image hosting

Post by **dave slagle** » Wed Mar 09, 2005 7:08 pm

feel free to use this space to host images.

Post by **dave slagle** » Wed Mar 09, 2005 7:10 pm

Post by **dave slagle** » Thu Mar 10, 2005 6:05 pm

HK-54 for dowdy

Post by **dave slagle** » Sat May 28, 2005 1:11 am

just shrunk it a bit to avoid the dreaded bottom scroll bar.

Guest · Post by **Guest** » Tue Apr 04, 2006 3:54 pm

This is the output from the right channel, inputs grounded.

earwax · Post by **earwax** » Tue Apr 04, 2006 7:00 pm

Fi preamp

slowmotion · Post by **slowmotion** » Tue Apr 04, 2006 7:30 pm

That Fi pre looks good, I think

Post by **dave slagle** » Sun Apr 30, 2006 7:21 pm

Post by **dave slagle** » Mon May 01, 2006 3:23 pm

Post by **dave slagle** » Mon May 01, 2006 7:59 pm

Post by **dave slagle** » Tue May 02, 2006 3:32 am

Post by **dave slagle** » Thu May 18, 2006 6:29 pm

Post by **dave slagle** » Thu May 25, 2006 5:45 pm

pultec

Post by **dave slagle** » Wed Jun 14, 2006 5:36 pm

hello

Post by **dave slagle** » Sun Jul 02, 2006 11:53 am

Guest · Post by **Guest** » Sat Jul 15, 2006 1:18 am

message

Post by **Dave Cigna** » Thu Dec 07, 2006 2:37 am

Post by **dave slagle** » Wed Dec 20, 2006 3:23 pm

plots

Post by **Dave Cigna** » Sat Dec 23, 2006 11:19 pm

a colorful drawing

Post by **dave slagle** » Sun Dec 24, 2006 1:13 am

JeffreyJ · Post by **JeffreyJ** » Sun Dec 24, 2006 7:22 am

ok.. I know I am suspect for having used parafeed for years.. but I am totally following my ears on all of these decisions.. and, yes, my last amp was series feed.. by choice...

but when looking at parafeed, at least give it the benefit of the doubt and return the ac loop to cathode.... get that nasty cathode resistor and cathode cap out of the loop... at least as much as possible.. it is *parallel* feed after all...

and, related, can't we also return the output tube grid resistor to the cathode of the proceeding stage? I know it changes bias, but we can correct for that... I just never tried it...

related, part B: is the "middle" ac path: plate of driver tube > cap > grid > grid resistor > ground and back through teh driver tube? man.. kinda makes that grid resistor super ugly.. I don't like resistors and there's a *big* one...

and lastly.. likely one for me... why not put a *choke* under teh cathode of a parafeed output stage of the return is to cathode... cool, huh? if your PS is quiet, I see no issues... maybe even a benefit...

anyway.. supposed to be cleaning.. fifty folks coming over tomorrow.. ugh!

Peace,
Me

Post by **Dave Cigna** » Tue Jan 16, 2007 12:22 am

Transfer characteristics of 6AR8 beam deflector tube. It's sorta a small pentode with two plates and a pair of beam deflectors. When the difference between the deflector voltages is zero the cathode current is shared equally between the plates. When a difference is applied the current is directed more towards one or the other plates.

If you consider the deflectors as inputs then it is a differential amp (with PP outputs) in a single bottle. Appears to be pretty linear too, but the gain is low.

Post by **dave slagle** » Mon Jan 29, 2007 8:27 pm

Post by **dave slagle** » Tue Jan 30, 2007 5:38 pm

Post by **dave slagle** » Wed Feb 07, 2007 11:34 pm

Intact Audio

image hosting

image hosting

bruce's amp resized.

fi

nt

bb

pultec

j

nt

h

plots fo NC

parafeed loops...

hh

hh