I have here, BM 901, 2400, 4000 and now the 4400. all of them had bad electrolytic capacitors, the 901 and 2400 also bad bridge rectifiers, I changed only caps in the 2400 and after half year I had to change main bridge rectifier, the BM 4000 played good for 5/6 month and then I had to change Darlingtons in left channel, changedcall of them as left went bad the right channel was do to come also.

If a car has 300,000 miles on the odometer you will have to think about some repairs, its the same with old electronics, after 30/40 years something is prone to renewal. We are lucky that B&O vintage are somehow easy to repair, and except for some special items, we still can get parts.

So if your vintage starts to have failures, you will have to do something, the lesson I've learned is, do it all, not only caps, and do a throughout cleaning while doing it. Eugene on the forum told me that a couple of years ago, I didnt listen, so I had to open up my BMs again and do it.

My BM 2400 and my BM 4000 are both playing like new, and what a joy it is to turn them on and listen to some sweet music, I get soft in my heart and proud of my work, thinking, May the gods keep the vintage forum going.🙂

yeah agree 110% - it same with old bikes - people ask me why you spend the time and money to fix it - hard to explain why i like to rescue 1 for years to come I suppose, products these days usually won't last warranty....

Hi Søren,

Great analogy with the 300,000 mile car…. it all makes sense.

However your statement begs yet another question, how do we know if our vintage electronics are performing at their peek performance level?

As mentioned my Beomaster 4500 has an issue with refusing to respond to any command, so something is amiss and will eventually need attention.

However the Beomaster 2400 has never been worked on and as far as I know is performing s it should….. but how do I really know this? I mean the 2400 doesn’t do anything wrong, is very stable, and sound very good….. but could it sound great?

Jeff

Guys, I am really rather serious about this, how can one possibly determine if a Beomaster is performing up to spec, or just merely hanging on?

Particularly in the case of my Beomaster 2400, this amp is original down to the dust from the factory.

In a different time frame I formally used it to power three sets of very inefficient speakers, to my discredit at high volume, and the Beomaster “acted” like it was unphased , it got plenty hot alright, but the sound quality was consistent and quiet acceptable.

Today the Beomaster 2400 has a more gentle life powering a pair of S45 speakers and it sounds just fine. It is not in the league with the Beomaster 4500 or McIntosh 2255, but there is nothing remotely wrong with the sound. Nice bass and very nice treble plus all the volume one could want.

What does this indicate, if anything?

What intrigues me is if there are failing components in this Beomaster 2400 what it would sound like if everything was up to spec?

Jeff

Well I suppose we won't (unless you want to go the extra mile and have it rechecked in lab or, trust your ears) - it's a bit like with about any other aspect of life 🙂

Reminds me of the McIntosh clinics of years ago.  They'd set up shop for a day at your local McIntosh retailer with their test equipment and you could bring in your McIntosh (or other) component and they'd bench test it right in front of you to see how well it met key published specifications.   Great PR stunt, as the McIntosh components usually outperformed the published specs.

The 2400 is a sweet sounding amp, but  my 4000 is my favorite until now, my hearing is not the best but somehow I can hear a little more detail, on the other hand I prefer the 2400 and S45s for back ground music, the sound is relaxing and you can keep it on for hours and you wont get tired bothered of it.

What you can check on your 2400 is the temp. on the cooling ribs on the back of the unit, if they get a little more than hand warm all over after 1/2 an hour playing at normal listening level, your amp is OK, if there are differences from right to left, something is wrong.

I measured the ESR Ohms on some of the capacitors I changed, and some of them were way over limit, I changed all electrolytic, some trimmers, all lamps and bridge rectifiers, adjusted the 15V supply and the idle current, and now its working like it should.

Yours is maybe one of few units that has never been touched, but its time, its old and the caps are bad or short before going bad, the same for some of the trimmers, if it was mine I would do it now before something starts giving trouble and maybe do more damage.

One typical failure on the 2400 is channel jumping, you select a preset channel and it plays there for maybe an hour, and suddenly it jumps to another channel, within short time (1-2 weeks) this get worse and time shorter before jumping.

The McIntosh clinics were legend, a very clever marketing campaign. The gentleman who used to do those clinics is no longer with us, and the clinics kind of went with him.

The factory still stands behind their product in the most incredible way. As mentioned several times here on different forums, I sent my McIntosh 2255 back to the factory for repair, they offered me a new one at cost, which I declined, and the rebuilt my amp replacing everything….. and when it arrived there was a note for the president saying that there was no invoice, because in his opinion it shouldn’t have broken in the first place….after 31 years! 🙂

Jeff

Hi Søren,

I read everything you said with great interest and it makes me a bit sad to think that I am (sort of) abusing my Beomaster 2400.... that is using it without servicing it.

I performed your temperature test and after a couple of record plays at medium volume the was no warmth coming from the cooling fins at all, so I tuned up the volume.

To the extreme left and right there is no heat to be felt, but the cooling fins themselves get warm, not very warm, but definitely warm and exactly the same temperature from one side to the other. I was extremely careful to check back and forth, there is no difference in temperature.

While I can not prove that this Beomaster has never been serviced, I can tell you this, I purchased it from an officer in the US Army, a VERY detail-oriented gentleman who if ever he had serviced the Beomaster 2400 he would have provided me a comprehensive report listing each part replaced, the part number, the cost paid, and a copy of the invoice. As there was no mention of any service, I can pretty safely assume that the Beomaster had not required any…. and he purchased the Beomaster 2400 new.

Jeff