Duelund Alexander Copper Foil Capacitors

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@tarquineous:
I'm also ordering Alexander along with Cast Cu. My current preamp is powered with Cast Ag (damned expensive). So for the amp, I will use Cast Cu only (have used Cast Cu on preamp and sold them, prior upgrading to Cast Ag). For Alexander, I just think to give it a try, as they are not that expensive compared to the others.

@gregg:
i have tried Mundorf Supreme, Silver Oil (SO), Silver Gold (SG), and Silver Gold Oil (SGO). Mundorf Silver Gold Oil has good tonal balance, spacious staging, transparent, but IMHO slightly analytical on top end (slightly less musical compared with Jensen Copper Paper Tube which slightly lower price than the SGO, but Mundorf Silver Gold Oil got better staging and top end resolution). So it's you call to choose.

AudioNote Copper Mylar In Oil has better resolution compared with their old Copper Paper In Oil (which prone to fail also, the Mylar version claims to have better reliability). But IMHO still too much mid and lacks of transparency. If you are a vocal lover, probably you can live with it sooo much (as they are not expensive), otherwise, you will feel the tones are not complete, as the high slightly roll-off. So i think now you know the different between both.

Other caps that I have tried as I could recall (not much, as this wipes my wallet fast):

V-Cap TFTF: cool Teflon sound, high transparency, too 'stiff' for me. Probably will fit on my 'future' 300B. CuTF is better, but I only heard in very short time of my friend's system (RS241 and #26).

Duelund Cast Cu (Copper Foil): very high musicality, spacious as Mundorf SGO, more live and musical than Jensen Copper Paper Tube.

Duelund Cast Ag (Silver Foil): ultimate separation, resolution and transparency (but not bright at all - forgot what most people say that silver is bright), very less (none?) sibilance (good source needed), a little bit thinner vocal than Cast Cu. To be honest, it doesn't really worth the money as the price tag is 4x Cast Cu, but for the ultimate one, I think we don't have much option...

Previously, I also have tried SideRealKap, WonderCap, Auricap, V-Cap CuTF, Hovland, Solen, Bennic (black and white), Wima MKP, MKS, FKP, Siemens old paper in oil (tubular and box packaging), Jupiter, most Russian K10, K40, K42, K72, K75, FT2/3, most Black Gate (related with coupling is C and N/NX/HiQ), Red/Black Cerafine, SilmicI/II, AmpOhm (some series), ASC (white), Nichicon Fine Gold and Muse, etc (hard to recall all of those names)... Some new, some NOS, some used, but surely must pass at least 200 hours prior serious listening test. Probably I lack of Cardas, Clarity Cap, Continental, and some newer brand.. What a short life, what a shallow wallet, but what a long list... :mad:

One of my caps comparison bench last year...
3_caps2.jpg


Thanks.
 
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That's quite a list, xneakers. More than I have tested, along the lines of Audiophile capacitors. For NOS, I have several drawers full of them ( one layer so I can access them).
I agree with your take on the Teflon/Tin capacitors. They are "coolish" sounding, and I would add they have a consistent smoothness to the entire range, which tames the slight glare usually found with Tin/Poly caps.
For electrolytics, I replaced the stock output capacitors with Black Gates. One thing right off the bat I noticed, is Black Gates are not warmer sounding or laid back, as some have described them. They are actually a bit brighter, and I would say stronger throughout the entire range. For electronics in general, I still prefer having at least one per channel in the power circuits.

I have to apologize for the Duelund Alexander in circuit test. The ones I ordered came in, but are too large to install in my headphone amp. Beware of their size! A 1uF is about the size of a 5 or 6 uF Jensen. My mistake. So what I will do is put them in the listening test rig, and compare them to a few others. I can do the test this coming weekend, as they are 80 to 90% run in now.

One note on V-Caps vs Mundorf in power supplies: The Mundorfs are a positive addition to the power supplies I have tried them in. I could not hear a difference with the V-Caps in the power supply. So I would suggest reserve them for speakers, or possibly AC line conditioners.
 
