Sep 242018
 

I want to share every step of the way with you about the Duelund-Altec crossover project that Frederik and I are embarking on, so that you can come as close to possible to experiencing the project as if you were doing the project for yourself.

A 32.30 kilogram parcel from Frederik (Duelund) arrived at 10:30AM this morning, containing the new state-of-art Duelund CAST tinned-copper capacitors, inductors, and resistors that will be used for building the crossovers for the Duelund-Altec Project.

I removed the boxes containing the Duelund CAST Sn-Cu components from the shipping container and laid them out on my coffee table.

Then I carefully unpackaged each box and removed the carefully wrapped Duelund CAST Sn-Cu components.

The schematic for Hiraga-style crossovers for the 16 Ohm Altec 803B low-frequency drivers and 16 Ohm Altec 804A high-frequency compression drivers of the Stokowski Altec’s is shown below.

Stock Altec crossovers have an adjustable high-frequency control to aid in achieving the appropriate high- to low-frequency balance in different rooms and/or for listener personal tastes, which is the knob on the right crossover in the photo below.

Adjustability is a truly useful feature that can be an enormous aid for getting the musical and sonic presentation of the loudspeakers dialed in appropriately.

Altec N-500-D crossovers with adjustable high-frequencies.

I have added 16 Ohm L-pads to the Hiraga-style crossover design to facilitate balancing the high- and low-frequency drivers output appropriate to the room and my personal tastes.

Once the optimum high-frequency to low-frequency balance has been achieved the L-pad can be eliminated and replaced by a fixed resister if so desired.

To build a pair of the crossovers you need the following Duelund CAST Sn-Cu components:

  • Six 6.6mH inductors for L1, L2, and L3.
  • Two 18uF capacitors for C1.
  • Two 10uF capacitors for C2.
  • Two 0.82uF capacitors for C3.
  • Two 140 Ohm 10W resistors for R2.
  • Two 24 Ohm 50W resistors for R3.
  • Two 100 Ohm 10W resistors for R4.
  • Two 10 Ohm 20W resistors for R5.

Duelund CAST Sn-Cu 6.6mH Inductors for L1, L2, and L3

Duelund CAST Sn-Cu 6.6mH inductor for L1, L2, and L3.

I’ll be interviewing Frederik and asking him to describe the details of each of the Duelund CAST Sn-Cu components in future posts, just as was done for the Duelund-Westminster Project, but at the moment I just want to introduce them to you.

Duelund CAST Sn-Cu 6.6mH inductor for L1, L2, and L3.

Each Duelund CAST Sn-Cu 6.6mH inductor is 7 inches across (17.78cm), 1.5 inches tall (3.81cm), and weighs 3257 grams (7.18 pounds).

I wished my photos did justice to the incredible quality of these Duelund CAST Sn-Cu components, they are truly stunning to behold in person, with each one being a handcrafted work of esoteric audio art. I must admit I am rather in awe of them.

Duelund CAST Sn-Cu 18uF capacitors for C1

Duelund CAST Sn-Cu 18uF capacitor for C1.

Each Duelund CAST Sn-Cu 18uF capacitor is 7 1/4 inches across (18.42cm), 2 inches tall (5.1cm), and weighs 2478 grams (5.47 pounds).

Duelund CAST Sn-Cu 18uF capacitor for C1.

Duelund CAST Sn-Cu 10uF capacitors for C2

Duelund CAST Sn-Cu 10uF capacitor for C2.

Each Duelund CAST Sn-Cu 10uF capacitor is 6 inches across (15.24cm), 1 1/4 inches tall (3.18cm), and weighs 1309 grams (2.89 pounds).

Duelund CAST Sn-Cu 10uF capacitor for C2.

Duelund CAST Sn-Cu 0.82uF capacitors for C3

Duelund CAST Sn-Cu 0.82uF capacitors for C3.

Each Duelund CAST Sn-Cu 0.82uF capacitor is 2 7/8 inches across (7.3cm), 3/4 of an inch tall (1.91cm), and weighs 153 grams (0.34 pound).

Duelund CAST Sn-Cu 0.82uF capacitor for C3.

Duelund CAST Sn-Cu / Graphite Resistors

Duelund CAST Sn-Cu / graphite resistors.

Frederik humorously refers to the new Duelund CAST Sn-Cu / graphite resistors as “Jeff-istors”, as their design arose out of a discussion where I shared my listening impressions with Frederik about trials with various prototype and other resistors.

