Clean power supply?

[K-MAN]

I've noticed the voltage on allot of home outlets tends to fluctuate allot and have allot of rf noise coming through. I was wondering what people here use as far as power bars with built in surge protection and line conditioning? I have a hard time deciding what to use since they range from $10 to over a $100. I'm not sure how much these would help the audio but I'm sure that it's good to have the added protection for our vintage amps.

[TomMcNally]

My feeling is that a tube amp with a power transformer
is the last thing that needs any kind of line conditioner.
Tubes by nature can take a wide tolerance in voltages,
and they aren't really affected by a little swing.
Tube equipment can take a blast from lightning and
still work, while the solid state equipment blows to
bits.
What kind of "RF Noise" do you have ? Is there a big
50,000 watt AM radio station nearby ?

[K-MAN]

There's some high power lines that run by my place which create allot of noise.

[TomMcNally]

It would be interesting to put shorted RCA plugs into your
tube amp - and listen to see what kind of noises you hear.
Hum ? Pops and clicks ? I would think any power line
noise would be induced into the interconnect cables and
source devices, and probably not the amp itself.

Check it out sometime when you have a chance and
let us know.

[erichayes]

Hi K,

A lot--two words. Sorry for being picky.

In general, I agree with Tom. The main exception for me is with my smaller amps that don't use delayed or manual B+ activation and do have inrush limiters. If I lose power long enough for the 200+ µF capacitors to discharge, but not long enough for the IRCL to cool off sufficiently--usually around 4 or 5 seconds--I'll pop the line fuse every time. That's the only reason I have the one I use for the telly on a UPS. Otherwise, what Tom says.

As far as radiated interference from high tension power lines is concerned, that usually enters the system upstream of the power amp. You can verify this by disconnecting the inputs from the power amp and inserting shorting plugs in their place. If you are still experiencing hum/noise problems, you need to go through the amp and reexamine your grounding and lead dress. If all's well with the amp, then the obvious next step is to check the viability of the interconnects and whatever component(s) in front of the amp inputs.

Keep us all informed of your results, and good luck.

[erichayes]

Geez, Tom . . . are we the Tweedle twins? Did Min get hold of you?

[SDS-PAGE]

I did get hold of Tom. He was cool with 1kV+. Too bad that guy flaked though. Hope your eye surgery went well, Eric. -Min

[erichayes]

For the record, Min, I'm now able to read both the analog and digital clocks on the mantel across the room with my left eye. The thing that's pissing me off is that as my left eye improves, I'm discovering how much the right cataract is goofing up my vision. The price you pay for getting older . . .

I'm thinking that it might be a good idea if the Bay Area Boyz (you know who you are) and I converge on your campus to piillage and plunder your labs that are undergoing metamorphoses, equipment-wise. I'm an ex UC employee, and my dad was a perfessor of public health at UCB 'way back when, so I know the drill about acquisition and disposal.

Could be a fun picnic.

[TomMcNally]

Hi Eric -

Glad to hear things went well.

I noticed that you and I think alike on a few things.
Parallel thoughts too !

I took a look at the 845 schematics, I think it may be
a lot of work and expense, but it's possible.

... tom

[SDS-PAGE]

I'm thinking that it might be a good idea if the Bay Area Boyz (you know who you are) and I converge on your campus to piillage and plunder your labs that are undergoing metamorphoses, equipment-wise.

Yeah, that ought to be fun. Will keep y'all posted. Meanwhile I have contacted someone at electrical engineering dept. (our academic adviser used to work there) about scopes that they might throw away. They will probably have a couple available for me in a few weeks. They upgrade all the time, so those scopes probably are in good shape. Might give away extra one here at the forum. -Min