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Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 80

post #1186 of 5868
Quote:

Originally Posted by zedmeco View Post

 

the tubes sounded fab, there is no denying it, but half way through, the crackling started again.....

 

You know, I am beginning to think that it may well be the tubes and not your strapping technique....

 

Each time you tried, "half way through" they started to crackle. So you turn the amp on, everything sounds good, but "half way through", or once the tubes reach their normal operating temperature, they crap out. Maybe one or both of these tubes are defective. Of course the only way to know for sure is for you to try with another set of tubes! :)

 

But I would not be surprised if you decide enough is enough...

post #1187 of 5868

 

Good thing i got the tube rolling thread its like coming home man its bad on the other threads, bickering ,complaining ,personnal attacks,WOW. Breathe in breathe out br...............

post #1188 of 5868

Trying something different now - since both channels on the Little Dot MkIII are completely independent of each other, I am running two different tubes at the same time, using a mono recording, and using the balance control on my receiver to switch between the right or left speaker.

 

The tubes are TS 6AH6WA and GE Tektronix 4825A/6AU6A. It's like mix and match in a candy store; both are great tubes with a slightly different flavor. I could try to describe the differences but they are very minor, and together they sound wonderful.  What's the difference in flavor between a light green and dark green jelly bean? Who cares? (If someone stopped by and listened I don't think that they could tell that I am using two different tubes.)

 

(OK - critical listening reveals that the GE is a little more mellow and not as bright in the treble. The GE goes a little lower but the TS is a little more detailed. Listening to an old 78 mono recording the only real difference is that the surface noise is more audible with the TS tube. But if you are just enjoying the music you won't notice - these tubes are so similar sounding.)

 

It seems to me that you could audition different classes of tubes at the same time, just being very careful to use the right strap and jumper settings. On order are some triode and diode/triode tubes.

We'll see.....
 

post #1189 of 5868
Quote:
Originally Posted by hypnos1 View Post

Hi fellow newcomer to this forum.

 

Re. your interest in the Senn HD650, may I say that I have been overwhelmed by the sound (or should I say "sonic experience") of these when fed by the amazing MKiv SE - and so, I should imagine, the MKIII. It seems to me they fulfil pretty much all the criteria you mentioned, assuming a good source...I must admit I have probably helped things along by replacing the stock cable with one I made up using 8-stranded pure silver cable, but the stock is still pretty good!

 

I do however feel I must guide you - if you are not already there  -  to follow the threads from Audiofanboy, Gibosi et al with regard to the latest discoveries they have made concerning driver tubes. So long as you are happy implementing the wire modification they mention, taking careful note re the "cleanliness" of insertion and use of thin STRANDED wire, I would urge you to forego the VERY lengthy burn-in time needed for the Voskhods (mine had 100+ hours!) and go for the Tung Sol 6485s. Have just received mine, and straight out of the box were far superior to the Voskhods and the Tesla 6F32s others have mentioned. After just 10 hours' burn-in the sound coming through the Senns is nothing short of unbelievable...I am in sonic heaven!

 

I suggest you read all the threads you can find on this topic and I am sure you will find the confidence, as I did, to discover what the LD can really do - not to mention the Sennheisers.

 

Good luck.

Thank you for your welcome and your advice, hypnos1. I have no doubt the Senn HD650 are at another level...closer to "audio nirvana" perhaps.  Very expensive, however. For the moment, I'll try the Tung Sols, any good dealer you can suggest ?

post #1190 of 5868

Yesterday, I reached a small milestone in my "headfi" life. I can no longer say "old ears and cheap gear", as I have received new headphones, Hifiman HE-300. <I am wearing a very huge grin> lol

 

While certainly nowhere near the same league as the HE-500s or the Senn 650s, they are a significant upgrade from my $50 cheap budget headphones, so I can no longer say I have "cheap gear". But I am a little sad.... "old ears and mid-fi gear" just doesn't have quite the same ring to it. lol

 

As you would expect, I am getting used to a whole new sound, a much better sound, but a different sound. For now, I need to spend some quality time with my current reference tubes, the TS 6485, GE 4825A/6AU6A, Sylvania 8532W/6J4 and Sylvania 6AQ6, to reorient my mind and ears, before I can begin to evaluate any new tubes.