Duelund CAST Sn-Cu / graphite resistors

Essentially, the new Duelund CAST Sn-Cu graphite resistors use multiple graphite resistive elements and larger (DCA12GA) tinned-copper leads to provide higher levels of musical and sonic performance.

If you imagine the size of a cigar, you’ve got the size about right for the new Duelund CAST Sn-Cu / graphite resistors, as they are 6 inches long (15.24cm). The vary a little in diameter depending on their resistance values, but if you think of them about as big around as your thumb you’ve got it about right. A Duelund CAST Sn-Cu / graphite 140 Ohm resistor weighs 64 grams (2.3 ounces).

Much more detailed descriptions of the new Duelund CAST Sn-Cu components will be coming in individual future posts.

Ok, that’s all for now, and as always, thanks for stopping by, and may the tone be with you!

  16 Responses to “The Duelund CAST tinned-copper capacitors, inductors, and resistors have arrived!”

  1. May I know what is the price tag for all the parts?

  2. Hi Jeff,

    The size of these components is huge!
    The sound of Altecs with a new crossover should be something special.
    I don’t have my own experience, but some people like older Altec drivers from 40-50s more than from 60-70x.

    Regards,
    Alex.

    • Hi Alex,

      The Duelund caps, inductors, and resistors are definitely sizable! 🙂

      All of the vintage Altec pro drivers sound really good, as well as the new versions offered by Great Plains Audio. Like everything else, people have their favorites, but really you can’t go wrong with any of the vintage Altec drivers as long as they are in good condition.

      I’ve got various models of Altec drivers that span the periods you mention, and I like them all!

      Kind regards,

      Jeff

  3. Jeff, I am envious about your ability to access such fine parts. When I built my Tannoy HPD 315’s, Alpha Core Inductors, Mundorf S-I-O caps, and Dueland resistors (the old style with the tiny lead wires that break fairly easily). Between your Westminster Royals, and now the Altecs, there’ll probably be more in these parts than my entre system cost to build.

    I would sure like to hear what kind of difference all those quality Dueland components would make, though I’m pretty happy with what I’ve got sounds.

    Good stuff, enjoy,
    Dan

    • Sounds like you’ve got some nice Tannoy’s, Dan.

      I’ll be doing my best to describe the difference the Duelund crossovers make with the Altec’s. I suspect it will be similar to what I heard with the Westminster’s – huge!

      Kind regards,

      Jeff

  4. Hi Jeff,

    I will be very interested in giving your Altecs A7 speakers a listen when the new crossovers are installed. Such an interesting project.

    Yours,
    Pete

  5. Impressive components!
    Did you try/listen this crossover with standard components before switching to the Duelund stuff?

    Regards,

    Mikael

    • Hi Mikael,

      I’ve been listening to the Stokowski Altec’s for about 3 years with their original Altec N-500-D crossovers.

      The original Altec N-500-D crossovers sound pretty good overall, and you can read about basic listening impressions with them HERE.

      Kind regards,

      Jeff

      • Sorry, my question wasn’t clear. I wanted to ask, did you try the Hiraga’s crossover on the Stokowki with standard components?

        Regards,

        Mikael

        • Hi Mikael,

          I have no plans to do that. The Hiraga crossovers on my A5’s are optimized for them, so I don’t really want to tear down my A5’s just to try their crossovers on the Stokowski Altec’s.

          With my available time I’d rather just get the Duelund CAST Sn-Cu crossovers up and running, which I am much more excited about.

          If I did the comparison, based on what I’ve already heard trying some of the Duelund CAST Sn-Cu cap’s in my A5’s Hiraga-style crossovers, I suspect the end result would be something like “The A5 crossovers sound great, but the Duelund crossovers are amazing!”, so I’d rather just cut to the chase.

          Kind regards,

          Jeff

          • Thanks for your answer.
            Given that Hiraga’s crossover were designed for the 288/1505 couple, it could have been safer to check that it also works with the 804/511, before buying expensive components.
            But life is funnier with chances. 😉

            Regards,

            Mikael

          • Hi Mikael,

            Ok, now I see what you were getting at with your questions.

            Actually, no chance is involved, as I know from listening sessions with other A7’s utilizing Hiraga-style crossovers that the Hiraga crossover design works very nicely with the 804/511 combo.

            Other wise I would have done as you had suggested earlier, but there was no need, as I already knew the Hiraga design worked very nicely in the context of A7’s.

            Kind regards,

            Jeff

  6. Ok, that’s what I wished to know.
    Have fun with this new project with unique speakers.

    Regards,

    Mikael

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