Outstanding Video! You have wonderful way of explaining the technical aspects of why and what you are doing, that even a novice like myself can follow and easily understand, Bravo!!!!!
thank you so much for making this video. i have just started on amps and could not find a good video explaining first start up and checks . i have just finished my jcm 800 build and i was not going to turn it on before finding a video on voltage checks and yours was perfect. you explained everything so someone new could understand. you also explained why you had to do these check. I would recommend this video to anyone new to amp building. i cant wait to see more of your videos. thank you again
very helpful video! i had a bad (new) EL34 and it red plated. i wasnt paying attention and didnt notice until i saw smoke coming off the glowing resistor on the tube socket. thankfully the resistor did its job and didnt ruin anything
Haha I just built a Mojotone build using Alex's pcb and was wanting to find a vid on first power up and this is the first vid that popped up. I should know just go to your channel by now
Great Video! You don't recommend using a variac to wind up mains on startup? I know some guys do that. Also, can you show how you connect the bias current meter? I don't think that was shown.
Ah ok, gotcha. Its one of these, www.amazon.com.au/dp/B07CR5DN1V/ref=cm_sw_r_cp_awdb_imm_E9CBNWAVFNKP1YFT7FP0 You plug the probe socket in between the tube and the chassis socket
Noticed the multimeter connection to the mA port. Is there any reason to not use the 10A port when measuring 6.3v AC heater voltage? Don't the heaters draw typically exceed 3A in your average Marshall amps?
Neither is an amp when connected to speakers. That's why it's a "simulated" load, not a mathematically perfect one. It's useful for getting real-world reading
Perfect timing! I’m nearly finished my amp and this is gold! Thanks Jason!
Outstanding Video! You have wonderful way of explaining the technical aspects of why and what you are doing, that even a novice like myself can follow and easily understand, Bravo!!!!!
Thanks!
thank you so much for making this video. i have just started on amps and could not find a good video explaining first start up and checks . i have just finished my jcm 800 build and i was not going to turn it on before finding a video on voltage checks and yours was perfect. you explained everything so someone new could understand. you also explained why you had to do these check. I would recommend this video to anyone new to amp building. i cant wait to see more of your videos. thank you again
Welcome aboard!
very helpful video!
i had a bad (new) EL34 and it red plated. i wasnt paying attention and didnt notice until i saw smoke coming off the glowing resistor on the tube socket. thankfully the resistor did its job and didnt ruin anything
Haha I just built a Mojotone build using Alex's pcb and was wanting to find a vid on first power up and this is the first vid that popped up. I should know just go to your channel by now
Great video. Looking forward to part 2.
Thanks Jason. This is very helpful (as always).
Great video, thanks Jason.
Great video. Very helpful!
Great Video! You don't recommend using a variac to wind up mains on startup? I know some guys do that. Also, can you show how you connect the bias current meter? I don't think that was shown.
I don't own one, never have. Just flick the switch mate! I show a still picture of the probe setup in the video at 16:58
I can see how the meter itself is setup but you just say it’s connected to the power tubes but doesn’t show how. Thats what i was asking about.
Ah ok, gotcha. Its one of these,
www.amazon.com.au/dp/B07CR5DN1V/ref=cm_sw_r_cp_awdb_imm_E9CBNWAVFNKP1YFT7FP0
You plug the probe socket in between the tube and the chassis socket
Great vid! One other safety recommendation I would add: remove any watches/bracelets/rings on the hand you are using the probe with. 🤘🏻
Agree with that tip!
Noticed the multimeter connection to the mA port. Is there any reason to not use the 10A port when measuring 6.3v AC heater voltage? Don't the heaters draw typically exceed 3A in your average Marshall amps?
You’d one use the 10A socket if you’re attempting to measure the heater current, which should not be necessary.
Just a bit careful on the no high voltage on standby, still loads on filter caps etc…
Probably better to use a 10ohm load resistor instead of 8. Impedance and resistance are not 1:1
They are not the same thing at all.
Neither is an amp when connected to speakers. That's why it's a "simulated" load, not a mathematically perfect one. It's useful for getting real-world reading