Tube score!

I picked up an old Roberts reel-to-reel tape recorder for free today. I grabbed it thinking it might have some tubes that I could use in my Fender Champ 600. Got it home, and opened it up, and it's got a pair of 12AT7's a pair of 6BM8's and a GCA4 rectifier. Score! I had been wanting to try a lower gain preamp tube in my Champ. I popped in the first 12AT7, and it sounded great. A little quieter, with much more headroom. The tone is also much clearer, with a less ice-picky top end. I tried the other 12AT7, but it sounded weaker and was crackly. So I guess it's no good. I did a quick Google search, and it looks like the 6BM8's aren't used in any amps, but the 6CA4 could be useful to someone.

6BM8's....Gibson Discoverer, one version. There may be others. The 6CA4 is a rectifier used in some Gibsons...

About what year did TVs stop using tubes?
Just in case I see one at a garage sale or something for cheap...
Thanks.

?????? early-mid-70's???? just a guess....

6BM8's....Gibson Discoverer, one version. There may be others.

my old '60 Epiphone Devon Tremolo uses a pair of them for preamp and power combined. not the easiest tubes to find these days!

About what year did TVs stop using tubes?
Just in case I see one at a garage sale or something for cheap...
Thanks.

I'd be cautious picking up old TVs for tubes without checking the contents -- the Heathkit TV my dad built in 1969 contains 20+ tubes, absolutely none of them useable in the "classic" guitar amps.

- Scott

I'm pretty sure that I used a 6CA4 as recto in my 18-watt "clone" build. It seems to be the de rigeur for those amps, though I'm no expert on what else that might mean.

TV tubes are often series-heater tubes, known in Yurrp as 'P'-tubes (PL84, PCC81, and so on). You could build a guitar amp with them (I've seen one commercial amp with P tubes in it) but the heater wiring is completely different

steven