"Crushed Glass" - Low voltage tube obsession gone too far?

Started by frequencycentral, September 20, 2008, 11:07:26 AM

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duck_arse

you're typing, I'm typing,  both the same thing, nearly.
don't make me draw another line.

flood

hah, yeah, our posts just crossed each other. i don't have a largish resistor handy, will pick them up from the office tomorrow to try out this new tweak.

the setup which seems to be working great for me at the moment:

a. increase the coupling cap from the first plate to the grid, i went up to 10uF. the effect doesn't strike you immediately, but i swear it sounded like there were tracked dual saw VCOs or something. hard to explain.

b. your suggestion - swap out pot with a fixed resistor for the "top" - I used a 1M linear pot though, with a pretty cool result - it seems to control timbre and makes some pitch changes too.

c. following from b. - use the LDR (in parallel with 1M - or higher value?) for the "wiper-to-ground" part of the pot. i get a massive frequency sweep here. it kind of dies out at the top end, but the low frequencies are pretty good.

i still have to try the LDR from the grid of the second triode, too exhausted right now and need to call it a night. i will get around to doing that though. alternatively, i'll try using a pot in that position as a variable resistor to see if i can use it as a pitch setting thingy. i'm quite sold on the above combination though and am going to start planning my enclosure around it. need to whip up a quick 555/4017 sequencer circuit now and see how that works...