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Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 73

post #1081 of 7566

Can someone compile all of these new findings into a spreadsheet or something? i.e. everything outside of the official owners manual.

 

so much new information everyday! I lost track after the 6AU6 finding.


Edited by mab1376 - 4/18/13 at 2:27pm
post #1082 of 7566
Quote:
Originally Posted by mab1376 View Post

Can someone compile all of these new findings into a spreadsheet or something? i.e. everything outside of the official owners manual.

 

so much new information everyday! I lost track after the 6AU6 finding.

 

All these findings have been posted in the last twenty or so pages... If you are willing to do the grunt work, that is, comb through the postings, collect the data, and then organize everything into a spreadsheet, I would be happy to check it all over for accuracy and completeness. :)

post #1083 of 7566
Quote:
Originally Posted by gibosi View Post

Standard disclaimer: "Old ears and cheap gears" :) 

 

But it is worth keeping in mind that we have different electronics, different headphones/speakers and different preferred "sound signatures". So while I think we can agree on the best tubes, we will likely have different rankings among them:

 

1. Sylvania 6J4/8532W EF92 setting, pins 5&6 cut, and stubs either taped or sealed with paint/varnish (I got some nail polish!)

2. Sylvania 6AU6/6136 EF95 setting, pins 2&7 strapped

3. GE 6485 EF95 setting, pins 2&7 strapped

4. TS 6485 EF95 setting, pins 2&7 strapped

 

And I received a pair of Westinghouse 6AU6/8425As today, but haven't had a chance to do more than unpack them....

 

gibosi,

 

Maybe an interesting thought to look for a little headphone upgrade in order to enjoy all your current and future tubes even more ;).

 

You did quite a bit of legwork there with Audiofanboy already. Since, I have now heard a GE 8425/6AU6 and TS 6485 (6AH6), how would you compare your top Sylvania 8532W and Sylvania 6136/6AU6 to those I know. What do you prefer and why is your top tube the best? Back in the old 5654 days ;), I liked the Sylvania JAN 5654W quite a bit.

 

I know it takes time to formulate a good answer. It is appreciated.

 

PS: Would you please confirm the jumper options, which I edited in post 1077 on the last page (and add anything else you would like to add ;) )? Cheers.

 

 

mab1376,


The beginning of a live update is made with AFB's post 1072.

post #1084 of 7566
Quote:
Originally Posted by Acapella11 View Post

Maybe an interesting thought to look for a little headphone upgrade in order to enjoy all your current and future tubes even more ;).

 

You did quite a bit of legwork there with Audiofanboy already. Since, I have now heard a GE 8425/6AU6 and TS 6485 (6AH6), how would you compare your top Sylvania 8532W and Sylvania 6136/6AU6 to those I know. What do you prefer and why is your top tube the best? Back in the old 5654 days ;), I liked the Sylvania JAN 5654W quite a bit.

 

I know it takes time to formulate a good answer. It is appreciated.

 

PS: Would you please confirm the jumper options, which I edited in post 1077 on the last page (and add anything else you would like to add ;) )? Cheers.

 

 

Yes, I have been thinking a lot about getting better headphones. However, there are lots of choices and I am not having much success in narrowing it down to two or three. What makes it so difficult is that I have not had a chance to listen to really good headphones and therefore, all I have are reviews and the opinions of others. And of course, this alone is not enough to make me feel very comfortable pulling the trigger. However, there will be a Head-fi meetup in my town soon, and I am hopeful I will be able to "meet" some nice headphones. I would really like to make a purchase later this summer....

 

The only thing I would add to your post 1077 is to emphasize that other than the "traditional" EF91/92 tubes, all the other non EF91/92 tubes that work with the EF92 jumpers also work just fine in the EF95 setting with the pin 2-7 pin socket bridge/wire mod. This would add the EF95 setting for 6DK6/8136, 6GM6 and 6GY6/6GX6 in your list.

