Question on the trimmers.There are three that I can't seem to find and they are 470 ohm,4.7 ohm and 2.2k ohm.What should I use in place of those?
AU-X1
- Thread starter Willy6
- Start date
Is 5 ohm ok for 4.7ohm
I mean 4.7k ohm replace by 5kohm.
Also back to the murata ceramic caps the 1,3 and 9 pf values were only available in the RCE series at the mouser in Texas.Should I get those or search for the RDE series elsewhere?
Either RCE or RDE are fine, just so long as they are at least 100V and are C0G/NP0
A link to the RCE series.
http://www.mouser.co.uk/Passive-Com...atuZ1yxboka&Keyword=Murata+RCE+series&FS=True
A link to the RCE series.
http://www.mouser.co.uk/Passive-Com...atuZ1yxboka&Keyword=Murata+RCE+series&FS=True
Ok thanks I just put in the order
See post #7 here - there are other references
http://audiokarma.org/forums/index....0-phono-stage-riaa-equalization-error.716418/
There is no direct comparison with Silver Mica here, however AK member ConradH has compared them directly, favouring Ceramic - with the important proviso that the Ceramics must be either C0G or NP0.
Enjoy.
No direct comparison in the link I gave, however they HAVE been compared elsewhere with Ceramic winning overall.
I am completely satisfied that Ceramics are best, with Silver Mica a good second. (paging @ConradH for confirmation)
Leestereo
Super Member
Another consideration is the possibility of failure due to silver ion migration (aka silver mica disease), especially when installed in an amplifier circuit: "Due to this silver ion migration, silvered-mica should not be used under DC voltage stresses when combined with exposure to continuous high temperature and humidity conditions for extended periods" (The Capacitor Handbook, Cletus J. Kaiser, pg. 97).
Ronito6
Super Member
Ronito6
Super Member
I wondered why those small blue caps started showing up so prominently in other more recent restorations.
Considering the issue then: if you have mica already installed, how long is their service life if they are used in a DC circuit? How soon do you hear a difference?
I cannot imagine it being a worse issue than electrolytics in the same environment. (In which case, it would not be much of a worry for a couple or three decades.
Considering the issue then: if you have mica already installed, how long is their service life if they are used in a DC circuit? How soon do you hear a difference?
I cannot imagine it being a worse issue than electrolytics in the same environment. (In which case, it would not be much of a worry for a couple or three decades.
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Leestereo
Super Member
There is some anecdotal evidence that current silver mica capacitors may be better sealed and hence able to withstand humidity and heat effects better. However, DC voltage may still be a problem; note that both Hewlett-Packard and Trimble Dayton Service Technologies specify in their respective engineering design guides that silver micas not be subject to DC voltage. Also, although no specific numbers are given, The Capacitor Handbook does state the following (pg. 97): "Silver ion migration can occur in only a few hours when silvered-mica capacitors are simultaneously exposed to DC voltage stresses, humidity, and high temperatures." Of course, YMMV, but caveat emptor!
