50 Hz Hum Driving Me Insane!!!

[Brian Huether]

I have this tube amp head, and when I power it on, I hear a fairly loud 50
Hz hum (I am in Germany). This happens even if it is the only thing powered
on and plugged in. My understanding of ground loops is that they involve
multiple devices. Does anyone have an idea why I inevitably hear 50 Hz hums
in my apartment? I hear it also if I turn on my monitor speakers and nothing
else is connected.

thanks,

brian

[Scott Dorsey]

Brian Huether > wrote:
>I have this tube amp head, and when I power it on, I hear a fairly loud 50
>Hz hum (I am in Germany). This happens even if it is the only thing powered
>on and plugged in. My understanding of ground loops is that they involve
>multiple devices. Does anyone have an idea why I inevitably hear 50 Hz hums
>in my apartment? I hear it also if I turn on my monitor speakers and nothing
>else is connected.

Is it a hum or a buzz?

Do you hear it on an AM radio?
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Artie Turner]

Brian Huether wrote:
> I have this tube amp head, and when I power it on, I hear a fairly loud 50
> Hz hum (I am in Germany). This happens even if it is the only thing powered
> on and plugged in. My understanding of ground loops is that they involve
> multiple devices. Does anyone have an idea why I inevitably hear 50 Hz hums
> in my apartment? I hear it also if I turn on my monitor speakers and nothing
> else is connected.

Teach the amp the words! ;^) Seriously, do you have other appliances
running on the same circuit? I have this electric space heater that
causes every audio product in the room to produce a 60 Hz hum. Try
turning off EVERYTHING - refrigerator, heat, etc - and see if the hum in
the amp/monitors goes away.

AT
>
> thanks,
>
> brian
>
>

[Mike Rivers]

In article > writes:

> I have this tube amp head, and when I power it on, I hear a fairly loud 50
> Hz hum (I am in Germany). This happens even if it is the only thing powered
> on and plugged in. My understanding of ground loops is that they involve
> multiple devices. Does anyone have an idea why I inevitably hear 50 Hz hums
> in my apartment?

You have a radiation or shielding problem. Try moving the amplifier or
turning it in another orientation. Or it could be a problem with the
power supply in the amplifier providing properly filtered DC.




--
I'm really Mike Rivers - )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Fletcher]

"Brian Huether" > wrote in message
...
> I have this tube amp head, and when I power it on, I hear a fairly loud 50
> Hz hum (I am in Germany). This happens even if it is the only thing
powered
> on and plugged in. My understanding of ground loops is that they involve
> multiple devices. Does anyone have an idea why I inevitably hear 50 Hz
hums
> in my apartment? I hear it also if I turn on my monitor speakers and
nothing
> else is connected.


Gee... I was wondering if someone could explain grounding/shielding a stray
field / EMI problem to me in, oh hell... 5 or 6 sentences on a usenet group?

Search "Michael Faraday, 1791-1867" on google or something... you may find
him somewhat inspirational...
--
Fletcher
Mercenary Audio
TEL: 508-543-0069
FAX: 508-543-9670
http://www.mercenary.com
"this is not a problem"

[Brian Huether]

Whatever. I don't need to understand Fourier Analysis in order to apply a
low cut filter to audio. Same applies here. All I need are ideas as to why
it might be there. I want to know The Top 10 Causes of Hum. This hum occurs
when EVERY appliance, etc is unplugged. If you were an audio consultant and
someone said, "Ok chief, tell me what could be causing this?", would you
say, "Well, get yourself well versed on Faraday Induction and then let's get
together for a consultation." Granted, I am not paying you, but the point is
people can come towards solutions to problems without needing to have expert
knowledge themselves. I figured maybe someone could point me towards a
possible solution and offer some insight (like that AM radio comment and the
advice about unplugging all appliances). If I know typical causes (power
lines, motors, etc) then I can route them out.

