BLUEGLOW ELECTRONICS FORUM

Hello all, Merry Christmas, Happy Holidays to all!!! A few weeks back I watched one of Marks Video's (Pretty sure it was a blueglow, but hey my memory is getting bad) where he used a 2 channel's on an oscilloscope and quickly demonstrated the math functions.. I could have sworn I saw he selected mat...

+1 on that kit!!!
Im chomping at the bit... Been waiting for we know who (lol) as the teasers for the next build were exactly what I want to build....

Mike, My take on this is the 110V version give you the ability to dial past 120. Useful when using load limiting (Not that a few volts less probably matters anyway) My setup is main house -> Vairac -> Isolation transformer than the load limiter if needed. When dialing the variac up, I watch the outp...

Regardless of PP, SE tube measurements, a lowly resistor the same method applies. I think some guy called Ohm as in Ohms law derived the relationship. We could convert the watts to BTU's by multiplying by something like 3.14 but that would be silly, not to mention piss folks off... So, current flow ...

Hugo wrote: ↑Tue Apr 20, 2021 8:25 am For the 6L6 and it is typically 11mA for a push pull configuration. That is in a range where you can no longer ignore it.

Understood! And 11mA showing up would be something i wouldn't want to disregard.. I guess it pays to know your valves!

Just to further my education, and from Marks videos... whatever current the plate sees, the cathode also see's, at least close enough to measure the cathode bias resistor and from its voltage drop, ohms law would get you to 99.9% of plate current. Again, from what I thought I learned, the grid doesn...

Set up for the video, did a dry run and measured more believable numbers! I think I know what I did wrong yesterday. My lesson for today, if Im in doubt of the results, step back, take a second and run through all while making believe Im going to have Mark watching! Attached is a screen shot of my d...

Poking around my amp, I figured I should try to figure out the OPT. I always hear folks say as far as big iron goes, its on the top of the list to upgrade if possible. Saw Marks excellent video a ton of times. Saw uncle Doug's as well, as many times as needed to really understand the deal. Between b...

Update... The schematic is not 100% correct. They have 2x 0.1uF caps and 2x 0.47uF caps in real life, while the schematic shows 4x 0.1uF... I managed to get the board out of the amp and trace the circuit, and see that they used a .47 uF coupling cap between the 12AT7 and the 300B. Im curious to lear...

Can you measure the voltage drop across the 33k resistor? Can you measure the 33k resistor? And, because I don't exactly understand whats happening there, is there only the one 33k ? If so, wont that one resistor show double the current as it's getting split by two tubes? I have a feeling the opt is...