David Allen Bassman Head

[jbylake]

Hi. I've got a Bassman Head that has been totally rebuilt by David Allen of Allen Amplification. The first channel is unreal, sounds a little like a Marshall, and the second channel is pure ROUND fender bassman. The pick dynamics are incredible...but...
When the amp is idle, you can hear a faint ticking or clicking, not sure how to define it, sound. It doesn't interfere with the operation of sound of the amplifier, but I'm a little worried that something is about to go wrong. Does anyone know what this might be? Is it a bad thing..is it about to blow:worried Thanks ahead for your help, as I am pretty much ignorant on the internal workings of an amplifier.

Thanks,
j.

[Blue Strat]

See if either volume control affects the level of the noise and report back.

[Blue Strat]

Most likely culprit (and the only thing you can do anything about yourself) is tubes. Remove V4, the small tube closest to the power tubes. Try the amp again. If the noise is gone, the problem is one of the preamp (small) tubes or a component in the preamp. You can either substitute some known good preamp tubes or take it to a tech.

[jbylake]

Most likely culprit (and the only thing you can do anything about yourself) is tubes. Remove V4, the small tube closest to the power tubes. Try the amp again. If the noise is gone, the problem is one of the preamp (small) tubes or a component in the preamp. You can either substitute some known good preamp tubes or take it to a tech.

Thanks, I live just a few miles from David Allen, I think I'll take it to him. The only reason I haven't done so is that he is very hard to get ahold of, and I get the feeling he'd rather not have people come directly to his shop (although he is a very nice person and easy to deal with).

[Blue Strat]

Yep, he's a great guy. I know he's pretty busy with his production line of amps and may not be doing many repairs/mods at this time. Ask though.

Walk in business is VERY time consuming when there's no "gate keeper" to mitigate the time suckage:)

[TheAmpNerd]

Walk in business is VERY time consuming when there's no "gate keeper" to mitigate the time suckage:)

There is nothing quite like the customer who can't make up his mind
for whom you are customizing an amp...hand holding and helping
the special needs musician make a decision for 30 plus hours....

And people wonder why some of the custom work gets expensive!

[jbylake]

There is nothing quite like the customer who can't make up his mind
for whom you are customizing an amp...hand holding and helping
the special needs musician make a decision for 30 plus hours....

And people wonder why some of the custom work gets expensive!

Actually, it took me about 20 minutes of discussion with Mr. Allen to explain what I wanted, and if it was possible. How much longer would it have taken over the telephone? And I got what I wanted and more. And yes the price was appropriate, including "personal" conversations.

:Spank
j.

[tlpruitt]

Do you wear a wristwatch? If so, try taking it off and putting it far away from the guitar and amp and see if the sound goes away.

Also, +1 on the preamp tube being the possible culprit. Sometimes you can see a small flash in a tube when it ticks. Make sure you turn the amp off when you remove each preamp tube during the process of elimination.

-Tim

[Gary Brennan]

. Make sure you turn the amp off when you remove each preamp tube during the process of elimination.

-Tim

I would like to know if this really necessary for preamp tube only swaps vs. just using the standby switch? Opinions?

gb

[Blue Strat]

Standby switch is ok, but there's still some minimal risk that doesn't exist with full power off.

[ChickenLover]

My rebuilt BF Bassman was doing something very similar if not the same. I had replaced just about every resistor/cap in the amp during the rebuild/mod. The only thing I hadn't replaced were the 1M and 68k resistors on the input jacks...I replaced all of those with new and the problem went away. It could also be an old carbon comp plate resistor.

But I'm sure DA will find it/fix it.