Dec 132013

The Duelund-Westminster Special Edition (SE) external crossover project was a rousing success, and you can read about its step-by-step progression by following the links in the Review Archives here …

Duelund-WRSE screenshot

… or you can cut to the chase and read the final feature article I wrote about it for Positive Feedback Online here.

Screenshot of PFO Duelund-WRSE article

For those of you who have been following the Duelund-Westminster Project’s evolution, you’ll want to know that there has been some terrifically exciting developments: Silver. (photo courtesy of Wikipedia)

Silver bullion bar from Wikipedia

In the Duelund-Westminster Project I used the copper Duelund CAST capacitors and inductors for the external crossovers, and if you’ve read the article, you know they are amazing hand-crafted ultra-fidelity components that blew my mind with their superb performance.


However, quite a lot of you have been asking me what I thought about the silver Duelund CAST components, which I really couldn’t comment on, as I didn’t have any experience with them – until now. (the exception being the Silver-Carbon Duelund CAST resistors which I used in the external crossovers – they’re awesome!)

As I’ve posted earlier, Frederik Carøe – the founder of Duelund Coherent Audio – asked me if I would like to try a pair of his exotic 6.8uF silver Duelund Coherent Audio CAST capacitors in the Duelund-Westminster external crossover. I’m no dummy, of course I said “Yes!”.

So far I’ve provided three introductory posts about the silver 6.8uF Duelund CAST capacitors:

In my first silver post, I provided you a little sneak peek into what is involved in creating silver CAST capacitors, and about which I’ll explain more in the future.  

Raw Silver Foil Winding (1)

One thing I didn’t mention was how much silver goes into making the silver 6.8uF Duelund CAST capacitors – a couple of kilograms, actually. The silver spot price is $632.28 per kilogram at the moment. That’s for raw silver and it doesn’t count the silver losses due to silver migration when making the silver foils (a substantial issue in the manufacturing of silver electronics. Here’s a link to a Bell article on silver migration from 1955, and silver migration is still an issue today, and it makes manufacturing components with silver very expensive compared to copper), or for the overage of silver foil needed before trimming it back to dial in the exact capacitance value, or the extra labor involved in prepping silver foils for the CAST process, etc.

Frederick has to base his prices for the silver CAST components on the silver spot prices at the time he buys it, because of the silver price fluctuations that occur, so prices can vary somewhat over time. I am trying to somewhat tactfully prepare you for how much the silver 6.8uF CAST capacitors cost – you need to brace yourself, because they cost a lot!

In my second ‘Today’s Fresh Catch’ post about the 6.8uF silver Duelund CAST capacitors, I showed you some nice photos of them straight out of their shipping cartons, and other than the nice silk-covered silver ribbon leads, there was no indication of the beauty that lies within them.

6.8 uF CAST Silver Caps

In my third post about the silver 6.8uF Duelund CAST capacitors, I described installing them into the crossovers in the C1 position of the Duelund-WRSE external crossovers …

Silver CAST swap with Copper CAST

… and noted that other than their silk-covered silver ribbon leads, the 6.8uF silver Duelund CAST capacitors (left below) looked like their sibling 6.8uF copper Duelund CAST capacitors (right below) – what you don’t see is the magic concealed within.

6.8 uF CAST Silver Cap next to the Cu CAST cap

After getting the silvers installed into the crossovers I settled back to do a little listening. I was trying to temper my expectations because the silvers were cold out of the box, and not run-in or conditioned at all, and I knew they would only get better over time, so I was ready to cut them some slack if they sounded like ‘new’ capacitors.

The result of replacing just the pair of copper 6.8uF Duelund CAST capacitors in my crossovers with the pair of silver 6.8uF Duelund CAST capacitors … and you’ll probably be as crushed by hearing this as I was experiencing it … blew my farking mind – they are beyond awesome! Sorry about having to tell you that, because if you’re an average bloke like me, you probably can’t afford them, and man-oh-man, they are stunningly good,, and you’ll sure wish you could afford them!

