Tube Adapters

RE: Tube Adapters, posted on January 5, 2017 at 11:43:12
krankkall Audiophile Posts: 296 Location: New Mexico Joined: April 5, 2014	I have seen many different types on flea-bay, usually of the Chinese-made variety. I have made my own out of NOS Octal tube bases and NOS Amphenol Octal sockets, so I could substitute dirt-cheap 6AR6 tubes, in place of 6L6 tubes. Steve

RE: Tube Adapters, posted on January 5, 2017 at 10:07:01
Mechans Audiophile Posts: 1804 Location: East Coast Joined: May 23, 2004	The headphone people who are into tubes are almost manic about out doing each other with tube derivatives requiring an insane number of adapters. I keep reminding them that each uneeded interface degrades the sound but they pay no heed.

RE: Tube Adapters, posted on January 5, 2017 at 10:43:32
jcmusic Audiophile Posts: 1387 Location: New Orleans, La. Joined: June 13, 2006	Well I will not disagree with you but, I am using an adapter and a 6f8g tube in place of the 6sn7 with awesome results. So in this instance it improves the sound vs degradation.

RE: Tube Adapters, posted on January 5, 2017 at 11:55:12
Mechans Audiophile Posts: 1804 Location: East Coast Joined: May 23, 2004	A lot of people like that tube. Evidently it preceded the 6SN7. I haven't used them but have heard that there very very good. Which 6SN7S did you try?

RE: Tube Adapters, posted on January 5, 2017 at 12:42:42
jcmusic Audiophile Posts: 1387 Location: New Orleans, La. Joined: June 13, 2006	I have tried just about every 6sn7 out except a few hard to find ones. In the end the 6f8g beat out all of my 6sn7 tubes. Now it has been brought to me that the 6j5g are even better that the 6f8g tubes. So that's why I want to try some.

RE: Tube Adapters, posted on January 5, 2017 at 12:47:27
Sondek Audiophile Posts: 9621 Location: Fort Worth Joined: May 17, 2000 Contributor Since: April 5, 2002	Have you figured out how to get around the single triode vs. dual triode issue? That seems like a show-stopper to me. They may well be out there and it's my own ignorance of them, but I have never seen an adapter to plug two single triodes into, that then plugs into a single socket for a dual triode. I guess technically it'd work, but I seriously wonder how elegantly it would function.

RE: Tube Adapters, posted on January 5, 2017 at 12:52:00
jcmusic Audiophile Posts: 1387 Location: New Orleans, La. Joined: June 13, 2006	Yes those adapters are on eBay right now but,they take up space hence the reason for needing a single tube adapter. My amp use one half of the 6sn7.

RE: Tube Adapters, posted on January 5, 2017 at 17:34:39
Alpha Al Industry Professional Posts: 2958 Location: N. Carolina Joined: February 16, 2004 Contributor Since: December 3, 2015	That seems to be a waste of a perfectly good 1/2 of a dual triode. I don't understand why they designed it that way. But, 6J5G is an excellent sounding tube. I use them to drive pentodes in my SET amp.

RE: Tube Adapters, posted on January 5, 2017 at 18:04:39
jcmusic Audiophile Posts: 1387 Location: New Orleans, La. Joined: June 13, 2006	Hi Al, I actually called you today but you had not arrived yet and I forgot to call back. I will try and call again tomorrow..

RE: Tube Adapters, posted on January 6, 2017 at 04:30:55

Nunki
Audiophile

Posts: 644
Joined: November 27, 2010

i can offer 4 adapters for trying EL156 in KT88/6550 position...

:))

RE: Tube Adapters, posted on January 5, 2017 at 12:55:40
Sondek Audiophile Posts: 9621 Location: Fort Worth Joined: May 17, 2000 Contributor Since: April 5, 2002	Ah. My mistake. I wrongly assumed you were using both halves of the 6sn7.

RE: Tube Adapters, posted on January 5, 2017 at 13:01:40
jcmusic Audiophile Posts: 1387 Location: New Orleans, La. Joined: June 13, 2006	It's OK no problem.

RE: Tube Adapters, posted on January 5, 2017 at 12:24:40

Sondek
Audiophile

Posts: 9621
Location: Fort Worth
Joined: May 17, 2000
Contributor
Since: April 5, 2002

Steve, I've got five or six pair of them leftover from when I had gear that used 6sn7. The same is true of the 6f8g as is true of the 6sn7. TSRP and NU's are the most desirable and best sounding 6f8g. Syls and RCA are good too, but not up to par with the TS and NU. I don't think the 6f8g predated the 6sn7 by all that much, but they are an older and in one respect inferior design to the 6sn7. That grid cap and wire made them problematic with respect to any mobile applications. They are also a good bit taller than 6sn7 and take up more vertical real-estate. Otherwise, I enjoyed them every bit as much as my 6sn7s.

RE: Tube Adapters, posted on January 5, 2017 at 11:20:33
Sondek Audiophile Posts: 9621 Location: Fort Worth Joined: May 17, 2000 Contributor Since: April 5, 2002	I would suggest that the 6f8g you are using is what is improving the sound over an inferior 6sn7 and NOT the adapter. Maybe better 6sn7's is what you really need?

RE: Tube Adapters, posted on January 5, 2017 at 12:45:18
jcmusic Audiophile Posts: 1387 Location: New Orleans, La. Joined: June 13, 2006	I am not suggesting the adapters are making the sound better, I am saying the 6f8g tubes are making it better.

