If the caps are not trimmed to exact value on our equipment they will degrade the sound regardless of their quality.
Well, I decided to take the risk. I ordered my new capacitors from Sonicraft. They will come in two sets of four identical caps. Jeff from Sonicraft will match the quad sets to the
exact specified capacitance for no added charge. I found the correct capacitance values written on the caps inside my speaker. When I will have received the Sonicaps, I will measure their capacitance and see how much they differ from the reference.
I received the caps.
For the tweeter: I received two sets of 4x0.33 uF.
I measured the capacitance of the caps with a RadioShack multimeter. For the original caps, I measured 1.370 and 1.363 for the left and right speaker respectively. The value written on the original caps are 1.37. For the Sonicaps, the capacitance of the two sets are 1.363 and 1.361. The difference are in the range of 0.3-0.5%. The value measured by Jeff are 1.34 for both sets (I requested 1.37, but the Sonicaps were too close to their specs to be able to reach 1.37).
For the mid panel: I receive two sets of 4 x 12 uF.
Unfortunately, my RS multimeter cannot measure capacitances above 40 uF. According to the value written on the original caps, the capacitance I need is 48.11. I estimated the capacitance of one of the Sonicaps set by measuring the 12 uF individually and summing up the results: 48.26 uF (+0.3% from 48.11).
Sound:
I have installed only the mid caps yet. I noticed a larger and more detailed soundstage. After a few weeks, the sound is still changing. According to Jeff, the Sonicaps take a long time to break in.
I don't know when I will have the tweeter caps installed. Actually the problem is that I damaged my amp while trying to breakin the tweeter caps directly: I connected the caps in serie with a 4 ohms resistor to the speaker terminal and accidently made a short
.
Is this Sonicaps DIY upgrade better than the official Auricaps upgrade? I don't know and I don't plan to try the Auricaps. If you wish to try this upgrade youself, it is at your own risk. The saving cost is about 50%.
Notes:
- I think there is way to have a set of Sonicaps that match the original capacitance more closely. The idea is to sent your original caps to Jeff, let him measure their capacitances with his own instrument and then match the quad sets to the exact measured capacitance.
- The stock caps reach the desired capacitance by starting with a large cap and adding smaller caps (I suppose this is called a
"cascade"). Jeff 's approach is different: select by hand a set four caps of similar capacitance. I don't know which method is best, I am neither a speaker designer nor a capacitor manufacturer.
- Using twinset of 24 uF instead of quadset of 12 uF would have saved money. Jeff recommended the quadset instead because the 12 uF caps are faster than the 24 uF.
- The capacitor upgrades for VMPS speakers are quite more expensive than for other speakers, even with the less expensive Sonicaps as described here. I think this is normal and due to the fact that the crossover point of the mid driver is unusually low.
Bruno
