaming I will do so on a very deserving pair of Realistic Optimus T-120 speakers.

Rich,

Once they are played in a little more, you will have to review the S40s against the S45-2s for us. I know I am very curious as to how pronounced that "phase link" is in the S45-2.

Re: S40 Refurb Project

Rich — Mon, 23 Aug 2010 21:04:19 GMT

So - we are happy, and we are listening to some refurbished S-40s.

Now - I've got to decide what to do with them. Regardless of who ends up with them, I still would like to fix that gouge on the top, but I'm not sure how to proceed with that. My brother-in-law the general contractor is coming over tomorrow, I suppose I should pick his brain.

If I decide to keep them, I'll probably change the grill cloth like I did with my S-45-2s. If I decide to give them away, I'll just let the new owner decide if there's anything more cosmetically to be done. If I decide to try to sell them, I guess I'll leave the grills as is and just try to cover the gouge.

Fun project. And I learned a lot.

Re: S40 Refurb Project

Rich — Mon, 23 Aug 2010 20:58:34 GMT

I remounted the tweeter (with new screws, 3/4" #6), then slid the new foam sheet into the cabinet through the woofer opening. I pulled the foam up to the top of the cabinet with one hand while sort of shielding the crossover network with my other hand. There is just enough extra length on the foam sheet that it folds at the bottom of the cabinet to cover the bottom side.

And finally, I remounted the woofer, again with new screws (also 3/4" #6, but I think 1" will be better with those plastic spacers).

I swapped the S-40s into my desk top system for the S-45-2s and gave them a Loser test.

Re: S40 Refurb Project

Rich — Mon, 23 Aug 2010 20:50:37 GMT

Thanks, Evan. I let them play at moderate level for 5 hours while I was gone, and now I'm home again and listening to Beethoven's 9th on the S-40s. Very pleased with what I've heard so far.

So then, after the Americanization of the back side, I flipped them over and soldered the new wiring to the drivers. And then I made another minor mod - I discarded the original foam and replaced it with this stuff. The sheet in the picture is exactly twice as much as is needed, so I simply cut it in half and used one half in one speaker and the other half in the other.

I did the same mod in the S-45-2s. This step is probably completely unnecessary, but I gotta tell ya - I hate the Beovox foam I've seen so far.

Re: S40 Refurb Project

Evan — Mon, 23 Aug 2010 16:22:16 GMT

Rich:

(For those who can't wait until the end, yes, they sound fine. Listening to "Abbey Road" with the S40s right now. The bass on these S40s [and my S45-2s] are just wonderful. Won't win any loudness contests, but at low to just-above-moderate levels, WOW. Tight, clean, musical.)

I was listening to my all original S45-2s a lot earlier today. I kept saying what you did over and over to myself, very impressive speakers. At one point I stopped what I was doing and went over to the BeoMaster, I kept pressing and pressing the Voxes, incredible all the way up to nearly 80% volume, I chickened out there . I absolutely adore them.

Great job Rich, way to go!

Re: S40 Refurb Project

Rich — Mon, 23 Aug 2010 15:09:48 GMT

Next I Americanized them with a new terminal cup. Sorry if that offends. The new terminal cup has five way binding posts and is gasketed.

Re: S40 Refurb Project

Rich — Mon, 23 Aug 2010 15:04:06 GMT

I replaced the old wires with some new 16 gauge mid-grade stuff (from a speaker supply outfit). And of course I replaced the old caps with the giant Solen caps. I resoldered. Much easier than the 3-way S45-2s I did last month. Lastly I put some hot glue on the sides of both caps, plus the top, connecting them. This is the other crossover, the one I didn't mark with the what goes where key.

The giant Solen caps ended up covering one mounting screw hole, but I just moved up one set and the crossovers still fit fine.

Re: S40 Refurb Project

Rich — Mon, 23 Aug 2010 14:56:44 GMT

Next I desoldered (as best I could) the existing network and removed the wires and capacitors.