Here's my only tube amp. For being so small it has great almost-clean sound for my Strat!

Problem is...... I know nothing about tubes. Where are they on this board? Is that them in the lower part of the board? Can I learn to change them? The manual says only an authorized service person should do tube changes!?!?!? But it looks less scary than pokin' around in my LGW!!! If I could only find where they are! I wont mess around without some good advice first!


Any help or advice will be greatly appreciated.
Thanks much, Tommy

They should be behind the chasis pan hanging horizontally, pointing towards the front of the amp. A total pain to get to as you'll probably have to take the chasis out.

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Originally posted by TastyRiffs101:
Here's my only tube amp. For being so small it has great almost-clean sound for my Strat!

Problem is...... I know nothing about tubes. Where are they on this board? Is that them in the lower part of the board? Can I learn to change them? The manual says only an authorized service person should do tube changes!?!?!? But it looks less scary than pokin' around in my LGW!!! If I could only find where they are! I wont mess around without some good advice first!


Any help or advice will be greatly appreciated.
Thanks much, Tommy

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oh damn! Thanks! That makes it a bit tougher to do myself! But still not too crazy. How do they pop in .......do they screw in like a light bulb?

It looks as though there are a couple of screws on both sides of the amp that hold the chasis in. If you set the amp face down and remove those it will be MUCH easier to remove the chasis and in turn locate the tubes for removal as well as align the replacements. You may have to disconnect the speaker too. Good Luck!

quote:

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Originally posted by TastyRiffs101:
Here's my only tube amp. For being so small it has great almost-clean sound for my Strat!

Problem is...... I know nothing about tubes. Where are they on this board? Is that them in the lower part of the board? Can I learn to change them? The manual says only an authorized service person should do tube changes!?!?!? But it looks less scary than pokin' around in my LGW!!! If I could only find where they are! I wont mess around without some good advice first!


Any help or advice will be greatly appreciated.
Thanks much, Tommy

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Thank you so much!!

On the VC-508 the power tube is a EL84, and the preamp is a 12AX7 (both stock tubes are Groove Tubes) and the rectifier is solid state. The tubes on this amp are mounted directly on the underside of the PC board, hidden behind the chassis and the speaker baffle. You have to remove the chassis from the cab to change a tube. One thing that will improve the tone of this amp is to replace the 12AX7 with a 12AT7. Be extremely careful if you change the tubes yourself. The capacitors retain high DC voltages of around 400 volts even when the amp is not on, and touching the wrong thing can be lethal. I would recommend taking the amp to a qualified tech who can show you the proper way to discharge the capicitors and change the tubes.

The tubes fit into sockets. You gently pull them out and then push in the new replacements. Be careful not to bend or break one of the pins that fit into the sockets. If you look at the 1st picture you posted you can see the bottom side of the 2 sockets on the PC board -- they are the 2 brown disk-shaped objects at the bottom of the picture with a character that looks like a "7" on tab at 12 o'clock.

FVB