So come on people, if you don't have something useful to say (so far every
reply besides this one has been useful and courteous), then squelch your
psychlogical need to belittle others by demonstrating your PERCEIVED mental
superiority, and ignore this post.

thanks in advance,

brian

"Fletcher" > wrote in message
ink.net...
> "Brian Huether" > wrote in message
> ...
> > I have this tube amp head, and when I power it on, I hear a fairly loud
50
> > Hz hum (I am in Germany). This happens even if it is the only thing
> powered
> > on and plugged in. My understanding of ground loops is that they involve
> > multiple devices. Does anyone have an idea why I inevitably hear 50 Hz
> hums
> > in my apartment? I hear it also if I turn on my monitor speakers and
> nothing
> > else is connected.
>
>
> Gee... I was wondering if someone could explain grounding/shielding a
stray
> field / EMI problem to me in, oh hell... 5 or 6 sentences on a usenet
group?
>
> Search "Michael Faraday, 1791-1867" on google or something... you may
find
> him somewhat inspirational...
> --
> Fletcher
> Mercenary Audio
> TEL: 508-543-0069
> FAX: 508-543-9670
> http://www.mercenary.com
> "this is not a problem"
>
>

[Brian Huether]

Just a follow-up. The hum ocurs when all appliances are unplugged. Not sure
how to test the AM radio thing. Since the hum comes out of speakers upon
power up, I wouldn't know how to distinguish the speaker hum from a hum on
AM radio. Also, if I move speakers (or the amp head when it comes to its
hum) the hum does not go away.

I live in an apartment and underneath me is a large furnace room that serves
6 units in this apartment. Could something in there generate a magnetic
field?

thanks,

brian

"Brian Huether" > wrote in message
...
> I have this tube amp head, and when I power it on, I hear a fairly loud 50
> Hz hum (I am in Germany). This happens even if it is the only thing
powered
> on and plugged in. My understanding of ground loops is that they involve
> multiple devices. Does anyone have an idea why I inevitably hear 50 Hz
hums
> in my apartment? I hear it also if I turn on my monitor speakers and
nothing
> else is connected.
>
> thanks,
>
> brian
>
>

[Artie Turner]

Brian Huether wrote:
> Just a follow-up. The hum ocurs when all appliances are unplugged. Not sure
> how to test the AM radio thing. Since the hum comes out of speakers upon
> power up, I wouldn't know how to distinguish the speaker hum from a hum on
> AM radio. Also, if I move speakers (or the amp head when it comes to its
> hum) the hum does not go away.
>
> I live in an apartment and underneath me is a large furnace room that serves
> 6 units in this apartment. Could something in there generate a magnetic
> field?

I'm guessing that there are electric motors associated with that furnace
that could be a source of your problem. I think the other poster wanted
to know if a stand-alone - not connected to your audio gear - AM radio
emitted the hum when everything else was off.

AT
>
> thanks,
>
> brian
>
> "Brian Huether" > wrote in message
> ...
>
>>I have this tube amp head, and when I power it on, I hear a fairly loud 50
>>Hz hum (I am in Germany). This happens even if it is the only thing
>
> powered
>
>>on and plugged in. My understanding of ground loops is that they involve
>>multiple devices. Does anyone have an idea why I inevitably hear 50 Hz
>
> hums
>
>>in my apartment? I hear it also if I turn on my monitor speakers and
>
> nothing
>
>>else is connected.
>>
>>thanks,
>>
>>brian
>>
>>
>
>
>

[Victor]

"Brian Huether" wrote:
> I live in an apartment and underneath me is a large furnace room that
serves
> 6 units in this apartment. Could something in there generate a magnetic
> field?
-------------------------------------------------
Here we go...
That's very well could be you answer to you problem...
Does this "room" have an electric heaters, or does it have an air
conditioner for summer time?
A/C compressors well know to put some "noise" in power lines.
Do you have access to other apartments, so you could bring your amp. and
check for "noise".
If you have the same results - MOST LIKELY problem in the utility room.
Another possibility - if you have separate hydro meters for each app.,
someone screwing with meter.

Victor

P.S Also check if there is any voltage between ground pin in power socket
and any water pipe.

