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    VTA SP14 and Mundorf Silver in Oils

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    mijohn

    Posts : 33
    Join date : 2013-06-19

    VTA SP14 and Mundorf Silver in Oils

    Post by mijohn on Wed Jun 26, 2013 2:16 am

    I have been considering ordering the Mundorf SIO caps for my SP14 build and would be interested in the opinions of those who have used them in their SP14 and compared them to the alternative cap they have fitted.

    I have concerns about their use in enclosed tube amps like the SP14 however, in regards to heat. In my research I have found that a typical preamp enclosure with 4-5 tubes plus a couple of transformers could be operating at 50-60c (122-140F)

    One user found that after less than 200 hours his Mundorf SIO's had dropped their rated value. In another case the SIO's failed completely.
    On the plus side others have reported no problems even after 4 years of service.

    One of the previously mentioned user's whose SIO's had failed was told by a Mundorf rep that at high operating temperatures the oil degrades the silver foil causing them to loose rated value. 
    Up until 2011 the Mundorf website was specifying an ambient operating maximum temperature of 70C/158F but currently has downrated that to 55C/131F for their Silver in oils.

    Zimmer64

    Posts : 112
    Join date : 2013-01-29
    Age : 52
    Location : Switzerland

    Re: VTA SP14 and Mundorf Silver in Oils

    Post by Zimmer64 on Wed Jun 26, 2013 5:23 am

    I ordered them, but have not yet finished building... I also bought the Mundorf Gold / Silver ones for the second output. I will report back in a few days (only input selector and volume left to be wired).

    I am also very much interested to hear what experience other's have made.

    Michael


    Last edited by Zimmer64 on Wed Jun 26, 2013 7:14 am; edited 1 time in total (Reason for editing : Typos)

    PeterCapo

    Posts : 380
    Join date : 2008-12-05

    Re: VTA SP14 and Mundorf Silver in Oils

    Post by PeterCapo on Wed Jun 26, 2013 8:46 am

    I had inquired with Mundorf at one time about this.  They got back to me confirming a concern about temperature.  Only thing is, in their e-mail response to me, they said the limit is 70°C while their own webpage says 55°C.  In either case, they said that the supreme silver/oil is not recommended for use in tube amplifiers.  The assumption on their part must of course be that tube amp temperatures could go higher than the temperature limit of the supreme silver/oil.

    There have been similar concerns with the Jensen PIO.

    I wrote back to Mundorf asking for clarification as to whether the maximum is 55°C or 70°C for their supreme silver/oil.  If I get an answer, I’ll let you know.

    PS - So they got back to me quickly. Unfortunately, their response did not clarify anything. They said their webpage is under construction and to use the data from their last catalog, wherever that is. So, who knows what the situation really is, whether 70°C or 55°C... Sorry guys.

    mijohn

    Posts : 33
    Join date : 2013-06-19

    Re: VTA SP14 and Mundorf Silver in Oils

    Post by mijohn on Wed Jun 26, 2013 10:47 am

    Michael, I look forward to reading your report of what you hear!

    Peter, I found a Mundorf catalog dated September 2011 and that has it at 70ºC. It has the SilverGold Oil at 85ºC, so maybe that doesn't have the same limitation.

    The website has 55ºC in one place and 70ºC in another!

    Before I saw your reply I sent e-mails to two Mundorf  international distributors to see if they can resolve the conflict. I will let you know what they say.

    The statement by Mundorf that the Supreme silver/oil is not recommended for use in tube amplifiers is probably good reason to consider something else!

    PeterCapo

    Posts : 380
    Join date : 2008-12-05

    Re: VTA SP14 and Mundorf Silver in Oils

    Post by PeterCapo on Wed Jun 26, 2013 10:58 am

    Problem is that we don't seem to be able to get consistent, reliable information.  Yes, for some time now, their web page has said 55°C for the supreme silver/oil.

