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 394

post #5896 of 7468
Quote:
Originally Posted by TrollDragon View Post

I was chatting with a serious tube guy the other night and telling him about the rolling thread here... The first question he asked was WHY? Rolling tubes without the knowledge of how they operate and without doing the calculations and adjustments to the circuitry is basically pointless.

I told him we were looking for the best sounding tubes for the amp and he corrected me by saying that without doing any of the calculations and modifications we were just finding the "Least worst compatible tubes"...

Much truth to that and something to think about.

 

Well, one could argue that in rolling through the EF91, EF92, EF95 and 408A tubes, collectively speaking, we tried all the "compatible" tubes. And not satisfied, we decided to try everything and anything that looked like it might work, to see if we could find something better. And at this point in time, the so-called "least worst compatible" tubes I have been rolling recently are far-and-away better than the "compatible" tubes. (But of course, I should insert the standard disclaimer, "This is with my ears and gear".)

 

This seems to me to be the old "measurements vs ears" debate.... and I freely admit my bias.... I trust my ears, even though they are old and well-worn....

 

"If it measures good and sounds bad, it is bad. If it sounds good and measures bad, you've measured the wrong thing" - Daniel R. von Recklinghausen

 

Cheers

post #5897 of 7468
Quote:
Originally Posted by gibosi View Post
 

 

Well, one could argue that in rolling through the EF91, EF92, EF95 and 408A tubes, collectively speaking, we tried all the "compatible" tubes. And not satisfied, we decided to try everything and anything that looked like it might work, to see if we could find something better. And at this point in time, the so-called "least worst compatible" tubes I have been rolling recently are far-and-away better than the "compatible" tubes. (But of course, I should insert the standard disclaimer, "This is with my ears and gear".)

 

This seems to me to be the old "measurements vs ears" debate.... and I freely admit my bias.... I trust my ears, even though they are old and well-worn....

 

"If it measures good and sounds bad, it is bad. If it sounds good and measures bad, you've measured the wrong thing" - Daniel R. von Recklinghausen

 

Cheers

 

Hey gibosi. You've hit the nail RIGHT on the head...I don't think our collective appraisals and results can be discounted just because we haven't done the maths...OK, it might take us much longer, and have to kiss a hell of a lot of frogs before finding the 'Prince', but that is also a good part of the fun - not to mention great camaraderie - in what we have been doing for a good while now. And isn't it just GREAT when we do hit upon the Prince/Princess!?...I for one wouldn't have wanted to miss all we have been through, no matter how "pointless" some may want to call our efforts/pain/trials/enterprising spirit/education...not to mention fun and joy...I rest my case also...

 

Carry on folks....take ye not any heed of disbelievers!

post #5898 of 7468

  After 24 hours of burn-in for my 6SN7 GTA Sylvania Chrome top from1953 and 1954 the sound it improved alot at first i was a bit disapointed how bright/harsh it sound and now they are not harsh at all  i love them they are more detailed than my RCA black plates these 6SN7's are really a nice tube for my LD amp.These is where i'am going to stopped buying 6SN7's i do have more than enough to play with my LD it's time for me to look for any other type of amp that it can use 6SN7's i'am wondering about Bottlehead Crack.:biggrin:

post #5899 of 7468

It's time for me to try the 6AS7 as power tubes.....

post #5900 of 7468

Still waiting for the tubes to cooldown for tube changed.I hoped you guys can come up with another type of tubes that we can use with LD.These 6SN7 is killing my wallet i need something inexpensive:wink:.

post #5901 of 7468
Quote:
Originally Posted by i luvmusic 2 View Post
 

 ......it's time for me to look for any other type of amp that it can use 6SN7's i'am wondering about Bottlehead Crack.:biggrin:

 

The Crack comes with a 9-pin miniature socket with the heaters configured to run 12AU7 tubes in 6 volt mode. Some have reported that they have successfully rolled 6SN7. However, others have reported that the 6SN7 is too noisy. I suspect that one could use the same external DC heater PS you have been using in the LD, and that would solve the noise problem. And further, you should be able roll ECC40, E80CC, 2C51, 7N7, 7AF7 and so on.....

 

Unfortunately for me, the Crack is designed to work with 200 Ohm headphones and up. If it could drive lower impedance phones, I would probably get one.

post #5902 of 7468

Oops my bad can't try 6AS7 for now i need to wait for my regulator comming from Chinada(it's on speedboat) i just tried the 6AS7 and it did overloaded my 5A regulator 2 6AS7 and 1 6SN7(5.6A) is to much for my 5A regulator.I forgot about that regulator inside my power supply.FAIIIIIIIIIIL:(

post #5903 of 7468
Quote:
Originally Posted by gibosi View Post
 

 

The Crack comes with a 9-pin miniature socket with the heaters configured to run 12AU7 tubes in 6 volt mode. Some have reported that they have successfully rolled 6SN7. However, others have reported that the 6SN7 is too noisy. I suspect that one could use the same external DC heater PS you have been using in the LD, and that would solve the noise problem. And further, you should be able roll ECC40, E80CC, 2C51, 7N7, 7AF7 and so on.....