[Brian Huether]

Thanks for the info! That gives me quite a few leads to exhaust!

thanks,

brian

"Victor" > wrote in message
.. .
> "Brian Huether" wrote:
> > I live in an apartment and underneath me is a large furnace room that
> serves
> > 6 units in this apartment. Could something in there generate a magnetic
> > field?
> -------------------------------------------------
> Here we go...
> That's very well could be you answer to you problem...
> Does this "room" have an electric heaters, or does it have an air
> conditioner for summer time?
> A/C compressors well know to put some "noise" in power lines.
> Do you have access to other apartments, so you could bring your amp. and
> check for "noise".
> If you have the same results - MOST LIKELY problem in the utility room.
> Another possibility - if you have separate hydro meters for each app.,
> someone screwing with meter.
>
> Victor
>
> P.S Also check if there is any voltage between ground pin in power socket
> and any water pipe.
>
>
>

[Mike Rivers]

In article > writes:

> I want to know The Top 10 Causes of Hum. This hum occurs
> when EVERY appliance, etc is unplugged. If you were an audio consultant and
> someone said, "Ok chief, tell me what could be causing this?", would you
> say, "Well, get yourself well versed on Faraday Induction and then let's get
> together for a consultation."

You have wires in the walls of your house. They radiate an
electomagnetic field. There are wires in your amplfier and coming out
of it, some even traveling through the same walls that have the
electrical wires that are radiating the electromagnetic hum field.
They act as an antenna, picking up that magnetic field.

Top Ten Causes of Hum:

1. Something acting as an antenna for line frequency electromagnetic
radiation. Solution - better shielding of either the device or the
radiator.

2. Poor design of internal equipment grounding (The Pin 1 Problem).
Solution - Rebuild the guilty equipment

3. Something wrong with the unit's power supply. Solution - Fix it.

4. through 10. All of the above.




--
I'm really Mike Rivers - )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> I live in an apartment and underneath me is a large furnace room that serves
> 6 units in this apartment. Could something in there generate a magnetic
> field?

Not if it's a coal furnace, but if it's electrical, or has large
motors for blowers or pumps it could be a source of the problem. Take
your amplifier to a friend's house and see if it hums there also.



--
I'm really Mike Rivers - )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Fletcher]

Brian Huether wrote:

> If you were an audio consultant and
> someone said, "Ok chief, tell me what could be causing this?", would you
> say, "Well, get yourself well versed on Faraday Induction and then let's get
> together for a consultation." Granted, I am not paying you, but the point is
> people can come towards solutions to problems without needing to have expert
> knowledge themselves.

Well... I am an 'audio consultant'... so I guess the first thing I'd like to say
to you is "**** you, pay me"... but you probably wouldn't hire me if I did...
so, are there any printing presses on the same power grid with you? They've
been known to **** things up. Are you anywhere near hi tension power lines?
They've been known to **** things up. Do you have an adjacent neighbor trying
to animate dead tissue? They've been known to be complete **** ups with massive
electric bills.

The reason I pointed you looking at Faraday Induction was pretty simple... see
there is this old native american saying that goes something like: "If you give
a man a fish, he'll eat for a day... if you teach a man to fish, he'll leave you
the **** alone and go fishing".

Go fish.
--
Fletcher
Mercenary Audio
TEL: 508-543-0069
FAX: 508-543-9670
http://www.mercenary.com
"this is not a problem"

[Marc Wielage]

On Sun, 16 Nov 2003 1:44:40 -0800, Brian Huether wrote
(in message >):

> I have this tube amp head, and when I power it on, I hear a fairly loud 50
> Hz hum (I am in Germany).
>--------------------------------snip----------------------------------<

In addition to what all the others say, problems with hum and ground loops
can be horrendously difficult to diagnose. There are no easy answers here,
only a lot of trial and error tests you can do over a period of time.

I'd suggest this: take the tube amp to another location -- preferably
another building, with a quiet room -- and see if the amp hums there as well.
If it does, then the amp itself has a flaw. You can try a third location,
but chances are, the amp is defective in some way. Try another amp and see
if the problem persists.