RE: Tube Adapters, posted on January 5, 2017 at 12:54:24

Sondek
Audiophile

Posts: 9621
Location: Fort Worth
Joined: May 17, 2000
Contributor
Since: April 5, 2002

I do understand that's not what you were suggesting. The point I was making was that the 6f8g was of so much better quality than the 6sn7 you were using as to deliver improvement despite the adapter. I used those same adapters for years like you've done and never felt they detracted from the sound. The real attraction for me to the 6f8g was that vastly superior examples (NU's and TSRPs) were readily available at fractions of the price of the same tubes in 6sn7 bottles. Sadly that is no longer true as the 6f8g secret is outta the bag.

RE: Tube Adapters, posted on January 5, 2017 at 13:00:41
jcmusic Audiophile Posts: 1387 Location: New Orleans, La. Joined: June 13, 2006	Agreed.

RE: Tube Adapters, posted on January 5, 2017 at 09:44:03

6bq5
Audiophile

Posts: 4385
Location: SF Bay
Joined: August 16, 2001

Having an octal based adapter to take a 9 pin is not a great idea for tube rolling-
putting a 6BQ5 in place of a KT88 would result in some damage to the tube and most likely the amp-
Similarly substituting a 12A_7 for a 6SN7 would not yieds listenable results-
This mostly has to do with pin-outs, bias (B+) voltages and filament voltages-

perhaps if you give us a better idea of what you are interested in achieving we could offer encouraging help
Happy Listening

RE: Tube Adapters, posted on January 5, 2017 at 09:52:02
jcmusic Audiophile Posts: 1387 Location: New Orleans, La. Joined: June 13, 2006	OK I want to try the 6j5g in place of the 6sn7.

RE: Tube Adapters, posted on January 5, 2017 at 12:30:21
6bq5 Audiophile Posts: 4385 Location: SF Bay Joined: August 16, 2001	ok- a single triode versus a twin triode- well, make sure that the heater pins are changed - 2&7 for 6J5 versus 7&8 for 6SN7- and the plate voltage should be reduced to 300 ... It can be done, but are you sure that you are replacing functionally similar tubes? is the 6SN7 being used as a Single Triode? Happy Listening

RE: Tube Adapters, posted on January 5, 2017 at 12:47:49
jcmusic Audiophile Posts: 1387 Location: New Orleans, La. Joined: June 13, 2006	Yes in my amp the 6sn7 tubes are only using one half, the other half is going to ground.i spoke with the amp builder yesterday and he told me that.

Why would anyone build an amp that way??, posted on January 5, 2017 at 13:25:43
Triode_Kingdom Audiophile Posts: 10044 Location: Central Texas Joined: September 24, 2006	6SN7s with only one half of each tube actually used? I take it this was built in someone's garage?

RE: Why would anyone build an amp that way??, posted on January 5, 2017 at 14:24:51
jcmusic Audiophile Posts: 1387 Location: New Orleans, La. Joined: June 13, 2006	Actually the builder is well known and his amps are highly sought after. I don't why he builds them that but I can ask.

So Who's the Builder?, posted on January 6, 2017 at 18:12:52
Triode_Kingdom Audiophile Posts: 10044 Location: Central Texas Joined: September 24, 2006	"Actually the builder is well known and his amps are highly sought after." ??

RE: Tube Adapters, posted on January 5, 2017 at 10:44:04
Palustris Audiophile Posts: 2408 Location: Cape Cod Joined: September 12, 2008	Since the 6J5 is half of a 6SN7 you will need two 6J5s to duplicate the function of the one 6SN7 tube. There are adapters on epay that will do this; just remember that the adapters take up a lot of space and may interfere with other components already mounted on the amp.

RE: Tube Adapters, posted on January 5, 2017 at 12:49:40
jcmusic Audiophile Posts: 1387 Location: New Orleans, La. Joined: June 13, 2006	Exactly that's why I want to try and build adapters for a single tube and run them in my amp, which only uses one half of the 6sn7 tubes.

RE: Tube Adapters, posted on January 5, 2017 at 13:39:22
Palustris Audiophile Posts: 2408 Location: Cape Cod Joined: September 12, 2008	OK, then the smart approach is to rewire the socket for a 6J5. You can then use a 6P5 or 6C5 as well.

RE: Tube Adapters, posted on January 5, 2017 at 14:27:47
jcmusic Audiophile Posts: 1387 Location: New Orleans, La. Joined: June 13, 2006	OK the other two tubes you mentioned, are they on par with the 6j5g?

RE: Tube Adapters, posted on January 6, 2017 at 08:22:13
Palustris Audiophile Posts: 2408 Location: Cape Cod Joined: September 12, 2008	The 6C5 is electrically equivalent to the 6J5. The 6P5 is an octal 76. The 76 is a predecessor of the 6J5. You will have to determine for yourself about par, but the 6P5 is available with cylindrical plates which some who revere the TS 6SN7 and 6F8 attribute to their good sound.

RE: Tube Adapters, posted on January 5, 2017 at 15:00:07

baileyler
Audiophile

Posts: 359
Location: Chadds Ford, PA
Joined: January 17, 2007

Don't forget 6L5, and 7193, 7A4 or 76 with a completely different type of adapter (plus there are others).

I am not aware of an adapter that will take one 6J5 in place of a 6SN7, but there are adapters for 2 6J5 and you could probably leave one off.

While I am not an expert, I have heard of people using 1/2 of a 12AX7 or 6DJ8 in an attempt to reduce noise floor.

While I am sure that the builder is quite good, there does not seem to be any reason to use 1/2 of a 6SN7 when 6J5 (and other similar single triodes) are readily available and dirt cheap.

By the way, here is a decent write up on the 6J5:

http://vinylsavor.blogspot.com/2013/03/tube-of-month-6j5.html

P.S.: I love adapters just because they give me more tubes to play with without having to rewire (which I am not good at).

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Tube Adapters

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