Recenly bought a Beomaster 3300 for 26 USD from a local audio enthusiast who wanted to shed himself of his collection of broken B&O equipment. Powered up OK lights functions etc but had no sound -none. What it didnt do was clip down or shut itself down after a short period of time. Taking a break from another project Sunday I opened her up and besides dust dirt and cobwebs  and after pulling of the tuning/tone control board my eyes were drawn to a dried brown spatter and a number of tiny brown crust balls in the areas around cap 67 at the beginning of the output stage.

So I bought a cap for a dollar and went ahead and replaced C68 since it was right next to it and "voila". I have a nice clean sounding BM3300. Cosmetically after a good cleaning it actually shows really well or as well as it can show. It really is a pretty nice sounding amp I would keep it as a main unit it it werent so damned ugly.

In the end I will probably donate it to one of the local dance companies.

The CD player that I purchased along with it for an additional $26 USD would play but only intermittandly. A look inside left me amazed that it would even play at all. The door wouldnt even open properly because the black cushions had melted themselves to the glass. nasty gooey mess that I had to clean up.

Pictures on;ly tell a part of the story the dust was so thick that it was literally rolling off as I was disassembling the unit. Not pictured is the ribbon cable to the laser pickup that was caked with dust on both sides. About a 3 hour cleanup. I will wait until  tomorrow to retest it just to give all the cleaning solution time to evaporate off.

Some people just dont take very good care of their stuff.

Interesting! A TDA1541 - not an A. Your feelings about the 3300 system mirror mine - why did they paint it grey and use vomit green lights!

Peter :

Your feelings about the 3300 system mirror mine - why did they paint it grey and use vomit green lights!

Certainly classed as an anomaly in the "flat" series. I think that the 4500 was an outstanding follow-up. Perhaps the 3300 should have been similar but with brushed panels -sort of following the progression of the period BeoCenters... with that said, it is different and I don't think that I *hate* it... it has a sort of 80's design charm to it -ugly or otherwise.

burantek:

I think that the 4500 was an outstanding follow-up. Perhaps the 3300 should have been similar but with brushed panels

Yes -if it wasn't for the fact that the 3300 was based on the previous 2000/3000 series, and the the 4500 was a totally new construction

The amp chip in the 3300 as I understand it is the same one used in the BC9000. I seems to offer a little more sound and clarity thasn the STK 463 used in the 2000/3000 sets. so I suppose it was an upgrade. I like listening to it.  I have another I have had for some time I use in my art studio or for bar-b-ques and such. for 26 dollars how can I complain. Even has clean cosmetics. No bashed up corners or scrathed panels.

The CD player is about as simple as it gets for B&O and produces a good sound, the Beocord I havent really looked at yet. I seem to be collecting up a number of beltless B&O cassette decks that I may or may not ever repair.

What I dont have is a Beogram 3300 record deck or remote. Those items continue to elude me.

I suppose Jeff is right as far as the flat range it is the "odd duck" of the lot.

Steffen:

burantek:

I think that the 4500 was an outstanding follow-up. Perhaps the 3300 should have been similar but with brushed panels

Yes -if it wasn't for the fact that the 3300 was based on the previous 2000/3000 series, and the the 4500 was a totally new construction

Strictly skin commentary on my part... no guts considered!

Eugene:

What I dont have is a Beogram 3300 record deck or remote. Those items continue to elude me.

They didn't elude me! I think I still have both but would need to take a look if you are interested... LMK.

burantek:

Steffen:

burantek:

I think that the 4500 was an outstanding follow-up. Perhaps the 3300 should have been similar but with brushed panels

Yes -if it wasn't for the fact that the 3300 was based on the previous 2000/3000 series, and the the 4500 was a totally new construction

Strictly skin commentary on my part... no guts considered!

I know what You mean (nudge, nudge, wink, wink -say no more) (Quote: Monty Python, for those who don't know)

I don't want to be fussy  but I was actually talking about the "skin"  -the cabinet on the 3300 is the same as the 2000/3000 so it would not be possible to make it look like a 4500 with brushed panels, at the time it was made. The cabinet on the 4500 is totally different -only the basic shape is the same. But it would have been nice if the 3500 had had brushed panels instead of the grey paint.

