6G3 schematic question

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xtian
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6G3 schematic question

Post by xtian »

I've sketched a basic first and second stages of the 6G3. What's the deal with the voltage divider on the plate of the second triode? My uneducated guess is that this would cut the volume (AC) way down. Am I wrong?

Trying to figure out if I should keep this arrangement, or take the signal straight from the plate at point B and delete the 15K resistor.
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martin manning
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Re: 6G3 schematic question

Post by martin manning »

Yea, split plate load. Keeps the PI from being over-driven.
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ChrisM
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Re: 6G3 schematic question

Post by ChrisM »

Search fast/gradual switch to see how this split load arrangement can be taken even further.
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rdjones
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Re: 6G3 schematic question

Post by rdjones »

xtian wrote:I've sketched a basic first and second stages of the 6G3. What's the deal with the voltage divider on the plate of the second triode? My uneducated guess is that this would cut the volume (AC) way down. Am I wrong?
Yes, the divider knocks the signal down by quite a bit, 13% of the full value. 15/(15+100)
Trying to figure out if I should keep this arrangement, or take the signal straight from the plate at point B and delete the 15K resistor.
If you want to recreate the original circuit, yes, the attenuation sets the correct gain staging.

The 6G3 should be viewed as the next evolution of the 5E3 which immediately preceded it.
The 12AY7 in the 5E3 was replaced with a 12AX7 (more gain).
The 5E3's cathodyne (no gain) was replaced with a LTP which adds some voltage gain.
When the absence of a full tone stack is taken into account both circuits have a decent amount of voltage gain through the preamps.
The attenuator compensates for the added gain in the first preamp and the PI.

rd
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xtian
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Re: 6G3 schematic question

Post by xtian »

Found a good thread, linked here for future ref:

https://tubeamparchive.com/viewtopic.php?t=1202
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