Head-Fi.org › Forums › Equipment Forums › Headphone Amps (full-size) › Little Dot Tube Amps: Vacuum Tube Rolling Guide
New Posts  All Forums:Forum Nav:

Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 39

post #571 of 8778
Quote:
Originally Posted by Acapella11 View Post

I got a similar shape getter, a square bent in the middle, looks kind of like a roof.

 

I see the cat is also curious about the getter ;)


Haha, yeah, she is always getting in my business! tongue.gif

post #572 of 8778

Do getter wires affect sound?

post #573 of 8778

Spoke to my retired friend who is an electronics engineer and started out in the tube era. He told me that the purpose of the getter is to

provide the materials for the getter flash (the silver coating on top of the tube) which absorbs any left over oxygen in the tube in order to make for a good vacuum.

According to him, once this is done in the manufacturing process, the getter has no function any more.

 

Interesting.....

 

The getter

We want a good, hard vacuum inside a tube, or it will not work properly. And we want that vacuum to last as long as possible. Sometimes, very small leaks can appear in a tube envelope (often around the electrical connections in the bottom). Or, the tube may not have been fully "degassed" on the vacuum pump at the factory, so there may be some stray air inside. The "getter" is designed to remove some stray gas.

The getter in most glass tubes is a small cup or holder, containing a bit of a metal that reacts with oxygen strongly and absorbs it. (In most modern glass tubes, the getter metal is barium, which oxidizes VERY easily when it is pure.) When the tube is pumped out and sealed, the last step in processing is to "fire" the getter, producing a "getter flash" inside the tube envelope. That is the silvery patch you see on the inside of a glass tube. It is a guarantee that the tube has good vacuum. If the seal on the tube fails, the getter flash will turn white (because it turns into barium oxide).

There have been rumors that dark spots on getters indicate a tube which is used. This is NOT TRUE. Sometimes, the getter flash is not perfectly uniform, and a discolored or clear spot can occur. The tube is still good and will give full lifetime.

post #574 of 8778

Interesting information Mordy and thanks to your friend. The information goes well together with your film, where the Barium transfer is shown from the getter, if I remember correctly. Actually, it is shown in both films but with KR, the getter is on the side.

The getter is just nicely distinguishable between tubes for us but then anode, cathode and grid seem to play the big role in sound reproduction.

post #575 of 8778

It's usually the most distinguishable quality which is whats used for reference here.

 

e.g. I wanted to hear the sound that was reviewed so i asked which he had since on eBay the only 2 variants saw other than date was the getter. Personally I didn't know it was useless after the manufacturing process, pretty interesting.

 

Regardless, I bought some Tung Sol's form the link I posted and I'll see if my sound matches the review. The sound I'm looking for is pretty much the Raytheons I have with a little better bass impact.

post #576 of 8778

Mmm I've been listening with the M8100's for a week now.

 

I can't say I like them. I find the treble decidely bad sounding; often unpleasant, sometimes harsh. Maybe not harsh in that they are fatiguing but they seem to just annoy me for some reason.

Also the tubes seem to be too warm and almost muddy.

 

I dare say I actually prefer the default GE tubes. I mean I can get used to the warmer sound but the treble with the mullards is a disaster IMO. It's getting to the point that I'm doubting my appreciation for the Little Dot at all to be honest, especially because I don't like the thought of order yet another pair of new tubes and going back to the stock tubes probably means missing out on the things I like about the m8100's (the more distanced sound stage and better bass response).

 

Meh.


Edited by Nirvana Woman - 12/20/12 at 10:40am
post #577 of 8778
Quote:
Originally Posted by Nirvana Woman View Post

Mmm I've been listening with the M8100's for a week now.

 

I can't say I like them. I find the treble decidely bad sounding; often unpleasant, sometimes harsh. Maybe not harsh in that they are fatiguing but they seem to just annoy me for some reason.

Also the tubes seem to be too warm and almost muddy.

