[nephilim]

I know that the tubes might need some time but I felt that the current setup is a bit too bright and could benefit from a tad more "slam", so I removed the Tung-Sol 6SN7 and put in my Mullard ECC31 (fed from external power supply because of the higher heater current). Works flawlessly with tamed treble (welcome with my HD800) and a bit more emphasis on the low frequencies. Will try the 6BL7 and FDD20 next. Unfortunately my beloved C3gS did not work - probably due to the adapter I use. There is some music coming through but just very faint.

 

[kiertijai]

I know that the tubes might need some time but I felt that the current setup is a bit too bright and could benefit from a tad more "slam", so I removed the Tung-Sol 6SN7 and put in my Mullard ECC31 (fed from external power supply because of the higher heater current). Works flawlessly with tamed treble (welcome with my HD800) and a bit more emphasis on the low frequencies
 
  Can we use the Mullard ECC31 here?  I think it is different than the other 6SN7
or is it OK to use with external power supply such as mojo V?

 

[donlin]

  I know that the tubes might need some time but I felt that the current setup is a bit too bright and could benefit from a tad more "slam", so I removed the Tung-Sol 6SN7 and put in my Mullard ECC31 (fed from external power supply because of the higher heater current). Works flawlessly with tamed treble (welcome with my HD800) and a bit more emphasis on the low frequencies
 
  Can we use the Mullard ECC31 here?  I think it is different than the other 6SN7
or is it OK to use with external power supply such as mojo V?

Personally, I'd stick with the specified tubes.

 

[nephilim]

First you need ECC31 to 6SN7 adapters. The next issue is that the Mullards draw 0.9A each. The ZOTL's fuse blows at 2.5A. You have to add at least the 12AT7's current times 2. It might work if you replace the ZOTL's fuse but that would probably stretch the limits (and void the guarantee, I would assume). So I would strongly recommend an external supply.
 
The following octal socket savers have wires for the heater pins and work like a charm:
 
http://www.ebay.de/itm/191741357847
 
And here are the ECC31 > 6SN7 adapters:
 
http://www.ebay.de/itm/201134198992
 
These will also work for 6N7G tubes.
 
Here is a quick photo showing the ECC31 in action. The switching power supply on the left provides the heater current
 

 

[hrq12345]

Got a pair of these 12AT7 tubes. Just put them in and found some better bass impact immediately. More impressions to come.

 

[kiertijai]

First you need ECC31 to 6SN7 adapters. The next issue is that the Mullards draw 0.9A each. The ZOTL's fuse blows at 2.5A. You have to add at least the 12AT7's current times 2. It might work if you replace the ZOTL's fuse but that would probably stretch the limits (and void the guarantee, I would assume). So I would strongly recommend an external supply.
 Is it better that we use Mullard ECC32?

 

[nephilim]

   Is it better that we use Mullard ECC32?

 
If you can afford it. It is much more expensive so it must be better
 
Seriously, it all depends on personal preferences. In my previous amp I quickly realized that I was not too fond of the TungSol 6SN7 (albeit I guess I understand why manufactures prefer to use them as stock tubes) and tried various other tubes. With the ZOTL I am now very curious to see how these tubes will perform in the new amp. The ECC31 are a very promising start. But obviously I cannot say that a certain tube works better or worse for you.

 

[zachawry]

In my obsessive researching of tubes over the past week, before my MZOTL2 even arrives, it seems that there are a lot more options available for 12AT7 than 6SN7. 
 
Is this true? I guess given the fact that the 12AT7s are supposed to have a larger effect on the sound, this is OK, but it's still curious. 

 

[jamato8]

  In my obsessive researching of tubes over the past week, before my MZOTL2 even arrives, it seems that there are a lot more options available for 12AT7 than 6SN7. 
 
Is this true? I guess given the fact that the 12AT7s are supposed to have a larger effect on the sound, this is OK, but it's still curious. 

