The Reference 6SN7 Thread

[FLTWS]

I have worked with quarter sawn oak, I have also heard it called tiger oak.

Tiger oak is lumber produced by a particular milling process called quarter sawing. The process results in lumber with a distinctive grain that is often used in high-end applications in which the appearance of the wood is an important consideration.

Works nice with the patina copper.

 

[Paladin79]

Works nice with the patina copper.

Yeah that was during my steampunk era. If I get good at dovetails, I want to use black walnut and white walnut for similar grain but a great color contrast. I do have copper I can use, maybe just one more steampunk amp.

 

[bcowen]

The desk is not maple so it probably sounds awful . BTW, for $12/pair, you are not buying the Fotons, you are relieving the seller of the storage burden.

Yeah, that's it! I'm just being helpful (as usual). I will proceed to pat myself on the back.

 

[LoryWiv]

came across the following as well
" everyone recommend the Tung Sol 5998 power tube as an upgrade, but looking on eBay there's a 5998 made by General Electric at half the price."
"5998A and 5998 are two different tubes. The 5998 is the one with the low output impedance, it sounds phenomenal on the Crack and opens up a lot of details. The 5998A is a good tube, I have an equivalent, but it's no 5998."
"I would stick with the 6080."
https://www.reddit.com/r/headphones/comments/7oomma/ge_5998a_vs_tung_sol_5998/

@HTSkywalker per spec. sheets the 5998A has higher transconductance (less plate resistance) then 5998. Clearly my understanding of these specs. is wrong or at least incomplete as I thought that would lead to lower output impedance for the 5998A. What am I missing in understanding the spec. data.?

 

[Marutks]

I have only perforated anode melz tube. Is solid anode version better?

 

[FLTWS]

With regards to 6080's and other equivalent power tubes, I found this in my Tube Related Info folder, comes from a post somewhere here at Head-Fi.

 

[donato]

I joined the Melz club recently too based on all of the chatter here and on other sites. I'm currently running a single 1980 Melz in my Viva Egoista 845 (below) and pair of 1979 Melz in my Cayin HA-300. I have a bunch of other 6sn7/VT-231/5692/CV1988/VT-99/6f8g, but since I put the Melz in, I haven't been much motivated to swap them out. I still have some other Melz (some perf some solid) on the way that seem to be taking forever and then just ordered some Fotons for the heck of it.

 

[Paladin79]

I have only perforated anode melz tube. Is solid anode version better?

To me and most everyone I had try it out lol. They are rare, but I love the sound. Please remember these have all other traits of what is called the 1578.

 

[bcowen]

I joined the Melz club recently too based on all of the chatter here and on other sites. I'm currently running a single 1980 Melz in my Viva Egoista 845 (below) and pair of 1979 Melz in my Cayin HA-300. I have a bunch of other 6sn7/VT-231/5692/CV1988/VT-99/6f8g, but since I put the Melz in, I haven't been much motivated to swap them out. I still have some other Melz (some perf some solid) on the way that seem to be taking forever and then just ordered some Fotons for the heck of it.

Those are some pretty 845's! Haven't ever heard the PSVanes....

 

[donato]

Those are some pretty 845's! Haven't ever heard the PSVanes....

Yes, those are the PSVane ACMEs. I've been very happy with them although the only other 845s I have tried are the stock Shuguang and PSVane Treasure Mk II.

 

[jonathan c]

Yeah, that's it! I'm just being helpful (as usual). I will proceed continue to pat myself on the back.

 

[HTSkywalker]

@HTSkywalker per spec. sheets the 5998A has higher transconductance (less plate resistance) then 5998. Clearly my understanding of these specs. is wrong or at least incomplete as I thought that would lead to lower output impedance for the 5998A. What am I missing in understanding the spec. data.?

@Paladin79 is the expert on this

 

[Paladin79]

@Paladin79 is the expert on this

I will look at the spec sheets as time allows, here are a couple basics.

u = Gm rP

rp = u / gM

 

[sam6550a]

I will look at the spec sheets as time allows, here are a couple basics.

u = Gm rP

rp = u / gM

The 5998A is higher gain [5.4], higher transconductance [15,500 umho], and higher plate resistance [350 ohms], than the 6AS7G. Ref Average characteristics, tube data sheet. Deviations will occur dependent upon the operating point of the tube.

 

[Paladin79]

The 5998A is higher gain [5.4], higher transconductance [15,500 umho], and higher plate resistance [350 ohms], than the 6AS7G. Ref Average characteristics, tube data sheet. Deviations will occur dependent upon the operating point of the tube.

Now I may have to check out the military version since it is marked 6as7g 5998, I really think the "A" version is medium gain vs low gain of the 6as7G. Those who have plugged in power tubes know there can be a substantial difference, the human ear can hear a one db change and there is certainly a change between low and medium gain tubes.

I am having trouble finding the GE 5998 but I did find the Tung Sol version, 5998 gain is 4.8-6.2, 5998A is 5.4.

6AS7G has an amplification factor of 2.

Here is someone calling a GE 5998A low mu.

https://www.ebay.com/itm/5998A-Dual...619378?hash=item1c4f2093f2:g:1moAAOSweW5U9snR

GE's spec sheet calls it low mu yet it has the same amplification factor of a Tung Sol, 5.4.

https://www.relltubes.com/filebase/en/src/Datasheets/5998A000.pdf