 

Predictably, my budget phones were tuned to a more consumer-oriented sound signature, with boosted bass and rolled-off treble, whereas, the HE-300s have a much more balanced sound. The first difference I have noticed is how different the 6AQ6 tubes sound. Listening through my old phones, with their rolled off treble, the 6AQ6s were on the verge of becoming my favorite tubes. Now, with the HE-300s, their treble sounds a bit too bright. However, I am still getting used to these phones. And I am told that the sound of dynamic headphones will likely change somewhat during the first month or so of use. So I have put the 6AQ6s aside for now and installed the 8532Ws. Much better. :)

 

Unfortunately, I am still trying to figure out how to securely strap pins 2 and 7 using my new socket testers, so I haven't been able to listen to the 6485s or the 8425As.

 

 

While the hookup wire easily fits into the space between the test point and the phenolic housing, it has proven difficult to obtain a secure and tight fit. My current thinking is to purchase some tiny brass sheet metal screws and screw them into the space between the test point and the housing. In this way, I hope to be able to secure the hookup wire tightly against the test point. But if anyone has another suggestion, I am all ears. :)

 

Oh and this is my 200th post! :)


Edited by gibosi - 5/5/13 at 5:46pm
post #1191 of 5868

Good god, I leave on holiday for 3 days, and I come back here to a full 30 posts! This thread used to be less active and dynamic lol!

 

Anyway, like what everyone else said, the pin 2&7 wire mod seems to work quite fine with stranded wire (if anything my 26 AWG wire with insulation is pretty huge compared to what most of you have used, and it worked great Every time I used it so...), and it still appears to me like the easiest, best and most versatile solution for pin strapping, including strapping pins 6&7 like acapella said. I'd probably have trouble using socket savers on my IV SE with the brass structures around the tubes...

 

This being said, the Next step in "modding" those amp would most likely involve some kind of socket saver hacking, so I'll be closely following gibosi's adventures on that front lol. If anyone bumps into 8-pin or 9-pin to 7-pin adapter (keep looking on ebay but can't find a pair of those that clearly states that it does that), I would also be Very interested.

 

Zedmeco, those TS 6485 are from the same seller I bought them from. They're awesome tubes, but the first pair I got had some severely oxidized pins. Both tubes I cleaned worked fine and sounded great from my first attempt at plugging them with pins 2&7 strapped, but one tube never made sound again after one day... My second pair has been working great for a week or so now and didn't require any cleaning (I had pretty much insisted I did not want another tube with bright green pins, and my plea was answered).

 

So, I'd suggest -if you haven't done so- a thorough cleaning of the tube pins (like both chemical and mechanical cleaning, i.e. deoxit + knife or sand paper), since that might help considerably with making good contact. Using good quality (stranded) wire to strap pins is the only other piece of advice I can give you, like everyone else said.

 

Still waiting on my replacement 8532W... No new tubes for three weeks in a row, I feeling a bit of withdrawal here lol...

post #1192 of 5868

Congratulations gibosi to your new your headphone. I think this was a very good choice. Enjoy it and discover all the new good sound. The upgrade to better gear would never be as much fun if we wouldn't take intermediate steps... ;)

 

I am also in the situation to use new gear, so we both have to get used to our new toys :)

 

Quote:
Originally Posted by MIKELAP View Post
Good thing i got the tube rolling thread its like coming home man its bad on the other threads, bickering ,complaining ,personnal attacks,WOW. Breathe in breathe out br...............

 

 

+1, the way we shape it, we love it ;)

 

Sorry for this long post, but I had to rectify some things and give value to some new findings.

 

TS 6485 (6AH6) vs. GE 8425 (6AU6) Update:

I hear the differences more using my 6H30P-EV than 6N6P-IR power tubes, which are a bit warmer themselves. Hence, these notes are taken while using the 6H30P-EV power tubes.

Warmth: The 6485 sound more open, a bit sparklier, the 8425 a bit mellower and warmer. I think ability to hear differences sometimes also depends on your personal form. Sorry, if I confused anyone ;).

Treble: Due to the more open, airy sound, the TS 6485 give the impression of more detail and space.

Stage: They also have a slightly better instrument separation, which goes along with a bit larger stage.

Bass: Both basses are satisfactory to me from the level of impact and punch. In comparison, the 8425 has a deeper bass, "rolls" more. Also, the bass has greater presence in the representation.

 

There is not a world between them but I found my preference again for the TS 6485 (6AH6) :)

 

I also have had a closer look to the Tung Sol 6BE6 and to be fair, the only disadvantage with using this tube is the lower gain compared to other ‘new’ tubes. Else, I would highly recommend to have a listen to them.