 

Unfortunately for me, the Crack is designed to work with 200 Ohm headphones and up. If it could drive lower impedance phones, I would probably get one.

The only thing that making me think twice is i listen to my Q#@ rather than my DT8@# 600 ohms but i'am still looking into it i really like to build my first tube amp.

post #5904 of 7468

Hi All,

 

"Rolling tubes without the knowledge of how they operate and without doing the calculations and adjustments to the circuitry is basically pointless.

I told him we were looking for the best sounding tubes for the amp and he corrected me by saying that without doing any of the calculations and modifications we were just finding the "Least worst compatible tubes"...

 

TD, why don't you ask your friend which calculations and adjustments to make?

 

hypnos 1, I agree completely with you about all the fun and exciting discoveries we have made, not to mention the tremendous upgrade in the sound of the LD amps.

 

Right on, Gibosi!

"Well, one could argue that in rolling through the EF91, EF92, EF95 and 408A tubes, collectively speaking, we tried all the "compatible" tubes. And not satisfied, we decided to try everything and anything that looked like it might work, to see if we could find something better. And at this point in time, the so-called "least worst compatible" tubes I have been rolling recently are far-and-away better than the "compatible" tubes."

 

Something tells me that we would not have achieved the heights we have reached if we followed the advice of TD's friend.....

 

When I hear the expression "the least worst compatible tube" all I can think of is this:

 

 

PS: Stay tuned for a report on a great underrated and inexpensive tube: the 6BL7.

post #5905 of 7468
Quote:
Originally Posted by mordy View Post
 

Hi All,

 

"Rolling tubes without the knowledge of how they operate and without doing the calculations and adjustments to the circuitry is basically pointless.

I told him we were looking for the best sounding tubes for the amp and he corrected me by saying that without doing any of the calculations and modifications we were just finding the "Least worst compatible tubes"...

 

TD, why don't you ask your friend which calculations and adjustments to make?

 

hypnos 1, I agree completely with you about all the fun and exciting discoveries we have made, not to mention the tremendous upgrade in the sound of the LD amps.

 

Right on, Gibosi!

"Well, one could argue that in rolling through the EF91, EF92, EF95 and 408A tubes, collectively speaking, we tried all the "compatible" tubes. And not satisfied, we decided to try everything and anything that looked like it might work, to see if we could find something better. And at this point in time, the so-called "least worst compatible" tubes I have been rolling recently are far-and-away better than the "compatible" tubes."

 

Something tells me that we would not have achieved the heights we have reached if we followed the advice of TD's friend.....

 

When I hear the expression "the least worst compatible tube" all I can think of is this:

 

 

PS: Stay tuned for a report on a great underrated and inexpensive tube: the 6BL7.

 

and on top of that I'll be testing 6f8g's soon!

post #5906 of 7468
I am not stirring up the pot or trying to get anyone's knickers in a knot, just passing along information from a person who has worked with tubes all their life, repairs and designs amplifiers.

Then again he mostly works with amps that have a B+ greater than 350V so things can get out of hand quickly when tube theory is not applied and followed.

beerchug.gif
post #5907 of 7468
Quote:
Originally Posted by TrollDragon View Post

I am not stirring up the pot or trying to get anyone's knickers in a knot, just passing along information from a person who has worked with tubes all their life, repairs and designs amplifiers.

Then again he mostly works with amps that have a B+ greater than 350V so things can get out of hand quickly when tube theory is not applied and followed.

beerchug.gif

 

Hi TD.

 

No offence taken, mon ami - can see where you're coming from...the pro is always going to be looking at things differently to the semi-, or amateur. And usually becomes bogged down in theory (certainly in higher voltage land)...whereas we are much more into practice! There is a place for BOTH in this world...

 

I am sure I speak for us all when I say we do appreciate your contribution to this thread...keep it up! :wink:

 

Cheers

post #5908 of 7468
Quote:
Originally Posted by hypnos1 View Post
 

 

Hi TD.

 

No offence taken, mon ami - can see where you're coming from...the pro is always going to be looking at things differently to the semi-, or amateur. And usually becomes bogged down in theory (certainly in higher voltage land)...whereas we are much more into practice! There is a place for BOTH in this world...

 

I am sure I speak for us all when I say we do appreciate your contribution to this thread...keep it up! :wink:

 

Cheers

:beerchug:

post #5909 of 7468

Hi TD.

 

No offense taken, mon ami - can see where you're coming from...the pro is always going to be looking at things differently to the semi-, or amateur. And usually becomes bogged down in theory (certainly in higher voltage land)...whereas we are much more into practice! There is a place for BOTH in this world...

 

I am sure I speak for us all when I say we do appreciate your contribution to this thread...keep it up! :wink: 

 

 

Ditto, keep up the good work! BTW, what happened to the protective circuit for DC coupled amps from the British designer?

post #5910 of 7468

I think it's a pretty good review that hit most of what I felt about a lot of those tubes right on the head.  I love my Tung-Sol tubes and my Voshkods.  The other ones don't really get any amp time.  

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