capacitor 1mF 10% 250V, polyester, ARCO 1.06, axial.

[stenak]

Hello.
I am building the Bastard(BSTRD) diy tube preamp, using two 6j5 with metal top.
Searching for a 1mF output capacitor, I found a capacitor 1mF 10% 250V, polyester, ARCO 1.06, axial.The colour of the capacitor is green. Is the capacitor any good for this use?

 

[Kay Pirinha]

What's the use for a 1000 µF output coupling capacitor in a tube preamp? How huge is a foil capacitor of this capacitance and 250 Vdc rating?


Best regards!

 

[stenak]

Sorry, but a small m stands for microFarad. 1 micro farad

 

[Kay Pirinha]

µ = micro = 10^-6
m = milli = 10^-3

 

[Enzo]

M = mega

m = milli

u = micro

Kay correctly used the Greek lower case mu, but most of us use the u instead because it is on the keyboard.

 

[stenak]

Ok..but my question is ..the capacitors quality, is it a good capacitor to use as a output capacitor?The Arco is probably 30-40 years old and never been used before

 

[Kay Pirinha]

Yes, most probably it will do - unless the amplifier's Eb voltage won't exceed the capacitor's 250 V rating.
Best regards!

 

[stenak]

The Bastard works with around 80-90volts, and 250v is ok. the problem is tahat the space for the outputcapacitor is so small on the pcb. Most audiophile capacitors often are made for 250- 400volts..And therefore they are big.

 

[stenak]

Here is the link for "the bastard"

The Muffsy BSTRD - Class A Tube Preamp PCBs from skrodahl on Tindie

 

[DF96]

Sorry, but a small m stands for microFarad.

Some old books (mainly American?) use 'mfd' for microfarad.
'mF' definitely means millifarad. Some people use 'mf' - which is ambiguous as we don't know whether they really mean 'mF' (millifarad) or 'mfd' (microfarad).

Polyester capacitors are very slightly non-linear, but this probably won't matter too much as long as this capacitor does not set the LF rolloff point for the entire system.

 

[dotneck335]

micro = µ
Alt + 230 will give this symbol