 

Because of the seven grids used, the jumper setting has a relatively large impact on the sound:

 

EF91/EF92: Airy, open, spacious representation, neutral. Cleaner than the TS 6485. This is my preferred setting. Here, the tube signature is very close to the TS 6485.

Treble: Extended, refined, not bright. Well resolved. I prefer the 6BE6 here to the TS 6485.

Mids: Quite sweet, round, clean.

Bass: The weakest bass weight compared to the other settings. Still enough for me. The bass quality is very good, well articulated and punchy.

Stage: Larger and wider than TS 6485.

I have also used the CV4015, since I was anyway on the EF91/92 setting. Smaller stage, not as deep, not as wide. Signature similar, sound not as clean and refined. Slightly coloured towards warm. The 6BE6 sounds more organized and accurate.

 

Because of their black background, these tubes are ideal for detail lovers.

 

EF95 (floating grids): More bass weight, more deep bass, but slightly lesser quality, warmer, darker than the EF91/92 setting. You trade in some of the open airyness. Depending on preference, this more bassy setting could be the one

 

Pin 2-7 strap: This must be the bass head setting. Maximum bass weight, weakest treble presence. Surprisingly, still extended and one could consider to live with it, kind of the LCD headphone way, if you have tried that before. Guitars sound crunchy but generally mids are more recessed. A bit dynamic compressed sound for my ears or too frequency spectrum shifted to lower frequencies.

 

The relative differences are similar with the Sylvania JAN 5750, even though I did not explicitly test this again.

The Tung Sol 6BE6 sounds for me superior to the Sylvania, not by a huge amount, but still, because the the Tung Sol sounds more open and airy, slightly louder and a bit more detailed.

 

So, I am using the EF91/92 setting as we speak, makes it also easier for every user. One problem while comparing 6BE6 tubes to the rest of the 'new' tubes is that they are not as loud as these, and adjusting the sound obviously also changes the sound impression if not perfectly matched. This is a quite common issue when comparing different gear but it means that we have to take these impressions with a grain of salt.

 

 

Label: 6BE6, 3223501 (the one is a bit smeared out). This would mean the tube is from week one in 1935^^ or I am misinterpreting something...


Edited by Acapella11 - 5/6/13 at 9:02am
post #1193 of 5868
Quote:
Originally Posted by Acapella11 View Post

Congratulations gibosi to your new your headphone. I think this was a very good choice. Enjoy it and discover all the new good sound. The upgrade to better gear would never be as much fun if we wouldn't take intermediate steps... ;)

 

I am also in the situation to use new gear, so we both have to get used to our new toys :)

 

 

 

+1, the way we shape it, we love it ;)

 

Sorry for this long post, but I had to rectify some things and give value to some new findings.

 

TS 6485 (6AH6) vs. GE 8425 (6AU6) Update:

I hear the differences more using my 6H30P-EV than 6N6P-IR power tubes, which are a bit warmer themselves. Hence, these notes are taken while using the 6H30P-EV power tubes.

Warmth: The 6485 sound more open, a bit sparklier, the 8425 a bit mellower and warmer. I think ability to hear differences sometimes also depends on your personal form. Sorry, if I confused anyone ;).

Treble: Due to the more open, airy sound, the TS 6485 give the impression of more detail and space.

Stage: They also have a slightly better instrument separation, which goes along with a bit larger stage.

Bass: Both basses are satisfactory to me from the level of impact and punch. In comparison, the 8425 has a deeper bass, "rolls" more. Also, the bass has greater presence in the representation.

 

There is not a world between them but I found my preference again for the TS 6485 (6AH6) :)

 

I also have had a closer look to the Tung Sol 6BE6 and to be fair, the only disadvantage with using this tube is the lower gain compared to other ‘new’ tubes. Else, I would highly recommend to have a listen to them.

 

Because of the seven grids used, the jumper setting has a relatively large impact on the sound:

 

EF91/EF92: Airy, open, spacious representation, neutral. Cleaner than the TS 6485. This is my preferred setting. Here, the tube signature is very close to the TS 6485.

Treble: Extended, refined, not bright. Well resolved. I prefer the 6BE6 here to the TS 6485.

Mids: Quite sweet, round, clean.

Bass: The weakest bass weight compared to the other settings. Still enough for me. The bass quality is very good, well articulated and punchy.

Stage: Larger and wider than TS 6485.

