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Old 2nd September 2011, 01:48 AM   #31
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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.
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Old 2nd September 2011, 06:21 AM   #32
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Quote:
Originally Posted by tarquineous View Post
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...

Quote:
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?

Quote:
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...
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Old 2nd September 2011, 08:49 AM   #33
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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.
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Old 2nd September 2011, 09:01 AM   #34
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Default DIY and Alexanders

Quote:
Originally Posted by xneakers View Post
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.
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Old 2nd September 2011, 04:35 PM   #35
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Quote:
Originally Posted by tarquineous View Post
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.
You mean CAST, right? VSF is one grade lower...

Thanks.
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Old 2nd September 2011, 05:55 PM   #36
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Originally Posted by xneakers View Post
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
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Old 3rd September 2011, 03:41 AM   #37
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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...
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Old 3rd September 2011, 04:38 AM   #38
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Quote:
Originally Posted by xneakers View Post
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!
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Old 3rd September 2011, 09:14 AM   #39
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A capacitor has no phase shift when operating in it's pass band.

Mike
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Old 3rd September 2011, 07:38 PM   #40
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Quote:
Originally Posted by tarquineous View Post
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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