Apr 202017

Frederik emailed me this morning with an exciting announcement of two new products that are in the works at Duelund, both involving tinned-copper, and both of which I find very exciting!


As most of you reading my blog are aware, the Duelund DCA series of tinned-copper tone-cables with their oil-soaked & baked cotton dielectric have taken the world by storm, first because of their awesome performance, and secondly because of their incredibly modest pricing.

Rarely does one find ultra-quality, ultra-performance, and modest pricing combined in a premiere product, like you do with the Duelund DCA12GA, DCA16GA, and DCA20GA.

The new Duelund Coherent Audio DCA20GA tinned-copper tone-wire.

Just this morning I was answering Griffin’s comment, saying that there was no such thing as a Duelund solid-core tinned-copper cable, but I wished there was.

In particular, I wished there was a Duelund equivalent of the vintage WE24GA headshell wires that Yazaki-san sent me to try, but which you can’t buy outside of Japan. They were wonderful from a musical perspective, and I immediately fell in love with them, but they’re not available! Argh!

Vintage Western Electric WE24GA for headshell leads.

Well guess what, right after I posted my reply, Frederik emailed me and told me that he now has in the works a DCA26GA solid-core tinned-copper cable with an oil-soaked & baked cotton dielectric, and it will be coming soon!

A solid-core DCA26GA tinned-copper cable could be an even better choice than the vintage WE24GA for headshell wires, because the WE24GA is kind of bulky for headshell wires, and it is a bit hard to accommodate in the space available between the cartridge and headshell connections. The DCA26GA would make for an easier fit.

You can bet you’ll hear more from me about the solid-core DCA26GA as headshell wires and as tonearm wiring when it becomes available in a couple of months!


Unfortunately, a lot of folks just can’t afford the price of the lofty Duelund CAST series of hand-made capacitors.

I think Duelund makes the best capacitors in the world in their CAST product lines, but they don’t come cheap.

A lot of you know how blown away I was by the prototype Duelund CAST tinned-copper paper-in-oil capacitors I tried in my vintage McIntosh MX110 tuner-preamplifier, and in the crossovers for my vintage Altec A5 Voice of the Theatre loudspeakers.

A pair of prototype 0.22uF Duelund CAST Sn-Cu capacitors that I’ve soldered into my vintage MX110Z McIntosh tuner-preamplifier.

The prototype Duelund CAST Sn-Cu capacitors humiliated every new and NOS capacitor they went up against in my tests, easily besting anything else in both sonics & musicality.

The C3 0.88uF Duelund tinned-copper capacitor bundle in my A5 breadboard crossovers.

In my opinion the Duelund CAST tinned-copper capacitors are in a league of their own, and nothing I have tried new or NOS even comes close.

The downsides of the Duelund CAST tinned-copper capacitors are their jumbo size & cost. The jumbo size makes it tricky or even impossible to place them in some circuits, and their jumbo cost makes it tricky or impossible to fit them into some budgets!

If I were going to recommend capacitors to you for a crossover or electronics project without cost & size being a consideration, the Duelund CAST tinned-copper capacitors would be where I’d suggest you start.

But now there is another potential choice that is very, very, interesting to me, because they are smaller and less expensive!

The new Duelund 0.22uF JAM tinned-copper PIO capacitor!

Frederik has been thinking about what a wonderful thing the DCA series of tinned-copper cables have turned out to be for audio enthusiasts, bringing the Duelund level of quality & performance to an affordable price level, and he decided he wanted to do the same thing for his Duelund tinned-copper capacitors.

Frederik has created a new less expensive & smaller version of the tinned-copper foil & paper-in-oil capacitor aimed at more compact spaces and budgets.

Frederik told me:

“As you know, I’ve been very interested in getting the tinned-copper foil technology used in a more cost effective approach than our full spec CAST 630v tinned-copper capacitors. So what we have done is to take a more classic approach, by creating a tinned-copper foil capacitor with an oil impregnated paper dielectric. This is placed in an oil filled metal enclosure. This takes us very close to vintage style capacitors, all the while giving us +600 volt capacity, and ensuring we can take tinned-copper foil capacitors to a much lower price point than before.”

