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Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 371

post #5551 of 7574
Quote:
Originally Posted by gibosi View Post
 

 

And I believe the LD can handle 1.5A heaters without having to use an external supply, so these may well be worth looking into as power tubes.

If i remember correctly LD can push 2.5A for powertubes, and 1.5A x 2 = 3A. Not recommended without external supply. :(

post #5552 of 7574

Thanks for correcting me. :)

post #5553 of 7574

Anyone tried gutted LD MK III/IV?My idea is to save some space on my Desk so i want to put my LD 1,MK III and the External Power Supply in one inclosure(maybe salvage some old Electronics case.or make one out of aluminum and wood)Some picture would be helpful to me.THANKS!

post #5554 of 7574

Spring cleaning my wife said...

post #5555 of 7574

"Brainless Tales:"

 

 

post #5556 of 7574

Over here this is still in demand  ruff winter this year .                                                                                                                                                                                             *

post #5557 of 7574
Quote:
Originally Posted by Artsi View Post
 

If i remember correctly LD can push 2.5A for powertubes, and 1.5A x 2 = 3A. Not recommended without external supply. :(

 

Ah so - some while back when I put out feelers for possible use of 6AS7s and 6080s as powers I assumed there were other factors going against their use in our LDs...eg. plate dissipation 13W (6080). Was I worrying unduly, and do we just need to provide an external heater supply of 2x 2.5A (6080) to be safe? If so , these 6080s sure do look interesting...

 

HOWEVER, despite fear of boring people to death re my Psvane CV181-T MKIIs, another 24 hours or so (on the already 100) have brought even  more magic to the table - they obviously love my C3GSs (and vice-versa). The sound I am getting reminds me of what the Senn HD700 produced over my 650s, so their combined cost is still way below the 700s!. Perhaps my wallet can now rest easy (not to mention my nervous system...). And perhaps I shan't need to explore the 6080s? Mmmm...Actually, I still have the Sylvania 6SN7GT - VT231s to trial - when they arrive from the States (my Psvanes came quicker from Hong Kong!!).

post #5558 of 7574

Hi Artsi and Gibosi,

 

A 6BX7 tube is on the way which uses a 1.5A heater - should not be a problem for my 5A voltage regulator and power supply.

 

Re the 6AS7, 6080 and similar tubes with a low amp factor of 2, what would be the result using such a tube as a driver in the LD MKIII together with my 110W ss Sony amp driving speakers?

 

As it is now, the LD volume control is always set at near clipping (around 3o'clock), and the Sony volume is on low. (As a comparison, when using headphones I cannot use a higher setting on the LD than 9 o'clock without risking my hearing.)  The Sony amp has a LED bar graph that indicates less than 1-2W (!) to get more than adequate listening levels. If I play really loud and go higher than say 30W on this meter I experience audible hum (that may be masked by the music).

 

Using the 6AS7 etc tubes, would I need to increase the volume level substantially? The tube I am using now, the 8FQ7, has an amplification factor of 20.

 

.

post #5559 of 7574

Man, there is always something new...

 

Here is a 6080 replacement, the mighty 6336 tube. With a heater drawing 4.75A I assume that you can use it as a space heater (Good for the Montreal winter?)

 

http://www.radiomuseum.org/tubes/tube_6336.html

post #5560 of 7574

I haven't used 6BL7GT / 6BX7GT in this circuit but have elsewhere and it is a cracking tube, in fact it is one (perhaps the only one left) of what I call the 'premium audio' tubes that is both relatively un-discovered by 'mainstream' audio, but great examples are easily bought at great prces still. Just as the Woo 6 used the 6FD7, 6EW7, 6DR7 etc which are now drying up, then the next mainstream roller amp might consider the 6BL7GT / 6BX7GTs. Some cracking 6BL7GT / 6BX7GTs tubes but I prefer the earlier full base ones rather than the button / coin based ones.

post #5561 of 7574
Quote:
Originally Posted by mordy View Post
 

Re the 6AS7, 6080 and similar tubes with a low amp factor of 2, what would be the result using such a tube as a driver in the LD MKIII together with my 110W ss Sony amp driving speakers?

 

As it is now, the LD volume control is always set at near clipping (around 3o'clock), and the Sony volume is on low. (As a comparison, when using headphones I cannot use a higher setting on the LD than 9 o'clock without risking my hearing.)  The Sony amp has a LED bar graph that indicates less than 1-2W (!) to get more than adequate listening levels. If I play really loud and go higher than say 30W on this meter I experience audible hum (that may be masked by the music).

 

Using the 6AS7 etc tubes, would I need to increase the volume level substantially? The tube I am using now, the 8FQ7, has an amplification factor of 20.

 

Since you have a very unique system, I doubt that anyone here knows for sure...  As Artsi's experience confirms, the lower gain of the 6AS7 will result in lower volume levels, but the only way to know if it is too low for your system is to try one. The 6BX7 you have on the way will give you more information. If it works well, then it might be worth trying a 6AS7. And if the output of the 6BX7 is too low, then of course, a 6AS7 would be even lower....

post #5562 of 7574

I am about to purchase some matched Mullard M8100 / CV4010 tubes and have the choice between two different years:

 

1981 (Week 27) or 1983 (Week 35 or 44)

 

Does anyone know if there is any sound quality or build differences between the two years, or if there are any differences between them at all even?  I've searched and searched without an answer unfortunately.

post #5563 of 7574
Quote:
Originally Posted by mordy View Post
 

Man, there is always something new...

 

Here is a 6080 replacement, the mighty 6336 tube. With a heater drawing 4.75A I assume that you can use it as a space heater (Good for the Montreal winter?)

 

http://www.radiomuseum.org/tubes/tube_6336.html

Removes the humidity thats for shure !

post #5564 of 7574
Quote:
Originally Posted by BassInMyFace View Post
 

I am about to purchase some matched Mullard M8100 / CV4010 tubes and have the choice between two different years:

 

1981 (Week 27) or 1983 (Week 35 or 44)

 

Does anyone know if there is any sound quality or build differences between the two years, or if there are any differences between them at all even?  I've searched and searched without an answer unfortunately.

 

Generally speaking, older is better. However, as these are only 2 years apart, I doubt there is any significant difference. So buying the cheapest pair might make the most sense.

post #5565 of 7574
Quote:
Originally Posted by gibosi View Post
 

 

Generally speaking, older is better. However, as these are only 2 years apart, I doubt there is any significant difference. So buying the cheapest pair might make the most sense.

 

Thank you for the quick response!

 

I guess I have to debate now on getting the 1981 version or waiting for something older to pop-up on eBay...

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