    Based upon my reading around the internet, anecdotally, the problem has been thought to be the oil causing problems inside the capacitor, perhaps in combination with temperature/voltage applied...  I don't know if the Mundorf and Jensen oils are made to mil-spec standards - I tend to doubt it.  I imagine the K40Y-9 solves these problems since they were probably designed with nuclear war in mind.

    mijohn

    Posts : 33
    Join date : 2013-06-19

    Re: VTA SP14 and Mundorf Silver in Oils

    Post by mijohn on Wed Jun 26, 2013 11:28 am

    If I am going to spend $80 or more on a couple of caps I expect them to last the course!
    I like your nuclear analogy! The K90Y-9's will definitely be in one of the output positions, I just have to find something for the other.

    tubes4hifi
    Admin

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    Re: VTA SP14 and Mundorf Silver in Oils

    Post by tubes4hifi on Wed Jun 26, 2013 7:43 pm

    somebody stick a thermometer in their SP14 preamp and let it run for 30 minutes or so, let us know what the temp turns out to be.
    Sorry, I sold all my preamps to keep up with orders!

    mijohn

    Posts : 33
    Join date : 2013-06-19

    Re: VTA SP14 and Mundorf Silver in Oils

    Post by mijohn on Thu Jun 27, 2013 12:05 pm

    I got a reply from Brian at Madisound in response to my email to them about the conflict of temperature information on the Mundorf website:

    "In their latest catalog they just sent me with the last shipment, the
    rating is 70 degrees centigrade."

    If that's correct it's good news.

    Zimmer64

    Posts : 112
    Join date : 2013-01-29
    Age : 52
    Location : Switzerland

    Re: VTA SP14 and Mundorf Silver in Oils

    Post by Zimmer64 on Thu Jun 27, 2013 3:42 pm

    Hello friends,

    I finished my SP14 tonight. Here are my initial observations. With the top off the caps stay cold, of course. With the top on the top plate does get warm, but not hot. I ran it for about 1.5 hours and it felt warm as a hand. I very much doubt that there are 70 degrees centigrade inside, the top plate would feel much warmer I suppose.

    Sound wise the Gold / Silver Mundorfs seem to have a better high frequncy resolution compared to the Silver / Oil ones. But one has to keep in mind, that neither the tubes, Russian NOS, nor the caps are broken in after 2 hours.

    Overall, great preamp. I still need to chase a mild AC hum (which disappears when I touch the top plate (grounding issue I guess). But what I hear so far is really good. Punchy bass, dynamic sound, great stage, wonderful reproduction of acoustic instruments.

    Since I decided upgrade to Goldpoint switch and attenuator, I ran into two issues. First, the mounting holes needed to be 2 mil larger. Secondly, there is not enough room for the attenuator. It touches the outer output coupling cap. I had to use a bit of force to speeze it in.

    I will upload a couple of pictures over the weekend to my blog.

    Best

    Michael

    Elrick

    Posts : 71
    Join date : 2012-09-02
    Location : Bellingham WA

    Re: VTA SP14 and Mundorf Silver in Oils

    Post by Elrick on Fri Jun 28, 2013 12:21 am

    I tested my system tonight.  My PAS3 shell has the  regulated power supply, PH10 and Aikido board, that's 6 tubes plus rectifier in a small case with poor ventilation. I thought it would be hotter than it actually measured. I thought I might drill some air holes in the case, not sure
    I need to now.



    The case was open a crack to allow the probe so that probably helped a bit.  



    Case closed, thermistor snaked through vent hole in the back.

    mijohn

    Posts : 33
    Join date : 2013-06-19

    Re: VTA SP14 and Mundorf Silver in Oils

    Post by mijohn on Fri Jun 28, 2013 5:00 am

    Zimmer64 wrote:Hello friends,

    I finished my SP14 tonight. Here are my initial observations. With the top off the caps stay cold, of course. With the top on the top plate does get warm, but not hot. I ran it for about 1.5 hours and it felt warm as a hand. I very much doubt that there are 70 degrees centigrade inside, the top plate would feel much warmer I suppose.

    Sound wise the Gold / Silver Mundorfs seem to have a better high frequncy resolution compared to the Silver / Oil ones. But one has to keep in mind, that neither the tubes, Russian NOS, nor the caps are broken in after 2 hours.

