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
Was hoping someone could help me find out which capacitors are on the Penta 1 Crossovers. Some of the capacitors need to be replaced as well as some other components but I am not sure where to get the proper parts.
Brandyn,
The exact parts are listed in the archieved forum http://archivedarchivedforum2.beoworld.org/forums/p/7549/56578.aspx
But it is also possible you have a slightly different version so opening the penta and looking at the values isn't that bad of a idea.
Where are you located? (for the shops)
I am located in Toronto.. I open them up and pulled the cross overs out, however some of the caps on the crossovers I am unable to find. and I am now sure what caps can be used instead.
I think dillen can give you a kit containing all the caps needed. Otherwise you could give the values needed and we can look for you.
The boards differs from the early mk1 with 82uF to the latest version with 68uF with the very small blue caps.
If your high/low board (pcb 14) contains 82uF capacitors, then so does your board for mids (pcb 15) should.
Like in the above showed mentioned archived topic, you can see that there exists Penta's with boards which are exchanged/swapped/modified without the necessarely knowledge when doing so.
Thanks guys. I have taken the crossovers to an audio guy near me as I just wanted to get them fixed up. One question I have though, is the guy that is looking at them suspects that the tweeters may be blown because the resistors for the Tweeters are burned and the shunt coil is fried as well.
If the tweeters do need to be replaced, does anyone know any good replacements and How can I test the tweeters without a volt meter ?
I had someone rebuild the crossovers for me, and he actually improved them compared to the stock crossovers by doubling the amount connected in series for lower capacitance and higher voltage.
Also, the Tweeter section of the crossover was blown and all the parts needed to be replaced. Whatever happened also took out my tweeters.
Let me know what you guys think
Brandyn: Let me know what you guys think
Fitting two identical capacitors in series, each of twice the capacitance of the one original they replace will givea higher voltage rating, that's correct.But it will not give a lower capacitance (it will be the same as the original) and it will give a doublingof the (less wanted) series resistance (impedance and/or ESR if you want).Buying twice the amount of capacitors needed - and at twice the capacitance value (!) will also be very costly.And why on earth would you do this when 100V bipolar caps are readily available?I don't get it.
Paralleling electrolytics and foil caps, I feel, is not a great idea either but that's a different story (distortion).
My guess is that this repairer couldn't get the correct values as bipolar electrolytics and thereforechose this somewhat unusual solution.It may work in daily use but it's not something, I would recommend.
Martin
Well he seemed to know what he was doing and has been in the business for over 30 years restoring vintage audio equipment. The fact is that the boards were badly damaged and I didnt have the expertise on repairing them myself, and to be honest, they sound much better now than they did the last time they were working.
So ill take it as a win.
oh and read the following article.. http://www.coilgun.info/theorycapacitors/capacitors2.htm
"Capacitors connected in series will have a lower total capacitance than any single one in the circuit."
As been told/lectured at school: 1/Cx= 1/C1 + 1/C2.
It's the same calculating as resistors parallel.
But looking at the upper 2 in series placed capacitors with the 2 positive leads connected, that's not the proper way to construct a bipolar capacitor.
In my opnion another example (on this forum) of tinkering without knowledge.
I'm afraid I have to agree. The shown method of creating the required capacitor value is not the best way to do it - parallel combinations are better as they reduce the series resistance.
Also, you should never use polarised capacitors on a crossover circuit - this is very bad practice.