NAD Apmeg V2 with issues

[jon]

I just scored a really nice Ampeg V2 for cheap ($200), but it has a few flaws.

Cabinet had a minor separation in one corner, that is now fixed. Hammer and wood glue. Thankfully the Tolex wasn't damaged, it's stretched a little.
The PI tube is wrong, a 12AX7 not the 12DW7 it should be. No big deal just a trip to the caddy. Here's the big one. The amp has three twist lock caps a 40-40-40 @ 500v which is fine, and two 40-100 @ 450v (shielded to be wired in series). One of the 40-100's is completely dead, one is open on the 100 uF side. Someone tried to recap the amp but did a really bad job and used the incorrect values. And wired it wrong. A total hack made Bruno look neat. Silicone and wire ties.

So do I buy the correct caps from fliptops.net or do I just buy generics and fit them wherever. The amp is really nice, and while I originally bought it to fix and flip I might hang on to it for a while.

Any thoughts

[Diablo1]

I rebuilt my V4 with the correct caps to fit back in the cardboard insulation tubes. Used a heat gun to soften the wax holding the old caps in the cardboard tubes. The twistlock caps are very expensive, but the amp looks and sounds like it did when it left the factory.

[IMG768]http://i268.photobucket.com/albums/jj29 ... 0395_2.jpg[/img]

[IMG768]http://i268.photobucket.com/albums/jj29 ... G_0393.jpg[/img]

[selloutrr]

All options work the caps were +\- 35%

Make sure the 12dw7 socket was not modified for the 12ax7 they are not a direct drop in swap.

[Milkmansound]

that was my first tube amp! Got one in high school and played through a Lee Jackson 4x12 cabinet. Loud! Great clean sounds out of that thing. Worth fixing up and hanging on to for a while - you can use that amp for anything!

[AL]

Make sure the 12dw7 socket was not modified for the 12ax7 they are not a direct drop in swap.

selloutrr - A 12ax7 will drop right in the dw7 socket. But they are different tubes. The dw7 is half 12au7 and half 12ax7. Did you mean someone may have modified the surrounding circuitry?

Drop in replacements are certainly easier but there is plenty of room inside a V series to add capacitors. I usually put in a few turret boards and just leave the old twist lock caps in place. It's cheaper to do this but takes more time obviously.

AL

[Luthierwnc]

I haven't worked on a V2 but have rehabbed a couple of V4/VT22s. You can now get the twistlock values at Antique Electronics. Diablo1 was fortunate to get the cardboard covers with wax. Both of the ones I had used mastic -- exactly like roofing cement. It is paint thinner soluble so they can be gotten off as long as you do it outside.

If you don't mind a little hack-butchery, there are a few more things you can do. One is to put in a bias adjustment. Have a look here for a thread I started a few years ago about a major tune-up on the amp:

http://www.ampegv4.com/forum/viewtopic.php?id=409

That is a really useful site, BTW.

The traces on these things are pretty delicate. Use solder wick. I actually flooded some of the points with fresh solder so it would come up easier than the crusty stuff. Another thing to consider is rewiring the line-out so it can drive an FX loop. If yours is the same as the 4-tube version it is basically a dual line-out. There were people who actually used them for slave amps in the day. IIRC, at least one of them is a shorting jack so it is just a matter of wiring one out and the other in.

I also put in 1k sandbox resistors to replace the 470R screens. The originals get so hot you can't even read the color codes anymore. Given the state of modern power tubes and the ungodly plate voltages those things produce, it is a good idea. Replace the power supply diodes with something heavy and modern.

Good luck, sh