Here I am trying to mod the speaker with better cap. Hope someone can help to share some steps to avoid the mistake.

Here is the KEF cresta 10 crossover



I have change the cap to all Elko Glatt (Mundorf oem). sounds quite good except the bass is restricted. After I put back original 10uF cap (which is Likon) it is ok and sound surprisingly smooth and revealing.

However When I measure the 7uF (old unit), I found the capacitance is 18uF. Normally the old cap the capacitance will drop after time, but why is it the value higher than what is stated. I measure the other unit and found the same high value.

Then I try put in the 10uF (which is measured to be 12uF) and now do the testing.

I meausred the old unit and new unit of the same capacitance.

I found all matches well (6uF and 10uF) except the 7uF. The 7uF gone to 20uF. So I dont think my meter has got problem.

Anyway, I tried replacing the 7uF with 10uF M-cap (elko oem) and found the treble is blur. The music is no more natural. So I put back the 6.8uF M-cap (Elko )

I am also told to use lower cap to replace the new cap. e.g. 7uf with new 6.8uF cos the new cap the capacitance is always higher. true ?

I put that obligatto into my soundstage 1.5.

After that, I find it very interesting.

but now we are talking about speaker crossover. modifying the cap does not mean it will get out of its tune but more to suit my ear.

the designer ear is not my ear.

Obbligatto sounds more analogue. Its vocal is more warm yet with detail. The vocal is also more forward, smooth and clear. quite good for value.

I didnt take photo. may be abel can help.

check this out.

http://www.humblehomemadehifi.com/Cap.html

It is huge. I only use 0.47uF for my soundstage 1.5, and it is huge and heavy.

I am waiting for Jantzen cross cap to arrive. Then I can mod again loh. This time I will reduce the capacitance at 7uF to 5.6uF.

Does anyone know if I can test out the freq response of the X O network.

e.g. 6SN7 tube coupling cap 0.1 uF is 333V.

I havent learned up the network yet. the 7uF cap is normally not there. I increase the cap value and found the vocal flatter. I was thinking lowering that 7uF will bring in more higher treble ? the 6uF works on high pass. is the 7uF works on high pass as well ?

clarity, dynamics, bass response. 1st order, 2nd order , 3rd order filter. the circuit diagram is a 3 rd order XO.

My 6.8uF Jantzen cross cap is on the way. will try

1. parallel 2x6.8uF cap.
2. bypass 7uF i.e. 2nd order. (isnt that -12dB/octave and a much gentler slope than 3rd order which is -18dB/octave). All this while, my tweeter survice the -18dB slope.

The sifu of series crossover is cooking now. will get to it around the corner.

This post has been edited by ccschua: Jan 5 2009, 11:29 PM

That would be great. Now I am pampered with too many items. I just received some white sausage too.

The cap just received. Again the Malaysia posmen is too lazy to wait for people to answer their call.

Dunno how to complain about my problem.

By tomorrow I would be able to receive the parcel.

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Added on January 8, 2009, 11:48 pmoh nice.

got all the cap now.
the Jantzen and the solen.
plus the taiwan unknown cap.

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Added on January 8, 2009, 11:55 pm

This post has been edited by ccschua: Jan 8 2009, 11:55 PM

For me, it is better to describe what is the setup. matching is always the first thing to check.

Open it and trace the circuit.

u should see the connection from input to output, tweeter and woofer. Normally more symtoms can be found if u check the cross over.

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Added on January 11, 2009, 11:34 pmJust tested the Jantzen Cross Cap. I am surprise at how clean the sound is and very detail presentation. It is definitely good cap.

This post has been edited by ccschua: Jan 11 2009, 11:34 PM

Yours look very similar to mine, except u have 1 resistor less than mine. Again I do not want to speculate what is the cross over network. can u trace the circuit from input to the output and put in a sketch like mine in the 1st post.

I dont like the wire connection using clip on. prefer solder.

Hi Chef,

welcome back. take it out as shorting it with some lead wire?

I have also come across the Vishay Roederstein MKP1837. What do you think of this little sweetener ?

The Jantzen really opens up the soundstage, become clearer and the bass more punchy.

Sorry I didnt notice your post. The white cap is polypropylene cap from Taiwan. The sound is towards clear and transparent. The weird part is when I use it, the bass is very restricted. I guess need time to run in. that;s the trouble with new poly cap.

yeah. the MKP 1837 Roederstein. It doesnt seem to work on my speaker. funny. Will in future try again.

I have that too and i use a lot of them for the zero franken mod. Also i use that for my shigaraki clone cd transport. I found it good.