Your drawing was in accordance with your description in post #46. Also, the photos shown do not conflict with it even though we cannot see the drivers themselves.CliffR52 said:
Cliffs original drawing is the factory intended way to do this. It does make a difference. Changes should be for a good reason.
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@ Cliff.
I would simply short out the protection circuit altogether by soldering a length of wire across the 18R//PTC combination.
The effective removal of the protection circuit will have no significant audible effect in relation to this simple crossover. If you don't believe me, wire 0.8 ohms worth of resistance in place of the protection circuit and do a comparison.
I would simply short out the protection circuit altogether by soldering a length of wire across the 18R//PTC combination.
The effective removal of the protection circuit will have no significant audible effect in relation to this simple crossover. If you don't believe me, wire 0.8 ohms worth of resistance in place of the protection circuit and do a comparison.
He should be able to by now!
Thanks for your efforts in redrawing the schematic.
So do I, JMF.
Trouble is, Cliff has been unable to source the exact replacements, as he indicated earlier.
Do you know of an Australian source for the C955 PTC?
Sorry about that.
I'm all over the job.
My mother was hospitalized and not doing too well.
Haven't had a lot of sleep over the last week or two.
It is a 3.3uF capacitor.
I don't know where I got the 6.4
If you recommend this crossover layout, I'll go with it.
If the mid and high end up too bright would I add lower value resisters in parallel with the 18 Ohm Resistor (say 1 or 2 ohms) and add until the correct level is achieved?
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I posted 2 other replies with photos but I think they may have failed due to upload limit?
The decision to eliminate the Thermister was based on previous advice.
The thinking behind it was that a 30 - 40 year old thermister might not be functioning correctly and possibly be compressing the music signal.
If I couldn't source a replacement it was thought it best to eliminate it.
But if a source is readily and cheaply available then I thought it's a good idea to fit a new one. The thinking behind this is, that Thermister might become problematic with time, a brand new one would see me out before starting to play up.
Don't know your thoughts behind the thinking.
Can I still run with your second schematic but just add the thermister in parallel with the 18 ohm resister??
thanks
Cliff
PS: Sorry if there's been rework on your part due to my typos.
B is the positive.
The tweeters (as well as other drivers)are colour coded.
All are marked with a red terminal, which I presume is +ve.
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One would have had to read Cliff's previous thread to understand that his decision to remove the PTC was based on an entirely different scenario.
Simply removing the PTC in the present scenario would leave an 18 ohm resistor in series with the mid/high drivers, not a good idea!
There followed the usual wide ranging discussion! 'Tis the nature of the forum and can be frustrating at times, but we are all friends here.
One would have had to read Cliff's previous thread to understand that his decision to remove the PTC was based on an entirely different scenario.
Simply removing the PTC in the present scenario would leave an 18 ohm resistor in series with the mid/high drivers, not a good idea!
There followed the usual wide ranging discussion! 'Tis the nature of the forum and can be frustrating at times, but we are all friends here.
And the common thing amongst us, the love or attraction to Loudspeakers.
DIY, in my opinion is the way, but to resurrect vintage has the potential of putting a smile on your face for minimal outlay, not to mention going easy on the planet.
Yes, and this would be the best thing to do now that we have sourced an Australian supplier of the C955 PTC.
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