I've only tried Silver-gold, Silver-oil, and Silver/Gold-oil in power supplies. I prefer any with oil, especially in tubed equipment. The Polys did not sound right to me, so I can understand why the Mundorf Supremes were not preferred over the V-caps.

I listened to the Alexanders last evening. Compared them to V-cap, Mundorf SGO, Westcap, Aerovox, Jupitor Flatstack, and Vitamin Q. So far the Alexanders are not above the rest. They are slightly prominent in the midrange, but lack the body of Westcap, and the clarity of Mundorf SGO. Not bad, but nothing that puts them above the rest so far. will do more testing with a different source in the next couple of days.
 
I've only tried Silver-gold, Silver-oil, and Silver/Gold-oil in power supplies. I prefer any with oil, especially in tubed equipment. The Polys did not sound right to me, so I can understand why the Mundorf Supremes were not preferred over the V-caps.

Poly sounds fast... Oil gives some warm touch...
It's your call... But I prefer combination between electrolytic, teflon/film, oil - each at 'correct' value... and at least an ASC and WKz inside...

0-WKZ.jpg


I listened to the Alexanders last evening. Compared them to V-cap, Mundorf SGO, Westcap, Aerovox, Jupitor Flatstack, and Vitamin Q. So far the Alexanders are not above the rest. They are slightly prominent in the midrange, but lack the body of Westcap, and the clarity of Mundorf SGO. Not bad, but nothing that puts them above the rest so far. will do more testing with a different source in the next couple of days.

Well, the price is just 'affordable'... so don't expect too much anyway... Fred has warned me that as I'm currently using CAST Ag, the Alexander probably 'just for fun'...

Thanks.
 
Xneakers has my curiosity going (a little more than it has been). Regarding the capacitor set with the Polys, I have an earlier Bel Canto amp (SE Mosfet) that I put four 51uf solens, four 5uF Auricaps, and four oil filled capacitors in the power supply. Four each because it is a balanced circuit. That combination really brought life into the amp. And Black gates were put in the input stage. I didn't mention this because the topic is Alexanders and tube equipment. But I appreciate finding someone who has gone this far.

Since then, and after a few other tests, i have stayed away from the Polypropylene in power supplies, unless a very large value, and the room is available.

So it looks like the Duelund Alexanders will wind up in a similar scenario.

M Gregg asked about Jupiter capacitors in power supply. Based on what I have heard and done so far, I would say put the largest capacitance Jupiter(s), that will fit, for bypassing the power supply, then bypass further with some Mundorf SGO. Again, as large as practical. I doubt if there is further gain, other than making a sub-chassis for more room, or completely rebuilding the amp.
 
Xneakers has my curiosity going (a little more than it has been). Regarding the capacitor set with the Polys, I have an earlier Bel Canto amp (SE Mosfet) that I put four 51uf solens, four 5uF Auricaps, and four oil filled capacitors in the power supply. Four each because it is a balanced circuit. That combination really brought life into the amp.

You put all those three in parallel? Or with CL/CR filter?

And Black gates were put in the input stage. I didn't mention this because the topic is Alexanders and tube equipment. But I appreciate finding someone who has gone this far.

Which Black Gate on the input? I 'never' got satisfactory result with Black Gate on the coupling (not the 'quote' since this is objective measurement). But NX/HiQ on DAC could be quite 'OK' if you love transparent sound...

Since then, and after a few other tests, i have stayed away from the Polypropylene in power supplies, unless a very large value, and the room is available.

Off course you need high 'total' value on PSU, even with Poly. Basic scenario is you will need around 2200uF per 1000mA. If your pre/amp use around 100mA, probably you will need at least 220uF. Most preamp will use around 20mA, so you can live with at least around 50uF, no less... This is aligned with the theory... But you can always combine Poly and Electrolytic with R or L in between... and they will produce different sound... Like what I'm doing now, combining V-Cap, Jensen 4pole, WKZ, ASC, and Jensen Copper (before was Obbligato Oil Caps), each separated with Choke.

So it looks like the Duelund Alexanders will wind up in a similar scenario.