The new Duelund 0.1uF JAM tinned-copper PIO capacitor!

Woo hoo! What great news!

I can’t help but wonder if the new Duelund JAM tinned-copper capacitors will be my dreamed about heir of the Bumblebee & Black Beauty for the modern age? Is the Duelund JAM my dream come true? I hope so!

Notice that it is black … but what about the ‘JAM’ on the casing? Is JAM a reference to ‘jamming’ in the musician sense, or is it a reference to musicality generally … just what does JAM mean?

Frederik says:

“You may know our entry level capacitor is called the Alexander, named after my first born son. As more children have come into the world since then, I decided to honor them in the name of the new capacitors. JAM is actually both a nod to the musicality made possible by this capacitor, but also refers to the first letters in our children’s’ names. (J)oachim and (A)lexander, my two boys, and (M)irah, Magnus’ first born daughter.”

Now that is way cool, it is a reference to musicality, and more importantly, to family! Join me in congratulating Frederik on the addition of the new ‘baby’ JAM to the Duelund family of capacitors!

I’ve already got all kinds of project ideas popping into my head for the new Duelund JAM tinned-copper capacitors!

The Duelund JAM tinned-copper capacitor is an exciting development for audio enthusiasts, music lovers, and musicians, and all I can say is, “JAM baby JAM!”

Frederik says:

“Parts ConneXion takes delivery of these next week. The pricing for the 0.1uF is $63.26 MSRP, and they’re doing a 25% off intro pricing special of $47.44, with the 0.22uF at $71.50 MSRP, with 25% off special for intro pricing at $53.63.”

The new Duelund 0.22uF JAM tinned-copper capacitor.


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

 Posted by at 11:40 am

  37 Responses to “Breaking News! New Duelund Sn-Cu Capacitors & DCA26GA Wire Coming Soon!”

  1. Being a lifelong audiophile, we named our son(now 19) Jared Adam (Meyers) so his initials would be JAM.

    Thanks Duelund for another exciting product.

  2. Jeff,

    JAM Vs. the brown paper dynamites would be very interesting 😉


  3. The Duelund DCA26GA Sn-Cu wire is exciting news for vinyl enthusiasts like me. I have the Western Electric wire that Yazaki-san recommended, and it was a significant improvement over the “audiophile” grade wires Inhad in there before. Having tried Duelund DCA20GA in internal wiring and unshielded RCA interconnects, I can only imagine the improvements the new head shell wires will make.

    With the new JAM Sn-Cu PIO caps, I am in a pickle about whether to move forward with the Duelund CAST Sn-Cu PIO caps or to try the JAM caps in my McIntosh MC240 amp. Parts Connexion now has the 0.1uF Duelund CAST caps in stock at an introductory discounted price. I’m leaning toward the CAST caps for their ideal, uncompromised construction. Since these would replace the Sprague Bumblebee caps at the amplifier inputs, I would think selection of the capacitors is critical. The JAM caps might be better suited in the other positions like those in the feedback loop within the amp. It’s tempting to try rolling both.

    In any case, Frederick and the Duelund teams are making DIY audio very fun these days.

    • Howdy Rich,

      I’m looking forward to giving the DCA26GA a try as headshell wires as well, and I’m thinking there might be a tonearm rewire in my future as well.

      The Duelund CAST Sn-Cu PIO caps are amazing, that’s for sure. They’re also huge, so they can be hard to fit in tight spots, but when you’ve got the room you can’t go wrong.

      I’m really looking forward to checking out the new JAM caps as well, and it definitely would be fun to compare the two.

      Definitely kudos to Frederik and the Duelund team! They continue to surprise and impress me with each new offering, and it sure makes for exciting mods!

      Keep me posted it you get there before I do!



  4. The 26ga wire might be more sucessful than my expriment with the 20ga as headphone cables for my Audeze lcd2 , the 20ga was far too stiff, and the smell was a bit much too!

    • In my excitement I missed that the wire is solid core, so unlikely to be suitable for headphone cable.

      I might try some of the belden 8402 as headphone cable if i can get a long enough length here in Europe.