 

I am quite sure that the reason I am preferring the Sylvania 6136/6AU6 over the TS 8485 is very much a function of my budget headphones. The midrange on the TS 8465 seems too laid back, almost recessed. I hear a very strong base and very clear detailed highs with the midrange sucked right out. It sounds almost hollow to me.

 

The mids of the Sylvania 6136/6AU6 are not quite as forward as the GE 8425A/6AU6 but sound very smooth and effortless, plus a razor-sharp 3-D presentation, makes these tubes much more fun and enjoyable.

 

And the Sylvania 6J4/8532W seem very similar to the Sylvania 6136s, but better. They are very musical, the midrange is bit more forward and liquidy, high frequency percussive details are sharp and clear, and the bass seems to have more authority. And as with the other recent exceptional tubes, imaging is superb. It is a very fun tube.

 

So in short, of course, I choose tubes that make my budget headphones sound better. Moreover, I am 66 years old and it is almost certain that my hearing is diminished to some degree. Thus I never encourage people to take my judgments too seriously -- "old ears and cheap gears"...

post #1085 of 7566

Hey, I am also 66, and I still trust my hearing as far as music is concerned. Here is a simple hearing test that you can do yourself. My hearing works from 20Hz to 12KHz by this test, and I believe that most music is well within this range.

 

http://www.youtube.com/watch?feature=player_embedded&v=2G9Q-r2leyw#!

 

Truth is that I do have certain hearing problems, not all related to selective hearing (honey, can you do this for me? etc), but with music I can always turn up the volume. To this you can also add the experience of listening to music for many years, and I am not so worried about my judgment being totally off. As with everything else, taste varies, but I definitively believe that we can come up with a list of the top five or so tubes or tube categories that will bring the greatest listening pleasure using the LD amps.

 

The quest goes on!
 

post #1086 of 7566

That was an interesting test. It appears my hearing works up until about 9khz. (Unfortunately, I have a little tinnitus). But yes, like you, I do not think my judgement is totally out in left field. I have been listening to music for many years and in the '80s I designed and built loudspeakers as a hobby. (My latest and greatest were 15" JBL subwoofers with Focal/Dynaudio MTM satellites). I think a quality set of headphones in the only significant "upgrade" I really need. :)

 

And yes, I think we can quite easily come up with a consensus list of top recommendations. But of course, as long as Audiofanboy is out there searching for new and promising tubes, this list will likely continue to evolve.

post #1087 of 7566

A pair of Westinghouse 6AU6/8425s. These are Mordy's discovery. Until I saw his, I didn't know there were any 8425s other then GE. I am still preoccupied with the 6J4/8532Ws at present, so haven't had a chance to see if they even light up. But thought I would provide a picture.

 

 

Interestingly, the Tek label numbers and text are different. One says "selected pair" and the other says "checked tube." Moreover, one has a square getter (dated 1962) and the other has a round getter (no date found). Obviously, this is not a Tek "matched pair". However, the eBay seller tested and matched them and I am looking forward to checking them out.

post #1088 of 7566

I bought a pair of the Westinghouse 8425s off of eBay recently and while they're not burned in I personally can't hear a lot of difference between the G.E. and Westinghouse Tek tubes. If anything the Westinghouse are a bit less in your face but just as clear. 3D detail may be a bit better as well.

I'm curious about these tubes though. They have the etched "6AU6" with dots around it. I was under the impression that this etching/dot pattern means a G.E. manufactured tube. The getter structure is the same on both of mine but the plates are slightly different. One has four small square holes and the other four larger square holes. Definitely not an official Tek match up but they do have nearly the same date code.


Edited by inphu510n - 4/20/13 at 1:18am
post #1089 of 7566

Hallo everyone,

 

I've edited and reformatted the current state of 'new' driver tube families and their settings to operate them. Feel free to add information. This should update everyone, who hasn't read through the thread since page 50 in order to know which 'new' tubes work and how to to operate them. The tubes have been tested with the LD I+, MKIII and MKIV.

