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
Went up to McAllen to pick up my Internet and Ebay buys, here the Beovox M70s with the trumpet stands (2 different sellers) Opening the boxes for the M70s I found very good packing.
Top and bottom was covered with Cellfoam to fill up the gap, the 2 corners you see in the pic is some heavy foam broken out from some other packing, but a perfect fit on all 8 corners, very good packing
Both speakers out of the box, Bobble wrap, double and in places triple, I left it like that for the 1,200 Km transport in my trunk.
The trumpet stands was another matter, bad packing and not totally dismantled.Both stands in one box, and the center shaft still in the "foot", with the center shaft out it would have been much easier to pack it well.
Some dings and scratch, as I knew it from Ebay photos.
The other one was worse, deep scratches from one of the speaker supports
Worse than to see in the pic, here one of the speaker supports as I took it out of the box, not kidding.
Here the total of the packing material. I got them to a good price, but that price is not so good anymore.
Collecting Vintage B&O is not a hobby, its a lifestyle.
Coming home to the City, I had one day rest before going to Aguascalientes some 500 Km northwest of La ciudad, but I found time to unpack. Here one of the Beovox M70s.
Looks nice, no bigger problems getting it to look very well. Here both of them, check my small Beovox 3702 in the back with the beautiful red vine colour, NOT red as some members has mentioned..
As I have a good workshop I am sure I will get the trumpet stands looking, if not perfect at least better. The M70s has a bad tweeter but there Rich came in and shipped me one for free, thank you Rich, but upon checking i found Both the phase link drivers frozen, no movement what so ever with the 3 finger press and release test, so probably a loose magnet, hoping the drivers are OK after repair. But the price was good so making new frets and repairing the drivers makes as good winter evening fun. I ordered the caps for the crossovers, the grill cloth are there, or maybe I go looking for something like Richs hurricane design.
Nice looking speakers and stands but they will look 100% better by the time you finish with them. They are a great addition to your collection...Congratulations.
Having a pair myself, I will eagerly follow this new Mexico thread!
Jacques
They will give your 2400/4000/4400 a whole new sound dimension. Luckily you were able to get yours with the stands.
Ricardo: They will give your 2400/4000/4400 a whole new sound dimension. Luckily you were able to get yours with the stands.
I agree. These are monitor-class speakers and their sound is really first-class. After I did the crossovers, I did not perceive any change in character. When measured, the capacitors were still within tolerances. Perhaps because they were used regularly? They came from a house clearance and there were two pairs. The Beomaster 6000 had already been sold, unfortunately.
I would like to find cheap P30s or 45s as rear speakers. I use s45-2s, they are a match, but not in size!
Enjoy their restoration Søren!
PS: please replace those horrid rusty screws, that's the first thing I do when restoring old equipment!
chartz: I would like to find cheap P30s or 45s as rear speakers.
I would like to find cheap P30s or 45s as rear speakers.
I have both. The P45 is significantly larger than the P30, as well as a better sounding piece. However, it seems a waste to use the P45 as just a rear speaker. They deserve a place of honor, especially if you have to fix stuck woofers! But then again, the P45 and M70 use the same tweeter, so I suspect they would be a good match in the same system.
I don't mean to put down the P30. It is a nice little speaker, but probably needs to be in a smallish room. I use mine for testing vintage receivers when I first get my hands on them (Jacques: see my McIntosh MAC 1500 thread over at TapeHeads). Their cabinets are really chewed up, so it wouldn't be a great loss if I fry them.
I love big Macs, especially valve ones. Never found at that price here... You can muliply by 10 easily.
Rich:Been listening to my M70s all afternoon and now into the evening. Patiently waiting for this thread to take off.
Patiently waiting for this thread to take off.
Me too, just came home from a 12 day business trip, tomorrow will go with helping the FS with Xmas things, but I see an opening between Xmas and new year.
May I humbly suggest you work on the phase links first? There will be plenty of down time on those waiting for epoxy and glue to set at various stages.
But you probably already thought of that.
My work plan: Strip both cabinets down to bare cabinet. taking care to mark all component to which cabinet. Check all drivers for correct resistance and function, Check crossovers, get all parts ordered that I dont already have (new screws Jacques), then onto the phase links, During waiting time sand and renovate cabinets, at last the crossovers, all new caps, off the shelf from Parts Express, maybe I will change all the wiring from crossovers to drivers and line in.
When all is ready, assemble and first test without back plate and insulation, then if all good, assemble the rest, and then sit down and enjoy music from my BM 4400
Will try to take a lot of pics as I go, but sometimes I just get so into the job at hand that I forget everything else, until the FS gets angry. Will do my very best.
The trumpet stands will have to wait to the last. I will fit them in my lathe and polish them until I get the nicks and scratches (or most of them) out, the original polish is kind of crude and mate, I will try to match that and at last protect them with a Polyurethane spray.
