Running tubes too cool is bad for me!
Music ceases to be amplified.
The filament voltage being run 1v low is standard best practices for obtaining lowest noise. Good tubes will last decades in my preamp. A full set of good tubes can be had for under $100. I have plenty of both types stashed, so I can't bring myself to loose sleep over it.
Actually the damn thing is so quiet I regularly fall asleep and leave it on all night...
"All very simple ...." Got tubes, transformers, chassis, but no inspiration; could you please share the schematic?
Great to see someone using these tubes. Guess you have some 20-25W to fiddle with?!
Here, drew it. The bias regulator is by Pete Millett as on his website"All very simple ...." Got tubes, transformers, chassis, but no inspiration; could you please share the schematic?
Great to see someone using these tubes. Guess you have some 20-25W to fiddle with?!
In my set up it is 15W, but can be upped to 20-25W if needed, sure
As to build advice - simple solid core wire works well enough for the anode cap. I tried to make something fancy from copper bar, did not succeed much
Thanks a lot! I will look into this. As it is a tetrode it is definitely easier to handle as triodes I guess.
I have a transformer that will give me a B+ of 700V.
I have a transformer that will give me a B+ of 700V.
I have been into deep thoughts myself about a cool anode cap, but then again ... "it's just only 700V on the anode plate .... "
I've not tried REW for a while, I had trouble calibrating my AI,couldn't get it right. Had more success with ARTA and the easiest scope/sig gen/THD/FFT is Soundcard Scope.
Grand fettling there Dr, I have some 6BG6's on order at present.
Like the way you terminated the top cap wiring, I do that too, especially with screened grid caps.
Andy.
Here is a Bottlehead crack I picked up used and fixed up a bit. Electrically all I needed to do was redo some suspect heater wiring and I switched it to take 6CG7 while I was at it, other than that it is stock. The sound with my AKG sextett phones was so pretty I decided it needed a sexier look. I made the new base from curly maple with a thin black inlay and changed the proportions to be a little less clunky. I hand rubbed a finish with tung oil and wax. I made a vented bottom plate from some aluminum perf metal, secured the top plate to the base, painted the end bell and added a vintage knob. Not a fan of tube rolling so I just picked tubes from my stash to work the best in their positions. I.E. the highest transconductance 6080 I had with matched sections.
