I'm very close! ... but I hit a snag. I snipped the lead to one of the 2k2 to the EL84, used my roundnose pliers to loop it for crimping to the wire and while looping the lead it snapped! Must have been a nick or something in the lead. The length leftover is really short I don't think I can make it work.
Worst thing is I don't have another 2k2. So now I gotta get another one and pay $15 shipping. Not happy...
I have a box of stuff for a dumble build with a bunch of Rs. I'll see if I have another larger W resistor to use tonight when I get back from work that's somewhat close in value.
Last edited by surfsup on Thu May 12, 2011 8:23 pm, edited 1 time in total.
I have a bunch of vintage Carbon Comp resistors at home, I probably have what you need, or really close. PM me what town your in, maybe I can swing by and drop some Resistors off for you to play with.
nice build, that I'm sure will sound great.
just an idea for all the switched pots you've got:
You can use one for the sparkle /bright switch, another for including or excluding the famous 56/82K (or whatever value could be) grid leak so to tame the overall gain, and the last could be used to change the slope resistor in the tone stack, or to select two different cut frequencies at the rc filter
Surfsup... I've been following these X10 threads closely since listening to the initial Greg V demo, and am grateful to you and the others who have been decoding this very cool amp. I'm looking forward to building one down the road. Your project looks fantastic. All the careful planning is paying off and you should end up with a great amp.
I tested all my grounds and lead connections using continuity and testing for resistance making sure it reads 0.001 or less on my DMM. Everything is fine.
I plugged a 1/4" pedal jumper into the input and each speaker jack, tested for grounds and continuity. Everything is fine.
I plugged a power cable in, clipped the dmm to the third prong and again tested all the grounds. Everything is fine.
I plug it in, throw the power switch. I read 333VAC at the first resistor, 330 after, and a whopping 462VDC after the diodes! 333*1.4=462 so seems right. It is that I have no tubes installed? I should be getting 300 at the resistor and 335V after the 1k 5W resistor. Please let me know if this will be fine with the tubes in, drawing current?
Also, I assume at these voltages I shouldn't flip the standby switch (w/o tubes)?
Last edited by surfsup on Thu May 12, 2011 8:45 pm, edited 1 time in total.
Well I put the tubes in, the two blue ohmite 1k 5w resistors started to smoke so I shut it down and moved it outside. I didn't have time to check any voltages or anything. They were fine with just the main on/off switch on. Only after I hit the standby. Any ideas?
The datasheet for these resistors shows max voltage 460 and now they need replacement:
Edit to add: For safety, hot should go to the back terminal of the fuse block, so when you're pulling the fuse, it breaks contact from the hot *first*.