ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Hello experts!
Two years ago I accidentally acquired a pair of relatively well-preserved Beolab Penta MK3s. Since then, I've been happy every time I listen to music. Last year I changed the mid-tone surrounds because the foam had decomposed into a sticky mass.
Now I have been quietly reading along in the forum and have come to the conclusion to work up the amplifiers and crossovers. Since it will probably take me a long time to do this, I looked for another working pair of Pentas and finally found them last weekend. The speakers are now disassembled, and I swapped the first two capacitors in the power supply. (I bought a complete set from Beoparts).
Despite being 25 years old, the old capacitors still have their printed value of 10,000 yF ... I am amazed!
Now my first questions: Does it make sense to swap the power transistors now? The amplifier is now disassembled, and the transistors MJL 3281A ISC and MJL 1302A ISC cost 30, - € ...not the world ...
And what is still to be done? I have read about the improvement of the crossovers according to The_Bogener, but can not find any details!
Can you help me?
Regards
Christian
(Aunt Google translate the text)
Hi,
Congrats on your multiple pair of Penta speakers. I did a repair video that might help you/give you some thoughts for service repair in the future. https://youtu.be/psY_RV1NjHM
I replace all main board capacitors, the 2 large power supply capacitors, trim pots, OPAMPS and the 6 main power transistors. Links to parts used are in the description.
I replaced the 6 large transistors to show how to do it, but it seems to be an optional job in many peoples eyes. I believe as long as the ones you have are not faulty it isn't a necessary repair.
I will be doing a crossover video soon.
Hope the above gives you some helpful tips.
Bristol based B&O fan with a collection including the following: BC9500, Beogram 9500, Beosystem 3, BeoVision Avant DVD 32, AV9000, Beolab 3500, Beolab 3000s, Beolab 4s, Beolab 6000s, Beovox Pentas, Beovox 3000s.