I have also used the CV4015, since I was anyway on the EF91/92 setting. Smaller stage, not as deep, not as wide. Signature similar, sound not as clean and refined. Slightly coloured towards warm. The 6BE6 sounds more organized and accurate.

 

Because of their black background, these tubes are ideal for detail lovers.

 

EF95 (floating grids): More bass weight, more deep bass, but slightly lesser quality, warmer, darker than the EF91/92 setting. You trade in some of the open airyness. Depending on preference, this more bassy setting could be the one

 

Pin 2-7 strap: This must be the bass head setting. Maximum bass weight, weakest treble presence. Surprisingly, still extended and one could consider to live with it, kind of the LCD headphone way, if you have tried that before. Guitars sound crunchy but generally mids are more recessed. A bit dynamic compressed sound for my ears or too frequency spectrum shifted to lower frequencies.

 

The relative differences are similar with the Sylvania JAN 5750, even though I did not explicitly test this again.

The Tung Sol 6BE6 sounds for me superior to the Sylvania, not by a huge amount, but still, because the the Tung Sol sounds more open and airy, slightly louder and a bit more detailed.

 

So, I am using the EF91/92 setting as we speak, makes it also easier for every user. One problem while comparing 6BE6 tubes to the rest of the 'new' tubes is that they are not as loud as these, and adjusting the sound obviously also changes the sound impression if not perfectly matched. This is a quite common issue when comparing different gear but it means that we have to take these impressions with a grain of salt.

 

 

Label: 6BE6, 3223501 (the one is a bit smeared out). This would mean the tube is from week one in 1935^^ or I am misinterpreting something...

 

 

About the 6BE6 pin layout, it just occurred to me that since the last grid (grid 5 similar to grid 3 in a pentode) is hardwired to the cathode on the same pin 2, the pin 2&7 mod is essentially pointless, apart from its experimental value of course, but it's not necessary per se, as the by-the-book way to strap that type of tube would be exactly what you did using the EF92 jumpers.

 

Just my 2 cents, it might explain why the tube sounds even weirder with the wire mod than it does leaving one grid floating, as tying that grid to the cathode might actually lead it to play a role in the tube (for instance, I'd read an example where strapping grids differently made the tube a current trinkler, letting only a little bit of current go through, making sound quite different than normal).

post #1194 of 5868

Dear A11,

 

It amazes me that we get the same listening impressions although our equipment is totally different. A couple of different quotes comparing the Tung Sol 5685/6AH6WA and GE 4825/6AU6 tubes. (My remarks from post 1188 above are in jelly bean green colors)

 

TS 6485 give the impression of more detail and space  - the TS is a little more detailed

In comparison, the 8425 has a deeper bass - The GE goes a little lower

 

Regarding the "errant" Tung Sol date: TS had several factories. Some of the tubes I have seen have either a 3 or 7 factory number listed.

Thus 3223501 refers to the EIA  (Electronics Industry Association)  number 322 assigned to Tung Sol. 3 is the factory. We are left with 501 which would lend itself to the first week of 1950. (According to the Tube Museum site the first tubes 6BE6 were made in 1946.)

 

About comparisons: Listening to a set of Tung Sol 6676 (6CB6/6CJ6) - this is definitively an upgrade over the EF95 tubes. The presentation is crisp and fairly detailed with a very punchy low end. However, with the exception of the punchy bass, the sound is more solid state (ss) like and a little dull sounding (lacking in microdynamics?) If I did not have the superior 6AH6/6AU6 tubes I would have more or less liked these tubes, but now I don't.

 

About the pin 2-7 strap: I did notice that the little stranded wires at the ends of the strap are thinning out from rolling different tubes (no effect on sound). What happens if a little piece of wire breaks off and falls into the socket pin hole? Could there be any ill effects?

 

Cheers,

post #1195 of 5868

Congrats gibosi on your new HE300 they are pretty nice so nice that they deserve a picture let us know how they sound .

post #1196 of 5868
Quote:
Originally Posted by mordy View Post

It amazes me that we get the same listening impressions although our equipment is totally different. A couple of different quotes comparing the Tung Sol 5685/6AH6WA and GE 4825/6AU6 tubes. (My remarks from post 1188 above are in jelly bean green colors)

 

TS 6485 give the impression of more detail and space  - the TS is a little more detailed

In comparison, the 8425 has a deeper bass - The GE goes a little lower

 

 

Great, isn't it =)

 

Quote:
Originally Posted by Audiofanboy View Post

About the 6BE6 pin layout, it just occurred to me that since the last grid (grid 5 similar to grid 3 in a pentode) is hardwired to the cathode on the same pin 2, the pin 2&7 mod is essentially pointless, apart from its experimental value of course, but it's not necessary per se, as the by-the-book way to strap that type of tube would be exactly what you did using the EF92 jumpers.