If it doesn't hum in the new location, then the problem is in your original
room. Unplug everything you can, and see if that eliminates the problem. Be
sure to disconnect cable TV lines from the system, since those can also carry
residual hum components to audio systems. There may also be built-in
problems with the AC wiring in the building, particularly if the grounds
aren't done correctly; only a good electrician will know for sure. You could
also try a very heavy-duty AC power filter/uninterruptible power supply, but
it could be very costly to track down the problem.

There may also be noise and RFI coming from outside the building, leaking
into the amplifier stage. I once had a situation where my recording
equipment was affected just at certain hours of the day. After walking
around the neighborhood, I found a neighbor three houses away was tuning his
motorcycle once a week at that time. His alternator was throwing enough
spikes in the air to affect my system, well over 100 feet away. I had
another friend whose house was terribly affected by a radiated signal from a
nearby AM transmitter; in his case, his only recourse was to move.

--MFW

[Mike Dobony]

"Brian Huether" > wrote in message
...
> I have this tube amp head, and when I power it on, I hear a fairly loud 50
> Hz hum (I am in Germany). This happens even if it is the only thing
powered
> on and plugged in. My understanding of ground loops is that they involve
> multiple devices. Does anyone have an idea why I inevitably hear 50 Hz
hums
> in my apartment? I hear it also if I turn on my monitor speakers and
nothing
> else is connected.
>
> thanks,
>
> brian
>
>

Tube amps are supposed to have a hum. Tube amp emulators also hum. Are you
sure it is not just part of the package? My pastor has the same problem.
He didn't realize that the tube amp emulator DOES hum! Now he reduces the
emulator and it is fine. What is your amp's make and model number? How old
is it? Did it just start with this hum?

--
Mike D.

www.stopassaultnow.org

Remove .spamnot to respond by email



---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.537 / Virus Database: 332 - Release Date: 11/7/2003

[Brian Huether]

Hi,

Well the thing is, it isn't just the amp. If I have everything turned off
and unplugged, and power on just a monitor speaker, then there is
considerable hum coming from the speaker. I think I really need to take the
advice of others and get some of my equipment plugged into other peoples'
places. My amp heads are a Diezel VH4S and a Koch Powertone II. Both modern
tube amps.

regards,

brian
"Mike Dobony" > wrote in message
...
>
> "Brian Huether" > wrote in message
> ...
> > I have this tube amp head, and when I power it on, I hear a fairly loud
50
> > Hz hum (I am in Germany). This happens even if it is the only thing
> powered
> > on and plugged in. My understanding of ground loops is that they involve
> > multiple devices. Does anyone have an idea why I inevitably hear 50 Hz
> hums
> > in my apartment? I hear it also if I turn on my monitor speakers and
> nothing
> > else is connected.
> >
> > thanks,
> >
> > brian
> >
> >
>
> Tube amps are supposed to have a hum. Tube amp emulators also hum. Are
you
> sure it is not just part of the package? My pastor has the same problem.
> He didn't realize that the tube amp emulator DOES hum! Now he reduces the
> emulator and it is fine. What is your amp's make and model number? How
old
> is it? Did it just start with this hum?
>
> --
> Mike D.
>
> www.stopassaultnow.org
>
> Remove .spamnot to respond by email
>
>
>
> ---
> Outgoing mail is certified Virus Free.
> Checked by AVG anti-virus system (http://www.grisoft.com).
> Version: 6.0.537 / Virus Database: 332 - Release Date: 11/7/2003
>
>

[Peter Larsen]

Brian Huether wrote:

> I have this tube amp head, and when I power it on, I hear a fairly loud 50
> Hz hum (I am in Germany). This happens even if it is the only thing powered
> on and plugged in. My understanding of ground loops is that they involve
> multiple devices. Does anyone have an idea why I inevitably hear 50 Hz hums
> in my apartment? I hear it also if I turn on my monitor speakers and nothing
> else is connected.

Does this appliance required a ground connection and if so, does it have
one?

How old is the appliance and if it is old has it been left unused or
been in regular use?