  5. Hi Jeff,

    I have changed all of my cabling to Western Electric being 10gauge for power cables and speaker cables and very old western electric 16 gauge for balance cables from cd to pre and pre to power monos. The sound that I am getting using western electric is far superior to the top tier Audioquest cable that was being used in my system.

    After reading your webpage about duelund cables and more importantly the oil impregnat, I thought let’s use good quality bee’s furniture wax on the Western Electric cable. I did the balance cable first by rubbing the wax over the outer sleeve . The improvements was very noticeable. I also now done the same over the speaker cables. Once again the improvements it was very noticeable. I am not sure if anyone else have tried this.

    My system is a all valve affair including my CD player and with 150watt of triode power per channel from each mono. My pre and mono power amps have separate power supplies.

    I thought to let you of my experience with western electric cable with bees wax.

    • Hi David,

      That’s a great discovery with the beeswax furniture polish!

      With the results you’re getting with the Western Electric and the beeswax furniture polish, I think I’d like to give it a try as well.

      I’ve got some WE18GA power cords to try on my MC30’s that Yazaki-san sent me, and a before & after experiment with the beeswax sounds like fun!

      What brand of beeswax furniture polish are you using?

      Kind regards,


  6. I have obtained the bee wax from our local antique dealer here in Australia. I have not done the power cables yet, may get some time this coming weekend.

    The results obtained when coating the balance and speaker cables was well worth doing in my system.


  7. Hi Jeff,

    A lot has happened wow glad its all worked out. Been without all tube setup for a bit so I couldn’t report further progression in my sound quality. I got a suggestion for Fred if you talk with him. What about a tinned bypass cap for capacitors in our crossovers, or could these be used for that? Like the silver one he sells.


  8. Hello!
    I’ve got a pair of Duelund JAM 1.0uF caps in a budget vintage project – a pair of Klipsch Forte I that I restored.Currently hunting for a decent pair of Altec’s in Arizona as well.

    I’ve about 50 hours on these crossovers in this configuration, so need more time. Also, my amps are in transition, so it is difficult to give early impressions. Will report back on this once everything has settled in, and my amps are in house. Very excited to hear how things develop.

    Thanks for the continuing support and insight.


  9. Hi Jeff,

    Choosing between the CAST Sn/Cu and Cu/Ag capacitors, which might be most desireable as an interstage coupling cap on an EL34 based amplifier, assuming I was running and generally liking Mundorf SGO? I would really like to preserve the current voicing in the high frequencies, but increase the color and weight of the lower registers. The Cu/Ag hybrid seemed like a logical choice, but I know that many folks advocate against bypassed coupling capacitors. I’d love to know your thoughts, as you are among the few that’s had the opportunity to hear the entire Duelund range.

    Best Regards,

    • Hi Jake,

      I’ve never been able to compare my prototype Duelund CAST tinned-copper capacitors to the same value of Duelund CAST silver or regular copper capacitors.

      The CAST Sn-Cu caps I have are for use in electronics, and the CAST silver, CAST silver-copper hybrid, and CAST copper capacitors are for use in my WRSE’s crossovers.

      In my crossovers’ C1 position I prefer the Duelund CAST silver capacitors by quite a large margin over the CAST silver-copper hybrid, or CAST copper capacitors, which are both great capacitors, but those CAST silvers are simply amazing!

      In my MX110Z preamp I’ve tried quite a lot of new, NOS, and boutique capacitors, but nothing even comes close to the Duelund CAST Sn-Cu capacitors, they’re like an order of magnitude better than anything I’ve ever tried, both musically and sonically. They are truly remarkable, and I can’t imagine using anything else in my amplification electronics.

      If I were going to build a net of crossovers for my vintage Altec A7’s or A5’s with the Duelund CAST capacitors, I would definitely go for the new CAST Sn-Cu capacitors, I think they would be amazing based on what I’ve heard with them in my MX110Z.

      Can’t say anything in relation to the Mundorf’s, I’ve not tried them.

      All the best to you in your adventure!

