Yay! *chanting* sticky, sticky, sticky!
Originally Posted by SeriousCat
"Is there any reason why you don't connect the red lead to the resistor until the amp is switched on?"
Very, very good point. Nothing away from Kev'. Excellent work.
When you have been poking in amp (and related murderers) gizzards as long as Kev and I have we do tend to get a bit blase perhaps, your brain/muscle interface sort of gets trained to avoid stupid things(still do 'em of course, caught a right old belt off a pedal a week ago!).
I always advise noobs to stock up on croc leads and make connections cold, then switch on and watch the smoke.
And I still swallow a bit hard when I see 760V on the meter, don't think my old ticker could cope with that!
Dave.
Oh yeh! I forgot the new S1's are pumping out figures like that!
LOL!
K
pah, get thee to a colour CRT then.........................(yes I know its only milliamps)
many a screwdriver was 'launched' accross an office.............(too much hassle to get the camel bump starter out of the tool box)
......"Bertie is pretty much a zen master..................."
"pah, get thee to a colour CRT then........................."
I hiss all over your CRT and raise you a microwave...2.5kV at an AMP! You would just not live.
But yes crt's were hairy. The one that was really scarery was a huge widesceen Philips job we had to swop. It came with special handles for two men and you needed two more to steady and align the cabinet. I bet that monster was near to 100nF.
Dave.
I remember having to swap a small mono crt at an HMIT (as it was then) site..........I was merrily doing the business (having NOT discharged it with the camel bump starter) and the 'liaison' chappie wouldnt shut up......distracted me, screwdriver whent over the hole in the tube..........screwdiver went awol and landed in a pinboard on the wall
......"Bertie is pretty much a zen master..................."
Good post.
I would like to add that this method underestimates the current draw by about 10 mA due to the resistance between the bottom of the resistor and the earth bond (you won't be able to measure this with a DMM).
Steering this thread back towards the merits of biasing HRDs/BDs... I've followed Kev's advice and stuck a pair of 6V6s in the power stage of my blues deluxe. They're the Russian NOS ones for a bargainous £10 a pair at Langrex. Biasing was dead easy following Kev's step by step guide - thanks again - although I'd expected to be moving from a higher multimeter reading to a lower. As with the 6V6s in the amp biased for 6L6s the mV was about 25 so I tuned up to 40 as suggested. Gigged the amp on Friday night and really impressed with the revamped tone. Sweet, singing warm tweedy breakup at an ideal volume from what is now more like a 20-watter. As in 4 on the clean selection is now where 2.5 was volume-wise but with nice hair. I think with a better speaker I might have the amp I actually want...
You did indeed. I am now an evangelist for the cause.
Everyone should get in on the 6V6 action - wake up your Blues Deluxe!
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