2204 PI voltages
- Thread starter ClintN667
- Start date
SpiderWars
Well-known member
Since they both share the cathode and power supply node you’d think it has to be either the plate or grid. Or the tube itself.
What is the power supply node voltage? I.E. the voltage on the other side of the 82k and 100k plate resistors (either one, should be the same).
What is the power supply node voltage? I.E. the voltage on the other side of the 82k and 100k plate resistors (either one, should be the same).
syscokid
New member
Can just the PI tube be pulled, and then test for voltages?
SpiderWars
Well-known member
Absolutely! Good check too. The plate voltages and the PI node voltage should all the same since no current should be flowing thru those plate resistors with no tube installed.
Thanks I will pull it and check! I will then check on the plate resistors
syscokid
New member
Measure at the pins, or at the tube side of the 82k & 100k plate resistors with no PI tube installed.
SpiderWars
Well-known member
With the amp OFF, voltages drained, and unplugged; check the resistance from pin 2 to ground. It should measure just over 1M (as should pin 7 to ground but that triode seems to be fine). You did connect the cathodes at the socket (as shown in layout above) right?
syscokid
New member
I think this is the pic of his Ceriatone build. Pic is not very clear, but it looks like the cathodes are hooked up right. Can't tell if the PI is grounded properly though. Jumper wire is probably under the board.
So I put in a new tube and they are measuring a little over around 250
I'm getting closer. This has some different options than a standard ceriatone so I'm hitting little snafus from the modifications. I am using an IEC with the mains fuse, the lighted rocker switches and I ommited the half power switch. Not necessarily heavily modified but since this is like my 6 ot 7th build Im hitting stuff that is taken me out of my comfort zone. It's been fun so far. I'm hoping to have everything sorted by the weekend then I'm going to try to build a mata amp GT120 next. I have the PCB and I have sourced the iron just gotta find a proper chassis. I'm hoping this one is a good choice for the next step up. I didn't want to try a yeti, sloclone etc yet
syscokid
New member
Many times, I have chased my tail trying to find the bug in an amp that was misbehaving. Only to finally find out that the problem was a weak tube.
SLO-clone? I highly recommend C3 Amps. Built their 50 watt version. Excellent quality throughout the whole kit!
I may do that. I've done a mod101 amp, a couple Champs, a valvestorm plexi, a ceriatone plexi, 2 headfirst pcb based 2204, and now this 2204. I've been learning a lot but I'm not doing this enough to feel like I definitely know what I'm doing if that makes sense. I'm definitely not repeating mistakes and learning more and more each build but I feel like I need much more practice. I want to go one step harder but I don't want to go too far above me skill level.
Hey Jason,
I ended up finding a few mistakes with help from Alex Catlow. My voltages are good now and it sounds killer. I'm hoping to grab a headshell for it sometime this month.
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yeah he showed me some things he is working on and he definitely isnt scared to go off the beaten path. I think he was rebuilding some transformers from KLD