Sylvania Chrome top 6SN7 tube

[labjr]

I have some Philips ECG JAN 6188 tubes which I think is a 6SL7 and 5691 JAN tubes which have green writing on the base.

Both made in the 80's. The date code seems to be to the right of the logo. One says "8626" underneath it says "ABA" .

Says "4/86" on the box.

The other says "8539" the box says "9/85"

I would assume this is the date code, and that they all use a similar coding system.

By the way, the Philips JAN 6188 is one of the fastest sounding octal base 6SL7 types I've ever used in my amps.

[fdegrove]

Hi,

I have some Philips ECG JAN 6188 tubes which I think is a 6SL7

The 6188 is the industrial version of the 6SU7WGT.

Cheers,

[Original Burnedfingers]

I have managed to find this

6SN7GT, 6SN7WGT, 6SN7GTA, 6SN7WGTA 6SN7GTB 1950s Sylvania Commercial and Military Green Label “Chrome Dome” or “Silver Top”, first top getter on the list, non-fatiguing, smooth, with good detail resolution, bandwidth and speed. Bass can be a bit warm and exaggerated, a good think if your speakers are bass shy. Does not have the midrange ambience and resolution of the VT-231 types. But very good overall.

I managed to find an old Sylvania Red Label that I can remember as being retired from an old "Bendix TV" we had when I was young. Dad always changed tubes usually when they didn't need it. It was replaced in 1959.


J

[fdegrove]

Hi,

Does not have the midrange ambience and resolution of the VT-231 types.

The VT range is in no way different from their domestic equivalent; the 6SN7GT, it's just a number used by the military.

VT231

Cheers,

[Original Burnedfingers]

You have got to love the beauty of these tubes. Whoops! Sorry Frank. You have got to love ALL TUBES!

The Red Label on the left is from the 1953-1959 era as it was pulled from the first TV I grew up with. The Green label on the right(not JAN) is most probably a commercial model.


Quote
The VT range is in no way different from their domestic equivalent; the 6SN7GT, it's just a number used by the military. May I assume sonically there is little difference?


J

[fdegrove]

Hi,

May I assume sonically there is little difference?

If you can find a VT-231 from say, Tung-Sol, and a 6SN7GT with the same date code then there shouldn't be any difference sonically.

Some vendors will try to push the VT-231s as there are still so much more around that had been sitting idle for decades on the military stock shelves.

Cheers,