> brian


Kind regards

Peter Larsen

--
************************************************** ***********
* My site is at: http://www.muyiovatki.dk *
************************************************** ***********

[LeBaron & Alrich]

Brian Huether > wrote:

> If you were an audio consultant and
> someone said, "Ok chief, tell me what could be causing this?", would you
> say, "Well, get yourself well versed on Faraday Induction and then let's get
> together for a consultation." Granted, I am not paying you, but the point is
> people can come towards solutions to problems without needing to have expert
> knowledge themselves.

If you hit Google with your trouble you will see that several weeks of
reading material are avaialble from previous RAP discussions about your
very problem. Seeing as how you aren't paying anyone to rewrite that
which they have already written, some repeatedly, maybe the effort to
Google is a resonable investment on your part.

You want it simple? You have 50 Hz radiating into your amp and mon
system. You good to go now? Or will you need more info?

--
ha

[Ben Bradley]

In rec.audio.pro, Marc Wielage > wrote:

>On Sun, 16 Nov 2003 1:44:40 -0800, Brian Huether wrote
>(in message >):
>
>> I have this tube amp head, and when I power it on, I hear a fairly loud 50
>> Hz hum (I am in Germany).
>>--------------------------------snip----------------------------------<

>...

>I'd suggest this: take the tube amp to another location -- preferably
>another building, with a quiet room -- and see if the amp hums there as well.
> If it does, then the amp itself has a flaw.

True, but it arguably may also have a flaw if it's amplifying some
50 Hz field in his apartment...

If changing the location of the amp (either within the apartment,
or trying it in a different building) makes no difference in the
volume or 'tone' of the hum, then the amp is definitely passing the
hum through to the speaker from the power line. This may indicate a
power supply problem (a full-wave recctifier with one of the diodes
not working might cause excessive hum at 50Hz. A bad filter capacitor
might cause 100Hz hum), but could also be insufficient internal
electrostatic shielding between sensitive inputs and line-voltage
sections.
It could just be a bad tube, such as the rectifier in the power
supply, or any other tube that may have the cathode shorted to the
filament. Do you have good tubes you could swap in?

[Brian Huether]

Isn't that cute. Are you ever going to realize that you have no obligation
to help people that post? You can choose to ignore stuff and that way you
are giving away no fish. By the way, I really appreciated your post on your
forum about building gobos. I am not being sarcastic. It was a very
straightforward answer to my question. But then here you are playing a
totally different game. How many faces do you have? Mirrors must be dizzying
for you...


>
> The reason I pointed you looking at Faraday Induction was pretty simple...
see
> there is this old native american saying that goes something like: "If
you give
> a man a fish, he'll eat for a day... if you teach a man to fish, he'll
leave you
> the **** alone and go fishing".
>
> Go fish.
> --
> Fletcher
> Mercenary Audio
> TEL: 508-543-0069
> FAX: 508-543-9670
> http://www.mercenary.com
> "this is not a problem"
>
>

[Brian Huether]

I always get a kick of that type of attitude. One could conceivably find the
answer to any question by searching on the internet. So people who have an
adversion to helping people could always take the easy way out and say,
"Search". Sorry, I prefer getting my answers through interaction with people
instead of interaction with archived posts. Call me crazy - I think human
interaction is a good thing. Clearly many people on this forum are of a
vastly different disposition.


"LeBaron & Alrich" > wrote in message
...
> Brian Huether > wrote:
>
> > If you were an audio consultant and
> > someone said, "Ok chief, tell me what could be causing this?", would you
> > say, "Well, get yourself well versed on Faraday Induction and then let's
get
> > together for a consultation." Granted, I am not paying you, but the
point is
> > people can come towards solutions to problems without needing to have
expert
> > knowledge themselves.
>
> If you hit Google with your trouble you will see that several weeks of
> reading material are avaialble from previous RAP discussions about your
> very problem. Seeing as how you aren't paying anyone to rewrite that
> which they have already written, some repeatedly, maybe the effort to
> Google is a resonable investment on your part.
>
> You want it simple? You have 50 Hz radiating into your amp and mon
> system. You good to go now? Or will you need more info?
>
> --
> ha

[Your Add Here!]

