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
Just been to collect this little gem, ebay acquisition for which I paid slightly more than I intended. However first viewing is quite positive.....cosmetically it is a little grimy and of course the preset cover is missing, it has however left behind one of the fixing tabs that hold it in place, little dentistry will be required. Not put power to it or opened it up yet but the screws don't suggest that the case has ever been off in the past, woodwork has one or two what looks like raindrop spots as if it has been caught out in a light shower at some point......
another view
Got a capacitor replacement kit on order from Dillen, with hindsight I should have ordered a preset cover at the same time
bottom cover removed......little dusty with light traces of oxidisation on some surfaces, otherwise looks good.
This Beomaster is my favourite B&O receiver, in use every day chez Jacques. Very nice!
Jacques
little dusty on the component side but otherwise looks in very good shape
Same here Jacques, in use 8-12 hours a day, if not with the TV sound then with the radio running, a real work horse, and the biggest job I ever done
Collecting Vintage B&O is not a hobby, its a lifestyle.
Started to pull down the front panel for cleaning........lot of sticky residue collected here and there, could be some sort of switch cleaner/lubricant.
The volume control slider back seems to have been dissolved at one end, or maybe just mangled in service.
Generally the slider lens all look a little tired and faded,
Following a clean with warm soapy water the sticky feel has gone however they still retain a certain opaqueness, I'm reluctant to use anything stronger especially on the reverse side of the lens where the curser is marked, it may be simply UV damage that cant be reversed.....anyone found a solution to this? is it just a case of polishing the lens front and it may clear.....
Will continue to disassemble and clean as I go along......still have not powered this up yet, it has the original European style 2 pin plug moulded to the power cable that I'm reluctant to cut off as it is original....I can get an adaptor of course, thing is with this type of plug how does one reconcile not having the live and neutral clearly identified? our beloved three pin plug is fused on the live side and I'm used to having that protection at the power source, I feel this may spark some amused comments ;¬) none the less back to the business at hand.
Well done - these are great machines - Tim and I dismantled one with the idea of making a 4401 when we had not found one with the idea of fooling B&O into thinking it was a real one. However Frede found a couple of real ones and kindly gave me one, so Tim put the other one back together and sold it - I think it lives in Portugal now!
The 4401 is obviously far superior!
Peter
On the power supply side, I have a block for the 2 pin plugs as I run most of my kit with the original plugs and that then has a three pin at the end - once plugged the correct way in the block, you don't need to take them out so they will always be correct.
Peter.....I cant believe you would be so devious! as to the 4401 being far superior it's clearly wasted on one so unscrupulous as your self, I may just call round and take it off you for my collection ;¬)
The power supply adapter solution sounds good.....I will identify the live side and do as you say, I think I have a single plug adapter that will do the job.
Gave the slider lens a further polish with toothpaste, cant make my mind up if its made a difference or just wishful thinking on my part........perhaps I'll go a bit further and use jewelers rouge and a soft buffer wheel.
Craig: Following a clean with warm soapy water the sticky feel has gone however they still retain a certain opaqueness, I'm reluctant to use anything stronger especially on the reverse side of the lens where the curser is marked, it may be simply UV damage that cant be reversed.....anyone found a solution to this? is it just a case of polishing the lens front and it may clear.....
Funny, mine have a vaguely blue-ish tint to them. I guess yours was at a smoker's place then. In this case, nothing can be done.
Not all Beomaster 4401 are black.
Matin
Craig:The power supply adapter solution sounds good.....I will identify the live side and do as you say, I think I have a single plug adapter that will do the job.
You should be able to find adapters that have a fuse installed and clamp over the flat euro plug. Looks very neat when installed. I received one with the Beocord I won at one of the prize draws. It may not be suited to the old '70s plugs though.
All modern (starting from some time in the early '80s, probably) kit with a flat 2-prong Euro plug are double insulated and it shouldn't matter which way you connect the wires. These are marked with two concentric squares on the type plaque. BM4400 doesn't seem to be one of them though.
Anyway, remarkably the old UK instruction sticker seems to have survived on my BM4400's original power cord - you might appreciate this:
--mika
Mika.....thanks for that, it's worthwhile information.....following on from the faded/discoloured sliders I have tried all manner of pots and potions said to leech out the bromide which causes UV damage in plastics, peroxide solution (retrobrite) being the most promising......however it failed miserably. So turning to a doner BM4000 I salvaged the sliders and following inspection found them in really good shape, crystal clear. Naturally when offered up to the slider backing assembly they where found to be different! the recessed cut outs for the 4400 are placed differently to those required for the BM4000. The picture shows both sliders, the subject BM4000 blu tacked to our garden table, for comparison.
