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Philips 6SN7 GTA & GTB

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Hi

In the ocean of 6sn7 I've seen

Philips GTA : - a type with a chrome dome, black base
- Another type with brown base, grey plates (similar to russian 6H8C)

Philips GTB :- a type with side getter, grey plates
- Another type that I've, with black base identical to russian 6H8C
All with the typical yellow boxes Philips miniwatt

Philips produced 6sn7 GTA/GTB or rebranded different manufacters???
Or others rebranded the Philps manufacters ???

Anyway can you tell me the quality of these Philips 6sn7 GTA/GTB tubes for HIFI ???

Thanks in advance for helping a novice
 
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The 6SN7GTA/B is a "hardened" version developed for TV vertical deflection duty. The changes involve an increase in PD from 3.5W to 5W, the inclusion of control grid radiator wings for operation at Vgk > 0V.

The 'GTB version has a controlled heater characteristic for series string operation.

6SN7s work quite well for Hi-Fi, being a linear triode, and good, low distortion loadlines are easy to find. Some NOS types do, however, tend to be microphonic.
 
You are asking for the sonic differences of this Tubes, right?
If you have negative feedback you will have no sonic differences.
If you have no neg. FB you will have some small diff. between the diff. tubes.
What sounds better?
There are only two things that can tell you the truth:
your two ears!
Good luck
Hilmar
 
I don't have these tubes to try.
I asked for my knowledge and before to spend money...
I agree about the ears...... But forum is also a way to share opinions, experiences and to learn.
Before asking for I searched but no significant information was found.


Ciao
 
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Hi

In the ocean of 6sn7 I've seen

Philips GTA : - a type with a chrome dome, black base
- Another type with brown base, grey plates (similar to russian 6H8C)

Philips GTB :- a type with side getter, grey plates
- Another type that I've, with black base identical to russian 6H8C
All with the typical yellow boxes Philips miniwatt

Philips produced 6sn7 GTA/GTB or rebranded different manufacters???
Or others rebranded the Philps manufacters ???

Anyway can you tell me the quality of these Philips 6sn7 GTA/GTB tubes for HIFI ???

Thanks in advance for helping a novice

No, the run of the mill 6H8C sounds bad. The run of the mill variety is nothing more than a cheap $5 tube. Not worth the trouble.

I would paste some pictures if I knew how. Its been a long time since I have wandered in here and things have changed.

How do you tell someone how a tube sounds? You don't. People hear things differently thus the array of different capacitors and resistors not to mention the wonderful world of wire.

If my memory is correct the Philips 6SN7GTA is similar to the Sylvania 6SN7GTA Chrome dome. Nice sonics kind of heavy on the bass.
 
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Philips purchased Sylvania ECG from GTE in the very early 1980s - remember this well as I was working at GTE Laboratories at the time.

Philips changed nothing except the logo and color of the screen printing to blue, but the internals are the Sylvania design. This is quite a good tube, IMHO there is no difference at all sonically between the GTA/GTB and despite claims to the contrary I did not hear big differences with the Sylvania tubes over a production span of +25 yrs (made much longer than that, but the early ones are very expensive). I have a few GT, other than the fact that they quietly self destruct if over voltaged and are hideously expensive these days they do not sound particularly different than their descendants. The Sylvania is my favorite 6SN7, I do not have any of the ones made during the Philips era any longer and don't buy them - I'd rather have the older ones, and I like these better than RCA, GE, Raytheon or Tungsol..

Cannot talk to any other Philips branded 6SN7 other than the ECG part.

FWIW Brimar made a very good 6SN7, and the early RCA GT with smoky glass is very good too, but are now prohibitively expensive.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.