 

Just my 2 cents, it might explain why the tube sounds even weirder with the wire mod than it does leaving one grid floating, as tying that grid to the cathode might actually lead it to play a role in the tube (for instance, I'd read an example where strapping grids differently made the tube a current trinkler, letting only a little bit of current go through, making sound quite different than normal).

 

Makes sense. Cheers.

post #1197 of 5868
Quote:
Originally Posted by Johnnysound View Post

Thank you for your welcome and your advice, hypnos1. I have no doubt the Senn HD650 are at another level...closer to "audio nirvana" perhaps.  Very expensive, however. For the moment, I'll try the Tung Sols, any good dealer you can suggest ?

Hi there again J,

 

I got my 6485s, as did a couple of others here, from an ebayer in Germany - german-tubes - with very good deals in multiple units. It seems Audiofanboy requested tubes with CLEAN pins  - good idea - or else make sure you clean them thoroughly yourself (please excuse me if I'm "telling Grandma how to suck eggs"!!)...

Stateside on ebay.com it seems on offer are 5 units for $15.99 - also an excellent price for such marvellous tubes.Go buy , whichever applies...

 

I sincerely hope you manage to acquire some HD650s - if you're lucky perhaps even second-hand? I wish you all the best anyways.

 

Good luck with the 6485s also...

post #1198 of 5868

Have been comparing my tubes to the current reference TS 6AH6/GE 6AU6 tubes mentioned above.

 

Currently I am listening to a pair of RCA 1964 6AU6 tubes made for Bogen amplifiers. These tubes grow on you. They are not so much in your face as the the TS tubes and don't have the powerful punch in the bass nor their analytical preciseness.

What they do have is a huge 3D sound stage with the music seemingly emanating from outside of the speakers on some recordings. The sound is startlingly realistic with a sweet and warm mid range and a tuneful strong bass. Highs are extended and clear and there is great clarity to the sound with very good imaging. Compared to the heft of the TS tubes there is a swiftness and lightness and musical quality to the sound.

 

On the negative side, the RCAs are quite bright, but I do not have any difficulty compensating for it with the treble control on my receiver when listening through speakers. With my ATH AD-700 headphones plugged straight into the MkIII without any tone controls the sound is on the bright side, and the bass is a little flabby - seems that the speakers have a better control of the bass than my cans.

 

If you buy these tubes right it is like going to the 99c store - you may want to give them a try....

 

What Acapella writes about how a person's form may affect his perception of the sound is definitively true. However, another factor is also very important. During the day when all kinds of electric motors, appliances, fluorescent lights are on there is a lot of electric interference that may affect the sound. Listening at night when most of these things are off will usually improve the sound.

 

In summary, these 6AU6 RCA tubes are sweet, lively and musical. They are more on the subtle side, and it takes a little time to get used to them - curious if somebody else tried them and what impression they have.

post #1199 of 5868

Hi Mordy,

A large stage is always a treat for me. Sounds interesting. One thing, I thought about now comparing the two Tung Sol tubes, which have some similar traits: Is there a 'house sound'? Or is it just an urban myth?

 

 

With respect to the Tung Sol 6BE6, which I highly recommend trying, and also other 6BE6, 6BY6 and 6CS6 tubes: Something I did write only 'between the lines': If you do not consider higher gain important, because your can is easy enough to drive, then these 300 mA heater current tubes do not get as warm as 6AH6 450 mA tubes. I can easily touch them during operation. Also, you can use standard settings to operate them (EF91/92, EF95). This is not a concern for me but might be for others. So, they are easy enough to roll. Of course, I recommend as well trying the 6AH6 and 6AU6 tubes because they sound excellent as well and have higher gain if needed.
 


Edited by Acapella11 - 5/7/13 at 12:13pm
post #1200 of 5868

Acapella11. the 6ah6 and 6au6 if i understand correctly only work with pin 2 and 7 strapped according to the chart right and those are the best sounding ones these days and the ones you just mentionned 6BE6 ects are better or worse  than the 6AU6 6AH6. Thanks.

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