    Overall, great preamp. I still need to chase a mild AC hum (which disappears when I touch the top plate (grounding issue I guess). But what I hear so far is really good. Punchy bass, dynamic sound, great stage, wonderful reproduction of acoustic instruments.

    Since I decided upgrade to Goldpoint switch and attenuator, I ran into two issues. First, the mounting holes needed to be 2 mil larger. Secondly, there is not enough room for the attenuator. It touches the outer output coupling cap. I had to use a bit of force to speeze it in.

    I will upload a couple of pictures over the weekend to my blog.

    Best

    Michael

    Congratulations on a successful build, I hope you find the source of the hum soon. I will be interested to hear your comparison of the caps after they have broken in more.
    If you're using the VTA chassis it has good ventilation so that will help a lot to keep it cooler.

    I am still not convinced however, that the 70ºC figure is the right one and will be conservative and go with the 55ºC one for now with regards to the Silver in Oil cap.
    The link below is to the Mundorf Silver in Oil web page:

    http://www.mundorf.com/english/bauteile/kondensatoren/mcap-svrechts.htm

    mijohn

    Posts : 33
    Join date : 2013-06-19

    Re: VTA SP14 and Mundorf Silver in Oils

    Post by mijohn on Fri Jun 28, 2013 8:29 am

    Elrick wrote:I tested my system tonight.  My PAS3 shell has the  regulated power supply, PH10 and Aikido board, that's 6 tubes plus rectifier in a small case with poor ventilation. I thought it would be hotter than it actually measured. I thought I might drill some air holes in the case, not sure
    I need to now.
    If the Mundorf Silver in Oils lived in your PAS3 they might soon expire from heat stroke! 120ºF is getting close to 50ºC
    But I think the other components would be inside their rated working temperature. The tubes would last longer with more ventilation and the electrolytics may dry out faster, but I'm sure Roy will know what's normal for this amp.
    Holes in the top of the amp would help the ventilation, but not the resale value if you're concerned about that.

    Zimmer64

    Posts : 112
    Join date : 2013-01-29
    Age : 52
    Location : Switzerland

    Re: VTA SP14 and Mundorf Silver in Oils

    Post by Zimmer64 on Sat Jun 29, 2013 1:16 am

    Guys,

    Since I am native german :-) , I looked up the german web site of Mundorf. They publish 70 for the Silver/Oil and 85 degrees centigrade (158 respectively 185 degrees Fahrenheit) for the Gold/Silver caps. I would assume that there is some kind of a mixup when they did the English translation. I will call them on Monday directly and report back.

    Michael

    mijohn

    Posts : 33
    Join date : 2013-06-19

    Re: VTA SP14 and Mundorf Silver in Oils

    Post by mijohn on Sat Jun 29, 2013 8:24 am

    Zimmer64 wrote:Guys,

    Since I am native german :-) , I looked up the german web site of Mundorf. They publish 70 for the Silver/Oil and 85 degrees centigrade (158 respectively 185 degrees Fahrenheit) for the Gold/Silver caps. I would assume that there is some kind of a mixup when they did the English translation. I will call them on Monday directly and report back.

    Michael
    Thanks Michael, hopefully you will get a definitive answer from them.

    They told Peter Capo that their website is under construction so maybe the 55ºC figure belongs to an outdated page that hasn't been taken down yet and that the product has since been improved and up-rated?
    I dug back further to the start of the pages that lead to the Silver/Oil page and there is a Copyright 2008 line, so that could mean it is out of date.

    http://www.mundorf.com/english/index.htm

    tubes4hifi
    Admin

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    Re: VTA SP14 and Mundorf Silver in Oils

    Post by tubes4hifi on Sun Jun 30, 2013 5:33 pm

    somebody out there must have a $30 laser thermometer AND and SP14, or some other tube preamp with Mundorf S-Os in it, where are you?
    Point it at the Mundorfs after it's been running with the cover on for over 20 minutes!

    ruffian

    Posts : 43
    Join date : 2010-02-26

    Re: VTA SP14 and Mundorf Silver in Oils

    Post by ruffian on Sun Jun 30, 2013 10:33 pm

    So many screws on that chassis Roy.... Maybe tomorrow, rig isn't on tonight.

