If you are not finding the C. Comps in the values that you need, expand your search to places that specialize in musical instrument amplifiers.
In the US. that would include places like AES and Tube Depot. In fact, Tube Depot has 1/2, 1, and 2 watt 1K CCs in stock, including some Allen Bradley.
I am building several of Pete's designs, so I stocked up on 1K CCs a couple years ago!
Dan
In the US. that would include places like AES and Tube Depot. In fact, Tube Depot has 1/2, 1, and 2 watt 1K CCs in stock, including some Allen Bradley.
I am building several of Pete's designs, so I stocked up on 1K CCs a couple years ago!
Dan
It would be better to omit the volume pot, but then again it all depends on the rest of the system... where the pot may actually bring the required very small amount of capacitance.... that will balance the sound to being just right. The best is to try and see.
I tend not to use any wiper scrubbing/unnecessary contact resistance points in a signal chain... and of course the additional wiring, but I like the minimalist approach. If I have to use a pot, then it is a TKD pot from 2CP range...
I tend not to use any wiper scrubbing/unnecessary contact resistance points in a signal chain... and of course the additional wiring, but I like the minimalist approach. If I have to use a pot, then it is a TKD pot from 2CP range...
https://www.partsconnexion.com/TKD-73338.html
You mean like this? Appears to be compatible with Pete's PCB has he has solder pads for the smaller spaced pins. Might be a good compromise as it is stepped and yields a safety margin in the event someone puts the volume on full via the bluetooth / or digital realm stage....
I modified something similar... a very long time ago. That amp used ECL86 valves... slightly different. I did not have a circuit diagram, so I back-engineered it sort of speaking... and then performed the modifications. The amp sounded really well and was able to drive my Dynaudio 4-ohm (minimum impedance 3.8 ohms across full frequency range) speakers with great results. See attached... you may find it useful for your build....
I used this one:
https://www.partsconnexion.com/TKD-70897.html
...but the one you suggested will work as well.
R10 and R11 are not only grid stoppers, they also supply Screen Grid current, which can be many mA, within the range of linear power peaks.
R12 and R13 are grid stoppers and do not pass any significant Control Grid current, . . .
as long as you stay in the Linear signal power range of the amplifier circuit in Post # 1.
It is designed for Class A1.
It is Not designed for Class A2 (control grid current).
Drawing control grid current will shift the bias of the output tube, cause distortion, take time to recover, etc. . . . Turn the Volume down.
I don't know anything about a 6T10 pentode. It might need a grid stopper too. If it does, I mentioned in Post # 13 how to connect a grid stopper.
All the input wiring might contribute to causing an RF oscillation, especially when the volume control is turned up fully.
R12 and R13 are grid stoppers and do not pass any significant Control Grid current, . . .
as long as you stay in the Linear signal power range of the amplifier circuit in Post # 1.
It is designed for Class A1.
It is Not designed for Class A2 (control grid current).
Drawing control grid current will shift the bias of the output tube, cause distortion, take time to recover, etc. . . . Turn the Volume down.
I don't know anything about a 6T10 pentode. It might need a grid stopper too. If it does, I mentioned in Post # 13 how to connect a grid stopper.
All the input wiring might contribute to causing an RF oscillation, especially when the volume control is turned up fully.
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