Could be... :) Could be not... :)

M Gregg asked about Jupiter capacitors in power supply. Based on what I have heard and done so far, I would say put the largest capacitance Jupiter(s), that will fit, for bypassing the power supply, then bypass further with some Mundorf SGO. Again, as large as practical. I doubt if there is further gain, other than making a sub-chassis for more room, or completely rebuilding the amp.

Before, I used to do bypassing. But later on, I prefer to stick with a good caps. Bypassing mostly will alter the sound, except if you use at least 1/100 value. Doing multiple LC/RC stage definitely better.

Thanks.
 
Xneakers, I haven't used the chokes, or LC/RC configurations in my own mods. Will have to look into that...probably better if done right. More room and wiring is of course required. Let me know of a good information source ( book, website etc).

In the Bel Canto amp, I replaced the electrolytics in the input stage power supply with Black Gates. All others were in parallel in the output stage. The amp has been to Bel Canto for a control board upgrade, and they apparently liked what was done. They commented on the amp sounding very good.

My SET amp does have two stages of power supply capacitors, separated by a choke. It came with large Black Gates (which is rare). SETs are a lesson in themselves. It is easy to degrade the sound with the wrong type of capacitor. This is the amp where I learned, rather rudely, that the Polys were not right for it. So I used oil filled bypasses, and it sounds fine.
 
My friend just put in a pair of .22 Alexanders copper foil coupling caps in my single ended 845 amp today. I wasn't expecting much right off the bat, but was pleasantly surprised. The sound was very full bodied with excellent detail retrival. If this is the very worst that they will sound, I will be happy. I have heard reports that it could take up to 400 hours for them to fully break in.......so if that means that they are going to improve further, I will be a very happy camper.

These caps replaced a pair of VTV silver foils. I know it's early to really comment on these, seeing that they were just installed today....but I think they are definately worth their asking price.

I have Ampohm copper foils in another tube amp that I may replace with these Alexanders. I wait to see how much they change during the breakin period first.
 
Xneakers, I haven't used the chokes, or LC/RC configurations in my own mods. Will have to look into that...probably better if done right. More room and wiring is of course required. Let me know of a good information source ( book, website etc).

So you put all of them in parallel? Just beware of some coloration produced if you are doing less then 1/100 for bypassing.

Hmm... there is no specific source I think, but you can start from uncle Google... or ask on this forum... many good Gurus are around I believe...

In the Bel Canto amp, I replaced the electrolytics in the input stage power supply with Black Gates. All others were in parallel in the output stage. The amp has been to Bel Canto for a control board upgrade, and they apparently liked what was done. They commented on the amp sounding very good.

I see, so your input means on the power supply, right?

My SET amp does have two stages of power supply capacitors, separated by a choke. It came with large Black Gates (which is rare). SETs are a lesson in themselves. It is easy to degrade the sound with the wrong type of capacitor. This is the amp where I learned, rather rudely, that the Polys were not right for it. So I used oil filled bypasses, and it sounds fine.

That's why we have the Magic of Black Gate...
 
They will get better. I just reached about 40 hours on the Alexanders. I compared them to BAT coupling caps, V-Cap, Mundorf SGO, Aerovox, and Modright oil impregnated.

They are close to the BAT capacitors, likely because they are both copper, and made t the same plant (Jensen). The Alexanders are darker, but have slightly more body in the lower midrange. Tone and voices are very good with the Alexanders. The SGOs have a slightly more vivid upper range, but unacceptable bass weight. The SGOs are also more tiring after 10 minutes for me. The V-Caps lack the correctness of tone, in my opinion, compared to all the oil filled mentioned, except the Modwright oil impregnated, which is a little thin overall.
The Aerovox wins overall for me, but they do have a slight fatigue factor. But so does music or anything else for that matter. The Aerovox capacitors I have are also not available. I found 12 at the Aerovox warehouse a few years ago.

I think xneakers may be right. To get better, we may just have to go with the VSF. That is if they will fit, and one has the funds.

Incidentally, I have the Ultratone Silver foil capacitors. They may be the worlds brightest capacitor, the Mundorf Silver Oil close behind. The Mundorf Silver Oil sounds much better to me.

My most suitable project is a balanced preamp, that uses four 3.0 uF capacitors. That would be quite expensive.
 
