Tube score!

cotecj · June 28th, 2008, 11:49 AM

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.

Wally · June 28th, 2008, 03:35 PM

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

Little Ricky · June 28th, 2008, 03:58 PM

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

Wally · June 28th, 2008, 04:30 PM

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

woodman · June 28th, 2008, 06:28 PM

Quote:

Originally Posted by Wally

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!

Scott S · June 29th, 2008, 12:24 AM

Quote:

Originally Posted by Little Ricky

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

marshman · June 29th, 2008, 06:53 AM

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.

sjhusting · June 30th, 2008, 03:55 AM

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

June 28th, 2008, 11:49 AM	#1 (permalink)
cotecj Tele-Meister Join Date: Feb 2008 Location: Maine Age: 31 Posts: 218	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.

June 28th, 2008, 03:58 PM	#3 (permalink)
Little Ricky TDPRI Member Join Date: May 2008 Location: Mid-Atlantic Posts: 93	TV TUbes About what year did TVs stop using tubes? Just in case I see one at a garage sale or something for cheap... Thanks.

June 29th, 2008, 06:53 AM	#7 (permalink)
marshman Tele-Holic Join Date: Feb 2007 Location: SE PA Posts: 717	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. __________________ 42

June 30th, 2008, 03:55 AM	#8 (permalink)
sjhusting Tele-Holic Join Date: Jul 2003 Location: Germany Posts: 621 14 Photos	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 __________________ Go octal

June 28th, 2008, 03:35 PM	#2 (permalink)
Wally Friend of Leo's Join Date: Mar 2003 Location: Lubbock, TX Posts: 3,769	6BM8's....Gibson Discoverer, one version. There may be others. The 6CA4 is a rectifier used in some Gibsons...

June 28th, 2008, 04:30 PM	#4 (permalink)
Wally Friend of Leo's Join Date: Mar 2003 Location: Lubbock, TX Posts: 3,769	?????? early-mid-70's???? just a guess....