cathode follower tube buffer using 6n6p

nightanole · 24th June 2010, 01:23 PM

I have little experience with tube amps (built 1 spud) and have 8 Russian 6n6p tubes. Im building a preamp and would like to use the tubes as a buffer for the output to lower the impedance after the pot.

Is there a simple schematic someone has for this using a cathode buffer with 1 tube? Im in the USA so I was thinking of just getting 2 6.3vac transformers and running 1 to the wall to step down to 6.3, then connect the other one to step it back to 120vac and use a full bridge rec to convert to 170vdc.

Can i just copy Lamps version that he uses for his dac's?

Arnulf · 24th June 2010, 08:56 PM

Read: The Valve Wizard -Cathode Follower

And yes, your transformer arrangement is sound.

Gordy · 25th June 2010, 12:12 AM

Quote:

Originally Posted by nightanole

Is there a simple schematic someone has for this using a cathode buffer with 1 tube?

Consider the DC coupled follower designed and documented by forum member SY. It's called Heretic: A Heretical Unity gain line stage

Quote:

Originally Posted by nightanole

Can i just copy Lamps version that he uses for his dac's?

You mean this? Preamplifier_with_HEAD

You can adapt it, but the performance may be mediocre.

Eli Duttman · 25th June 2010, 01:13 AM

While undoubtedly sound, SY's design is anything but simple and could be a trap for a builder with little experience.

FWIW, I suggest 10M45S constant current sink loaded cathode followers and a bipolar PSU. That sort of arrangement places only 1 cap., at the unit's O/P, in the signal path. A 4.7 μF metalized polypropylene part bypassed by a 470 nF. 716P series Orange Drop does that job well, without spending a lot.

A $25 AnTek model AN-05T160 power trafo looks like a reasonable fit for the job. To get a bipolar supply, each rail would be 1/2 wave rectified, but making the 1st filter caps. big deals with that matter. A single filter choke can be shared between the 2 rails, in the grounded leg. A pair of 600 PIV Schottky diodes for rectification are inexpensive enough and yield "noiseless" operation.

nightanole · 25th June 2010, 02:12 AM

Oh man Eli is following me again. Um with a BP supply i halve my voltage so supply caps would be alot cheaper. Any schematics or something to go on? Since im a beginer i cant make anything from scratch. I just wanted to get some tube sound to my Tamp and 3886 amp i built up.

Heres what i was going to adapt.

http://www.lampizator.eu/lampizator/...X/IMG_5144.jpg

its got 2 caps in the audio path, but the first can be small so i can get something nice. The output cap might set me back alittle if i go full metal film.

smbrown · 25th June 2010, 08:40 PM

Nightanole, But that's not a cathode follower, it's an anode follower. However, with the lowish plate impedance of the 6n6, you may not need a cathode follower. I use a 6n6 preamp and take the output from the plate, no problem.

SY · 25th June 2010, 08:43 PM

It's not even an anode follower, it's a common cathode amplifier. The design is... questionable.

Ezequiel (kel) · 25th June 2010, 09:19 PM

see this, but it has to change for 6n6p, that and a very good blog 10000 circuits...

http://circuitoseletronics.blogspot....-follower.html

Moderator Warning Note:

the link does take you to a cathode follower, but also opens new windows for at string of advertisements

nightanole · 26th June 2010, 12:50 AM

Sorry wrong lamp

http://www.lampizator.eu/LAMPIZATOR/...X/IMG_5143.jpg

heres the cathode version

Wavebourn · 26th June 2010, 01:01 AM

Quote:

Originally Posted by nightanole

Sorry wrong lamp

http://www.lampizator.eu/LAMPIZATOR/...X/IMG_5143.jpg

heres the cathode version

Nope. It's still a common cathode inverting amp.

Try again!

24th June 2010, 01:23 PM	#1
nightanole diyAudio Member Join Date: Feb 2009	cathode follower tube buffer using 6n6p I have little experience with tube amps (built 1 spud) and have 8 Russian 6n6p tubes. Im building a preamp and would like to use the tubes as a buffer for the output to lower the impedance after the pot. Is there a simple schematic someone has for this using a cathode buffer with 1 tube? Im in the USA so I was thinking of just getting 2 6.3vac transformers and running 1 to the wall to step down to 6.3, then connect the other one to step it back to 120vac and use a full bridge rec to convert to 170vdc. Can i just copy Lamps version that he uses for his dac's?

