Capacitors for RIAA Circuit

[blu_glo]

Siemens Styroflex haven't been made since around 1980, far as I know.

They still seem to be available must be NOS then. A quick look on LCR website confirms that they at least are still making polystyrene, several variants indeed... Polystyrene - LCR Capacitors

 

[rayma]

They still seem to be available must be NOS then. A quick look on LCR website confirms that they at least are still making polystyrene, several variants indeed... Polystyrene - LCR Capacitors

LCR is a different brand.

 

[WntrMute2]

LCR is a different brand.

Explain please.

 

[rayma]

Explain please.

They are two different companies.

Siemens company made Styroflex brand name capacitors, both pp and ps types until around 1980.
Photo here: 10x SIEMENS Styroflex KS Capacitors 3300pF -630V-1% (3.3nF) LOT of 10 PIECES | eBay

LCR Capacitors company now makes:
Photo: 500pF 160V 5% LCR AXIAL POLYSTYRENE CAPACITOR ad2R27 | eBay
EXFS-HR Polysterene
FSC Polysterene
FSC-EX Polysterene
FSR-VM-FSR-AX Polysterene
HS Polysterene
HSC Polysterene Coated
HSQ Polysterene
SUF710 Polysterene

 

[WntrMute2]

They are two different companies.

Siemens company made Styroflex brand name capacitors, both pp and ps types until around 1980.

LCR Capacitors company now makes:
EXFS-HR Polysterene
FSC Polysterene
FSC-EX Polysterene
FSR-VM-FSR-AX Polysterene
HS Polysterene
HSC Polysterene Coated
HSQ Polysterene
SUF710 Polysterene

Gotcha. Which of the above current LCR brand should I look at? The choice is staggering.

 

[rayma]

Gotcha. Which of the above current LCR brand should I look at? The choice is staggering.

Count yourself lucky, there were slim pickings for quite a long time.
Some series are just packaging variants though. For your needed value, get the highest voltage rating available, usually 630VDC. For phono use get 1% for channel matching, otherwise 5% is ok.
Try both pp and ps types, since for the Siemens caps, the pp version was decidedly better.
These are cheap, so buy a bunch and keep them in business.

 

[kodabmx]

X2 MKP safety caps work well... Actually prefer them to Orange Drop and the like.

These are one example of a great price for the product.
MKP Safety Capacitor X2 275V 0.1uF/100nF/104K/0.22/0.47uf/220nf/330nf/224K/474K | eBay

 

[K.A.B]

Forgot to tell i never use audio caps after years of trying i find out most of the ordinary components are well up for audio and the price i have ability to try more caps to find right cap. One of best caps i choose to use is they how are made for pulse applications.

 

[jackinnj]

For phono use get 1% for channel matching, otherwise 5% is ok.

1% capacitors are usually about 10x the price of 5% film capacitors, and the range of values is much smaller.

I buy a lot of 10 WIMA Polypropylene and just measure them.

And in terms of an RIAA network, if you have none which are spot on you can always adjust the value of the resistors with parallel or series combinations.

Mouser carries XICON polystyrene.

 

[Mark Tillotson]

Paralleling several capacitors averages out tolerance variations, and allows select-on-test from a batch of cheap capacitors to be more economic (you don't need to discard the outliers, just match them to the opposite outliers).

You can do the same with series strings too, handy if only low voltage parts are available with reasonable tolerance.

 

[Zung]

Yes, capacitance or, better still, LCR meters are between USD 20-80 nowaday: a very worthwhile investment. Just make sure you get the good ones (1% or better). Those built into DMM's are usually not good enough.

 

[analog_sa]

Very cheap for 1% tolerance parts.

The datasheets mention nothing about 1%.

 

[rayma]

The datasheets mention nothing about 1%.

The Mouser catalog listing says 1%, but maybe it's wrong.

 

[analog_sa]

It probably is wrong. The datasheets say either 5 or 10% which makes much more sense.

 

[WntrMute2]

Thanks guys. I've ordered the Kemet ones and am trying to reach the LCR guys without success. I'm in the US and they don't seem to have a distributor here.

 

[scott wurcer]

Thanks guys. I've ordered the Kemet ones and am trying to reach the LCR guys without success. I'm in the US and they don't seem to have a distributor here.

These guys still are well stocked with NOS TRW and others. I picked resistors based on cap values here. I used a handheld Beckman impedance bridge that I picked up for essentially nothing and the 2.5% values were almost always better than 1%. I posted in another thread +- 0.1dB RIAA "out of the box".

Polystyrene Capacitors - Great Selection and Prices

 

[ticknpop]

If Polyesters suit you Mr Snell then enjoy,
Polyester are small and inexpensive, but audibly poorer sounding than Polypropelene, teflon, and polystyrene.... and yes passing a signal for a couple of hundred hours to break them in improves the sound, if you can’t hear it don’t criticize those who can with. Most Riaa caps in higher end vendors products are 1%. If your going to DIY theres no reason to waste your time building mediocre audio components, you can buy those cheaply enough......

 

[blu_glo]

"Paralleling several capacitors averages out tolerance variations, …."
You can do the same with series strings too, handy if only low voltage parts are available with reasonable tolerance.

IIRC this is not quite correct.
The tolerance of any number of randomly selected 5% capacitors in a network produces a bulk capacitance of same 5% tolerance.
Now if you deliberately selected one 5% high and one 5% low yes, that would cancel.

 

[DF96]

No, the Central Limit theorem says that if you combine lots of 5% tolerance components then you are more and more likely to get a result which is much better than 5%.

The alternative is to buy just a few extras and select, as channel matching is more important than absolute value. Buy three 10% capacitors. They will be separated by no more than 20%. Choose the two closest ones - these will be separated by no more than 10%, which is equivalent to a pair of 5% components.

 

[Zung]

I'd much prefer going straight to the 1% ones: they don't cost that much, the NOS are about USD1 a piece, and you don't have to play russian roulette with the laws of statistics. I usually start with the 1% and then select them for best interchannel balance to the limit of my LCR bridge, about 0.75%, but that's only me .