 

I dare say I actually prefer the default GE tubes. I mean I can get used to the warmer sound but the treble with the mullards is a disaster IMO. It's getting to the point that I'm doubting my appreciation for the Little Dot at all to be honest, especially because I don't like the thought of order yet another pair of new tubes and going back to the stock tubes probably means missing out on the things I like about the m8100's (the more distanced sound stage and better bass response).

 

Meh.


Sorry to hear you don't like them. :/  Do they have the actual 8100/Mullard logo printed on them? I know there are different versions...just curious.

post #578 of 8778
Quote:
Originally Posted by dxanex View Post


Sorry to hear you don't like them. :/  Do they have the actual 8100/Mullard logo printed on them? I know there are different versions...just curious.


KQDD CV4010

 

I've tried my hand at messing with the little dot's gain settings a bit. Used to have them at gain 4. Now they're at 10. There definitely seems to be a change in that the sound seems to contain more of a 'hall' effect, so to speak. The bass is also much, much stronger.

At least that´s my first impression. I want to say it´s also solved the weird treble issue, but I´m not sure about that yet. The gain setting seemed to change things up quite a lot. Gonna give it a few days listening on this gain setting and see how I like it. Right now I feel it sounds rather funny, but in a good way I suppose.

 

Thanks for your concern by the way, it´s appreciated ;).

post #579 of 8778

It is good that could sort the treble out by changing the gain, interesting. My personal favourite setting was a gain of 5, I thought it sounded better than 1 to 4 and 10 didn't make that much of a difference to me, but I cannot recall what the details were why I preferred 5 ;). I should check that out again.

 

The sound signature you are describing points towards a preference towards Tung-Sol 6AJ5 (colder than M8100 and sweeter treble) only the bass will be lesser in quantity, although the 6AJ5-bass quality is good. In my experience you often trade better treble extension and more of it for a loss in bass quantity with these tubes. The CV4015 I am using at the moment is a "colder" brighter tube with very resolved treble and  great in terms of focus and instrument separation. Then again you lose some bass over the Mullards, but it is of good quality. Actually JAN 5654W tubes could be a good suggestion. Clean and nice treble extension, not too much deep bass, but good mid bass punch.

I won't suggest the other from me preferred Mullard M8100 (with label) because I am not sure you might get the same treble issue you just experienced.

 

If you are interested in the JAN 5654W tubes, I could send them for a good price from UK; bought out of excitement a couple too many ;)

 

Just on a side note, you are using HD650 headphones?

 

The risk about tube rolling is also the fun of it and there may always be some tubes that won't be in the selection later. Look at it as a little adventure :) Tubes are not that expensive after all, plus over time you nail nicely down what you actually really like.


Edited by Acapella11 - 12/20/12 at 5:51pm
post #580 of 8778
Quote:
Originally Posted by Acapella11 View Post

It is good that could sort the treble out by changing the gain, interesting. My personal favourite setting was a gain of 5, I thought it sounded better than 1 to 4 and 10 didn't make that much of a difference to me, but I cannot recall what the details were why I preferred 5 ;). I should check that out again.

 

The sound signature you are describing points towards a preference towards Tung-Sol 6AJ5 (colder than M8100 and sweeter treble) only the bass will be lesser in quantity, although the 6AJ5-bass quality is good. In my experience you often trade better treble extension and more of it for a loss in bass quantity with these tubes. The CV4015 I am using at the moment is a "colder" brighter tube with very resolved treble and  great in terms of focus and instrument separation. Then again you lose some bass over the Mullards, but it is of good quality. Actually JAN 5654W tubes could be a good suggestion. Clean and nice treble extension, not too much deep bass, but good mid bass punch.

I won't suggest the other from me preferred Mullard M8100 (with label) because I am not sure you might get the same treble issue you just experienced.

 

If you are interested in the JAN 5654W tubes, I could send them for a good price from UK; bought out of excitement a couple too many ;)

 

Just on a side note, you are using HD650 headphones?

