Dueland CAST PIO

Hello I had a few questions regarding this cap and was wondering if any owners who have heard this cap first hand can help me out.

I am thinking about adding this as a CAP upgrade on the speakers I am trying to get. I have heard from owners on forums saying it made a significant difference to their speakers for the better, but when I contacted some other speaker manufacturers they tell me that just because you add the Dueland CAP does not necessarilly mean you will get better sound. They say withs ome speakers they might sound great, but with some other speakers, they might even make the sound quality lower.

My questions are.

1. Will the Dueland CAST PIO cap upgrade change the signature sound of the speaker as intended by the designer?
Or will it simply make everything sound a bit better not effecting the original sound?

2. How much did the Dueland CAST PIO improve your system?

First they are Duelund Capacitors and they do offer great performance at a price though. I assume that you want to use them in the crossover for the tweeter requiring either one or two capacitors depending on topology, that can get very expensive, most likely costing many times that of the tweeter it self.

Theres a very good capacitor test Here as you can read the CAST gets absolutely top grade by the guy performing the test, i.e. it is his opinion.

I do use the Duelund VSF capacitors in some of my Superleague speaker models and have on customers request upgraded them to the CAST model in some.

As with anything theres a diminishing return on costs once a certain level is reached and while the CAST are excellent capacitors the VSF models are very good too, other favorites of mine includes the Jupiter HT Beeswax caps and the Jantzen Superior and Silver Z capacitors.

Do they change the sound drastically, no, its more like a spice for lack of a better word, they all flavor a little different.

Good Listening

In my vintage speakers, the Duelund CAST was the best sounding of many, many caps I tried in the tweeter high-pass crossover. It had the best inner detail and overall coherency. As far as I am concerned, there were no negative qualities in its sound at all, which is something I cannot say about any other capacitor brand.

In general, I do agree that simply substituting a high priced boutique capacitor for whatever the designer used in the first place is not always an improvement. That applies to some very expensive caps like V-Caps and Mundorf Silver/ Gold/Oil. But in the case of Duelunds, it's hard for me to imagine a situation where its superior clarity and coherency would not be an overall improvement.
You might get more information in general if you visit another forum. Audio Asylum DIY Asylum.
I`d say there`s no 'guarantee' of results for any change made to an audio component,it depends on the specific situation/application. I replaced the my speaker`s solen cap(tweeter location) with the Duelund CAST and the improvement was quite noticeable.Overall it became more natural,open,transparent with improved tonality and dynamic contrast(these qualities were already very good but became better). I can`t hear a single negative compromise at all.For my application it was a bargain given the level of improvement and refinement,worth every cent I spent.Fortunately the crossover only has a single capacitor,some speakers have multiple caps and the cost can escalate in a hurry.

I also placed Duelund CAST in my DAC(output caps) and again splendid results,no downside with this in any regard. The character or instrinsic sound of the DAC and speaker weren`t change just improved and revealed.
They will indeed improve your speaker unless it is one of very low quality. What speaker are you talking about? I use these caps in all my projects and they always sound fantastic!

If your speaker is capable of revealing better gear in front of it etc....this cap upgrade will be a definite improvement. If your speaker is made by Sears as part of their MCS series of the 70's, then perhaps not :-)

Tell us more and we can help.......
Grannyring makes a good observation, the better your system/components the more likely will be the impact provided by the Duelund CAST. They are utterly pure and natural so that much is unveiled sonically(but in no sense are they analytical).Sometimes the capacitor can be the bottleneck.
Thanks for all the inputs from the owners of Dueland. I am trying to upgrade the crossover of Vapor Cirrus Black.
I already got the Amorphous RAAL tweeter upgrade, but was wondering if the crossovers were upgraded to the Duelund CAST, if it would make a difference. Ryan over at Vapor Audio suggested that the cap upgrdae to dueland will give it less than 10% of the sound imporvement, but I will be able to tell a difference. The price for the caps are $2,500+.

$350.00 for a single tweeter and $850 or so for the single woofer.

Not sure if both the Woofer and the tweter have to be done together, I will E-mail him tommorow and find out.

I have heard speaker with the Duelund CAST upgrade today, and the violin sounded fantastic.

If somehow I can get the Duelund CAST just for the tweeters that would be sweet, but I would have to check with Vapor audio on that.

Or, do you guys know if they have to be upgraded together?
What types of capacitors are in the speaker now?
My crossover only has one capacitor which is at the tweeter and as I wrote
earlier the change was significant. I would speculate that if you only
replaced the tweeter cap in yours you should still appreciate the

Salectric asks a good question, if the current capacitor is very average the
CAST will make a greater upgrade impact than if you already have a high
quality capacitor there now. For me the jump from Solen to CAST is a large
one.Mundorf Silver/Gold oil to CAST a smaller gap change would be
expected. Which location has the greater influence on the sound, tweeter or
the woofer? My gut says likely the tweeter capacitor. What does your
builder say? The CAST are so natural, the music reproduced just becomes
more real and has increased emotion .
The jump from the Mundorf SGO is huge my friend as I have done it. Nothing special about that SGO Mundorf cap to be very honest. It is good, but a $10 JFX FB Premium film cap is better. Ya, I have compared both!

