Dec 032017

As I mentioned in my last post, I just got a note from Frederik Carøe that the first batch of the 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 was really impressed with the Duelund 0.01uF tinned-copper bypass capacitors’ performance on the 6.8uF Duelund CAST pure copper foil PIO in the C1 position of my Westminster’s high-frequency crossover sections.

Duelund CAST “hybrid” Sn-Cu capacitor in C1 of the HF circuit of the WRSE crossover.

To my surprise, the Duelund CAST “hybrid” Sn-Cu capacitors’ performance in C1 very nearly rivaled the performance of the ultra-performing (and ultra-expensive) Duelund CAST pure silver PIO capacitors in terms of sheer musicality.

I decided I liked the Duelund CAST pure silver PIO capacitors in C1 the best, and put them back in C1, but the difference in performance wasn’t nearly such a large gulf between the Duelund CAST “hybrid” Sn-Cu capacitors and the Duelund CAST pure silver foil PIO capacitors like it was when I compared them to the Duelund CAST pure copper foil PIO capacitors.

Duelund caps on the audiodharma Cable Cooker.

I put the Duelund CAST “hybrid” Sn-Cu capacitors on my Cable Cooker for a week of conditioning, and I’m getting ready to put them back in the system to hear what happened.

Cooked Duelund CAST Sn-Cu “hybrid” cap awaiting installation in C1.

Check back in a little bit and I’ll post some impressions of what happened as a result of the conditioning, and how they compared to the Duelund CAST pure silver PIO capacitors in C1.

Left crossover C1 cap swap complete.

Right side C1 cap swap complete!


I got delayed on following up on this post, but it turned out to be for the good!

As I mentioned above, I put the Duelund CAST “hybrid” Sn-Cu capacitors on my Cable Cooker for a week of conditioning, and … well … it didn’t work out so well.

I thought because of their sheer size I would condition the Duelund CAST “hybrid” Sn-Cu capacitors for a full 7 days, but it turned out to be too long, with the result being that I “over-cooked” them.

That’s the first time that I’ve over-cooked a set of capacitors, and it was immediately obvious on first listen.

The over-cooked Duelund CAST “hybrid” Sn-Cu capacitors sounded really wonky, with the mid-range on down sounding murky and distant, and with the highs sounding screechy and forward. Definitely not a happy result.

If you’ve over-cooked your caps you need not worry, as it turns out the way to “heal” them is just to let them play music for a week or so and they’ll sort themselves out. Whew!

Bob Dylan’s “Fallen Angels” – a heavenly album!

I really like Bob Dylan’s Fallen Angels album. It’s full of jazzy old Americana standards: “Young at Heart”, “Maybe You’ll Be There”, “Polka Dots and Moonbeams”, “All the Way”, “Skylark”, “Nevertheless”, “All or Nothing at All”, “On a Little Street in Singapore”, “It Had to Be You”, “Melancholy Mood”, “That Old Black Magic”, and “Come Rain or Come Shine”.

The musicians are Bob Dylan (vocals), Charlie Sexton (guitar), Stu Kimball (guitar), Dean Parks (guitar), Donnie Herron (steel guitar, viola), Tony Garnier (bass guitar), and George Recile (drums).

The musicianship is superb, the recording is superb, and if you like jazzy old standards I think you’ll really enjoy this album.

System photo December 2017.

After the Duelund CAST “hybrid” Sn-Cu capacitors settled down, on Fallen Angels they sounded natural, rich, with great “tone” and lots of timbral texture, and a really nice presentation of rhythm, melody, and beat.

They also show off the high-quality sonics of this recording: it’s big sense of space, its wide soundstage, excellent imaging, and nice layering of the instruments in the soundstage.

Lucinda Williams’ “World Without Tears” album.

Lucinda Williams’ World Without Tears is an excellent album musically, but can be a bit “challenging” sonically, as it can be a bit forward and “edgy” sounding.

