TW Express schematic question

[Phil_S]

I've build a few amps and am thinking about a TW Express. On the schematic, I see an unfamiliar symbol. Between the input jack and V1A, there is a circle around the grid input wire attached to a ground triangle. I hope this is clear. What is this thing?

If left to my own invention, I'd guess this is an indication to use shielded wire? I'd be grateful for a confirmation.

Thanks.

[mlp-mx6]

You are correct.

[Fischerman]

And you might consider using shielded wire from the Volume control back to V1. In general, the grid wires are the most sensitive to oscillation problems (at least IMLE).

[Phil_S]

Thanks. That was almost too quick. I was just returning to say, "oh, never mind, I looked at the pix of Francesca." AFA shielded and oscillation, I've built 7 amps in the last 4-5 years and am familiar with that problem. I appreciate that pointer on the volume pot. I'm a bit of a purist and tend to avoid shielded except as a last resort. I find chopsticks are very useful.

I gather this is a very challenging project (clone of an Express) to get right and there might actually be something unholy in trying it. I gather this amp is almost as much about what isn't there as it is about what's there. I've been wondering if I should attempt it or do something else. There is something drawing me to the project.

[bueller]

Do it! Chase the tone. It's an experience worth having.
I've made made (2) Expresses and (2) Derailments (SE-TW), didn't like any of them and tore them into something else (Marshall), and yet I learned tons of tweaking tricks along the way. I figure the more I try, the more I learn about the process, and what my ear wants to hear.

These amps are not polite, they are loud. Mine have all been very ear fatiguing to point where I can't listen to them. Odd harmonic at odds with each other, I guess. And yet I still try .......

It's really a simple build, no loops, reverbs, channel switching, etc. etc. and the absolute hardest to get right.

[drhulsey]

I've been wondering if I should attempt it or do something else.

My Express was my first build. You have plenty of experience, so have at it I recommend following the Francesca layout and lead dress VERY closely. It was a great deal of fun and not too stressful on a novice. It should be a breeze for you