Hello guys .
I have in my pre for b+ two 100mf 400v film caps installed. I want to bypass them with 0.1 mf film caps which rated 250v. In the b+ rails i have in tubes plates 217v dc measure exactly. This voltage is after the ECL82 and goes to tubes plates . The transformer winding output is 230v ac and i suppose (didn't measured) that is approximately the same after the diodes and to the 100mf caps.
My question is.....
Is it safe to bypass them with 250v caps? Is it enough 250v . I ordered them and i didn't pay too much attention by mistake to the voltage rating.
I will post pic of my external tube preamplifier PSU.
Also pics of the actual pre inside. 12au7 12at7 per channel. All hook up cables are pure silver, dact pot, visay and takman film resistors and all film caps , tube sockets of teflon and pure ofc cooper , rca jacks pure cooper. Aslo in the PSU the heaters regulators are SPARKOS discreet regulators SS7812. The construction is pure dual mono from pre to psu. The preamplifier WAS KORATO KVP20 dual mono version from factory. WAS. ........ Now is something else . Its completely reconstructed and rebuilt but the circuit remains as it was from factory and the actual values of all the new and higher quality parts (resistors caps diodes regulators) also as it was from the factory.
I have in my pre for b+ two 100mf 400v film caps installed. I want to bypass them with 0.1 mf film caps which rated 250v. In the b+ rails i have in tubes plates 217v dc measure exactly. This voltage is after the ECL82 and goes to tubes plates . The transformer winding output is 230v ac and i suppose (didn't measured) that is approximately the same after the diodes and to the 100mf caps.
My question is.....
Is it safe to bypass them with 250v caps? Is it enough 250v . I ordered them and i didn't pay too much attention by mistake to the voltage rating.
I will post pic of my external tube preamplifier PSU.
Also pics of the actual pre inside. 12au7 12at7 per channel. All hook up cables are pure silver, dact pot, visay and takman film resistors and all film caps , tube sockets of teflon and pure ofc cooper , rca jacks pure cooper. Aslo in the PSU the heaters regulators are SPARKOS discreet regulators SS7812. The construction is pure dual mono from pre to psu. The preamplifier WAS KORATO KVP20 dual mono version from factory. WAS. ........ Now is something else . Its completely reconstructed and rebuilt but the circuit remains as it was from factory and the actual values of all the new and higher quality parts (resistors caps diodes regulators) also as it was from the factory.
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"Is it safe to bypass them with 250v caps?"
No.
230V AC peek rectified even 325V, so the 400V for 100uF is the right value for bypass capacitor too.
p.s.
What else do you expect from the bypass?
Is ECL82 the HV regulator?
No.
230V AC peek rectified even 325V, so the 400V for 100uF is the right value for bypass capacitor too.
p.s.
What else do you expect from the bypass?
Is ECL82 the HV regulator?
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Adding 0.1 uF to 100 uF (both MF) will give you 100,1 uF. This looks like wasted money to me, especially since the 100uF is MKP.
And you should use 400 V capacitors if you don’t like exploding capacitors. Better safe than sorry.
And you should use 400 V capacitors if you don’t like exploding capacitors. Better safe than sorry.
Not that you are asking, but those aluminum bodied gold chassis mount resistors are NOT mounted to the chassis. They need serious de-rating just in the breeze like you have them.
Yes mate ECL82 is the hv regulator.
Aaa i knew it that i was making the wrong order with 250v caps. I am so stupid i can't believe my self.
WntrMute2 you mean i have to mount them to chassis?
Well, yes. If you want them to handle their rated wattage, otherwise they handle just a small fraction.
Thanks WntrMute2.
These are visay dale 10w rated. They replaced the original from factory that was rated at 2w.
I thought that if i leave them like that it would be enough for the wattage they draw.
Aaaaaaxx i have to drill again. it's my worst
These are visay dale 10w rated. They replaced the original from factory that was rated at 2w.
I thought that if i leave them like that it would be enough for the wattage they draw.
Aaaaaaxx i have to drill again. it's my worst
I am not saying that the 10W ones won't be OK carrying 2W but I would look at the data sheet and at least be aware of the amount to de-rate. You could also replace with Ohmite Brown Devil line which are designed to be in free air.
How hot are the resistors when the amplifier has been on for some time. If you measure, you will know.
If you can still touch the body with your fingers you’re probably safe. Switch the amplifier off before you touch anything inside!
If you can still touch the body with your fingers you’re probably safe. Switch the amplifier off before you touch anything inside!
That turret strip looks as though it is screwed down to the chassis. But turret tags are riveted, so turret strips need to be spaced clear of the (conductive) chassis. No point in putting insulation over leads that are in the air if a turret strip can touch the chassis.
Looking at #6 I think the turret tags are well placed. The built quality is superbe and I don't expect such a mistake on that level.
Don't confuse this with the OP's pictures.
Don't confuse this with the OP's pictures.