Best

 

 

Tubes     Jumper Settings / Mods  
Families                       Alternative Names Remark EF95     EF91/92

EF95 + Pins 2-7

Socket Wire Mod

EF91/92 +

Cut off and tape

Pins 5 & 6

6AG5, 6BC5, 6CE5 EF96, 6J3P(-E), 6186   yes no yes (2) no
6AH6 6J5P, 6485   no no yes no
6AU6 EF94, 6136, 8425   no no yes no
6CB6, 6CJ6 6676   no (1) yes yes no
6DK6 8136   no (1) yes yes no
6EW6     no (1) yes yes no
6GM6     no (1) yes yes no
6GY6/6GX6     no (1) yes yes no
6J4 8532 Triode no no no yes
             
             

Recommended modes of operation are highlighted in green.

 

(1): Operation with "floating" grid 3 is strongly not recommended.

(2): Mod doesn't add a function. Tubes are already internally strapped between pins 2 and 7. Use at higher risk only.

 

 

           

Tubes with A, W, WA, WB, WC specification share the same settings as the ones without.

 

Gibosi and Audiofanboy started using triodes with the LD I+ and MKIV.

 

 

 

Last but not least is here an addendum to clarify the pin numbering of the LD driver tubes and their socket. =)

 

 

Update: 21/04/2013, highlighted recommended and riskier modes of operation.

Update2: 22/04/2013: Operation with floating grid g3 set to fail safe mode.


Edited by Acapella11 - 4/22/13 at 11:41am
post #1090 of 7566
Quote:
Originally Posted by Acapella11 View Post

Hallo everyone,

 

I've edited and reformatted the current state of 'new' tube families and their settings required to operate them. Feel free to add information. This should update everyone, who hasn't read through the thread since page 50 in order to know which 'new' tubes work and how to to operate them. The tubes have been tested with the LD I+, MKIII and MKIV.

Best

 

Tubes     Jumper Settings / Mods  
Families Alternative Names Remark EF95 EF91/92 EF95 + Pins 2-7 Socket Wire Mod EF91/92 + Cut off and tape Pins 5 & 6
6AG5, 6BC5, 6CE5 EF96, 6J3P(-E), 6186   yes no yes no
6AH6 6J5P, 6485   no no yes no
6AU6 EF94, 6136, 8425   no no yes no
6CB6, 6CJ6 6676   yes (1) yes yes no
6DK6 8136   yes (1) yes yes no
6EW6     yes (1) yes yes no
6GM6     yes (1) yes yes no
6GY6/6GX6     yes (1) yes yes no
6J4 8532 Triode no no no yes
             
             
(1): Works flawlessly, technically not optimal because grid 3 "floats" disconnected.  
             
Tubes with A, W, WA, WB, WC specification share the same settings as the ones without.  

Gibosi and Audiofanboy started using triodes with the LD I+ and MKIV.

Thanks man thats going to help another page to add to my littledot mk3  data folder 

post #1091 of 7566

One small correction: 

 

 

6AG5, 6BC5, 6CE5 EF96, 6J3P(-E), 6186

 

These tubes, like the 6AK5/EF95s, have pins 2 and 7 strapped internally, and thus do not require the "2-7 Socket Wire Mod".

post #1092 of 7566
Quote:
Originally Posted by gibosi View Post

One small correction: 

 

 

6AG5, 6BC5, 6CE5 EF96, 6J3P(-E), 6186

 

These tubes, like the 6AK5/EF95s, have pins 2 and 7 strapped internally, and thus do not require the "2-7 Socket Wire Mod".

 

Hi gibosi,

 

I know. The table is for what would work and not what you minimally need. I have removed "required" from my text in the post and edited the table to add the information :). Thanks for pointing to the "required". So, for these tubes you could conveniently leave the socket bridge in and it would still work. Shouldn't make a difference, as you say, they are already internally strapped.