I had a similar problem in my studio (located in the basement of
anoffice building). RF which I couldn't track down the source of. A
really cool guy from the electric company came down and left like
$200k worth of test equipment in my studio for a week (apparently he
was intrigued and a patron of the arts). This guy was a blessing.
Anyway, the test results indicated that there was a tiny current
probably from a walwart at about 600 milivolts (?) somewhere in the
building and the wiring in the building was emmitting this signal like
a giant antenne, ****ing up my audio. (Note, my noise suppressing
isolation transformer didn't help). It turned out to be a walwart for
an answering machine at the dry cleaner next door. They removed it and
my headache went away. It was quite a strange situation. BTW - the AM
radio trick picked up this signal all over the place.

[Mondoslug1]

bluemt wrote:

>I had a similar problem in my studio (located in the basement of
>anoffice building). RF which I couldn't track down the source of. A
>really cool guy from the electric company came down and left like
>$200k worth of test equipment in my studio for a week (apparently he
>was intrigued and a patron of the arts). This guy was a blessing.
>Anyway, the test results indicated that there was a tiny current
>probably from a walwart at about 600 milivolts (?) somewhere in the
>building and the wiring in the building was emmitting this signal like
>a giant antenne, ****ing up my audio. (Note, my noise suppressing
>isolation transformer didn't help). It turned out to be a walwart for
>an answering machine at the dry cleaner next door. They removed it and
>my headache went away. It was quite a strange situation. BTW - the AM
>radio trick picked up this signal all over the place.
>
>

Wow. Excellent!

[Fletcher]

"Brian Huether" > wrote in message
...
> Isn't that cute. Are you ever going to realize that you have no obligation
> to help people that post? You can choose to ignore stuff and that way you
> are giving away no fish. By the way, I really appreciated your post on
your
> forum about building gobos. I am not being sarcastic. It was a very
> straightforward answer to my question. But then here you are playing a
> totally different game. How many faces do you have? Mirrors must be
dizzying
> for you...

One face... the difference being a question that can actually be answered
from another continent vs. one that can't be answered from another
continent... the difference being a straight forward question with a rather
easily definable solution... and a nebulous question that requires an 'on
site inspection' and a whole realm of knowledge to apply to that 'on site'.

Seeing as you're there... learn what you need to learn and you'll have the
answer to your question... or hire someone locally who can find the answer
for you... but either way, you're going to need to invest something to get
this one solved.

Time or money... your choice.
--
Fletcher
Mercenary Audio
TEL: 508-543-0069
FAX: 508-543-9670
http://www.mercenary.com
"this is not a problem"

[Mike Rivers]

In article > writes:

> I always get a kick of that type of attitude. One could conceivably find the
> answer to any question by searching on the internet. So people who have an
> adversion to helping people could always take the easy way out and say,
> "Search". Sorry, I prefer getting my answers through interaction with people
> instead of interaction with archived posts. Call me crazy - I think human
> interaction is a good thing.

So what are you doing wasting time in a newsgroup? Go to your local
studio or music shop or guitar amp fixer and have a face-to-face chat.



--
I'm really Mike Rivers - )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[LeBaron & Alrich]

Brian Huether > wrote:

> I always get a kick of that type of attitude. One could conceivably find the
> answer to any question by searching on the internet. So people who have an
> adversion to helping people could always take the easy way out and say,
> "Search". Sorry, I prefer getting my answers through interaction with people
> instead of interaction with archived posts. Call me crazy - I think human
> interaction is a good thing. Clearly many people on this forum are of a
> vastly different disposition.

Brian,

There has been so goddman much conversation about amps and humming (they
do it becuase they don't know the ****ing words) that you are being a
silly putz to suggest it is inappropriate for me to suggest you get your
own ass over to Google and do some candyass _research_ before you start
acting like people ought to rewrite the Brittannica for you right here
and right now.

The kind of problem you have has a whole lot of potential causes, and
for each of those there may be more than one solution. So either you
give enough of a **** about it to get off your duff and _do_ something,
or your hum is what you deserve.

So I guess you might as well enjoy the hum.

