Hi all. I am in learning mode so I want to make sure that I am on the right track with this crossover refresh.
The picture below is of the back the front and then a mirror of the back for a clear view of where everything is.
Am I correct in thinking the the only Electrolytic in the signal path is the 22uf ? The others appear to be parallel. Would I be correct in thinking that I would do well to use high quality NP Electrolytics for the 47uf's and the 100uf and the replace the 22 (T), the 6.8(M) and the 4.7 (T) with something like ClarityCaps or the like? The two plastic film caps are just outside 10% on one speaker so I thought I might as well replace them. Thanks for your guidance and teaching on this.
The picture below is of the back the front and then a mirror of the back for a clear view of where everything is.
Am I correct in thinking the the only Electrolytic in the signal path is the 22uf ? The others appear to be parallel. Would I be correct in thinking that I would do well to use high quality NP Electrolytics for the 47uf's and the 100uf and the replace the 22 (T), the 6.8(M) and the 4.7 (T) with something like ClarityCaps or the like? The two plastic film caps are just outside 10% on one speaker so I thought I might as well replace them. Thanks for your guidance and teaching on this.
If the speaker is very old, you may like to consider refreshing all the electrolytics, regardless of location.
Sorry, I might not have been clear. I would replace the electrolytics regardless. I was meaning that I would replace them with electrolytics again unless I hear otherwise.
Thanks Allen, this is why I'm here. I may have been under the misunderstanding that with the electrolytic going across the woofer there wasn't necessarily a benefit to changing it to a film capacitor.
I hear you Pete; if they were valves and dampers I would get right on it. I fear that I might make it more confusing if I tried to draw it out. 🥴
No, you were being perfectly clear, while I was being characteristically unhelpful!
I can't find the crossover schematic, but I did find a photograph of what is claimed to be the Kirksaeter monitor 150.
Unfortunatley, at my ripe old age, I would get dizzy trying to unravel the schematic from your supplied photographs.
What you require is the help of a younger man, like AllenB!
Considering the age of the current electrolytics, simply replacing them with affordable modern electrolytics is likely to result in a noticeable audible change.
If you wish to splash the cash on more expensive, esoteric electrolytics, then so be it.
Replace the film caps with high voltage polypropylene types and you'll be good to go!
Yes, my birth certificate says I'm 14.. or maybe that's the printed on date.
In any case I'm not currently in my office and may be at risk for making a mistake. The lower left 47uF appears to work with the larger inductor as second order for the woofer, with the resistor in series with the two right most capacitors in parallel, across the woofer in the way of impedance compensation.
The mid appears to be low passed by the small inductor in the top right corner, and second order high passed by the 22 and 4.7uF in parallel, and the upper middle inductor.
The tweeter then appears to be second order.
In any case I'm not currently in my office and may be at risk for making a mistake. The lower left 47uF appears to work with the larger inductor as second order for the woofer, with the resistor in series with the two right most capacitors in parallel, across the woofer in the way of impedance compensation.
The mid appears to be low passed by the small inductor in the top right corner, and second order high passed by the 22 and 4.7uF in parallel, and the upper middle inductor.
The tweeter then appears to be second order.
Thanks young AllenB!
Given your interpretation, I'm pretty sure that Piober will be content simply to replace the capacitors!
An important consideration would be to ensure that the replacement capacitors will physically fit on the existing board - so the dimensions of replacement components should be checked carefully.
Given your interpretation, I'm pretty sure that Piober will be content simply to replace the capacitors!
An important consideration would be to ensure that the replacement capacitors will physically fit on the existing board - so the dimensions of replacement components should be checked carefully.
That's a good thought. I guess I could add a board beside the PCB and run wire to the larger caps?
GM said:
Well that was an education. The PIO look to be pretty pricey; I wonder if there would be any value to just replacing the film caps with PIO.
Don't know; when I was most active, PIO was nearly free for the taking, i.e. 'rescued' from all the scrapped 'old tech' tube, early SS electronics, even washer, dryers for big ones.
Are these POLARIZED electrolytics??? They sure look like it with the + on one end. I'd definitely replace with non-polar (or bipolar or whatever they're called) electrolytics.