I would start with the Duelund caps on the tweeter. The improvement will be more than 10 percent and on the order of a significant amp upgrade.

Yes, do replace the tweeter cap first and enjoy for a while.

I have tried many caps and the Duelund CAST are special.

Your speakers are very good and deserve the Duelund touch!
On my 2-way vintage speakers, the Duelund CAST cap made a much bigger difference when used on the high-pass (tweeter) than on the low-pass (woofer). In each case, the Duelund was replacing a Mundorf Supreme (regular version) so this was a fair evaluation.

In general, if funds only permit upgrading one cap in a 2-way crossover, I would go with a Duelund on the tweeter since that should give the biggest improvement for the buck. In a 3-way crossover, things are more complicated. It's possible the midrange may benefit the most but the crossover will also be more complex so you may need more Duelunds.
Bill if the gap from the Mundorf SGO to the CAST is large I believe you as you've tried many capacitors and have much experience. I assume the SGO is better than my stock Solen capacitor so thought the contrast might be more subtle. The Vapor builder says 10% improvement, I wonder what cap is he comparing the CAST to?
Good question Charles. I assume one person's 10% is another person's 25%. Impossible to quantify and subjective reality.
That's true bill, it's purely subjective. I'll sum it up this way, I can only see a very positive result in choosing the Duelud CAST. Good luck Ssos101.
The current capacitor on the Vapor Cirrus are the VH Audio OIMP.

These are the standard specs coming with my speakers.

Standard Features
Exclusive Custom RAAL Ribbon Tweeter Element
AudioTechnology 7” woofer with Extended Bass Shelf tuning
Mass loaded constrained layer baffle
Laminated void free baltic birch ply cabinet with mass loaded constrained layer top
Vapor Audio’s proprietary Acoustic Inversion Layer dampening treatment to eliminate cabinet resonance and reduce cabinet wall resonance by over 20db.
Standard Crossover Features:
Jensen 12ga wax/paper Foil Inductors used on woofer and tweeter
VH Audio OIMP capacitors with VH Audio Teflon V-Cap bypass
All point-to-point hand soldered with Cardas Silver Solder
Dueland Resistors
Crossover is contained in separate vibration isolated chamber
Connectivity and Wiring:
WBT 0780 Binding Posts
Wired internally with braided Kimber TCSS for tweeter, Kimber 4TC for woofer

Tryingto figure out if the Duelund CAST on the Cirrus will be worth the upgrade. From what I have heard, the parts for these speakers are already pretty great so you wont really hear a major difference.

However, Ryan the designer at vapor did mentin that i WILL be able to hear a difference, just not more than 10%.
This is a quote from the designer at Vapor regarding the Duelund CAST.

"They are the best caps available, period. Also the most expensive caps available, period.

What they do is remove that last bit of hash from the reproduction that you didn't even know was there. The background becomes darker, details are more delineated in space, and everything just sound more present in the room with you."
You can do a lot worse than the OIMP with a small value V-Cap bypass. I believe that the CAST alone (no need for a bypass cap) will just sound more natural and pure. It'd make a very good speaker even better.
A single Duelund CAST cap (no bypass) will sound significantly better than an OIMP with or without a V-Cap bypass. I am not a fan of numerical descriptions of sonic differences---What does it mean to say something is 10% better? But the benefits of a Duelund over an OIMP will be quite easy to hear and very rewarding. That isn't a very hurdle to surpass.
Amen to the last responses. No not bypass and get Duelumd CAST caps.
Oops, I left out a word in my last post. I meant to say that an OIMP cap is not a particularly good sounding cap, with or without a bypass, and a Duelund CAST cap should surpass it easily and pretty much in all respects.
I don't know why anybody would say the OIMP isn't a good sounding cap. My experience, they're the best at their price point, and sound fantastic just as everything Chris VenHaus produces does.
Vapor1, I didn't mean to offend, but in the context we are talking about----Duelund CAST, V-Cap TFTF and CuTF, and Sonicap Platinum---the OIMP falls considerably short. I also don't find it to be a particularly good value. For the same or less money, I would choose a regular Mundorf Supreme (not Silver, Oil or Gold) or a Sonicap Gen1. Not to say that either of these is in the league mentioned above, but with proper selection of other parts they can provide very good sound for the dollar.

Duelunds really are at the top of the heap, however, at least in speaker crossovers.
Well said. Just a relative statement is all. In every single piece of gear I have placed them, amps, preamps, dacs, speakers, the result was astounding in terms of improvement. That is Duelund caps. Wish I could afford the silver Duelunds!
Thanks for all the inputs. I had a exchange of E-mail with Ryan over and Vapor at he said that the Duelund CAST can be upgraded just on the tweeters. He also suggested since we are gonna go with the single Dueland CAST over the V-OIMP capacitor, that we upgrade the resisters to Dueland CAST as well while we're at it.