The more observant reader will have noticed the bits of plastic debris around the piece of blu tack and concluded that the picture was taken retrospectively, having successfully modified one slider I decided to chronicle the exercise, the dremel with a small milling tool was ideal for the task.....and sat in the garden in the summer sun made the task more pleasureable.
Moving along nicely..........
The finished article with replaced lens alongside the modified piece.......a marked difference and well worth the effort, I will have to live with the green curser. I did consider re using the black upper and lower slider trims to irritate Peter (4401 superior) but decided against it ;¬)
Although not original, the green lines will look nice on the 4400 !
Having received a bag of capacitors from Martin I have started the recap exercise, again I was lucky enough to enjoy some summer sun as I made a start on the input board.....having took this picture I realized I had almost overlooked a 47uF cap hiding behind the wiring loom!
Having recovered from the previous oversight I'm quite pleased with the way this board has cleaned up, looks almost new. During the cleaning I noticed a finger print on the alluminium frame which surrounds the board, perspiration on the finger/thumb of the person who assembled the machine all those years ago visible now due to the light oxidization, couldn't help but think about who the person was and if they where still around...... reminds one that these machines where assembled by people and not smashed together by robots
Finally getting back to work on this......decoder was next up, I do like the circuit etchings on these boards it helps a lot when pulling out components.
Reservoir Capacitors next in line......I found these so much easier to replace than their counterparts in a BM4000, considerably easier to fit due to the bracket arrangement and the common connection bar between the two +/- terminals.
Will need to make sure the ceramic capacitor to ground doesn't cause a short.......
Having pondered this ceramic capacitor for a while I decided to look it up on the circuit diagram, naturally it was absent from my document which showed instead a direct connection to ground with no capacitor.....the best I can determine is that its job is to prevent noise feeding back into the mains supply? I'm sure some of the better informed members can elaborate on this.....the most important consideration for me is that I now have peace of mind regarding a possible short to ground ;¬)
I don't have this cap.
Are you sure you have followed the traces / wiring correctly? Because I don't think that power supply arrangement will ever work unless there is a direct hard connection to ground from the center tap of the transformer. It may be physically somewhere else and the cap still installed there as intended, though.
Could be that circuit ground and chassis ground are separated.In those cases it's typical to see a capacitor between the two.
Martin
I'm pretty sure I have a picture of the wiring to the capacitors taken before I started.....I will review and post in due course.
Not my best effort....but the cap can be clearly seen...
Having completed work on the De-coder I decided to replace the two presets R100 & R200 before refitting the board back onto the AF amp, following advice received from members I always check the resistance of the preset to make sure the replacement component is the correct value...then consult the circuit diagram to determine which value from the wiper to the fixed value connections is the important one. However these two presets appear to be missing from the component listing in the service manual available on this site. So I removed one to measure the value across the fixed points and discovered it to be 50k.
there followed what seemed like an eternity of searching before I could locate these two devils on the circuit diagram....I was beginning to doubt the integrity of the circuit diagram, especially as I couldn't locate them in the component listing.....however I eventually tracked them down and can now complete the replacement.
Very impressed! When finished, If you would like to borrow the 4401 and compare, I would be happy to oblige! It doesn't get a lot of exercise these days and could probably do with a run out!! Being a Frede piece, it comes with a comprehensive manual!
Peter: Very impressed! When finished, If you would like to borrow the 4401 and compare, I would be happy to oblige! It doesn't get a lot of exercise these days and could probably do with a run out!! Being a Frede piece, it comes with a comprehensive manual!
That's a very generous offer which I couldn't possibly refuse, thank you and as I don't live all that far from Earsdon (about 45/50min drive) it would be quite painless.....you need to enlighten me regarding "being a Frede piece" though as I'm not familiar ;¬)
Craig
Ok.....got him, Frede Kristensen of Classic Audio....will read up some more on him. Meanwhile decided, as I will be away for a couple of weeks very shortly (2 weeks windsurfing in Greece, I'm getting rather old for this I know) I would re instate the decoder and IF boards rather than have them sitting around loose.