[MIKELAP]

  Hi A11,
 
I notice that you use the OEM family 6N6P power tubes. If you would switch to plug and play 6SN7 type tubes (only requiring adapters) the sound would improve further, especially the bass.

Expecting those 6sn7 adapters from China hopefully this year lol  .

 

[hypnos1]

  The pin numbering inversion happened quite a few times back when we started with non-EF91/92/95 driver tubes.
 
Received now AK5-vector socket extender, C3G-AK5 adapter and a while ago already the Siemens C3GS tubes (thanks superdux).
 
Just listening to it and it sounds very promising with the HD800s. Larger stage than with the 6HM5 for sure and the first impression is quite nice. Will come back once they are further burnt in. Took a shot from the big tube adapter assemblies put together. Not the most beautiful setup but sounds good as far as I can tell.
 
 

 
For reviews of 6N6P standard compatible driver tubes, look at this post #3007. It includes impressions from Mordy, Audiofanboy and myself.

 
Hi A11.
 
Glad you are giving the C3gSs a try...they keep improving up to 50 hrs or even more. And as mordy says, the 6SN7 as power will do them a good bit more justice. But the real leap then comes when partnered with the 6AS7G/6080. I truly hope you give this option a try at some stage...the mods are not too difficult

.
 
I am beginning to suspect that those C3g adapters may not be helping the tube to achieve its full potential...when they work at all, lol!! But I do hope you have no trouble with yours....

 

[Acapella11]

  Hi A11,
 
I notice that you use the OEM family 6N6P power tubes. If you would switch to plug and play 6SN7 type tubes (only requiring adapters) the sound would improve further, especially the bass.

Hi Mordy,
 
They are 6H30P-DRs, but yeah, may as well try some 6SN7 plus vector extender and adapter and sell these.
 
Quote:

   
Hi A11.
 
Glad you are giving the C3gSs a try...they keep improving up to 50 hrs or even more. And as mordy says, the 6SN7 as power will do them a good bit more justice. But the real leap then comes when partnered with the 6AS7G/6080. I truly hope you give this option a try at some stage...the mods are not too difficult

.
 
I am beginning to suspect that those C3g adapters may not be helping the tube to achieve its full potential...when they work at all, lol!! But I do hope you have no trouble with yours....

 
Hi Hypnos1,
 
They are coming along very well. Looking forward to see how they burn in the next 50 hours. Doubt, I can restrain myself for long from looking into alternative power tubes.  
 
Another upgrade I am seriously considering is: http://www.powerinspired.com/ag500-ac-regenerator-500w-p-1723.html I had the opportunity to use it for a few hours and the difference was quite impressive on my setup.

 

[bbmiller]

  Hi bbm.
 
I have been using the LD MKIII with 2.5A power tubes with an external power supply for many many hours, and IMHO these tubes are perfectly safe to use with the LD amp with the provision that the amp is also cooled by an external fan.
 
Previous posts show how to assemble an external power supply and how to arrange simple cooling with inexpensive computer fans.

Were you to use a massive amount of aluminum fin heatsinks with a good enough thermal paste and fasten these heatsinks on three sides to the rear transformer could that in your opinion be a good alternative to fan cooling that would be totally passive?

 

[Acapella11]

Hi Hypnos1 and Gibosi,
 
How great differences in SQ have you found between different C3GS tubes?

 

[i luvmusic 2]

 If you want to go that route why not replaced the whole chassis and install a cooling fan in the back of the chassis.It's not just the Transformer heating up some internal components  heating up too.
 
Sorry! for butting in.........

 

[MIKELAP]

Time to relax and enjoy a little tube glow.                                                                                                                                                                                                                                                                     

 

[gibosi]

 
How great differences in SQ have you found between different C3GS tubes?

 
To the best of my knowledge, all C3g tubes were manufactured by Siemens, so there is nothing to be gained by rolling through the different "brands".
 
Good news for your wallet!

 

[Rossliew]

  Time to relax and enjoy a little tube glow.                                                                                                                                                                                                                                                                     

 
You managed to get a WA6, Mike? 

 

[gibosi]

  Were you to use a massive amount of aluminum fin heatsinks with a good enough thermal paste and fasten these heatsinks on three sides to the rear transformer could that in your opinion be a good alternative to fan cooling that would be totally passive?

 
I suggest that you search out and read lemonjelly's recent posts on this subject. The most vulnerable components appear to be a few resisters. Heatsinks and so forth likely wouldn't help. But replacing these resisters with higher rated ones is highly recommended.

 

[TrollDragon]

  Time to relax and enjoy a little tube glow.                                                                                                                                                                                                                                                                     

Spoiler: Booh Yeah...

 

Would that be a Sophia Princess 274B Mesh Plate???
 
Very Nice!

 

[MIKELAP]

  Would that be a Sophia Princess 274B Mesh Plate???
 
Very Nice!

Oui mon ami !

 

[mordy]

Hi bbm,
 
My LD MKIII sits on three 1" aluminum cones stuck to the bottom of the amp with bluetack (generic). I use two discarded 12V computer fans, 3" and 4" . These fans can be bought new for $ 4-5.
 
The footers allow ample air circulation around the amp. The fans are mounted above the amp and are drawing air away from it.
 
I don't see any reason to use massive heat sinks when there are much simpler solutions.

 

[mordy]

Hi,
 
Here is a very informative link about the C3g tubes. It is interesting to note that these tubes when new sold for around $200 each. The very high specs were needed to lower noise and improve gain on telephone conversations over transatlantic cables.
 
http://www.jacmusic.com/techcorner/ARTICLES/English-neu/Portraits/C3g/C3g-C3m-info.html

 

[mordy]

Hi G,
 
According to the price list from JACMusic, there are C3g tubes with the names of Lorenz, Telefunken and Valvo as well, in addition to Siemens. Don't know if these were rebranded,
Look at items # 92-102 on the price list.
 
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CCAQFjAA&url=http%3A%2F%2Fwww.jacmusic.com%2Fhtml%2Forder%2Fjacmusic-pricelist.pdf&ei=qYBIVPjjCu_CsATz3oDQDw&usg=AFQjCNGPMXPhuUTZ5BtAwtX4T7A5I_DIAg&sig2=SXAYs79ijQNAlPBsbduVxA&bvm=bv.77880786,d.cWc
 
There is also another type not mentioned before, the C3o. This is a C3m (20V tube)  manufactured for 6.3V usage.
 
Here is a very informative page about the history and usage of the C3g tubes:
 
 
http://www.jacmusic.com/techcorner/ARTICLES/English-neu/Portraits/C3g/C3g-C3m-info.html