    Zimmer64

    Posts : 112
    Join date : 2013-01-29
    Age : 52
    Location : Switzerland

    Re: VTA SP14 and Mundorf Silver in Oils

    Post by Zimmer64 on Mon Jul 01, 2013 8:58 am

    I just spoke to Mundorf in Germany, Mr. Grosch. Very helpful staff there!

    The situation is as follows:
    The web page is under construction. Reliable information can be found if you download their catalogue in the downloads section (http://www.mundorf.com/downloads/MUNDORF_Hifi_Studio_Catalog_2012.pdf).

    As far as the SIO caps are concerned the max recommended ambient temparature is 70 degrees celsius. That does not mean they immediately die if it gets hotter. They used to be higher (85), but were reduced as they leaked oil in some rare cases, especially tube amps  (the viscosity of the oil changes with heat). They never were rated at only 50 degrees.

    The Silver / Gold ones are ok up to 85 degrees ambient temperature.

    So the remaining question is then how hot does it get inside a SP14? I will order a temperature sensor for my DMM and report back.


    Last edited by Zimmer64 on Mon Jul 01, 2013 9:07 am; edited 1 time in total (Reason for editing : Added link to catalogue)

    mijohn

    Posts : 33
    Join date : 2013-06-19

    Re: VTA SP14 and Mundorf Silver in Oils

    Post by mijohn on Mon Jul 01, 2013 10:01 am

    That's good Michael, I think we can now safely use them in the SP14, I would be surprised if the temperature will get anywhere near 70ºC, but it will be interesting to see how hot it does get.

    I laughed when I read that they say "they never were rated at only 50 degrees"
    Maybe not, but it was rated at only 55ºC and we have the proof! Was that a typo?

    http://www.mundorf.com/english/bauteile/kondensatoren/mcap-svrechts.htm

    Thanks for the catalog download, I wasn't able to find the latest version on the web.

    PeterCapo

    Posts : 380
    Join date : 2008-12-05

    Re: VTA SP14 and Mundorf Silver in Oils

    Post by PeterCapo on Mon Jul 01, 2013 11:08 am

    Mundorf should proof-read their own website, under construction or not.  They have shown a 55 degree rating for some time.  If that is not correct, they should take it down.

    Technical Specifications:

    Capacitance: 0.01μF-10μF
    Dielectric: Polypropylene
    Metallisation: 99.99% Silver
    Dielectric strengh: 1,200 VDC
    Tolerance: ±7%
    Ambient air temperature max.: 55º Celsius
    Loss factor tan ∂: 0.0002 @1kHz, 0.00011@10 kHz

    ruffian

    Posts : 43
    Join date : 2010-02-26

    Re: VTA SP14 and Mundorf Silver in Oils

    Post by ruffian on Mon Jul 01, 2013 10:36 pm

    tubes4hifi wrote:somebody out there must have a $30 laser thermometer AND and SP14, or some other tube preamp with Mundorf S-Os in it, where are you?
    Point it at the Mundorfs after it's been running with the cover on for over 20 minutes!


    Here you go:


    Mundorf S/O, Temp 99 F or 37 C. Taken after running the amp for 2 album sides, then turning it off, unplugging and removing the cover. Tubes adjacent to it were at 150 F. I have the original style 4" chassis installed in a cabinet with maybe less than optimal spacing. The amp just does not run hot. Ambient room temp, 75 F.

    Good excuse for a tube roll. In go some Sylvania 6SN7WGT Brown Base.

    mijohn

    Posts : 33
    Join date : 2013-06-19

    Re: VTA SP14 and Mundorf Silver in Oils

    Post by mijohn on Mon Jul 01, 2013 11:16 pm

    ruffian wrote:
    tubes4hifi wrote:somebody out there must have a $30 laser thermometer AND and SP14, or some other tube preamp with Mundorf S-Os in it, where are you?
    Point it at the Mundorfs after it's been running with the cover on for over 20 minutes!