Take care not to twist the terminals of the tweeters. You WILL break the tiny leads connecting the terminal to the voice coil. Trust me. I know. There's a reason I had 1 spare tweeter and 2 spares of all the other drivers.
I am a lucky man, The FS went with my nieces two girls, the mother has to work until tomorrow, of course I agreed to keep the fort, home alone, and told her I was sorry that we couldn't do some Xmas works together.
So onto the M70is, I decided to do one speaker at a time, these speakers are big and because of the Xmas decorations all over the place, I had to decrease my space use. Back cover off
Less felt than I expected
Crossover
As far as I can see no damage, and no repairs done.
Felt out and bagged for reuse, here the woofer
First driver out is the phase link, and yes the magnet has shifted, I carefully lifted off the magnet, not to damage the coil.
Then the woofer, looks very nice I like the rubber surrounds
Tweeter and mid range out
The tweeter exactly the same as the one Rich gave me
Measured the coils on all drivers, all around 3.7 Ohms, except for the tweeter that one is open circuit, here the empty cabinet
One question, did any of you have a layer of foam between the speaker front and the grills, I found some staples with foam rests on the cabinet front
Yes, I have foam all over the baffle, like these.
I have been following the lose magnet repairs, whenever they came up, and has been thinking a lot about it, what I dont like is to cut the spider and perfectly good rubber surrounds, so I will try it my way, you are allowed to laugh at me if it does not work as I think it will.
Here the phase link with the lose magnet
The back plate with the center shaft came lose with a hit on the center shaft from a wooden hammer shaft.
I cleaned off the old glue with a small cutter and then with acetone to get read of all grease.
Here all clean
And now to fun part, the magnet has to be centered to the basket, I did that with my vernier, first a dry run, the coil is protected by a piece of photo paper, cut to size, that went good, I could place the magnet without touching the paper around the coil.
I then took off the magnet again, applied a thin epoxy layer on the outer half of the magnet, we dont want any epoxy near the coil. put the magnet back on the basket, checked with my vernier all around to center it perfectly. I then applied epoxy to the center shaft and centered it the same way to the back plate. Only one pic as I had to work fast, my epoxy has a pot life of 5-10 minutes before it starts setting.
When dry I will cut the dust cap attach the the back plate with center shaft, and shim to the coil in a dry run, after that I should have the ideal shimming size for gluing the plate, waiting for the epoxy to cure.
chartz:Yes, I have foam all over the baffle, like these.
Thanks Jacques, do you think this has any influence on the sound
Supposedly it has. It must avoid reflexions between the front and the grille, and even out high frequency response. But it seems that later ones were produced without it.
Your method seems fine and should work. I understand your reluctance to cut those spiders... I hate doing that too.
So far so good. You are essentially shimming for two operations - from the back side for re-attaching the magnet and then from the front for the shaft re-attachment. Sounds reasonable to me. Be patient and give the glue plenty of time to dry.
Tried the dry run, but the back plate with the center shaft always shifts to one side pulled by the magnet, and by that pressing the voice coil against the basket, Getting nervous about damaging the coil, no more tries today. Will have to make a tool for this, One steel ring to attach to the outside of the magnet with 3 screws to adjust the back plate to center. Lets see what I can find in the workshop tomorrow. Merry Christmas
Merry Christmas everyone!
I hope you had a merry Xmas, mine was partly shadowed by my destroying the voice coil on one of the phase link drivers, but then Rich came up again as my savior, he has 2 phase link drivers, and will ship them to me in Mexico.
But here the disaster story. I made a simple tool to center the magnet assembly into the voice coil, Well theory is one and practice another.Here the tool placed in position over the magnet, before that I glued and centered the magnet to the basket. The shaft was centered and glued to the back plate, I made a dry run. Without the tool in place, carefully I inserted the back plate, it snapped as always to one side, placed the tool over the magnet, secured it with 3 screws, then with the other 3 screws centered it checking with paper strips between voice coil and the shaft, that came out good, except for the adjusting screws will have to have a finer thread. The screws are metric 6 mm, thread is if I remember right 1.0 mm. I have M6/0.5 mm in stock so that will be a lot better (finer adjustment).
Here a side view
After centering in the dry run, I checked the voice coil, still OK, I then loosened one screw holding the tool to the magnet, the screws holding the back plate I left tightened, carefully pried the tool upwards with 2 screwdrivers, came off good. I mixed my glue applied it to the outer half of the magnet to avoid it getting into the center. I had my adjusting strips ready 0.15 mm. Then it was a simple job just to put the back,plate back where it was before. I centered the tool over the magnet and slowly moved it downward, just before the shaft went into the coil, the back plate slipped out of the 3 screws holding it, the back plate tilted about 45° with the shaft half way in the coil. I removed the tool, checked the coil, the coil now open circuit. Will bring pics of the coil later, I dont want to see it at the moment, still angry with myself.