6.8 uF CAST Silver Caps silver & silk leads - another view

Placing silver 6.8uF Duelund CAST capacitors into the C1 positions had a surprisingly dramatic effect, which when you think about it is pretty amazing, considering the already lofty performance level of the copper 6.8uF Duelund CAST capacitors that I use in the C1 position.

Here’s what I didn’t hear: any traces of grain, grit, brightness, harshness, etching, or other nasties. It was immediately apparent that the Tannoy Dual Concentric high-frequency drivers loved the silvers! In fact the silver 6.8uF CAST capacitors were smooth, rich, natural, detailed, shockingly transparent, and incredibly musical. I thought that set of attributes was particularly remarkable straight out of the box, and I can only wonder what heights the silvers might scale to with a little more time on them.

My friend Leo stopped by for a visit right after I put the silvers in the crossovers. Leo commented that putting in the silvers was like removing a veil that was in front of the loudspeakers, with much more detail coming through, and with many more instrumental layers being evident. Leo was right on!

When Leo stopped by for a little Hi-Fi fun & games I had no idea what the retail price for the 6.8uF silvers was, and I actually got the email from Frederik on their pricing while Leo & I were listening to music with them. If you do the math you’ll realize there’s thousands of dollars in materials cost alone, so you know the final product is going to be very spendy. The copper 6.8uF Duelund CAST capacitors came in at about $667 USD each at the time I wrote the article for PFO.  At the time Frederik made the silver 6.8uF Duelund CAST capacitors the price came in at $7500 Euros each (that’s $10,289.48 USD each at the time I wrote this). Yes they are extraordinarily expensive – that’s the cost of doing business with silver!

I’ll be reporting much more detailed impressions as I get more time on the 6.8uF silvers, but suffice it say they are extraordinary, and if you’ve got very, very, deep pockets they are going to be an absolute delight for you!

Frederick, I am absolutely in awe of what you have done with the silver 6.8uF Duelund CAST capacitors!

For you dear friends, if you haven’t noticed yet – I need to write a post about it – I’ve awarded Frederick’s brilliant CAST components a Positive Feedback Online Writer’s Choice Award for 2013. I said, “Personally, I believe that Frederik & Magnus’ Duelund Coherent Audio CAST product line of capacitors, inductors, and resistors are the finest being made in the world today for audio applications, and each one of them is an impressive work of audio artistry.” When I said that I was thinking of the copper Duelund CAST components, so you know what’s going to happen in 2014 for the silver CAST components!

labels of the 6.8 uF CAST Silver Cap next to the Cu CAST cap

Thanks for stopping by, and stay tuned for more on this developing story. Review to come in due time!

 Posted by at 5:12 pm

  5 Responses to “First Listening Impressions of the Silver Duelund CAST Capacitors – Wow!”

  1. I am jealous of you Jeff. I wish I could have had the money for these caps or at least have had the opportunity to listen to them.

    Especially with my system which is all silver in the signal.
    6.8 capacitance is quite big and the silver needed a lot so the price is prohibitive.

    At least I wish I could have the little autoformer with silver windings.

    • Hi Pambos,

      I think you’d love the silver CAST caps, they really do take things to the next level, but you are right, they are expensive!

      I’m hoping to figure out a path forward on the silver autotransformers too, but so far haven’t been able to. I’ll keep working on it!

      I hope you are doing well!

      Kind regards,


  2. Hi Jeff & Pambos:

    “There is nothinng either good or bad but thinking makes it so…” (Shakespeare’s Hamlet) I disagreel but I have to admit that in my mind for the obvious resons the Duelund Silver Capacitors don’t exist.

    For cost considerations, Is it possible to consider an Autoformer with silver windings for the level position only?

  3. Hi Frank,

    The level transformer will not be smaller and thus not cheaper. Thus, why not to have the option for adding or cutting dbs?

    I actually found myself last month to enjoy more the speakers with -1.5 db at high frequencies. After that I measured the speakers in my room and Believe it or not, in my room the level comes when the HF setting is at -1.5db!

    Is all about how the room the walls and the furniture in the room affect the frequencies, so is good to have the option.

  4. Hi Pambos:

    Thanks for that bit of insight.h3b3

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