Hi I am new to making valve circuits, today I built a simple singe valve amp using the PCL valve. I have got it working reasonably well. My question is are there any other valves that have the same pin connections?
I have been looking at different valve data but so far not found one. I have a mass of TV valves all new, that I rescued, so will try some more circuits.
Thanks
I have been looking at different valve data but so far not found one. I have a mass of TV valves all new, that I rescued, so will try some more circuits.
Thanks
Not that I am aware of. The PCL82 is a nice valve. In push pull you can achieve excess of 5Watts with hardly any distortion.
I have tried 3 different valves all PCL82 and they all sound different! I am using the valve in a single ended configuration 2 sound a bit distorted. But the last one I tried sound good.
ECL82 (6BM8) is same except for heater voltage. PCL82 is American 16A8, 8B8 is another variant with 8 volt heater. And there's the 11BM8 as well. 6HC8/17HC8 also looks interesting, though I've never come across one.
ECL86 / 6GW8 is another such tube with different pin connection. PCL86 / 14GW8 is same except for 13.3V heater.
ECL86 / 6GW8 is another such tube with different pin connection. PCL86 / 14GW8 is same except for 13.3V heater.
@Bagpussy... My first valve project back in 1976 used the UCL82. That was the version of the PCL82 designed for a 100mA heater chain and was used in some radios in the 1960s. It was a good experience and I learned a fair bit from it.
If you are hearing differences with different valves, one thing to try is to see if you can also measure differences. For example, measure the anode and cathode voltages around the valve, and anywhere else that you can think of. Do they change with different valves? Some small variation would be normal, but they would normally sound quite similar. Big variations could mean that one of the valves is faulty, or perhaps it's oscillating at a very high frequency. Does your circuit employ any negative feedback? My guess is perhaps not, and that would make differences between valves more obvious.
Do you have a circuit diagram that you can post, with some voltages mark on it? THat would help people to understand what you're seeing.
If you are hearing differences with different valves, one thing to try is to see if you can also measure differences. For example, measure the anode and cathode voltages around the valve, and anywhere else that you can think of. Do they change with different valves? Some small variation would be normal, but they would normally sound quite similar. Big variations could mean that one of the valves is faulty, or perhaps it's oscillating at a very high frequency. Does your circuit employ any negative feedback? My guess is perhaps not, and that would make differences between valves more obvious.
Do you have a circuit diagram that you can post, with some voltages mark on it? THat would help people to understand what you're seeing.
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