Nov 262017

I just got a note from Frederik Carøe that the first batch of new Duelund Coherent Audio 0.01 uF tinned-copper paper-in-oil bypass capacitors are ready and will be arriving at Parts ConneXion this coming week.

Duelund 0.01 uF tinned-copper bypass capacitors.

I’ve tried them in two applications so far and have been very impressed with the results.

My first trial of the Duelund 0.01uF tinned-copper bypass capacitor was in the crossovers of my vintage Altec Voice of the Theatre A5 loudspeakers.

0.01uF Duelund Sn-Cu bypass caps in the A5 crossovers.

That made for such a nice result I almost left them in place and called it good … but I really wanted to hear them as a coupling capacitor in the C1 position of my Westminster’s high-frequency crossover too (below) …

Duelund CAST “hybrid” Sn-Cu caps installed into C1.

You can see in the photo above where I added the new 0.01uF Duelund tinned-copper coupling capacitor to a 6.8 uF Duelund pure copper foil paper-in-oil CAST capacitor in C1.

I still find myself being surprised that a small coupling capacitor can effect such a large change to the overall voicing, and the results were impressive.

I compared the result to the 6.8uF Duelund pure silver foil paper-in-oil CAST capacitors ($$$) that I normally use in C1, and the new 0.01uF Duelund tinned-copper coupling capacitor plus 6.8 uF Duelund pure copper foil paper-in-oil CAST capacitor made a fine showing of what they are capable of, coming close to the level of musicality & sonics that the very expensive pure silver caps so easily accomplish.

Duelund hybrid Sn-Cu caps installed into C1 (upper left in crossover).

That’s saying quite a lot, because I didn’t think I’d ever hear another capacitor that would be able to even come close to what the pure silver 6.8uF Duelund CAST capacitors are doing sonically and musically in C1.

Certainly, the 6.8 uF Duelund pure copper foil paper-in-oil CAST without the new 0.01uF Duelund tinned-copper coupling capacitor couldn’t come close to the musical & sonic performance the pure silver Duelund CAST capacitors are capable of, as good as the CAST copper foil caps are in absolute terms.

The new 0.01uF Duelund tinned-copper coupling capacitor adds to the 6.8 uF Duelund pure copper foil paper-in-oil CAST capacitor that familiar tinned-copper vividness, sense of tactile presence, intensity of tone color resolution, sense of spaciousness, and engaging musicality that makes tinned-copper so enticing and exciting to listen to music with.

The hybrid tinned-copper capacitor combination is not as smooth and sophisticated sounding as the pure silver Duelund CAST capacitors, but it is a very musical presentation that I like a lot, and made an impressive showing.

I have plans to put the 6.8 uF Duelund pure copper foil paper-in-oil CAST – with its new 0.01uF Duelund tinned-copper coupling capacitor installed – on my Cable Cooker to give the hybrid some conditioning time, as I’m curious to hear if a little conditioning helps bridge that remaining gap to the performance of the pure silver Duelund CAST capacitors.

I’ll also compare the tinned-copper hybrid to the 6.8uF Duelund CAST capacitors with a Duelund silver bypass cap in C1, and report back.

0.01 uF Duelund tinned-copper bypass capacitors.

Please report back on your results using the new 0.01uF Duelund tinned-copper bypass capacitor, I’d like to know about what you are hearing from it in a variety of different applications.

Ok, that’s it for now, I’ll report back with more information about the 0.01uF Duelund tinned-copper bypass capacitors as I get more experience with them.

As always, thanks for stopping by, and may the tone be with you!

 Posted by at 6:13 am

  4 Responses to “Duelund Coherent Audio 0.01 uF Tinned-Copper Paper-In-Oil Bypass Capacitors”

  1. I have just put duelund jam and tinned-copper bypass on my tweeter.
    they are amazing much better than ClarityCap MR that was in there before

  2. WOW I’m having trouble getting my arms down
    even though I thought and hoped they were better than ClarityCap MR
    I’m a little shocked
    I did not really think they could be so much better
    that they actually justify the price compared to MR, but they do.

    • That’s fantastic, Hansen!

      That’s been my experience too with the Duelund tinned-copper capacitors, with both the Duelund 0.01uF bypass caps I’ve used in a couple of different crossovers (A5’s and WRSE’s), and the prototype Duelund CAST 0.22uF caps that I’m using in my vintage McIntosh MX110Z tuner-preamplifier.

      Kind regards,


  3. Personally I thought too expensive ,But the Duelund Silver .01 bipass Cap is the best out there Period. Their cast too much $$
    For my budget I have an alternate combo that is close .

    I will be putting a pair on my outputs in preamp After the holiday $100 a pop is not cheap . One expensive hobby !!

    Merry Xmas to All !!

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