    Here you go:


    Mundorf S/O,  Temp 99 F or 37 C.  Taken after running the amp for 2 album sides, then turning it off, unplugging and removing the cover.  Tubes adjacent to it were at 150 F.   I have the original style 4" chassis installed in a cabinet with maybe less than optimal spacing.  The amp just does not run hot.      Ambient room temp, 75 F.  

    Good excuse for a tube roll.  In go some Sylvania 6SN7WGT Brown Base.  
    You won't be frying eggs on your amp!

    The Mundorf's would have been slightly hotter than that before you removed the screws and the time it took to do that, but well within the rated temperature limit. Does the surface of the amp feel any hotter after its been going for several hours?

    Have you compared the Mundorf S/O with any other capacitor and how do they compare?

    mijohn

    Posts : 33
    Join date : 2013-06-19

    Re: VTA SP14 and Mundorf Silver in Oils

    Post by mijohn on Tue Jul 02, 2013 7:10 am

    PeterCapo wrote:Mundorf should proof-read their own website, under construction or not.  They have shown a 55 degree rating for some time.  If that is not correct, they should take it down.

    Technical Specifications:

    Capacitance: 0.01μF-10μF
    Dielectric: Polypropylene
    Metallisation: 99.99% Silver
    Dielectric strengh: 1,200 VDC
    Tolerance: ±7%
    Ambient air temperature max.: 55º Celsius
    Loss factor tan ∂: 0.0002 @1kHz, 0.00011@10 kHz
    I agree. The different temperature figures on various websites was confusing as well!

    ruffian

    Posts : 43
    Join date : 2010-02-26

    Re: VTA SP14 and Mundorf Silver in Oils

    Post by ruffian on Tue Jul 02, 2013 11:07 pm

    mijohn wrote:
    Have you compared the Mundorf S/O with any other capacitor and how do they compare?

    I also have the Russian caps in there. They are really close. I'm hard pressed to quantify any difference in the sound. I do find that I prefer the Mundorfs. Basing that on long term A/B. More than once I have thought that my rig was sounding real good and then I realize have forgotten which caps I'm running on, I take a look at which ones are patched in and it is the Mundorfs.

    I've never done a quick A/B. The times that I have tried that on other equipment the conclusion that I've drawn is that I can hear the equipment warming up.

    mijohn

    Posts : 33
    Join date : 2013-06-19

    Re: VTA SP14 and Mundorf Silver in Oils

    Post by mijohn on Wed Jul 03, 2013 2:55 am

    ruffian wrote:
    mijohn wrote:
    Have you compared the Mundorf S/O with any other capacitor and how do they compare?

    I also have the Russian caps in there.  They are really close.   I'm hard pressed to quantify any difference in the sound. I do find that I prefer the Mundorfs. Basing that on long term A/B.    More than once I have thought that my rig was sounding real good and then I realize have forgotten which caps I'm running on, I take a look at which ones are patched in and it is the Mundorfs.  

    I've never done a quick A/B.   The times that I have tried that on other equipment the conclusion that I've drawn is that I can hear the equipment warming up.
    I understand what you mean. The differences are not like night and day, but you know which you prefer in the long run.

    It is hard to compare the differences in a 'quick' A/B because by the time you have switched off, changed the caps over, switched on again and waited for the amp to warm up you have forgotten what you heard before. Also, it can be extremely tedious listening to the same piece of music over and over again!

    viridian

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    Join date : 2010-02-19

    Re: VTA SP14 and Mundorf Silver in Oils

    Post by viridian on Wed Jul 03, 2013 11:03 pm

    I tried the Silver/Oil caps as, large value, output coupling caps in my maxed out Bottlehead Foreplay 2 and, as much as I liked the mids and highs, they just de emphasized the bass. Much of high end audio emphasizes clarity at the expense of balance; to each his own. I switched to Jensen copper oil caps and never looked back. I even found Auricaps more balanced, in the long term, than the Silver/Oils. YMMV, and probably will.

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