Nest: this ain't direct human interaction; you're talking to your
computer. Find a tech near you and talk to him/her about your problems.
Then pay them to fix it. That'd be a pittance against the cost of those
amps.

--
ha

[Brian Huether]

I actually have done a lot of research, but the research tends to suggest
that anything is possible and troubleshooting requires tools I don't have. I
just figured maybe something about my particular scenario might bring up a
red flag to someone and narrow down the possibilities, which it has. Google
returns too much info on this. And I definately want to know the German word
for someone that specializes in this, because I am definately at the point
where I want to pay someone!

-brian

"LeBaron & Alrich" > wrote in message
. ..
> Brian Huether > wrote:
>
> > I always get a kick of that type of attitude. One could conceivably find
the
> > answer to any question by searching on the internet. So people who have
an
> > adversion to helping people could always take the easy way out and say,
> > "Search". Sorry, I prefer getting my answers through interaction with
people
> > instead of interaction with archived posts. Call me crazy - I think
human
> > interaction is a good thing. Clearly many people on this forum are of a
> > vastly different disposition.
>
> Brian,
>
> There has been so goddman much conversation about amps and humming (they
> do it becuase they don't know the ****ing words) that you are being a
> silly putz to suggest it is inappropriate for me to suggest you get your
> own ass over to Google and do some candyass _research_ before you start
> acting like people ought to rewrite the Brittannica for you right here
> and right now.
>
> The kind of problem you have has a whole lot of potential causes, and
> for each of those there may be more than one solution. So either you
> give enough of a **** about it to get off your duff and _do_ something,
> or your hum is what you deserve.
>
> So I guess you might as well enjoy the hum.
>
> Nest: this ain't direct human interaction; you're talking to your
> computer. Find a tech near you and talk to him/her about your problems.
> Then pay them to fix it. That'd be a pittance against the cost of those
> amps.
>
> --
> ha

[Brian Huether]

I suppose I could take power tubes from another amp but I am pretty sure
they all have this hum. I need to check on that.

thanks,

brian

"Ben Bradley" > wrote in message
...
> In rec.audio.pro, Marc Wielage > wrote:
>
> >On Sun, 16 Nov 2003 1:44:40 -0800, Brian Huether wrote
> >(in message >):
> >
> >> I have this tube amp head, and when I power it on, I hear a fairly loud
50
> >> Hz hum (I am in Germany).
> >>--------------------------------snip----------------------------------<
>
> >...
>
> >I'd suggest this: take the tube amp to another location -- preferably
> >another building, with a quiet room -- and see if the amp hums there as
well.
> > If it does, then the amp itself has a flaw.
>
> True, but it arguably may also have a flaw if it's amplifying some
> 50 Hz field in his apartment...
>
> If changing the location of the amp (either within the apartment,
> or trying it in a different building) makes no difference in the
> volume or 'tone' of the hum, then the amp is definitely passing the
> hum through to the speaker from the power line. This may indicate a
> power supply problem (a full-wave recctifier with one of the diodes
> not working might cause excessive hum at 50Hz. A bad filter capacitor
> might cause 100Hz hum), but could also be insufficient internal
> electrostatic shielding between sensitive inputs and line-voltage
> sections.
> It could just be a bad tube, such as the rectifier in the power
> supply, or any other tube that may have the cathode shorted to the
> filament. Do you have good tubes you could swap in?
>

[Roger W. Norman]

Actually there's one simple tool you can use. An AM radio tuned to an
unused frequency. Walk around your room and your equipment. If you hear
buzz getting louder and diminishing then you have a wiring problem in that
A) the ground is not correct, or B) some outside force like an industrial
area causing problems, or C) some inside force from motors or devices that
draw large amounts of current such as water heaters or refrigerators, etc.

You mentioned that you had unplugged all your appliances and it still was a
problem, so perhaps, through the process of elimination, you've knocked out
C. You can check A with a simple plug tester. If ground is somehow a
problem it will tell you. B is going to be your biggest problem in that you
probably don't know what's on your local grid and just driving around the
area isn't going to tell you.

