I am looking for some recommendations as to what kind and brand of caps to use in a tube phono-stage's RIAA circuit. I've had recommendations from REL-TFTs to Charcroft's Silver/Mica to Copper foil and propylene. Looking for help in selecting these.
Thanks in advance
Thanks in advance
I have 1% Relcap TFT teflons for RIAA caps, John Curl recommends them.
Relcap Polystyrene ( and MIT RTX) are a lot cheaper, but all are hard to get in 1% values especially if the cap values are not a common one, I had to custom order mine from Parts Connexion. Do not use silver mica.
I burn them infor 500 hours ( 2 weeks) before auditioning, in the right presmp they are wonderfull, smooth, detailed, but you have to have your power supply, resistors, and circuit topology all top notch before considering them., theres no sense in putting them in a $200 phono stage.
Relcap Polystyrene ( and MIT RTX) are a lot cheaper, but all are hard to get in 1% values especially if the cap values are not a common one, I had to custom order mine from Parts Connexion. Do not use silver mica.
I burn them infor 500 hours ( 2 weeks) before auditioning, in the right presmp they are wonderfull, smooth, detailed, but you have to have your power supply, resistors, and circuit topology all top notch before considering them., theres no sense in putting them in a $200 phono stage.
Polystyrene or anything other than ceramic or mica.
Components do not 'burn in' the bad design of schematic or your ears do!
5% are ideal your ears cannot detect anything more close tolerance.
Polyester are really nice;
Polyester Film Capacitors | RS Components
Components do not 'burn in' the bad design of schematic or your ears do!
5% are ideal your ears cannot detect anything more close tolerance.
Polyester are really nice;
Polyester Film Capacitors | RS Components
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Apart from personal taste the choice depends on whether the caps see a high dc voltage across or not.
Silver mica has never worked for me but was preferred by Thorsten in comparison to film in situations with a high polarizing voltage.
Silver mica has never worked for me but was preferred by Thorsten in comparison to film in situations with a high polarizing voltage.
With tube circuits, make sure the voltage rating is at least adequate, and preferably more.
The channels should be closely matched in values.
The channels should be closely matched in values.
My favourite. The Relcaps come in 2% but the Mit RTX are next to impossible to match.
Yes, this is far more important than capacitor dielectric. Capacitor brand matters not at all.rayma said:
5% components are fine but it will help if you match them more closely than this. Buy a few extra and pick the two which are closest in value.
Tefon or polystyrene/styroflex cap`s is on top for RIAA network.
BTW, one of Thorsten`s last RIAA preamp had Painton wirewound resistors (which are great, btw) and many Ansar MKP capacitors everywhere. In RIAA network, Ansar was bypassed with ERO MKP1837 (3.18e-3) and caramel (Sangamo ??) silver-mica (3.18e-4) equalization, to make a proper value.
Of course, capacitors should be around 1% tolerance.
You can put on the capacitors any way you want, but you'll quickly change them, I'm sure.
This is is pic of Thorsten last RIAA preamp.
Best diying.
BTW, one of Thorsten`s last RIAA preamp had Painton wirewound resistors (which are great, btw) and many Ansar MKP capacitors everywhere. In RIAA network, Ansar was bypassed with ERO MKP1837 (3.18e-3) and caramel (Sangamo ??) silver-mica (3.18e-4) equalization, to make a proper value.
Of course, capacitors should be around 1% tolerance.
You can put on the capacitors any way you want, but you'll quickly change them, I'm sure.
This is is pic of Thorsten last RIAA preamp.
Best diying.
Attachments
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F461BK104F630L KEMET | Mouser
F461BB333F630A KEMET | Mouser
This is what I could find after a long search. High enough voltage capability, 1% tolerances and polypropylene. I'm a little worried about the 1000 hour life-span.
Comments or further suggestions?
F461BB333F630A KEMET | Mouser
This is what I could find after a long search. High enough voltage capability, 1% tolerances and polypropylene. I'm a little worried about the 1000 hour life-span.
Comments or further suggestions?
That's a maximum stress rating, and is not important here. They'll last indefinitely.
Very cheap for 1% tolerance parts.
Very cheap for 1% tolerance parts.
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WIMA Polypropylene.
I haven't used MLCC but was much encouraged by the Linear Audio article in which they were reviewed favorably (by Scott's quadrature distortion measurement).
I haven't used MLCC but was much encouraged by the Linear Audio article in which they were reviewed favorably (by Scott's quadrature distortion measurement).
Philips KS series 1% polystyrene.
Even though polystyrene/styroflex capacitors are no longer manufactured, the KS are still widely available as NOS on eBay, at reasonable costs. The only con I can see is the steel leads, but overall it's a very good compromise. In spite of what has been said, the dielectric does make a difference: stay away from polyester and ceramic.
Even though polystyrene/styroflex capacitors are no longer manufactured, the KS are still widely available as NOS on eBay, at reasonable costs. The only con I can see is the steel leads, but overall it's a very good compromise. In spite of what has been said, the dielectric does make a difference: stay away from polyester and ceramic.
I use a variety of different types on film capacitors but then I try them in different places before deciding where to sit.
But I always use the MLCC on the first capacitor because I feel that it does the least damage, but I have not tried them in other places
Anders
But I always use the MLCC on the first capacitor because I feel that it does the least damage, but I have not tried them in other places
Anders
I've had very good results upgrading the RIAA stages in two different Phono amps to Russian surplus military teflon capacitors.
It was reasonably inexpensive as the uf values are low the improvment in resolution and spatiality was quiet noticable. As has been mentioned depending on brand they can take around 200hrs plus to burn before they open up and come on song. You can speed this up with a burn in rig or just hook up a music player to the inpurt and leave on shuffle.
Some pics
Russian candy
Hand matched for closest values out of the 10
3 under 0.5% tolerance
3 1%-1.5%
2 2% - 2.5%
Two unused at 3.5% the capacitor tolerance rating was +/- 5%.
Installed
It was reasonably inexpensive as the uf values are low the improvment in resolution and spatiality was quiet noticable. As has been mentioned depending on brand they can take around 200hrs plus to burn before they open up and come on song. You can speed this up with a burn in rig or just hook up a music player to the inpurt and leave on shuffle.
Some pics
Russian candy
An externally hosted image should be here but it was not working when we last tested it.
Hand matched for closest values out of the 10
3 under 0.5% tolerance
3 1%-1.5%
2 2% - 2.5%
Two unused at 3.5% the capacitor tolerance rating was +/- 5%.
An externally hosted image should be here but it was not working when we last tested it.
Installed
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From my post No.8 ....
I appreciate the comments I received and I apologize a lot. Baypass capacitor for 318usec is ERO KP-1832 film/foil (not 1837 as I wrote in post).
Sorry, again.
I appreciate the comments I received and I apologize a lot. Baypass capacitor for 318usec is ERO KP-1832 film/foil (not 1837 as I wrote in post).
Sorry, again.
Siemens Styroflex (either ps or pp) haven't been made since around 1980, far as I know.
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