Lucinda’s songwriting is superb, as you would expect from the daughter of an award winning poet and literature professor (Miller Williams), and she really knows how to dial in the emotional content of her music.

It’s been quite a while since I’ve listened to World Without Tears, and I thought it would be a good test of the Duelund CAST “hybrid” Sn-Cu capacitors to see how they handled the superb music but less than ideal sonics of World Without Tears.

Thorens TD-124 and Classic 301 turntables.

The Duelund CAST “hybrid” Sn-Cu capacitors handled World Without Tears pretty well, actually (and better than I expected), with the music coming through compellingly intact, with the sonics presented pretty well, but still a bit edgy and forward in the upper-midrange.

Well, that’s what the album sounds like, but I think the Duelund CAST “hybrid” Sn-Cu capacitors did a reasonably good job of preserving the musicality of the album, while not exagerating its issues.

The Alternate Blues

On The Alternate Blues – my favorite album for checking to see if a component is getting the horn tone right – the overall the horn tone sounded very good, with natural but not overdone piquantness in the tone of the trumpets, for example.

Cymbals, bass, guitar, piano, all sounded really nice and natural, with excellent timbral realism, with Joe Pass’ guitar having particularly good tone color resolution.

Check back with me a little later today and I’ll describe the performance of the Duelund CAST pure copper foil PIO capacitors without the Duelund tinned-copper coupling caps in place, as well as comparing them both to the uber spendy pure silver paper-in-oil Duelund CAST caps.


More soon!

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

 Posted by at 9:09 am

  6 Responses to “Take Two: Duelund Coherent Audio 0.01 uF Tinned-Copper Paper-In-Oil Bypass Capacitors! Update.”

  1. Hey Jeff.
    Looks like you’re having a ball. I’ve got a couple of questions for ya.

    First, I’ve noticed the decrease in price of a given line of capacitors generally corresponds to the respective decrease in capacitance of the line’s offerings. For example, 1uf is more than .47 uf, which is more than .33uf, and so on and so on, down the line. Looking at the list on Parts Connexion, I see the price of the Duelund .01uf tinned copper CAST-PIO caps are only less expensive than the line’s largest 2.2uf capacitors. I’m by no means assuming Duelund is trying to pull a fast one on their customer. However, is there any chance Frederik offered some transparency for why the .01uf cost is exponentially higher than all but the line’s largest capacitor? I only ask because I’m a hopeless sucker for business case studies that break down how production rates, logistics, and details like batch orders of raw goods, all inform a commodity’s price for a given market.

    Second, has he mentioned the possibility of offering a .033uf CAST-PIO cap? Or even a JAM version? Because that value just so happens to be specified for the first coupling capacitor in a McIntosh C20 preamplifier 🙂

    • Hi Grant,

      I just went out to look at the Parts ConneXion web page here, and it doesn’t look like they have the tinned-copper bypass caps listed yet.

      I think the ones you are referring at the top of the page are the CAST silver bypass caps, and silver is a lot more expensive that tinned-copper.

      I suspect when they get the tinned-copper bypass caps listed the price will be more like you were expecting to see.

      I do know Frederik will make up the exact value of caps you need if they’re not stock items, so you might want to send him an email and ask him about that.

      I hope that helps.



      • Hi Jeff.

        Ah, I see what you mean. Yes, the 01uf caps listed on the page are the same part number as the .01uf Cu/Ag Hybrids. Thanks for pointing that out, and for the nudge to go straight to Frederik for making caps with specific values. With all the various caps crammed in the C20, the potential for custom caps is a whole new kind of rabbit hole 😉


    • I see it Grant as well 269.95 each had me scratching my head.


  2. Is that a Waterloo in the system pic? Had a NGD recently Jeff?

    • It is indeed a Waterloo, Gareth, a WL1-4 with ladder bracing and a carbon fiber T-bar. It is amazingly light and responsive, and I’ve been having a ball with it! It is my most recent NGD! 😉



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