500 ohm grid stoppers for 6V6?

[Neal]

I've got a '67 Fender Deluxe Reverb on the bench for some minor maintenance issues. Somewhere along the line, someone put in 500 ohm grid stoppers between pins 1 and 5 on the 6V6's. What are the effects on tone and tube life compared to the standard 1500 ohm value?
My first inclination is to change them to 1500's, but the owner is happy with the tone.
Neal

[MWJB]

If the amp is stable and the customer likes the tone then there's not much point in changing them. Many early 60's Fenders never had them and worked fine. Before everybody starts ripping out their 1500 ohm grid stoppers I would state that I always fit them as a matter of course to new builds (easier to fit to the socket before wiring everything else up), it's just that some amps are happy without them.

Some people feel that the smallest value, that keeps the amp stable, is best tonewise.

There shouldn't be any difference in tube life.