Coupling capacitor NAF845SE

[pmcuk]

The FT ones are, I agree, very good indeed. I still can't usually navigate the size problem though. I have (some courtest of Andy, thank you) a load of the .1uF ones, but in cases where closer to 1uF is needed, a garden shed would offer suitable casework.

They're not cheap any more so it's worth conserving the ones you have left. I'm looking at other options for larger sizes. KBG caps aren't easy to find anymore either. Polystyrene maybe, or silver mica, but both are quite bulky. The Russian stuff is mostly available from Ukraine and ex-Soviet countries like Bulgaria, but stocks are nowhere near as good as before.

 

[rabski]

They're not cheap any more so it's worth conserving the ones you have left. I'm looking at other options for larger sizes. KBG caps aren't easy to find anymore either. Polystyrene maybe, or silver mica, but both are quite bulky. The Russian stuff is mostly available from Ukraine and ex-Soviet countries like Bulgaria, but stocks are nowhere near as good as before.

I ended up buying loads (of course), plus a fair few valves and power resistors. I have enough to keep me going, but in a few places they're just out of the question. To keep the -3dB point sensible for the phono stage I need 2.2uF. That's not going to work with bean-tin sized 0.1 no matter how much I squeeze

 

[Alvolake]

I once went through a teflon phase using FT3 0.47 everywhere but then someone pointed me towards K73-16 russkies which are tiny in comparison and as I am a technical ignoramus/virgin I didn’t bother reading whether they were teflon or not ( they aren’t) I used them first for coupling and in the end even inmy crossovers. If you haven’t yet, just try them, they cost nothing or never used to and be surprised.

 

[rabski]

The K73s are polyester and also very good, I agree. The only potential issue with them is voltage ratings. Most of the FT3 are 1kV or thereabouts, but a lot of the K73 are relatively low. In most valve coupling, the potential difference can be quite low voltage, but not in the final couplg to an 845. Assuming the circuit is decent (and it would be in a NAF), you need 630V rated to be safe.

 

[Alvolake]

Ah, I bought K73 ·-16s 0.1uF up to 630v with the diamond (military) . Enough for my P10. 20 units cost me 9 dollars on eBay . From a guy called Alexer1 (I´m assuming Ukraine, poor sod

 

[TJS]

I will try to change to hovland musicap 0.47uf 600v as i can buy it from my friend. Will start from hovland and listen...if i really please with the sound, then it stay and I can save money as hovland still cheaper than audio note, jupiter, duelund and Vcap... will report back to you guys once i soldered it and let the cap settle in few days