Hmm, funny though - I've had 2 BM3000-2's (original virgins) and none of them seem have the problem, I also have 2x BC3500 (with same type of transformer and the oldest is 1972) yet again no problem with so called common issue with hamming due deterioration of core of main transformer, never the less. 😮

Some are saying they're common (not rare) units - why in the heaven would you like to put anything what doesn't belong there in, than?  To me it will only make sense if the replacement parts won't be available at all, but the question of integrity and originality will remain NO Matter what.

There was another posts when people been going crazy because of few tiny holes in speakers, caused by handles been fitted to them, some went mad about "at what point you stop call it B&O" - yet many are more than comfortable to replace just about anything on their units, bit of double standards

is it?  🙁👍

bob

Bob wrote:

Some are saying they're common (not rare) units - why in the heaven would you like to put anything what doesn't belong there in, than?

So...whenever you replace electronics in there you use original stock from the 80s? Where do you even get Roederstein-branded capacitors these days? 😂

If it fixes the problem, why not replace old parts with better new parts? I always favour that approach before "get another unit to fix yours" - because that still leaves you with one working and not working unit...which is exactly where you started.

I've had quite a few of these humming transformers. Annoying to say the least. I'd put the chance of finding a "quiet" original one at 50/50.

Yeah I do,

(70's in this case ;)

and probably the reason why not is, that I don't want to build B&O replica's, regardless on fact if it fix the problem or not, (in that case possibilities be endless, just keep the "badge") 👍

beside there is lots of units very reasonably affordable to buy - hence question remains - is it worth fixing with substitute in first place?

I don't mind to have another unit for spares as there's always whole bunch of people needing spares and parts, but that's just me ...

I've already "answered" your remark: If original parts cannot be obtained and the unit is worth repairing - there is no other option than replacement substitute 😕 or just get another working unit 😐

ablaumeise wrote:

So...whenever you replace electronics in there you use original stock from the 80s? Where do you even get Roederstein-branded capacitors these days? 😂

If it fixes the problem, why not replace old parts with better new parts? I always favour that approach before "get another unit to fix yours" - because that still leaves you with one working and not working unit...which is exactly where you started.

I've had quite a few of these humming transformers. Annoying to say the least. I'd put the chance of finding a "quiet" original one at 50/50.

Bob wrote:

I don't mind to have another unit for spares as there's always whole bunch of people needing spares and parts, but that's just me ...

I've already "answered" your remark: If original parts cannot be obtained and the unit is worth repairing - there is no other option than replacement substitute 😕 or just get another working unit 😐

Now Bob tell me the difference between changing a transformer with a newer better one, and changing 30 ROE caps with new ones, the innards are no more original, but if you dont do the change you will have a not working unit, what I do is to keep the unit as close to original as possible and I would never do anything to change the performance or the design of the unit, but if I have a unit not working, I will do everything I can to get it working and looking like the original, I have used hours to keep my units working and looking that way. The way you are doing it, you will end up with 1 not working unit for each working unit you have, for me thats not the way to go, we have save all unit possible and as close to original as possible, but just scratch a unit to get get another one going is not the way to go.

Sorry Bob, but I have to agree with Ablaumaise on this one, I just wish he had a name easier to spell😂

This is a perfectly reasonable divergence of opinion - one that is seen is many different areas - classic cars are another example. Some will want absolute originality so that the device is just as intended: others will look to make the device better or more practical. Neither is wrong, but are looking at the issue from different standpoints. The ones I don't really get are those who use uprated parts and then clothe them in the coverings of the originals!

Peter wrote:

The ones I don't really get are those who use uprated parts and then clothe them in the coverings of the originals!

Yes, we can drill exterior of ROE's away and glue it over new elko 😁

Ola Søren,

Think is I can't tell you the difference - it's personal view, I've already said that one must make the decision for himself if the unit is worth "updating" in the first place or, shall became "spare donor" otherwise there be no line what's original  and looking like one.... I'm sure you'd know know the right  answer, shall you be at the receiving end (purchasing one of those) 😕

And no I don't have all units double, I don't collect anything coming my way, but make choices (don't need to own the whole production line) and keep what I like and want, not to mention can use, perhaps I was lucky that none of my unit suffered such a common fault, but personally I've reservations (no disrespect anyone) for one single reason: (even in my relatively short life on here) I don't recall more than 1 thread concerning hamming of Main transformer on BM3000-2 - you do the maths. 😕 to me 4 units without any problems in that area is rather statistically good enough not to take notice

Søren Mexico wrote:

Now Bob tell me the difference between changing a transformer with a newer better one, and changing 30 ROE caps with new ones, the innards are no more original, but if you dont do the change you will have a not working unit, what I do is to keep the unit as close to original as possible and I would never do anything to change the performance or the design of the unit, but if I have a unit not working, I will do everything I can to get it working and looking like the original, I have used hours to keep my units working and looking that way. The way you are doing it, you will end up with 1 not working unit for each working unit you have, for me thats not the way to go, we have save all unit possible and as close to original as possible, but just scratch a unit to get get another one going is not the way to go.

Sorry Bob, but I have to agree with Ablaumaise on this one, I just wish he had a name easier to spell😂

Bob

P.S. my ways aren't your ways .....

I only have 4 units (in 3 rooms) and 6 pairs of speakers apart from 2 Avant TV's, DVD1, bunch of remote controls, BG CD4500 (waiting to be re-united with BM4500), coming BG1202 and (yes I do have some spares for most of those, which aren't yet fully restored - to be used or passed on to new owner) I don't collect for the sake of it - I collect what I like use and appreciate on daily base - otherwise it'll be useless and won't enrich my life at all, there already are museums 😕

I take the time to source the units and original parts, and do recall many questioning why? (such S3702's) I already said - because is the only way; original and fully working 40years old system, and despite I rather enjoy reading ingenious ways to getting around and about fixing of the units - I wouldn't be very happy to own 1 for which I would have to alter diagrams ;)

 

Hi James:

How clean is your AC power?

I have a 9500 that had a loud humming transformer. I thought the thing had gone bad. Then I moved it to another location. No more noise.

Previously I lived in an old house with bad power.

Derek

If you want your original transformer rewound, I can recommend a workshop in Tel Aviv which does excellent work, at reasonable prices. 

They have done BM3400 and BM4000 transformers for me in the past. Long-term use shows no hum at all.

There are very few transformer manufacturers left who can still work on the C-core transformers. 

If interested contact me offline.

Regards

Menahem