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krushd · October 29th, 2009, 09:52 PM

Hello, you guys seem very knowledgeable here so maybe you can help me out.

I just bought a Kustom 12A used for $40. I thought that was a decent price
and it sounded OK to me. I figured I would replace the stock tube with a new
tungsol 12ax7, I have read that doing so will improve the sound.

When I got it home, I unscrewed the back plate and discovered that no tube
was present in the socket. The amp still worked fine without it.

Can most amps bypass the preamp or is the Kustom tube in there just to call it
tube hybrid but doesn't really effect the sound?

Really confused now, thanks in advance for any help.

Keith

rangercaster · October 29th, 2009, 10:14 PM

that's strange ... did it sound better when you put a tube in it ???

krushd · October 29th, 2009, 10:19 PM

I haven't bought the tungsol yet. Will order it soon.

Singin' Dave · October 30th, 2009, 12:09 PM

That is a bit odd. Most hybrids send a gain stage through the one preamp tube no?

eugenedunn · October 30th, 2009, 12:13 PM

Maybe that tube is for the drive channel?

Hiker · November 1st, 2009, 02:44 AM

Ads state that the 12AX7 is for the preamp section. Yours has personality!

October 29th, 2009, 09:52 PM	#1 (permalink)
krushd NEW MEMBER! Join Date: Oct 2009 Location: Chicago Age: 32 Posts: 2	Missing Preamp Tube? Please Help! Hello, you guys seem very knowledgeable here so maybe you can help me out. I just bought a Kustom 12A used for $40. I thought that was a decent price and it sounded OK to me. I figured I would replace the stock tube with a new tungsol 12ax7, I have read that doing so will improve the sound. When I got it home, I unscrewed the back plate and discovered that no tube was present in the socket. The amp still worked fine without it. Can most amps bypass the preamp or is the Kustom tube in there just to call it tube hybrid but doesn't really effect the sound? Really confused now, thanks in advance for any help. Keith Last edited by krushd; October 29th, 2009 at 10:34 PM.

October 29th, 2009, 10:14 PM	#2 (permalink)
rangercaster Tele-Afflicted Join Date: May 2008 Location: portland, or Age: 52 Posts: 1,546	that's strange ... did it sound better when you put a tube in it ??? __________________ "Work is the curse of the drinking classes." Oscar Wilde

November 1st, 2009, 02:44 AM	#6 (permalink)
Hiker Tele-Holic Join Date: Jul 2008 Location: Indiana Posts: 775 4 Photos	Ads state that the 12AX7 is for the preamp section. Yours has personality! __________________ Hammer On!

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October 29th, 2009, 10:19 PM	#3 (permalink)
krushd NEW MEMBER! Join Date: Oct 2009 Location: Chicago Age: 32 Posts: 2	I haven't bought the tungsol yet. Will order it soon.

October 30th, 2009, 12:09 PM	#4 (permalink)
Singin' Dave Tele-Afflicted Join Date: May 2008 Location: Chicago Age: 41 Posts: 1,052	That is a bit odd. Most hybrids send a gain stage through the one preamp tube no?

October 30th, 2009, 12:13 PM	#5 (permalink)
eugenedunn Tele-Afflicted Join Date: Dec 2006 Location: Sacramento, CA Age: 56 Posts: 1,124 41 Photos	Maybe that tube is for the drive channel?

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