[jonathan c]

Awesome! If that means as much money as I think it does, I'm flying you all out to christen the swimming pool I'm gonna get.

Edit: except @jonathan c ***

*** boo hoo!! I was just getting ready!!

 

[BrainSalat]

Have you tried reflowing or replacing the solder in the pins? They're notorious for needing that done. Once done, they are dead quiet in most cases.

Yes, I did it twice, with the previous ones and the hum didn't move a single humicimeter . I have re-soldered the pins of previous noisy tubes like Melz 6sn8 and it always worked, but not with these ones . Anyway, is not a problem anymore since I sold the Euforia and on the Envy the hum is nearly inaudible on low gain with the new Melz from 1955 (a bit more on mid, high gain) and nearly inaudible with the previous ones from 1963 (at any gain). One more reason to love the Envy.

 

[incredulousity]

Yes, I did it twice, with the previous ones and the hum didn't move a single humicimeter . I have re-soldered the pins of previous noisy tubes like Melz 6sn8 and it always worked, but not with these ones . Anyway, is not a problem anymore since I sold the Euforia and on the Envy the hum is nearly inaudible on low gain with the new Melz from 1955 (a bit more on mid, high gain) and nearly inaudible with the previous ones from 1963 (at any gain). One more reason to love the Envy.

What are you doing for power conditioning?

 

[BrainSalat]

I have a Dynavox X4100B. Do you think this could be the problem?.
But these are the only tubes which have this issue. I even have other Melz's that work completely silent.

 

[ostewart]

SYL 6SN7GTB
- low base
- angled T-plate
- top getter

Well I'm not happy

One is legit and a genuine Sylvania, the black plates are slightly matte finish.

The other has shinier black plates, a brand new base has been fitted and printed with Sylvania (massive gap between the tube and the base) and has flaking getter flash.

Internally aside from the plates they're similar but not the same, so it does make me wonder if they're from different production runs and just labelled to look similar.

Already messaged the seller as they're not a matched pair IMO

Legitimate looking one

Dodgy looking one:

 

[Isaacc7]

Well I'm not happy

One is legit and a genuine Sylvania, the black plates are slightly matte finish.

The other has shinier black plates, a brand new base has been fitted and printed with Sylvania (massive gap between the tube and the base) and has flaking getter flash.

Internally aside from the plates they're similar but not the same, so it does make me wonder if they're from different production runs and just labelled to look similar.

Already messaged the seller as they're not a matched pair IMO

Legitimate looking one




Dodgy looking one:

It’s hard to tell from the pictures what seems dodgy? There were different versions of the tube made over the years.

 

[ostewart]

It's just the fact one wasn't listed as having a brand new base, meaning is impossible to tell what the original label colour was. And that one is the one with chunks of better flash missing.

 

[adamaley]

In general, they are for adapting single triode tubes into a socket originally wired for a dual triode. Many different varieties, the one below is a homebrew for a pair of single triode 6J5's to plug into a (single) socket for a dual triode 6SN7. The ones @TLO is showing are for single triodes that also have external plate and/or grid connections, thus the additional external wires.

Do the two tubes need to be preferably matched? Can they also be different versions of the same tube type?

 

[Isaacc7]

It's just the fact one wasn't listed as having a brand new base, meaning is impossible to tell what the original label colour was. And that one is the one with chunks of better flash missing.

I see what you mean about the base now, that is weird. I’m not sure if bits of the getter flash missing is a big deal. I’m one of the audiophile heretics that thinks that tubes only need to be pretty close to each other in order to blend in well. I’d try them put and see if you can hear any problems.

 

[TLO]

Do the two tubes need to be preferably matched? Can they also be different versions of the same tube type?

Preferably, yes. Necessary, no.
IMO, if the 6SN7 socket is wired in parallel between 2 triode sections (amp sees it as a big single triode), it is advisable to have a matched pair but if the socket is series connected (two individual triodes), I dont think the amp will care.

 

[guzkiy]

hello all,
I would really appreciate some help identifying those tubes, sold as MELTZ 6SN7 but I am not sure
Please see the photos attached
Thank you!

 

[VanHai]

hello all,
I would really appreciate some help identifying those tubes, sold as MELTZ 6SN7 but I am not sure
Please see the photos attached
Thank you!

It looks legit, Meltz 1578.

 

[denniswaugh]

There are legit. manufacturing date 1982.

 

[Novik tube]

hello all,
I would really appreciate some help identifying those tubes, sold as MELTZ 6SN7 but I am not sure
Please see the photos attached
Thank you!

You can clearly see in the photo that this is 6H8C with a perforated anode, manufactured in 1982
1578 is very similar, but it is still a different tube, although made at the same MELZ factory
This is the standard version and it would be nice to have test results, since there were significantly more defective 6Н8С than 1578

 

[guzkiy]

You can clearly see in the photo that this is 6H8C with a perforated anode, manufactured in 1982
1578 is very similar, but it is still a different tube, although made at the same MELZ factory
This is the standard version and it would be nice to have test results, since there were significantly more defective 6Н8С than 1578

Thank you all for confirming, i can slip well now
@Novik tube : what do you mean by "significantly more defective 6Н8С than 1578"?