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
@chartz, inside Beolab... yes I know about PCB tracks and transistors but did you see internal wires between power transistors and PCB ( audio line ) ?? It is about 1,5 mm2 , between PCB and capacitors the same 1,5 mm2 and the same goes to the selection switches, then only 0,5 mm2 goes to the DIN connectors. One more time - only 0,5 mm2 goes to the DIN connectors to supply 60W power (less than 4ohm). I just only missed the weakest link.
Inside Beovox, yes I had the same thin wires but I changed it like always to 1,5mm2
My new cables is a 2,5mm2 oxygen free cooper for audio use with thick insulation.
In my opinion if you have about 10 meters between amplifier and speakers and you want use sometimes this cable with more powerfull power amplifier ( like Yamaha M2 ) and with harder to drive speakers this 2,5 mm2 is minimum.
Besides, as you noticed I didn't destroy Beolab, and it looks aesthetic.
BeO is like a good wine - the older the better...
Here you are comparison from Beolab. In this green oval you can see thick blue and red wires. It is the same dimension like all audio line. You can see also red, blue and black spiral thin wires. It is the same dimension like audio line from selector switches to DIN.
Larger lead dimensions won't hurt, I suppose.But, to be honest, I think you would experience a much greater improvement if you replaced those old output series capacitors.They were very high quality components when new, but they live in warm surroundings and are 50+ years old so will have past their best days.Perhaps the capacitors in general.
Martin
@Dillen, you have right like always. In this moment I try to find 3000uF capacitors. In both I have measured 4000uF but you know that it can be worster when Beolab work.
3300uF would be fine.
Thanks,
and what with 2500 uF / 100V ??
General handrule:
Don't go lower - and don't go much higher - in working voltage rating than the original.If the original cap is 70V, see if you can find this or 80V.A cap with a 100V rating may sound like a better choice, - but it isn't.A capacitor is in some ways like a rechargeable battery, if it only ever sees a fraction of its nominated voltage it will die fast.Don't go lower - and don't go much higher - in capacitance than the original.If the original cap is a 3000uF, see if you can find a 3300uF.
I ordered Mundorf MLytic MLGO AG 3300uF 63V and still searching 2500uF/100V.
A 2200 uF will be fine!
Jacques
Or 2700uF
I have in home my 2200uF/100V TDK/EPCOS with screw terminal (low ESR and high rated ripple current), I try first this.
I really wouldn't choose a low-ESR component for the filter capacitor.The rush-in current will give the rectifier and the transformer a harder life.
Low-ESR capacitors can be used in the preamplifier section and, perhaps, if you cannot find something closer to the original, as the output series capacitors.
It's my fault, I mean lower than similar capacitors, about 40 to max 80 mohm vs 60 to max 100 mohm and max 13A to 4,4 vs 5A to 2,2A compared with Nichicon and other witch I found. I think TDK/EPCOS will be OK.
I still wait for a Mundorf caps but I changed 2500uF power capacitor.
and .... Is it possible that now Beolab play louder and stronger ??
it is like I increase preamplifier level but I didn't touch input regulators.
Today I piked up this little beauties
little 3300uF compared to old one 3000uF:
Because I didn't want overheat caps I prepared rounded connector to capacitor pin, after that I soldered wires to connector and on the end I put conector with wires on capacitor and soldered it.
and finally my new Beolab power capacitors family:
@chartz.. switch-on thump was little bit reduced when I put EPCOS/TDK 2200, but a very little bit. The same when I changing source.
Yes, all old capacitors are over range:
2500uF -> 3800 uF
3000uF -> 4200 uF
3000uF -> 4100 uF
Difference... yes, Beolab play more powerfull and louder , a little something like you push "Loudness". When I stand next to the loudspeaker and choose vinyl to play next and the music play low, I feel like my trouser legs are rubbing against my legs. WOW.
Everything I did before improved the bass, now I opened up the highs. But In the same time I changed caps in 5702 crossovers and I don't know witch caps opened up this.
And this Beovox 5702.... excellent and amazing and very underrated. After all changes inside I have the best treble what I heard ever and bass stronger than M70.
Martynka: @chartz.. switch-on thump was little bit reduced when I put EPCOS/TDK 2200, but a very little bit. The same when I changing source. Yes, all old capacitors are over range: 2500uF -> 3800 uF 3000uF -> 4200 uF 3000uF -> 4100 uF Difference... yes, Beolab play more powerfull and louder , a little something like you push "Loudness". When I stand next to the loudspeaker and choose vinyl to play next and the music play low, I feel like my trouser legs are rubbing against my legs. WOW.
That's the result of the damping factor being restored.The lower output impedance of the amplifier, the more control over the coils in the speakers.Think of the coils being almost shorted by the amplifier, "grabbing, moving and braking" them. With worn out capacitors in series the "grab" won't be as tight and sound won't be as precise but instead it will feel more "elastic".
One more question @Dillen, after replaced 2500uF/100V I hear more noise from turntable. Touching the Beogram or walking next to the Beogram is transmitted to the speakers with interference. I think that Beogram sounds better, more detailed but with more distorsion.
Problem solved, Beogram cable was broken
New BeOlover in my family:
My audiophile cat