 

The risk about tube rolling is also the fun of it and there may always be some tubes that won't be in the selection later. Look at it as a little adventure :) Tubes are not that expensive after all, plus over time you nail nicely down what you actually really like.

 

I guess that's true. There's also many variables to consider such as mood, quality of recording, placebo effects, etc. It can be pretty disorienting sometimes.

 

I use the HD650's yeah. I'd definitely be interested in the jan654w's but I am not sure if it would be worth your effort. That is to say I'd be glad to pay for them but I can't speak on your behalf if you wanna go through the trouble of packaging and sending them. I currently feel that I need to give the m8100's some more time and eventually try some Voskhods if I really end up not liking the Mullards. Luckily, those are typically pretty cheap.

 

Anyway, I'll be sure to keep posting here :).

post #581 of 8778

It is straight forward for me to pack and send the tubes. I think it is worth trying the JAN 5654Ws. I've got the feeling they could match your taste pretty well.

If however, you really don't like them, then just send them back.

 

Please pm me if you are interested.
 

post #582 of 8778

I've given the M8100's a lot of time and thought and I just can not get along with them. I really dislike the way they render treble for some reason. It's not necessarily harsh, but there's just something about it that keeps annoying me. It's probably a rather irrational thing I guess. Gain settings didn't turn out to do anything for me in that regard. Now back to the stock GE5654's... Loving it... Yeah the treble is a lot less energetic, the bass is a little weaker and the soundstage narrower... But I like them.

 

I was lucky enough to have Acapella above me here send me a pair of jan5654w's for an amazing price... Will post my experiences with them when they arrive. Thanks again dude :).

post #583 of 8778

Scratch all that. Loving the Mullards these days... In fact the enjoyment has been so self-explanatory that it's hard for me to realise I was so disappointed with the Mullards for a while. Don't understand anything about it anymore...

post #584 of 8778

Hey Guys, according to your experience, which one is the most neutral - least warm sounding tube setup (power+drive) around?

post #585 of 8778

New here, finally felt I should give back a little on this topic after lurking for so long...

 

The most neutral I've heard for power tubes is -by far- the 6n30p-dr (that's on a MK IV SE mind you, so no 6n6p tubes, it's compared to the Electro-Harmonix 6h30pi, which quite warm and detailed). I have a pair from 1983, that cost me a leg, and they really make the amp sound tighter and more authoritative, and perfectly neutral (almost sounds like SS, but liquid and holographic). Takes the amp to a whole other level; more than the accepted 15% of improvement.

 

Easier and cheaper, the most neutral driver tubes I've tried among all three compatible families of tubes are the CV4015/M8161 made by Mullard (I have a pair from 1976, with the old military writings and no mullard logo). These sound very balanced, have great 3D imaging and excellent restitution of treble notes (a bit bright a high volumes on my set-up but hardly unbearable on the HD650, although I do find myself often lowering the volume with these tubes) while digging much lower in the infra-bass region that any EF95 tubes I've tried. It's sort of a no-compromise tube, and very un-tubey paired with the 6n30p-dr, but greatly enjoyable.

 

Still fairly neutral but warmer (more rolled-off highs and less infra-bass), paired the same neutral power tubes would be the Tung-sol 6aj5 tubes mentioned earlier (mine are from 1945). They share some qualities with the CV4015, but slightly less detailed and with a slightly smaller soundstage, but warmer and very enjoyable. It's the best compromise I found in the 6ak5/6aj5 family.

 

In the EF95 family, I find that my voskhod tubes and CV850 Mullard tubes (the Whyteleafe variety if I remember correctly) tend towards a more neutral sound signature (still quite warm though) than, say, the M8100. I am waiting on a lot of EF91 tubes from ebay, and those are supposed to be very neutral and SS-like as well.

New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Headphone Amps (full-size)
Head-Fi.org › Forums › Equipment Forums › Headphone Amps (full-size) › Little Dot Tube Amps: Vacuum Tube Rolling Guide