      Kind regards,


  10. The jams now putting these on another speaker as a2.2uf complement.
    My 68uf cap is too huge to ask for A Duelunds but the 2.2 add a nice added tone and detail yo the Clarity Csa cap. A fantastic bypass cap. Not cheap but not cast monies either.
    And 40% off currently on these parts connecxion.

  11. Hello Jeff I have a DHT preamp with a pr of Mundorf Supreme 23uf caps in a output loop
    Lundahl transformer coupled .I just bought a pr of the Duelund Jam 3.3uf caps
    I will report back after next weekend .i am sure these will take a solid 400 hours + to fully open up
    But wil let you know . I thought for sure you would have burned in a pr in a speaker or something
    To hear your opinion vs a Jupiter Copper foil for example or other Duelund caps
    That helps others know what to expect ,surprised not 1 review out on these yet.
    Please advise on Sonics if you know Anything .Thanks much,Paul.

  12. Hello Jeff 2 New very good caps being used the Duelund 3.3uf JAM caps
    In my preamp still running in but already have a very detailed presentation the drum snares,and brushes are very much you are there quality and a nice fullness at far less then the cast caps and over 90% as good currently 37% off at parts connexion introductory price while they last.
    The other cap just for speakers the New Jantzen Alumen Z Foil caps use a very thin
    Poly dielectric . Very fast, transparent and smooth ,not bright at all
    And best of all not expensive at all I mixed with Jupiter Copper foil .
    They match very well with other caps

    • Hi PJ,

      I too have found the Duelund tinned-copper caps to be amazing on percussion, it sounds so real.

      Thank you for sharing your results, I haven’t had a chance to try the JAM caps yet, so am glad to hear they are performing so well.

      Keep me posted on your capacitor adventures, and let me know how it all works out!

      Kind regards,


    • Hello PJ,

      Can you compare the sound of JAM vs (Jupiter Copper , Duelund Cast Copper , Audio Note Copper, Jensen Copper)?


      • I have phonostage that I built by EAR834 scheme (with “air” RIAA capacitors in a feedback and L-C-L-C power supply).
        I’m thinking about changing 0.1uF Audio Note Copper capacitor between the first and the second tubes.
        I want to get the same fullness like Audio Note Copper does but with more transparent high frequencies.

        I changed Audio Note Copper capacitor to Duelund Cast Cu in my 300B amplifier and I liked results a lot.

  13. Hi Jeff,

    It is difficult for me to decide which 0.1uF capacitor to put in my EAR834 phonostage between fist and second tube. This capacitor works in the circuit without feedback. So the quality of this capacitor should make a big difference.
    I doubt should I go to Duelund JAM or Jupiter Copper of save money for buying CAST-PIO Tinned Copper ?


    • Alex, fwiw i found the arizona blue capacitor to sound better than the jensen copper pio in the 0.15uf position in the 834 i built. I also have arizona red in the 1uf position. Then the russian sgm silver micas in the signal section (there is some talk about silver micas in the yazaki post from a couple of days ago) Sounds great to me!

      • Hello Joseph-san,

        I hope you try Red, Blue or Green, connected in parallel with our mica cap. MC-103DA ( 0.01 ) or MC-223DA ( 0.022 ) . It would be the best solution for the signal use capacitor and also very nice for power supply. In the Arizona line-up, I’d like you experience the sound of Green, 0.33 and it would be a super cap, I believe !!

        Thank you for your comment, so encouraged !!

        Shirokazu Yazaki

        • Yazaki-san,

          I beleive i am actually using a red not green as stated.

          Unfortunatly i havent managed to find a source of SPEC mica capacitors (im holding out for hifi collective getting hold of some, as well as the tepro resistors you have recomended!)

          I also replaced the jensen copper paper in oil capacitors in my 300b amplifier with the Arizona blue and red capacitors and rewired completly with WesternElectric tinned copper wire, a very nice improvemwnr has been my impression!

          Many thanks for your contributions!


