Question about ASAT bass hum

[bassclef29]

A guy who's selling an ASAT bass stopped by my home on his way to work. I had never played an ASAT before.

I plugged the bass into a good practice amp and put it through its paces. On Series mode, very audible hum resulted. This was true regardless of whether the bass was active or passive. Besides the hum, Series setting worked as it's supposed to.

Everything else checked out fine, no unwanted sonic artifacts in any other mode. But the hum in Series was a deal killer. I had to pass on buying the bass.

As alleged, the ASAT was ergonomically a greater challenge than my SB-2 because of the lack of upper horn extension of the body. You have reach further for the first few positions, as Thunderbird players do.

But back to my question: is prominent hum in Series mode normal? Intuitively, it seems not, but I'd appreciate hearing from Talkbass G&Lers who'd care to share their experiences.

Thanks,
Joe in San Diego

[spideyjg]

Probably had the series caps in it. Take 'em out, hum is gone.

Ergonomics are what keep me from several basses. I adore the look of a Ric but absolutely cannot play one.

Jim

BTW Joe, Wanda and The Maidens will be at Canes tomorrow night. Check out an SB-2 from the audience perspective.

[FidgetStone]

My 2002 vintage ASAT does not hum like that.

Spidey, what are "series caps"? I am not familiar with that term.

Thanks . . .

[bassclef29]

Spideyjg and Fidgetstone,

Thanks for the replies. Spidey, I don't expect I'll make it to the IM show, but thanks for the invitation. Since you and I are both San Diegans, shoot me a PM if you feel like it -- we can get together to bassify.

I am not a tech. It makes little sense for me to buy a bass that has a problem like this, even if it's one that's (probably) easily fixed. Though it sounded terrific in all settings but one, I'm glad I passed.

This bass was cosmetically just about perfect, though the falling-apart case was worthless. Also, it was the heaviest 4-string bass I've ever put over my shoulder, so no regrets.

Now I've got a notion for an L-2000. Its body is pretty much the same shape as the JB-2, which I do like. If I can find an L-2000 with a #6 or #8 neck, I'll be sorely tempted.

Cheers,
Joe

[spideyjg]

Originally Posted by FidgetStone

My 2002 vintage ASAT does not hum like that.

Spidey, what are "series caps"? I am not familiar with that term.

Thanks . . .

The L-1000, and for a long time the L-2000 had some capacitors that in series that would give the "single coil w/ bass boost."

However they also could leave you with single coil hum in series.

Remove them and it is gone. See them on the schematic.....

If you have 2 green caps on the middle switch, they're the ones.

Jim