6 volt rectifier tubes

RE: 6 volt rectifier tubes, posted on October 9, 2020 at 11:22:19
PakProtector Audiophile Posts: 12366 Joined: May 14, 2002	aside from a pair of damper diodes, there is type 6AX6, the smaller 6BY5 and the even smaller 6AX5. cheers, Douglas Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.

RE: 6 volt rectifier tubes, posted on October 9, 2020 at 13:33:23
vetmedrobert@gmail.com Audiophile Posts: 453 Location: Ontario Joined: September 20, 2007	Thanks, it would seem that 6by5 are abundant and inexpensive. They are rated for 175ma and the circuit I have in mind draws 150ma. Should work don't you think?

RE: 6 volt rectifier tubes, posted on October 10, 2020 at 21:21:09
Eli Duttman Audiophile Posts: 10455 Location: Monroe Township, NJ Joined: March 31, 2000	Look closely at the 6BY5 datasheet. That 175 mA. is per diode. If all you need is 150 mA., the 6CA4/EZ81 will do the job for you. That Noval type IS the "little brother" of the 5AR4/GZ34, including tolerance of comparatively large 1st filter capacitors. Eli D.

RE: 6 volt rectifier tubes, posted on October 10, 2020 at 21:48:22

vetmedrobert@gmail.com
Audiophile

Posts: 453
Location: Ontario
Joined: September 20, 2007

What about long term reliability for a rectifier run at maximum rating? In a SE circuit there is a more or less constant current draw, and although there are actually new production tubes available I am not crazy about the idea of replacing a rectifier tube every 6 months, or however long they may last at full rating. I like the idea of using this tube as I have several but wonder how long they will last.

RE: 6 volt rectifier tubes, posted on October 13, 2020 at 01:01:42

Stephen R
Audiophile

Posts: 1428
Joined: January 11, 2002

Check the link below.

Current rating for your rectifier will be well within rating for your current draw. Key point is "average current in a full wave circuit is .5 x I D.C. per diode"

Rectifier Design Guide

RE: 6 volt rectifier tubes, posted on October 10, 2020 at 22:31:37

Eli Duttman
Audiophile

Posts: 10455
Location: Monroe Township, NJ
Joined: March 31, 2000

Compare the Philips EZ81 datasheet with East German (DDR) RFT EZ81 datasheet. I see no glaring discrepancies. The Philips datasheet suggests some "wiggle room", especially if the value of the 1st filter cap. is held down.

I indicate the RFT variant, as AA sponsor Jim McShane shows a substantial number of RFT EZ81s being available for sale. Both EH and JJ offer current production 6CA4s. If the JJ 5AR4 is anything to go by, steer clear.

Eli D.

RE: 6 volt rectifier tubes, posted on October 9, 2020 at 17:05:45
PakProtector Audiophile Posts: 12366 Joined: May 14, 2002	If it is a cap-input filter, that would depend on the size of said cap. For an L-C filter, it should be quite happy. cheers, Douglas Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.

RE: 6 volt rectifier tubes, posted on October 9, 2020 at 11:40:13
rivervalley817	have you ever built any guitar amps ... maybe with an EZ81 implementation? just curious with regards,

heavy, posted on October 9, 2020 at 14:16:49
RayP Audiophile Posts: 727 Location: Maryland Joined: June 30, 2005	Any guitar amp that Douglas builds would have to be heavier than the speaker and box. ray

RE: heavy, posted on October 9, 2020 at 17:07:43
PakProtector Audiophile Posts: 12366 Joined: May 14, 2002	I recognized the 'portability' requirement. They still were not light. They worked really well with EV Wolverine 8"-ers in effectively open baffles. cheers, Douglas Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.

RE: heavy, posted on October 9, 2020 at 15:21:48
rivervalley817	I've heard that about his builds be well,

RE: 6 volt rectifier tubes, posted on October 9, 2020 at 12:29:17

PakProtector
Audiophile

Posts: 12366
Joined: May 14, 2002

The geetar amps I have built were light weight SE KT66 with E-Linear front ends that were quite happy with 5V4GA. At the time I happened to have quite a supply of them. The 6CA4 were not so plentiful, and the TX's had 5V heater windings, so the 5V4 got the job. For everything else, I prefer the single diode, dampers of various flavours.

I neglected another, more comparable to 6CA4, and that is type 6754. One of the Hy-G-300 Red Bank Bendix tubes.
cheers,
Douglas

Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.

RE: 6 volt rectifier tubes, posted on October 9, 2020 at 13:46:39
rivervalley817	thanks ...

Tube DIY Asylum

6 volt rectifier tubes

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