It had to happen eventually... capacitor upgrade question for the Mainline

[Paul Birkeland]

It's really not a great idea to switch caps like this with DC across them.  (Note that for speaker crossovers, this does not present any issues)

[swich401]

I still don't understand, is it a bad idea to switch them only when the amp is on, or bad idea in general even when the amp is off and unplugged?

My idea was that after I turn the amp off and unplug it, I switch both of the switches to the "discharge" position to bleed them through their respective discharge resistors, then switch both of the switches back to the "off" position, thereby taking both of the caps out of the circuit. Then by switching one or the other switch to the "cap on" position it would essentially be like having only the one cap directly soldered in, then I can plug the amp back in and turn it on??

[Grainger49]

The capacitors retain voltage for some time after the amp is turned off.  They have dangerous voltages when it is on.

If you wait 30s after the amp is turned off the voltage should be gone.  But I worry more about your picking up noise due to all the additional wiring.

Bottlehead is very careful in their design of circuits.  The Seduction/Reduction audio path is only about 3" long, maybe 4".  But this keeps the wiring from picking up noise.  You could pick up anything from hum to a radio station.

It is a situation of trying it and see if it picks up any  extraneous noise.

[Paul Birkeland]

If you're going to work it like that, you don't need the discharge resistors.

Just put the switches inside the amplifier, and you'll be fine. (This will prevent curious fingers from switching them while the amp is running)

In the Mainline, I would expect those caps to retain charge for a maximum of 10 seconds after you shut the unit off. 

-PB

[swich401]

Suffice it to say, the Mundorfs are a *little* bigger than the Dayton caps...

[Loquah]

LOL. Which Mundorfs are you using (model and capacity)?

Has anyone tried Auricaps? I'm thinking of those as a direct replacement for the Daytons.

[swich401]

I didn't want to spend too much; went with the Mundorf Supreme 10uF 600V.

I looked at ratings for the Auricaps in comparison to the Mundorf's (see my previous post with comparison websites), decided that the Supreme's were the ones for me.

For those interested, partsconnexion.com has a sale of 20% off their caps until midnight April 30th 

[Loquah]

Thanks for reminding me of the links.

I'm left wondering which of the 2 options (Mundorf Supreme vs Auricap) will provide a more faithful, transparent rendition of the recordings? I love the Mainline for its neutrality and don't want to make it overly warm. I love the Mundorf Silver / Gold / Oil Supremes in the S.E.X., but there's no doubt they're a little on the warm side so not sure if the Mundorf Supremes polys will bring the same warmth to the Mainline. Reports suggest that the Auricaps have a little warmth too, but perhaps not as much as the Mundorfs. That said, the write-ups you linked to would suggest that the Supremes offer superior transparency... I'm torn! 

[Loquah]

Sorry for the double post, but this is the sort of review that has me confused. Great info, but I'm not sure if I'm sacrificing something valuable (e.g. high frequency detail) for the other benefits of the Supremes.

Coming from the Auricap, the Supreme was on the other side of the fence, highly musical, entertaining and perhaps not the most accurate sounding of capacitors. Although the tonal balance is quite neutral, the Supreme has a very polished and refined midrange with the right amount of meat throughout the frequency range. Musical notes are presented with texture and fine nuances, making the Auricap sound dry in comparison.

Easily the most pleasing of the caps tested this far, the Supreme combines the weight and treble extension of the Claritycap ESA with the speed of the Wima MKP10. Coupled to its highly resolving and musical nature and affordable price, do consider the Supreme for your next purchase. To nitpick, the only criticism against the Supreme against its competitors so far would be a slight loss of resolution in extreme high frequencies, and its artistic rather than honest approach towards music. The latter point is subjective anyway and you may personally have a preference for this.

Taken from: http://singaporehifi.blogspot.com.au/2010/09/capacitor-shoot-out.html

[mcandmar]

Loquah, wait until you have upgraded the .1uf caps in the S.E.X. amp before forming any opinions on the Mundorfs.  I'm pretty sure you are experiencing what i found but in reverse, the .1uf poly caps are what you are really listening to now, not the full range of the Supremes abilities.