I took a pair of days off after the phase link disaster, and started on the cabinet of speaker 1.
The lower right corner was open a bit, so that was the first task
I have no corner clamp, so 2 normal clamps would have to do, not the best solution but it works, I snapped a bottle of Gorilla wood glue last time I was shopping, turned out to be some expanding sort of glue foam, but it worked.
Left to dry some 4 hours, then sanded the cabinet, soaked it with boiled linseed oil and left overnight, sanded it lightly, painted the front, let dry.
Soaked one more time. Here left to dry.
Good day, I didnt destroy anything.
While waiting for glu, paint and oil to dry, I opened speaker 2, the cabinet look OK, some scratches but nothing serious. Crossover exactly the same as in speaker 1, Took out all the drivers, the solder taps for the woofer was loose from the basket.
Measured the coils on all drivers. Tweeter is bad, and as in speaker 1, the phase link magnet loose.
So now I need one more tweeter, the seller told me all is OK just one tweeter bad, he screwed me good.
It comes to my mind to send Luigi, with his Louisville slugger, to visit the seller
Here the woofer
It will take a couple of cubas to fight off the bad vibes that is conquering my my mind.
was surfing a little for tweeters, found this one with the same coil resistance,but who knows how it will sound, and it is not original, at least it is made in DK https://www.madisoundspeakerstore.com/vifa-soft-dome-tweeters/vifa-bc25tg15-04-1-textile-dome-tweeter/
Rich:Check to see if the tweeter leads are broken near the terminal. I broke one of mine just barely twisting the terminal. I still have mine. I will try to fix it. Meanwhile, the 2 phase links went out today. Crazy expensive to ship to Mexico via FedEx. You should have them New Year's Eve. More details to come via PM. Right now we are on the road to go to my wife's second of three birthday parties. She turns 39 tomorrow.
Meanwhile, the 2 phase links went out today. Crazy expensive to ship to Mexico via FedEx. You should have them New Year's Eve. More details to come via PM. Right now we are on the road to go to my wife's second of three birthday parties. She turns 39 tomorrow.
I know its expensive to ship to Mexico but I want to get these speakers working, so extra Dollars are the solution will check one more time on the other tweeters
Look here.
I saw that one too Jacques, thank you. Where is he located, his prices are in Euros, so shipping will probably kill me. Rich is trying to repair the tweeter he still have.
He's our good old Martin in Denmark
Søren Mexico:Right now we are on the road to go to my wife's second of three birthday parties. She turns 39 tomorrow.
Have fun at the parties, my wife turns 36 , and has done so for the last 27 years
Søren Mexico: I saw that one too Jacques, thank you. Where is he located, his prices are in Euros, so shipping will probably kill me. Rich is trying to repair the tweeter he still have.
Rich succeeded. Let's see if any of the photos turned out.
Rich:Rich succeeded. Let's see if any of the photos turned out.
You just made my day, you did that yesterday too, after your message I got the drive back and recapped both crossovers, had to parallel some as I didnt have the right sizes, the schematics are not the same as mine. But also B&O used caps in parallel, There was two 16 uF in parallel on both crossovers
You can't really see any of the detail in the photos, so I'll just describe the process.
First, the voice coil leads come away from the dome 180 degrees apart to be joined to the terminals on the outside of the driver. The leads and "bottom" (outside of the speaker box) of the terminal are covered with a gooey black insulator. I scraped the terminal bottom clean and cleaned off about 1/4" of the lead with an X-Acto knife. I propped up the lead with toothpick and lined it up toward the terminal. I taped down the toothpick.
There was about a 1 mm gap between the lead and the terminal. I took 2 lengths of thin wire and lined them up along the lead. I then slipped one under the lead, and one over the lead. I taped the ends of the wires down, leaving where they touched the lead exposed.
I then made sure the 2 wires were touching the terminal. I then taped the other ends of the wire down, again leaving where they touched the terminal exposed.
Next, I soldered the 2 connections, creating an electrical bridge from the lead to the terminal. Leaving the whole assembly still intact, I verified continuity. I then checked DC resistance: 3.9 ohms. If memory serves, that's correct.
I then did a very low level check with music: it works!
I then took all the tape off and removed the toothpick. I then applied hot glue to all the areas the black gooey insulation had been removed. Lastly, I checked DC resistance again.
Tweeter repaired! I figured it could be done ever since I broke it (what? 3 years ago?). I just never had a reason to.
And now I'm off to birthday party 3 of 3 for the wife. I will be offline for probably 4 or 5 days.
Rich:Tweeter repaired! I figured it could be done ever since I broke it (what? 3 years ago?). I just never had a reason to.
A steely eyed missile man
Very nice surgery. Congratulations.-Sonavor