24th June 2010, 08:56 PM	#2
Arnulf diyAudio Member Join Date: Feb 2009	Read: The Valve Wizard -Cathode Follower And yes, your transformer arrangement is sound. __________________ mod verb, transitive /mod/ to state that one is utterly clueless about the operation of device to be "modded" and into "fixing" things that are not broken; "My new amplifier sounds great so I want to mod it."

25th June 2010, 01:13 AM	#4
Eli Duttman diyAudio Member Join Date: Apr 2004 Location: Plainsboro, NJ	While undoubtedly sound, SY's design is anything but simple and could be a trap for a builder with little experience. FWIW, I suggest 10M45S constant current sink loaded cathode followers and a bipolar PSU. That sort of arrangement places only 1 cap., at the unit's O/P, in the signal path. A 4.7 μF metalized polypropylene part bypassed by a 470 nF. 716P series Orange Drop does that job well, without spending a lot. A $25 AnTek model AN-05T160 power trafo looks like a reasonable fit for the job. To get a bipolar supply, each rail would be 1/2 wave rectified, but making the 1st filter caps. big deals with that matter. A single filter choke can be shared between the 2 rails, in the grounded leg. A pair of 600 PIV Schottky diodes for rectification are inexpensive enough and yield "noiseless" operation. __________________ Eli D.

25th June 2010, 08:43 PM	#7
SY diyAudio Moderator Join Date: Oct 2002 Location: Austin, TX Blog Entries: 1	It's not even an anode follower, it's a common cathode amplifier. The design is... questionable. __________________ “Listening to records is like ****ing a picture of Brigitte Bardot.” - Sergiu Celibidache

25th June 2010, 09:19 PM	#8
Ezequiel (kel) diyAudio Member Join Date: Oct 2009 Location: Brasil	see this, but it has to change for 6n6p, that and a very good blog 10000 circuits... http://circuitoseletronics.blogspot....-follower.html Moderator Warning Note: the link does take you to a cathode follower, but also opens new windows for at string of advertisements __________________ sorry if wrong, my English is google translator

25th June 2010, 02:12 AM	#5
nightanole diyAudio Member Join Date: Feb 2009	Oh man Eli is following me again. Um with a BP supply i halve my voltage so supply caps would be alot cheaper. Any schematics or something to go on? Since im a beginer i cant make anything from scratch. I just wanted to get some tube sound to my Tamp and 3886 amp i built up. Heres what i was going to adapt. http://www.lampizator.eu/lampizator/...X/IMG_5144.jpg its got 2 caps in the audio path, but the first can be small so i can get something nice. The output cap might set me back alittle if i go full metal film.

25th June 2010, 08:40 PM	#6
smbrown diyAudio Member Join Date: Jun 2004 Location: Portland, OR	Nightanole, But that's not a cathode follower, it's an anode follower. However, with the lowish plate impedance of the 6n6, you may not need a cathode follower. I use a 6n6 preamp and take the output from the plate, no problem.

26th June 2010, 12:50 AM	#9
nightanole diyAudio Member Join Date: Feb 2009	Sorry wrong lamp http://www.lampizator.eu/LAMPIZATOR/...X/IMG_5143.jpg heres the cathode version

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
help !! 5687 cathode follower as cd buffer	costa23	Digital Source	0	25th March 2010 01:06 AM
6N6P cascode + 6AS7 Cathode follower	croccodillo	Tubes / Valves	12	15th September 2007 09:33 AM
Cathode Follower Buffer Input Impedance	xcortes	Tubes / Valves	5	1st December 2005 05:10 PM
Basic Cathode Follower buffer	dsavitsk	Tubes / Valves	11	26th June 2005 04:25 PM
Question about direct coupling a anode follower into a cathode follower.	G	Tubes / Valves	45	29th July 2004 06:47 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read