Eugene:

Cosmetically after a good cleaning it actually shows really well or as well as it can show. It really is a pretty nice sounding amp I would keep it as a main unit it it werent so damned ugly.

In the end I will probably donate it to one of the local dance companies.

 

Being into aesthetics in electronics, I think it is quite pretty without the covers on!

Should do well playing some Gibson Brothers.

Steffen:

I don't want to be fussy 

Are you positive?

I just looked at my "flats" collection... I own all of them except the 2300 and 3500. No matter how I reconsider skins, guts, cabinets, or whatever point of reference you wish to make... the 3300 still stands out as the oddball. I must have an overly simplistic look on things?

burantek:

Steffen:

I don't want to be fussy 

Are you positive?

I just looked at my "flats" collection... I own all of them except the 2300 and 3500. No matter how I reconsider skins, guts, cabinets, or whatever point of reference you wish to make... the 3300 still stands out as the oddball. I must have an overly simplistic look on things?

Okay -then take a closer look. You'll see that the BM 2000/3000 and 3300 have the exactly same cabinet -the only difference is the "dashboard" where the lower aluminum part was painted grey on the 3300 -and the light panel with the metallic-grey background and the yellow lights. The 4500 is quite different. And then I haven't even mentioned the "guts" -that's where you really can tell the difference -try to disassemble them -no similaritary here. Believe me - I've also have a BM 3000, a 3300, and a 4500

Damn -now I seem to be a "nitpicker" -which was never my intention...

But you're right; the 3300 is the oddball, according to its looks. But then again: B&O design is a bit like sex -even it's bad, it's quite good

I also have a   1600 2400 3000 3300 and 4500 and while the 4500 tends to grab your eye with the mirror panels it is my least favorite of the five. My favorite for looks is either the 1600 or 3000. My favorite for sound is the 2400 followed by the 3300. I do use the 4500 with passive speakers only, RL60 or Klipsch Icon. Right now it is put away in storage

Most of my lady friends really like the "flats" the BM 1600 being the clear winner

So ... perhaps I am not so lucky !!

Starting with the CD3300, after letting it set overnight I power it up and "poof" I burn TR6502 on the stand by powerblock. After recapping and replacing the Transistor and voltage regulator I have no display lights or function control. Powers up fine. So I swap the display board into a working CD3300 I have to test it, something is dead on the display board or the board is gone completely.

So then I do a general recap on the BM 3300. Went into standby mode OK. So I plug in a pair of headphones and power it up with the volume at 30. Everything is OK for about 10 seconds and the I hear this loud "pop" followed by smoke, meanwhile the unit is still powered up I have lights etc. I wasnt until I unplugged the unit that "full power" was cut.

The smoke seemed to eminate from the area around IC1, I also  I am viweing D26 with suspicion althought I dont see "scorching" around the diode. What is clearly visable is scorching around IC1 the two caps adjaent and the bridge diodes above. The scorching was already present back when I replaced the two caps on Monday. I did check recheck and check again to make sure I didnt mix values or polarity on my caps and all is as it should be.

I suppose storing electronic equipment in an unventilated environment for several years and allowed to pile up with dust dust can be hell on the semi-conductors as well.

Luckily I have a good sense of humor.

Eugene

I see that the rectifier diodes at the top, are not of the same type. I would recommend that all 4 diodes in a full-wave bridge are exactly the same. Here I would recommend 4x UF4007 silicone, or 11DQ10 Schottky's.

Not to be rude, but NTE components are not always high-quality. I see that you use a lot of NTE in your repairs. A lot of their stuff is OK, but a lot is cheapo Chinese or Korean.

I would highly recommend finding a source for proper name-brand components - Panasonic, Nichicon, Elna, Philips, Vishay, Motorola, Siemens, etc, if you want to be sure of good results.

If that IC1 is blown, it could be that the decoupling cap does not have enough ripple capacity, and the IC rippled itself to death. I've seen that many times with substandard brand-new capacitors.

I'm more than happy to help you with sourcing the right (high-quality) components, but it means that you will have to be a little patient until the stuff arrives. But anyway, it's much faster than the time taken to install bad components, then destroy the unit, then investigate why. etc.

