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Little Dot MKIII Tube Rolling - Page 117

post #1741 of 2867
I switched out the 752 and the 559 for the two 8026. Microphonics are gone and the sound is much tighter. Overall I like the sound better although it sacrifices some soundstage.
post #1742 of 2867
Quote:
Originally Posted by erikzen View Post
It's also the first set of tubes I've tried that are noticeably microphonic.
Hmm do you mean there's noise in the music when using those tubes ? I hope not, and I hope they don't sound too tubey.. I want the sound to be cleaner and lighter and not so muddy.

Perhaps changing the 650 cable might help the problems more than tubes..
post #1743 of 2867
I have a pair of these WE 403b. I have to agree with some comments i read in a Darkvoice thread that said they have some wierd bass. I haven't listened to them in a couple of weeks and only have about 15 hours on them. I'll have to try them again. I just remember the bass response was strange, some parts boosted and some attenuated.
post #1744 of 2867
Quote:
Originally Posted by PascalT View Post
Hmm do you mean there's noise in the music when using those tubes ? I hope not, and I hope they don't sound too tubey.. I want the sound to be cleaner and lighter and not so muddy.

Perhaps changing the 650 cable might help the problems more than tubes..
They aren't necessarily noisy when you play music. You really only notice it when the music isn't playing and you rub against the headphone cable. However I just wonder if some of the same characteristics that make a tube microphonic might also make it sound good.

Anyway, I switched out those two tubes and put in two that are supposed to be matched, with the matching date codes and the sound is much tighter again. And these aren't microphonic at all.

So I don't know what a true WE 403B is supposed to sound like. But I can tell you this, I'm listening to these tubes right now and with Andreas Vollenweider playing through the LA7000, everything is sounding unbelievable.
post #1745 of 2867
Quote:
Originally Posted by ScottieB View Post
Another question... the smokey color to the glass at the top of the tubes - what is this for? And why do some tubes seem to have it perfectly centered at the top, while others seem to have it off to one side? Does this say anything about the quality or sound of the tube?
I think this answers your question:

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. THE ONLY RELIABLE WAY TO DETERMINE THE HEALTH OF A TUBE IS TO TEST IT ELECTRICALLY.


From:
How Vacuum Tubes Work
post #1746 of 2867
I'm taking one for the team and breaking the $8/tube rule. While I am happy about the price I've been paying for tubes I've found on eBay, I'm not 100% sure about the quality. Sure, they all work and seem to sound OK, but whether they are actually matched, or even the brand they say they are is often dubious.

I am going to buy two sets of tubes from Tube World and compare them to some of the "pot luck" tubes I've been getting to see if matching, brand names, original boxes make any difference in sound quality.

I placed an order for a pair of Raytheon JRP-6AK5W 1952 NOS with black plates and "D" getter, US Navy issue tubes in original boxes ($25/pair) and 1 pair of EF95 Mullard Whyteleafe plant NOS 1958 "D" getter halo in white boxes with the same date codes ($50/pair). I know those Mullards are pricy and might not be any better than the "unbranded" ones I purchased recently.

This should give me a pretty good idea of whether or not it is worth it (for my ears anyway) to be chasing after the more expensive tubes. I've run plenty of tubes so far that have not been matched and I haven't heard anything out of the ordinary like a channel imbalance or high levels of distortion.

I must admit that the smoothest sounding tubes were the matched Voshods which were $24 plus shipping from Yen. We'll see how these do.
post #1747 of 2867
Quote:
Originally Posted by erikzen View Post
I think this answers your question:

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. THE ONLY RELIABLE WAY TO DETERMINE THE HEALTH OF A TUBE IS TO TEST IT ELECTRICALLY.


From:
How Vacuum Tubes Work

Excellent, thanks! And thanks for the link - gonna have a look.
post #1748 of 2867
Quote:
Originally Posted by erikzen View Post

I placed an order for a pair of Raytheon JRP-6AK5W 1952 NOS with black plates and "D" getter, US Navy issue tubes in original boxes ($25/pair)
I ALMOST put that order in myself on Saturday, but held back - very curious to hear how they sound! thx, erikzen!
post #1749 of 2867
Quote:
Originally Posted by ScottieB View Post
I ALMOST put that order in myself on Saturday, but held back - very curious to hear how they sound! thx, erikzen!
Yeah, me too. I'm still trying to give them my credit card info though. Been playing phone tag. Actually, if these are any good it won't be such a bad deal.

$50 for the Mullards though, I think I was a bit over zealous with that purchase. That rivals the top of the line for any of the Yen tubes. But if they sound good I guess it's worth it to have them in my collection. I haven't seen any "Whyteleafe Plant" tubes before, although I don't know exactly what that means in terms of quality.
post #1750 of 2867
FYI

selling my Electro-Harmonix 6H30Pi-EH Gold's, if anyone wants a pair.

http://www.head-fi.org/forums/f44/fs...iii-iv-417537/
post #1751 of 2867
Quote:
Originally Posted by erikzen View Post
I recently won a pair of tubes on ebay sold as Mullard but they don't say Mullard anywhere on them.

They have this coding:

Valve Electronic CV4010 KQDD/K
Z42 5960-99-000 4010

Anybody know what these actually are?

I paid $8.50/tube

Oh well, $0.50 over the limit.
I just got a pair of these. Great tubes! I love the mids and highs - very tubey smooth with good detail. Bass seems a little loose and rolled off lacking some punch. Hopefully, it'll tighten up with burn in. So far these are up there with my favorites.
post #1752 of 2867
Quote:
Originally Posted by Max F View Post
I just got a pair of these. Great tubes! I love the mids and highs - very tubey smooth with good detail. Bass seems a little loose and rolled off lacking some punch. Hopefully, it'll tighten up with burn in. So far these are up there with my favorites.
They are great aren't they ... Another tube that is very very good is a Sylvania 6ak5wb late 1950's. Much better than the WE 403b's IMO
post #1753 of 2867
OK, I really am done with buying tubes now for this amp. Time to evaluate everything that I've got.
post #1754 of 2867
Quote:
Originally Posted by erikzen View Post
OK, I really am done with buying tubes now for this amp. Time to evaluate everything that I've got.
Yes ..don't forget the music cause tube rolling can be quite addictive and it IS about the music afterall ...but do keep an eye on eBay. Sometimes a great deal can be had altho its been getting alot harder lately.
post #1755 of 2867
Hi,

I'm new to this site and the (wonderful?) world of tuberolling. I have a couple of questions regarding tuberolling on the Little Dot MKIII.

As of now I've got it paired up with a Sennheiser HD-650. Allthough I'm pleased with the systems overall performance, I feel that it can benefit by switching the tubes.

What I'm looking for is some entry level tubes that can add some punch in the highs and mids. The HD-650 sounds really relaxed and smooth, and I would like to add a little spice, if that makes any sense.

This is my first time tuberolling, and I'm really looking forward to test out some new tubes.

PS: Do any of you know of a tuberolling 101-guide with a image/video-explanation of how to remove, clean and insert the tubes?

Thanks,
Lars
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