I have a Beomaster 2400 that plays with significantly more volume than my Beomaster 4500. How can this be? Admittedly I am currently running inefficient speakers, but this is only a temporary situation. Both amplifiers deliver clean crisp sound, with a slight nod going to the 4500 for “richness.”

 

However with volume, it is no contest with the Beomaster 2400 clobbering the more powerful Beomaster 4500. The 4500 is powering a set of Linn Isobariks while the 2400 is happily making do with a pair of McIntosh ML-2’s.

 

Now I am aware that the 4500 has a protection circuit and it is adjusting the volume downward. However, the volume is insufficient to really fill the room with music.

 

I have had it suggested that the 4500 may require service and that is well enough, but I do not have a reliable B&O service center and will need to have my McIntosh service center perform the service.

 

From experience they will need a little more direction than “it needs service.” The situation is such that I was forced to learn how to work on my four Beograms myself… but a Beomaster is going to exceed my abilities by a considerable margin, plus I lack proper test equipment.

 

Any suggestions would certainly be appreciated.

 

Also, thanks to everyone who helped with my button contact issue. That was such a straightforward repair: a simple re-gluing of the glass and all the buttons work again as if by magic.

 

Jeff

Replace the capacitors in the BM2400 and it will win, also in crisp- and richness.

The amplifier in the BM4500 is merely a japanese hybrid IC whereas
the one in the BM2400 is discretely built and DC-coupled.
Looking at the transistors used, it's practically one half of a BM5000.

Martin

Once again, all about figures! The 2400 was always described as a 30W per channel amplifier but would peak at 75W into low impedances - the sign of a well designed amplifier. The 4500 was described as having 55W a channel - but that is music power - I would equate it to about 25W and it won't peak the way a 2400 will. However the difference in volume is not really down to the power rating, more to the way the receiver is delivering into difficult loads. You are testing these two devices with some fairly hefty loads and I am not too surprised the 4500 is calling foul! The 2400 will manage but I dare say it warms up a bit! One of the things you could do with the 4500 is to get a pair of Beolab 150/200s. This is what they were designed for! You can then drive almost anything you want!

For reasons exceeding this conversation (my 500 watt McIntosh 2255 at McIntosh Laboratories for repair) I was powering three sets of inefficient speakers (at the same time) with the Beomaster 2400 and it was performing at nearly 75% of the big amp’s volume.  It appeared to be more than happy in this roll.

 

When the decision was made to ship the McIntosh off to New York I purchased the Beomaster 4500 as a temporary replacement not wanting to over-tax the 2400. (I was concerned that this large load might damage this truly flawless Beomaster.) I was surprised that the 4500 did not remotely compare volume-wise with the 2400.

 

Once the McIntosh is back in its rightful place I plan to mate the 2400 to a set of S-45’s and the 4500 to my set of S-75’s. I doubt the 4500 will have a problem with the S-75’s, but if it does, I will switch speakers.

 

So let me dare ask a truly stupid question, was/is powering sets of Linn Isobarik, McIntosh ML-2, and Fisher XP 66 speakers really a recipe for disaster? The Beomaster 2400 gave no hint of displeasure as there was no distortion.

 

Having just said that, I don’t wish to ruin a flawless receiver asking it to do more than it is capable of.

 

Jeff

I am sure it will be fine! Just don't run it into clipping and make sure it doesn't get too hot.

Another even better amplifier from this era is the Beomaster 2200. Actually far better than the 2400 but now much cheaper and unregarded. Find one of these and be very surprised!! The 2400 has the disadvantage of being really quite tight in the box!

Thanks Peter, as always.

 

I seldom run the Beomaster 2400 for any great length of time, normally 20 minutes at a time, so over-heating should not be a big issue. I will be mindful of this in any case.

 

Clipping also has not been a problem as I suppose I have erred on the side of caution before any distortion would occur. Although I dared to play this unit fairly loudly.

 

Thanks for the excellent tip on the 2200. I had not considered it thinking it pre-dated the 2400 and was therefore inferior by definition. You learn something every day. Thanks!

 

Jeff

The 2200 is a fascinating design. It is built in a similar way to the televisions of the day as a series of modules. The wiring is also unusual as the different modules are joined by pins which are themselves connected using wire wound around the pins. I remember when I bought my 2400 that Denis Carr told me that the 2200 was far superior and was almost handmade! I however went for the good looking 2400 instead!