The 6SN7 was a tube that was used in many applications and in great numbers. There are a huge variety of 6SN7's available. There are also a number of 12AT7's but I would bet there were more 6SN7 types. I use the VT99 with an adapter that uses a grid cap. 

 

[willsw]

  In my obsessive researching of tubes over the past week, before my MZOTL2 even arrives, it seems that there are a lot more options available for 12AT7 than 6SN7. 
 
Is this true? I guess given the fact that the 12AT7s are supposed to have a larger effect on the sound, this is OK, but it's still curious. 

 
I've noticed this as well. Perhaps is just that the 6SN7 variants have significantly different names and are slightly different enough to require such tube-wizardry as displayed by nephilim. I have no idea, really. 
 
I will say that though I understand the urge to immediately switch tubes, one could imagine that we shipped the units with stock Sovteks, or any number of new stock tubes, and that you may eventually consider the new manufacture Tung-Sols as an option. We unfortunately don't have the facilities to ship each unit fully burned in (that is definitely a future goal), and many have been very happy with the stock amp, so I might suggest listening to the amp as the Tung-Sols burn in, think about which aspects of the sound you'd like to push, and then start rolling. This may be too logical and I may be revealing myself as obviously not a tube-roller. 

 

[zachawry]

   
I've noticed this as well. Perhaps is just that the 6SN7 variants have significantly different names and are slightly different enough to require such tube-wizardry as displayed by nephilim. I have no idea, really. 
 
I will say that though I understand the urge to immediately switch tubes, one could imagine that we shipped the units with stock Sovteks, or any number of new stock tubes, and that you may eventually consider the new manufacture Tung-Sols as an option. We unfortunately don't have the facilities to ship each unit fully burned in (that is definitely a future goal), and many have been very happy with the stock amp, so I might suggest listening to the amp as the Tung-Sols burn in, think about which aspects of the sound you'd like to push, and then start rolling. This may be too logical and I may be revealing myself as obviously not a tube-roller. 

 
Point taken. I will definitely let the amp burn in and keep the stock tubes for at least the first couple weeks, both to get used to the basic sound and to have a basis for comparison.
 
On the other hand, I'm incredibly tempted to go crazy buying glass. I will try to keep this impulse in check.
 
So far I've only purchased the Genalex Gold Lion 12AT7s, and some Tung Sol 6SN7GTBs. Those Tung Sols are different than stock, right? If they're the same, I'm gonna feel pretty stupid.

 

[donlin]

Point taken. I will definitely let the amp burn in and keep the stock tubes for at least the first couple weeks, both to get used to the basic sound and to have a basis for comparison.

On the other hand, I'm incredibly tempted to go crazy buying glass. I will try to keep this impulse in check.

So far I've only purchased the Genalex Gold Lion 12AT7s, and some Tung Sol 6SN7GTBs. Those Tung Sols are different than stock, right? If they're the same, I'm gonna feel pretty stupid.

The Tung Sols you bought are the stock tubes.

 

[willsw]

Maybe he bought this one: http://www.kcanostubes.com/content/nos-tung-sol-6sn7gtb
 
It is now out of stock. Could have been the last one.  

 

[jelt2359]

Ever since I purchased another Otl amp, I went down this path too. Got a Cbs Hytron brown base, Tung sol round plate, national union, RCA, sylvania black base, sylvania metal base.

They sound so different! Id say 10% at least. And frankly in this hobby, that amount of difference is basically amounting to an entirely new amp.

Ymmv of course- the Mzotl is not your father's Otl....

 

[zachawry]

  Maybe he bought this one: http://www.kcanostubes.com/content/nos-tung-sol-6sn7gtb
 
It is now out of stock. Could have been the last one.  

These are the ones I got:
http://www.amazon.co.jp/gp/product/B00PXYPKPI/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
 
 
If they are stock, hopefully I can still return them. Will still feel stupid, though.
 
EDIT: I'm willing to believe I'm more stupid than the average buyer, but maybe you should include the exact names of the stock tubes on the website to prevent this from happening.