[Loquah]

Oh, good point. I was thinking that by doing a reverse order of yours that I wasn't restricted by the other caps at all, but of course they are all connected a linked in a single system.

I'm hoping the teflons will arrive this week...

[mcandmar]

That's the thing having two sets in a row its very hard to differentiate each other and makes the whole process that bit more complicated.  Also dont forgot about the burn in time too, the Mundorfs seemed to settle in very quickly for me but the Russian Teflons took forever, as in 100's of hours. Just be prepared to wait it out as they will sound terrible for a while.

[Loquah]

That's the thing having two sets in a row its very hard to differentiate each other and makes the whole process that bit more complicated.  Also dont forgot about the burn in time too, the Mundorfs seemed to settle in very quickly for me but the Russian Teflons took forever, as in 100's of hours. Just be prepared to wait it out as they will sound terrible for a while.

Is my memory correct that I can burn-in the teflons by rigging them inline with appropriate resistors and driving signal through them from an amplifier? I.e. from positive terminal of output to resistor, then from resistor to capacitor input lead, then from capacitor output lead back to the negative terminal on the amp? I'm thinking of using my Quattro (solid state) amp to do the hours so will rig up a 6.3mm jack to appropriate positive and negative connections similar to speaker taps.

[swich401]

Thanks for reminding me of the links.

I'm left wondering which of the 2 options (Mundorf Supreme vs Auricap) will provide a more faithful, transparent rendition of the recordings? I love the Mainline for its neutrality and don't want to make it overly warm. I love the Mundorf Silver / Gold / Oil Supremes in the S.E.X., but there's no doubt they're a little on the warm side so not sure if the Mundorf Supremes polys will bring the same warmth to the Mainline. Reports suggest that the Auricaps have a little warmth too, but perhaps not as much as the Mundorfs. That said, the write-ups you linked to would suggest that the Supremes offer superior transparency... I'm torn! 

Check out the new Auricap XO series of caps (www.audience-av.com/capacitors/axo_description.html) over the Supremes if you want neutrality; they seem to be an improved version of the previous version of Auricaps. I'm listening through a pair of HD800's with an Anedio D2 DAC - two very precise/clinical sounding pieces of audio gear - so I wanted to add slightly more musicality to my Mainline through a slightly off neutral cap; Mundorf Supremes.

Also check out the Jantzen Superior Z-Cap:
https://www.parts-express.com/jantzen-10uf-800v-z-superior-capacitor--027-497

Jantzen Audio Superior Z-Cap MKP 800VDC - 2% tolerance

Technical specifications: metallized polypropylene film, high-grade copper lead wire. The finish is a flame-retardant tape wrap, and the end of the caps is resin sealed to protect against humidity. Loss angle tan = 0.00002 to 1K; Loss angle tan = 0.00001 to 10K.

Sound: Very neutral and coherent balance, they don't seem to high-light anything and I mean that in a positive way! They are a little flatter in presentation than their more expensive brother, the Silver Z-Cap but still better than the Clarity Cap SA in depth and spatial information. In direct comparison with a Clarity Cap SA they are less up-front in the lower treble and have a better texturing of acoustic instruments like a violin for example. In the upper treble they are slightly brighter than a Mundorf Silver/Gold which probably explains the good spatial information and separation. Compared to the Jantzen Audio Silver Z-Cap I find them the more musical of the two and I will definitely add them to my favourites list.

Verdict: 10

That was taken from: http://www.humblehomemadehifi.com/Cap.html

[dubiousmike]

At least as of this morning, it looks like there's one pair of RTI's left in stock at tctubes if you want to go the teflon route.  (http://tctubes.com/teflon-capacitor.aspx)

Mine are only at 100 hours or so, and I believe Jamie said he was still hearing changes at around 500 hours (which is what AR apparently recommends in terms of teflon burn in) - so I'm probably in no position to give a final verdict.  But they do seem to be excellent caps!