[premiumverum]

Thanks for the update and thanks for sharing the process! Great find and great project!

RL60 are a very nice loudspeaker. I read on beoworld that the original ABR’s were a tad better in the bass deparment then RL60.2 with its bass port, but at the cost of fragility with the foam.

Finally a solution to save these nice speakers.

[premiumverum]

Very nice!

Do seal the holes. They may cause whistling noises. I agree with evan on the damping material, the seal between the plate and the rest of the housing should be airtight and not rattle to prevent noises.

[premiumverum]

Hi Stephen,

Looks pretty nice, I think it will be hard to find a better replacement anywhere.Worth a try!

I saved a picture of an official ABR replacement once, I’ll add it to this post. Looks very similar.

[premiumverum]

Hi, nice find!

No need for jumpers or anything.

These beograms, if not yet restored, all need new electrolytic capacitors and a thorough check for cold solder joints and cracked pcb traces. After this one can investigate the reason for the blown fuses.

Quite the job however, best done by someone with experience. I’m working on the 8000s younger brother 8002 and have often wondered if I bit off more than I can chew.

[premiumverum]

Checked C-E for continuitiy with the multimeter – nothing. I desoldered TR17, it gave a HFE reading of 381, seems normal.

 

I’m not sure what to do next. Maybe try another bc557b, maybe I got a dud? I could replace C20, unforunately I have no capacitance tester and no 47 uF cap on hand. I’ll have to go to the shop first anyway.

[premiumverum]

Hi Christian,

Compliments on your restoration of the MS150.2’s! I’m following with interest, replacing the speaker cloth is also in the planning for mine.

I am in the process of setting up my 8000 system again after some years in storage. What a sound, what beautiful pieces. Enjoy the fruits of your work!

[premiumverum]

OK, replaced D15 with a new 1N4148. No change!

I measured around in the circuit again and read up on using the BC557B as a switch. The 3 resistors are within spec.

Assuming I understand correctly: as the BC557B is PNP, making the base low (0V) should close the switch activiting the reset pin with 5,08V. However, for some reason there is 5,8V on the base. Yet the switch seems closed because C and E measure the same. Why is there 5,8V on the base, why is the switch closed with a positive voltage on the base? Maybe C20 is the cause but I can’t see how?

 

 

[premiumverum]

Thanks Christian.

The BG was recapped 5-10 years ago and any suspect joints were reflowed then. Could of course be a new crack somewhere, I hope not.

Your explanation helps me understand the problem. I am not schooled in electronics but the B&O hobby is teaching me step by step. The function of the zener has made my comprehension of the circuit more clear.

[premiumverum]

This is fine. The original caps have values that are not available anymore. Tolerances on these 1970s caps were +/-10% probably so e.g. 47uF instead of 50uF is close enough. Everything the previous owner installed is within spec.

Proof of the pudding is in the eating, as you said they sound very good. Close em up and start enjoying!

[premiumverum]

Maybe Dillen has a solution?

https://beoparts.com//?s=RIAA&search=Go

[premiumverum]

Looks like an interlacing problem. Can you change output resolution on the PS2 and PS3? Or the refresh rate?

I doubt you can change any useful setting on the MX8000

Refresh rate should be 25 or 50Hz.

Resolution 576i or 576p or PAL (I assume you are in europe?)

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