[simmconn]

Does anyone know if it's possible to make the 339i work with 6sn7 tubes?

So you are not happy with my answer?

 

[Pansbjorne]

So you are not happy with my answer?

Ngl I forgot lol. But I guess I'm looking for a way to get around the heater issue.

 

[simmconn]

I'd just go for it. The added heater current is 0.3A, which is only about 10% of the nominal for a 6080 plus a 6SJ7. It's not going to set your amp in fire. Besides, the heater voltage from the trans is too high to begin with. Adding a bit more load helps taming it down a little bit.

 

[Pansbjorne]

I'd just go for it. The added heater current is 0.3A, which is only about 10% of the nominal for a 6080 plus a 6SJ7. It's not going to set your amp in fire. Besides, the heater voltage from the trans is too high to begin with. Adding a bit more load helps taming it down a little bit.

I'll give it a try. Sounds like if somethings goin bad it shouldn't be too hard to notice?

 

[simmconn]

You can monitor the temperature of the trans at the same spot before and after the added heater loading (i.e. with 6SJ7 vs with 6SN7+adapter) to see any difference.

 

[beeexman]

I am using Philips (Mullard) 6080 tubes now. What is the difference between the 6080 and 7623 tubes? They look very similar

 

[hp4fun]

Fun never ends! I painted the tube shield in black but I was dismayed by my crafting in general, so one day when I was buying stationary in Target and found this pencil box. Works perfectly!

 

[bpiotrow13]

Fun never ends! I painted the tube shield in black but I was dismayed by my crafting in general, so one day when I was buying stationary in Target and found this pencil box. Works perfectly!

Looks nice! From whom You need to protect the tubes?

 

[bpiotrow13]

I am using Philips (Mullard) 6080 tubes now. What is the difference between the 6080 and 7623 tubes? They look very similar

Good question, i have had no idea there are 7623)

 

[hp4fun]

Looks nice! From whom You need to protect the tubes?

Oh, for lowering the noise due to the electronic field created by the cables below the tubes (339i does not have a proper shield)

 

[hp4fun]

I am using Philips (Mullard) 6080 tubes now. What is the difference between the 6080 and 7623 tubes? They look very similar

7236 (and not 7623 ) is a medium gain tube and 6080 is a low gain. There are a few discussions in https://www.head-fi.org/threads/for-6as7g-tube-rollers-here.410326/

 

[Pansbjorne]

Does any metal work?

Fun never ends! I painted the tube shield in black but I was dismayed by my crafting in general, so one day when I was buying stationary in Target and found this pencil box. Works perfectly!

 

[hp4fun]

Does any metal work?

Any. I tried copper and steel, and wanted mesh because of the heat.

 

[mordy]

Does any metal work?

It is called a Faraday cage and anything metal will do. (Obviously audiophile grade gold plated unobtanium will work the best - This is a joke)).
As far as I know a top cover is not needed but based on my expirements the results are better if you ground the enclosure to an exposed metal point on the chassis of the amp.
Being frugal I found a no cost solution - took an old window metal mesh screen and cut out a piece and folded it into a rectangle. Used two binder clips to keep it together and an alligator clip lead for ground.
It did help for hum from the tubes but with certain tubes I could not eliminate it completely. Still, using the cage, the hum was lowered and playing music mostly masked the hum. YMMV

You can cut the mesh to size for your amp and I am sure that there are more elegant methods to keep it together etc, but this is just to show the concept.
Have fun!

 

[Pansbjorne]

It is called a Faraday cage and anything metal will do. (Obviously audiophile grade gold plated unobtanium will work the best - This is a joke)).
As far as I know a top cover is not needed but based on my expirements the results are better if you ground the enclosure to an exposed metal point on the chassis of the amp.
Being frugal I found a no cost solution - took an old window metal mesh screen and cut out a piece and folded it into a rectangle. Used two binder clips to keep it together and an alligator clip lead for ground.
It did help for hum from the tubes but with certain tubes I could not eliminate it completely. Still, using the cage, the hum was lowered and playing music mostly masked the hum. YMMV



You can cut the mesh to size for your amp and I am sure that there are more elegant methods to keep it together etc, but this is just to show the concept.
Have fun!

I was just gonna use some like , copper mesh like you use for rats lol