          • Dear Joseph-san,
            Thank you for your comment about Red Cactus and Blue Cactus. I wanted to produce genuine Paper-oil filled Capacitor in early 2010. Yes, Red is the one and the tone would be pure and so beautiful for my hearing. Its tone is much depends on high quality Kraft Paper. Compared to another film capacitor, such as Mylar, polypropylene or Teflon as dielectric material, I have felt more natural and organic. Blue and Green have laminated dielectrics, made of Kraft-paper and Mylar and Blue’s structure of dielectrics is just the same as vintage “West Cap” for military use. And so Blue Cactus has the tone color with some kind of richer mid-low range, it could fitted well Jazz music, I believe.
            But our mica cap, MC-103DA (0.01) or MC-223DA (0.022) ,connected in parallel with Red, Blue or Green, you could find out another level of sound extending over before you. Not only richer and clearer tone but also spectacular sound stage, you might feel.
            If you had any interest in our mica cap., Please feel free to contact me below —,

            yazaki@spec-corp.co.jp or Shirokazu2017@gmail.com

            Thanks again for your comment, so encouraged.
            Best regards, Shirokazu Yazaki

      • Hi Joseph,

        Thank you for useful information.
        Now I use Audio Note Mylar-Oil-Copper on 0.15uf and 1uf positions in my DIY 834p project.
        I use variable air dielectric capacitors in the feedback.


    • Hi Alex,

      That’s a really hard question to answer because I haven’t tried the Duelund JAM or Jupiter Copper cap’s.

      As you know, I am extremely impressed with the Duelund CAST tinned-copper cap’s, and they have been hugely better than any other cap’s I have tried while experimenting with my Altec A5 crossovers and MX110Z preamplifier.

      The tricky part of using the Duelund CAST tinned-copper cap’s is their large size. If you can fit them into the circuit, they’re definitely the ones I’d go for.

      Kind regards,


      • Hi Jeff,

        Thank you for advice.
        I decided go to Jupiter capacitors. They are the smallest and I can place them near tubes sockets. They also much cheaper than CAST-PIO Tinned Copper Film. And I never tried any Jupiter capacitors before, so I’m curious to try…

        Duelund Cast-Cu capacitors did revolution in DIY audio world. One person did compareson between Duelund Cast-Cu interstage capacitors and Tamura and Tango interstage transformers. The conclusion was Duelund Cast-Cu are more transparent (I read it on one forum). In Jensen/Audio Note capacitors era good interstage transformers always overperform interstage capacitors.
        I never tried teflon capacitors. But I read a lot of reviews about them. I will not put them into my system even by free.


        • Hi Alex,

          Let me know how you like the Jupiter cap’s.

          Kind regards,


          • Hi Jeff,

            I got Jupiter Copper capacitors. I burned them 3 days in Frybaby2.
            I soldered capacitors into my phono-stage and listened. After that I connected Frybaby2 to phono-stage and run it about one hours. This extra hour didn’t do any difference.
            The tonal balance after installing new capacitors was even. It looks like capacitors path about 90% of break-in.
            Compared to Audio Note Copper capacitors that where before in phono-stage, Jupiter capacitors have more high frequency extension and bigger base. They have much more resolution in all frequencies spectrum included lower midrange. All violins, saxophones, trumpets have more body and midrange tones. Soundstage became more 3d and further.
            Arensky trio with Heifetz- Piatigorsky sound more energetic and emotional. Most of jazz music sound more real. But on rock music Jupiter capacitors show more records flaws too.
            I can compare Jupiter Coper to Duelund Custom Cu capacitors directly. But I changed Audio Note to Duelund Custom Cu in my integrated amplifier, so I can compare Jupiter Copper to Duelund Custom Cu capacitors indirectly.
            Duelund Custom Cu capacitors have bigger, deeper and slower base. Jupiter Copper capacitors sound faster and very energetic. Duelund Custom Cu capacitors have lusher, richer low midrange on vocals. Duelund Custom Cu maybe a little better in term of tone.
            For different kind of components, systems and tastes people can prefer Duelund Custom Cu or Jupiter Copper capacitors. Both capacitors age excellent.


          • Hi Alex,

            Thanks for sharing you results, appreciated!

            It sure is fun comparing different capacitors, and such, isn’t it!

            Kind regards,


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