DIY and Alexanders

So you put all of them in parallel? Just beware of some coloration produced if you are doing less then 1/100 for bypassing.

Hmm... there is no specific source I think, but you can start from uncle Google... or ask on this forum... many good Gurus are around I believe...



I see, so your input means on the power supply, right?



That's why we have the Magic of Black Gate...

Thanks, I'll look up some technical data. I've never liked the very small bypass capacitors for sound, like some technicians recommend ( or maybe they are really hobbiests ). There is probably a technical reason.
 
You mean CAST, right? VSF is one grade lower...

Thanks.

Yes, I should have said the CAST. I have an Aluminum foil VSF, did not use it in these last tests. But as I recall from previous tests, I was not very impressed when used as a signal capacitor.

Have you compared any signal transformers with the CAST series ? Most prominent names are Jensen, audio Consulting, and Lundahl. Most of these are much smaller than the CAST, except for the Audio Consulting.

Thanks
 
I never compare apple to apple between transformer and capacitor coupling. Only heard them, few brands like UTC, Lundahl, some Japanese (Tango or Tamura?). From my observation (caveat YMMV), transformer has very smooth, high speed, silky sound (dont know if I express them correctly). But somehow lacks of distortion/micro details which I love from the capacitor. This could be wrong, as I have heard CAST Ag (which probably considered the highest end), meanwhile never heard the considered highest end transformer (probably silver permalloy or whatsoever). So it's your personal call... None beats all...
 
I never compare apple to apple between transformer and capacitor coupling. Only heard them, few brands like UTC, Lundahl, some Japanese (Tango or Tamura?). From my observation (caveat YMMV), transformer has very smooth, high speed, silky sound (dont know if I express them correctly). But somehow lacks of distortion/micro details which I love from the capacitor. This could be wrong, as I have heard CAST Ag (which probably considered the highest end), meanwhile never heard the considered highest end transformer (probably silver permalloy or whatsoever). So it's your personal call... None beats all...

I'm pretty sure I know what you're referring to. I compare capacitors to a copper wire, or hook the alligator clips together, that I use to hook in the test capacitor. In some ways, a really good capacitor will sound better than the direct connection. More detail and vividness. In other ways, the direct connection is more relaxed, or you could say the capacitors are slightly "raced" or "hyped" compared to the direct connection. They all do this. That's the basic trait of signal capacitors.

It may be due to the 90 degree phase shift of a capacitor (voltage lagging 90 degrees).

A transformer, being a coil, will produce a 90 degree lag of the current. So if somebody got real crazy, they could put a capacitor in series with the transformer, and wind up with no phase shift. That would also be a new can of worms!
 
They will get better. I just reached about 40 hours on the Alexanders. I compared them to BAT coupling caps, V-Cap, Mundorf SGO, Aerovox, and Modright oil impregnated.

They are close to the BAT capacitors, likely because they are both copper, and made t the same plant (Jensen). The Alexanders are darker, but have slightly more body in the lower midrange. Tone and voices are very good with the Alexanders. The SGOs have a slightly more vivid upper range, but unacceptable bass weight. The SGOs are also more tiring after 10 minutes for me. The V-Caps lack the correctness of tone, in my opinion, compared to all the oil filled mentioned, except the Modwright oil impregnated, which is a little thin overall.
The Aerovox wins overall for me, but they do have a slight fatigue factor. But so does music or anything else for that matter. The Aerovox capacitors I have are also not available. I found 12 at the Aerovox warehouse a few years ago.

I think xneakers may be right. To get better, we may just have to go with the VSF. That is if they will fit, and one has the funds.

Incidentally, I have the Ultratone Silver foil capacitors. They may be the worlds brightest capacitor, the Mundorf Silver Oil close behind. The Mundorf Silver Oil sounds much better to me.

My most suitable project is a balanced preamp, that uses four 3.0 uF capacitors. That would be quite expensive.

Thanks for the reply and the comparisons you've provided. I am thilled with the Alexanders and can't wait to be able to log more hours on them to see what they are fully capable of. I can say that even at this early state, they certainly are keepers.
 
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