let's see
Yes volts not amps for your multimeter.
You calculate amps via ohms law V=I*R. Amps is I=V/R so you divide your voltage by cathode resistor value.
You can't measure amps easily with your multimeter without drastically modifying the circuit. Ohms law makes it very easy for us in a non intrusive way.
You calculate amps via ohms law V=I*R. Amps is I=V/R so you divide your voltage by cathode resistor value.
You can't measure amps easily with your multimeter without drastically modifying the circuit. Ohms law makes it very easy for us in a non intrusive way.
So you are running only at 3 mA then. If it were me I would drop the cathode resistors down to like 270 or so. from the data sheets looks like around 8mA is a good target.
Keep dropping your cathode resistor until you reach at least 8mA but I would not go over 10.
Keep in mind b+ will drop a little as you increase the current.
Keep dropping your cathode resistor until you reach at least 8mA but I would not go over 10.
Keep in mind b+ will drop a little as you increase the current.
Yes i thought so too.
Do I put more pressure on transformer doing this? Making the tube hotter i mean. It is pretty hot as it is.
I noticed tubes are a bit hotter now on the sides then before. and maybe it actually sounds at bit more open? not sure. Listen only half hour on it. Before i noticed that after 3h+ sounds opened up more.
I will try lower tomorrow. If i have some value that fits (serie or paralell it have to be) 270 i don't have in stock.
Do I put more pressure on transformer doing this? Making the tube hotter i mean. It is pretty hot as it is.
I noticed tubes are a bit hotter now on the sides then before. and maybe it actually sounds at bit more open? not sure. Listen only half hour on it. Before i noticed that after 3h+ sounds opened up more.
I will try lower tomorrow. If i have some value that fits (serie or paralell it have to be) 270 i don't have in stock.
By "hotter" I meant more current, but yes as you run more current through the tube will actually get hotter.
What rating is your transformer? in VA or Amps for the HV secondary?
Usually pulling a few more mA out of the xformer is not a big deal. My guess is that you have plenty of headroom. We are only talking less than 20mA total.
Also you can parallel resistors to get a lower value - google parallel resistor calculator and you can see if you have the right values to combine to get the value you desire.
What rating is your transformer? in VA or Amps for the HV secondary?
Usually pulling a few more mA out of the xformer is not a big deal. My guess is that you have plenty of headroom. We are only talking less than 20mA total.
Also you can parallel resistors to get a lower value - google parallel resistor calculator and you can see if you have the right values to combine to get the value you desire.
Ok good to know!
I checked my resistor storage and i can get 250. I will try that.
Another thing mentioned earlier that i really want to know is that how big/small coupling caps do i really need ?
Is 0,33 on input and 3,3uf ok? It feels like it's little "cut-off" under say 40-50hz.
I'm about to order some new ones.
Any ideas?
Also want to try a choke. Is 20mH to much? Do i replace this with the 10k resistor?
Thx
I checked my resistor storage and i can get 250. I will try that.
Another thing mentioned earlier that i really want to know is that how big/small coupling caps do i really need ?
Is 0,33 on input and 3,3uf ok? It feels like it's little "cut-off" under say 40-50hz.
I'm about to order some new ones.
Any ideas?
Also want to try a choke. Is 20mH to much? Do i replace this with the 10k resistor?
Thx
Here is what I would try.
1. No input cap...use 330 ohm resistor instead...grid stopper can help reduce/eliminate oscillation.
2. 5 or 10 H choke in place of the 100R in the psu...you need to keep the 10k in the second spot to drop enough voltage. Choke goes in the first spot.
3. For output cap use high quality film or pio cap...anything from 0.33uF to 1uF is good here. You could even bypass a nice film cap with a pio cap too(parallel).
SRPP+ PCB & Death of the CD this is a good read on srpp circuit.
1. No input cap...use 330 ohm resistor instead...grid stopper can help reduce/eliminate oscillation.
2. 5 or 10 H choke in place of the 100R in the psu...you need to keep the 10k in the second spot to drop enough voltage. Choke goes in the first spot.
3. For output cap use high quality film or pio cap...anything from 0.33uF to 1uF is good here. You could even bypass a nice film cap with a pio cap too(parallel).
SRPP+ PCB & Death of the CD this is a good read on srpp circuit.
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