Can't wait to hear it!
I believe you made a very wise decision,there should be no second guessing as the results will justify the additional cost.Congratulations with your new Vapor speakers.
Great.....super decision! Let us know after some 50 hours of break in.
I totally disagree.i have been modding Loudspeakers as well as electronics 
for 15 years. I just replaced the Mundorf  Supreme ,and silver oil with VCap OIMP
caps very nicely balanced but need a solid 100 hours to start opening up.
up to 400 hours to fully runin .the midrange now is much more liquid
the a Mundorf  Silver oil are nice but lacking in Bass and not as deep in soundstage depth vs the VH OIMP caps.
I would rate these a 11+ 
now if using a VAh CU teflon bypass then is as good or better then Jupiter Copper, or Audyn true Copper. The Mundorf cast are a 15+ Top of the hill hands down . But 4-5 times the cost for 3% or less .if you have money to  spend then do it. personally A The  Jantzen Copper inductors are excellent and as good as  most any. For Resistors the Path Audio are The best out there for Loudspeakers 
yes betterthen Duelunds cast  . I have done several speakers and under 1% total distortion  and are constant under all demanding conditions. One more thing with VH their matching of all capacitors to under 1% combined with these resistors 
precision at its highest No other company has tested this close for a  Loudspeaker system. For  most Audiophiles my recommendations would be 
considered  Excellent ,but as a Audiophille You can buy pure Silver duelund caps 
and spend $20,000. It is only money Right !!
Duelund resistors are weird. They have some sort of thermal coefficient built in they call a good thing, but it only works if the speakers heat up to match.

Audyn TC caps are outstanding bypass.  Right now 0.10uF at PE are running $16. Pretty good deal for performance.

@audioman58 Have you tried Mills resistors?


I was asked if I have used Mills resistors .Yes many times in the past . Please keep this in mind the higher the order crossover the more critical it is magnified. For example if you have a 5% resistor 
it can vary up to  Ten if you have other parts 5% or more a speakers Channel can vary by more then a 1/2-1 db which is clearly audible. I had found VH audio  OIMP cap with a V CU bypass and option to match all caps to within 1% or less to complement the Very accurate Path Audio resistors which are smooth and Very detailed and total distortion under 1% on average . In my Salk Bud Fried Transmission towers. It is incredibly accurate as well as a deep liquid midrange and detail across the board. My new favorite caps with bypass for roughly the same as 
Mundorf silveroil and personally like better then even their SGO caps.  Well worth tchecking out.and these and Path resistors take 
3-400 hours to Fully runin . 
And... this conversation just took a turn to a world I'm going to stay out of.

To be honest the midrange would be the most beneficial for your money  for almost 70%
Of the music is there. the cast are very expensive , the smaller the value 
The better for your wallet. The  VH oil caps with  a smaller value VH CU bypass caps are a outstanding combination  and not far behind ,for tweeter excellent 
If cast is on midrange. for Bass Munforf Supreme plenty good lower frequencies 
Not as critical . inductors Jantzen Of Denmark great inductors and value.
If you can get your capacitors matched to within 1% for each respective category 
Tweeter,mids you will hear the precidion especially if you use the Worlds best 
PATH audio resistors. under 1% typical a slightly warmer character rock steady 
Even under the most demanding music I have tried them all Duelund cast, mills 
CAdcock.  $30 each is not cheap , but last week parts connecxion had a  25% off Sale . these too like the capacitors take roughly 400 hours to fully settle in.
I just play them steady gor a few weeks ,and shut off 2x a day for 30minutes to Let the  caps discharge ,to help cycle in the cap breakin. I have been doing mods 
For almost 20 years the caps and  xover items has advanced a lot over 20 years 
In winding and methods. Duelund is old school but a lot of hand craftsmanship.
A great sounding  hockey puck ,or bigger 😎 !!
I have read some posts here and to say the Mundorf supreme beat thd VH audio 
Oimp caps is totally off yhd wall .I have been comparing caps in mods for at least 20 years . Munforf is a good cap . in my system or any that has the vh oimp capacitor after full breakin ,roughly 400 hours the vh cap does everything in s much more natural fleshed out fashion. I have mixed the  oimp cap with the excellent vh CU copper oil bypass caps for less money then a Mundorf silver gold oil caps
And it is s great combination I would say for sure better then  the Mundorf 
Which is a bit forwards sounding Especially the new Evo Supreme SGOIL caps.
Balance wise the oimp is as good or better,I learn towards better then the Munforf Silver oil on its own merits. naturalness is what it does best .I Totally agree with Ryan none better at its price point , mix the oimp cap 75%,then 25% vh-CU  bypass 
Cap,together this combo is my second favorite cap behind the Duelund Cast, for several times less money. anyone that heard this in a  preamp,or Loudspeakers . Excellent it took 
A very good under $5k speaker and transformed it  at least  $10k plus on musicality alone . it had Solen, then Mundorf supreme,the oimp was better across the board ,then put the combination 75,25% a substantial upgrade ,a great setup.
If you have not tried this ,with proper burn in 400 hours ,then you are in no position to make any educated type of statement.Try it you will like it !!