An average restoration at my lab takes about 3 months from when I receive it, to when it is returned to the customer. Of course, most of that time it is sitting patiently on the shelf, waiting for correct parts to arrive. And that is how it should be!

Menahem

Fixed the problem last night and the Beomaster is playing and sounding better as the new caps breakin. Good even heat dissapation accross the sinks, Warm to the touch at 50 but not hot.

The only thing I havent done is adjust the standby voltage or no load idle currnt setting. That information is missing from the service manual available on this site. I do see they used the same PREH trimmer on this set too. A set of Bournes cermets would be nice to finnish the job.

Eugene

I'm glad to hear that!

Can you tell us what the problem was, how you identified it, and how you fixed it?

I'll be more than happy to help you out with the trimmers - I have good stock of the Bourns Cermet trimmers which you need for this BM3300. Do you want only the Amp Bias trimmers, or all the trimmers for the unit? Send me a PM to reply.

Menahem

The photograph says a lot. I had seriously considered replacing that regulator 8 days ago when I restored the sound originally, That area had been heating up for some time before I ever took possession of the unit.

Being a good detective I literally and figuratively sniffed out the problem (crude I know) but effective I suppose. I also dosed up a cotton bub with ISP and started swabbing for a carbon trail. Where there has been smoke you will find heavy deposits of carbon. There was also a visable film around the IC

Also the sink portion of the regulator was discolored it had a blackish hue to it as something would that had been heating up for awhile.

I also replaced some 100uf 10V caps that I had hastily replaced with sub-mini's on Saturday. Dont really belive that was part of the problem but there really wasnt any good readon for instaling sub-mini's so I pulled them out.

I can certainly place an order online for any component, and have, Newark. Digi-Key and Allied come to mind but I am kind of old school. I prefer to go to the local shops, sit on a stool and, drink a cup of cofffee and hash out product with the guy who might be my neighbor who is just trying to  make a decent living for himself and his family.

When I do order online I typically try to order within my own home state (Ohio) to help put money and business into the local economy so that usually sends me to Parts Express or MCM, maybe not the best choices or products for what I am doing but I do feel bettter about it just the same.

As far as capacitors go what is under the hood are a combination of Nichicon, NTE, and Xicon and while I cant vouch for the performance of the Xicon caps over time what I can say is the short term performance has proven more than adequate for the price paid for them. ($5.00 for 100 2.2uf @ 100V as an example from Parts Express out of Springboro Ohio, or about 100 KM from home). I used Xicons exclusively on my BM1600 some months ago and while I wasnt immediatly impressed. Then everything "broke in" and settled down the sound became much sweeter, balanced and more detailed. It took several days of extended plays then it kind of just happened one evening.

I have had similar experiences with my speaker rebuilds. Then other times the improvements are noticeable from the start.  This little project falls in the category of immediate improvement but its not quite to where I would call it sweet. Maybe I should connect tem to a different set of speakers.

The only real question that remains on the trimmers is  do I buy single turn 10 turn 25 turn etc.

Eugene

I forgot to mention - the idle current adjustment is 12mV across ONE of the 2 Bias resistors on each channel.

First set when cold, at lowest volume without speakers connected, and then play at reasonably high volume for 10 minutes thru speakers. Disconnect the speakers, set lowest volume, and readjust again for 12mV.

Good for you that you support local vendors - I do too when possible, but the fact of the matter is that most local vendors here do not cater to professional requirements. The sales manager of one large vendor here had no clue what I was talking about when I asked for low-ESR capacitors, and he didn't appear very interested to learn when I attempted to give him a very basic explanation, so he didn't make a good impression on a potential customer.

Which, in effect, leaves me with no realistic option, but to buy through the catalogue houses. Here in Israel, Mouser's Israel office has done their homework well, and offers local pricing slightly below the US pricing (minimum quantities apply - so that encourages me to buy selectively, which in the long run is good), with guaranteed 5 business days delivery. Newark also has a local branch here, but their service is nowhere as customer-friendly as Mouser's.

There is no doubt that it takes time for the new components to "break-in" - I have had that experience many times. The end results are sweet! Your "new" BM will probably surprise you after about 100-200 hours.

Single turn trimmers are perfectly adequate - my favorites are the Bourns 3352.

Menahem