 

As a conclusion, this makes the Pin 2 - 7 Wire Mod a universal fool proof tool for the 'new' pentodes mentioned in the above post.

 

Best


Edited by Acapella11 - 4/20/13 at 5:43pm
post #1093 of 7566

The last entry 6J4/8532 Triode has NO under the column EF91/92 setting. Should it be YES? (The last column mentions the EF91/92 setting)
 

post #1094 of 7566

I think we do not want anyone to misinterpret this chart and try to run 6J4/8532 Triodes using the EF91/92 settings without cutting pins. So in my opinion, a NO in the EF91/92 column is correct. Also, this follows the same logic as for the 6AU6 and 6AH6: A NO in the EF95 column because pin strapping is required.

post #1095 of 7566
Quote:
Originally Posted by Acapella11 View Post

Hallo everyone,

 

I've edited and reformatted the current state of 'new' driver tube families and their settings to operate them. Feel free to add information. This should update everyone, who hasn't read through the thread since page 50 in order to know which 'new' tubes work and how to to operate them. The tubes have been tested with the LD I+, MKIII and MKIV.

Best

 

Tubes     Jumper Settings / Mods  
Families                       Alternative Names Remark EF95     EF91/92

EF95 + Pins 2-7

Socket Wire Mod

EF91/92 +

Cut off and tape

Pins 5 & 6

6AG5, 6BC5, 6CE5 EF96, 6J3P(-E), 6186   yes no yes (2) no
6AH6 6J5P, 6485   no no yes no
6AU6 EF94, 6136, 8425   no no yes no
6CB6, 6CJ6 6676   yes (1) yes yes no
6DK6 8136   yes (1) yes yes no
6EW6     yes (1) yes yes no
6GM6     yes (1) yes yes no
6GY6/6GX6     yes (1) yes yes no
6J4 8532 Triode no no no yes
             
             

(1): Works flawlessly, technically not optimal because grid 3 "floats" disconnected.

(2): Mod doesn't add a function. Tubes are already internally strapped between pins 2 and 7.

 
             

Tubes with A, W, WA, WB, WC specification share the same settings as the ones without.

 

Gibosi and Audiofanboy started using triodes with the LD I+ and MKIV.

 

 

 

Last but not least is here an addendum to clarify the pin numbering of the LD driver tubes and their socket. =)

 

 

Great work Acapella, it easily sums up how to use all the new tubes for people just haven't followed -or even those of us that have- the last couple dozen pages. My only fear is that the list will only get longer ;) ...

 

Just two remarks though. I really would not encourage people to use all those EF92 jumper setting tubes on the EF95 setting, leaving grid 3 floating. The literature is pretty clear on the fact that you're not supposed to have stuff floating around in your tube ungrounded or unstrapped around high tension. It may work OK on many tubes, until one day, it'll cause a problem for someone with a crappy tube. At any rate, if those tube types can be easily connected properly, why not do so really. And if anything, for jumper haters, it's is still pretty easy and by-the-book to wire mod pins 2 & 7 like the 6AU6 -which would be my favorite solution- so I would only encourage those two solutions, and not the EF95 jumpers alone.

 

And one more detail, about the 6AG5 type, not that anyone is really using it anyway. Yes, pins 2 & 7 are internally connected, so although it should work with pins 2 & 7 wire modded together, I wouldn't encourage that either, as I don't see the point of running the risk of having extra mod wires hanging around using a compatible tube, and, more importantly, having pin 2 & 7 strapped together twice could do some weird loop crap that we don't need... The same thing would be true for 6AK5 and 6AJ5 tubes btw.

 

Don't mean to be annoying, but I would hate for people to draw wrong conclusions by looking at this table real quickly and end up doing something like connecting their brand new 6J4 triode on any setting with all 7 pins "because all those tubes seem to work on all those jumpers settings anyway, so why wouldn't that tube work on any setting like all the others, I hate changing jumpers. Grrr".

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