V4 PCB component repair/updating

[Hangman]

no doubt, I wish I had invested in a number of quads of 7027s about 5 years ago. the prices are so high now.

I worry about the state of tubes in 10 years. With the Winged C factory shutting down there is really just the new sensor factory in russia, the JJ factory in slovakia, and then a number of chinese factories in china.

the new sensor stuff is getting better, but its still nowhere near the quality of the winged C or NOS tubes. and with the current political situation in russia, the future is uncertain.

JJ is fine... they're not as good as winged Cs were but they are at least more reliable than most offerings from new sensor. However, they certainly do not seem eager to develop newer tubes, or improved versions of their current line
I give them credit for making the only acceptable 7591 right now, but Id love to see a 7199 from them.

It's scary how the sock of NOS is running low. Tubes that used to be readily available just a few yours ago seem to be running low. Take the 6K11 for example, not too long ago it was around $8, the price has crept up to $30-$35. Lower prices can be found but the trend is less stock available and the prices higher. Substitutes are available that are more affordable.

I was recently looking for a tightly matched quad of NOS 7027A's. Pairs are a lot easier to source these days. I might need to modify my V4B bias circuit so that I can bias each pair separately. Fortunately the JJ's are available for those that want new production.

It makes you wonder where things will be in ten years.

The 7199 is such a great tube though, its a shame that nobody makes it. they were used all over in hi-fi amps, and ampeg used them in a lot of amps