But there's one other possible answer or at least avenue for possible
discovery, and that's to simply call a licensed electrician and let him/her
find the problem. There may not be a simple answer to correcting the
problem (there are simple answers regardless of the problem, but not free)
because it's an apartment building and one person complaining makes no
nevermind to the management, but at least you'll know what the problem is.
The other is to buy either a hum eliminator (actual name) or a balanced
power system. The hum eliminator works off the output of the amp and
interjects an optical circuit between two legs of the device, thereby
cutting ground between one side and the other. Whether they actually work
on powered outputs like outs from an amp, I don't know (read
www.ebtechaudio.com 's info on the hum eliminator). But a balanced power
device, like Equi=Tech or ETA or Furman will probably eliminate the problem
for all your devices since it forces half the voltage through one leg and
the other half through the other leg 180 degrees out, still supplying the
proper power, but taking out any noise just like balanced cables do. From
Equi=Tech's website (www.equitech.com).

"Balanced power eliminates all of these problems because there is never ac
interference present on the ground to invade signal circuits. Balanced power
often increases the dynamic range of a recording system by 16db or more.
When balanced power is applied, ground loops and hum problems, even subtle
ac noise coloration becomes a thing of the past. The difference can be
astonishing."

Offhand I'd say that probably all your apartment building has the problem
but most people just don't notice. And it's likely that it's a bad
grounding system being tied to some cold water pipe that's probably been
painted over. Effectively it gives large current a ground, but not a proper
ground for sensitive or amplifying devices.

That was 20 minutes worth of writing (hey, I had to go get coffee and spend
a couple of minutes talking to myself at the coffee machine) and a couple
for 'net research, but I don't charge anything less than 3 hours minimum, so
how about sending me a check for $360 USD! <g>

--


Roger W. Norman
SirMusic Studio
Purchase your copy of the Fifth of RAP CD set at www.recaudiopro.net.
See how far $20 really goes.




"Brian Huether" > wrote in message
...
> I actually have done a lot of research, but the research tends to suggest
> that anything is possible and troubleshooting requires tools I don't have.
I
> just figured maybe something about my particular scenario might bring up a
> red flag to someone and narrow down the possibilities, which it has.
Google
> returns too much info on this. And I definately want to know the German
word
> for someone that specializes in this, because I am definately at the point
> where I want to pay someone!
>
> -brian
>
> "LeBaron & Alrich" > wrote in message
> . ..
> > Brian Huether > wrote:
> >
> > > I always get a kick of that type of attitude. One could conceivably
find
> the
> > > answer to any question by searching on the internet. So people who
have
> an
> > > adversion to helping people could always take the easy way out and
say,
> > > "Search". Sorry, I prefer getting my answers through interaction with
> people
> > > instead of interaction with archived posts. Call me crazy - I think
> human
> > > interaction is a good thing. Clearly many people on this forum are of
a
> > > vastly different disposition.
> >
> > Brian,
> >
> > There has been so goddman much conversation about amps and humming (they
> > do it becuase they don't know the ****ing words) that you are being a
> > silly putz to suggest it is inappropriate for me to suggest you get your
> > own ass over to Google and do some candyass _research_ before you start
> > acting like people ought to rewrite the Brittannica for you right here
> > and right now.
> >
> > The kind of problem you have has a whole lot of potential causes, and
> > for each of those there may be more than one solution. So either you
> > give enough of a **** about it to get off your duff and _do_ something,
> > or your hum is what you deserve.
> >
> > So I guess you might as well enjoy the hum.
> >
> > Nest: this ain't direct human interaction; you're talking to your
> > computer. Find a tech near you and talk to him/her about your problems.
> > Then pay them to fix it. That'd be a pittance against the cost of those
> > amps.
> >
> > --
> > ha
>
>

[LeBaron & Alrich]

Brian Huether wrote:

> I actually have done a lot of research, but the research tends to suggest
> that anything is possible and troubleshooting requires tools I don't have. I
> just figured maybe something about my particular scenario might bring up a
> red flag to someone and narrow down the possibilities, which it has. Google
> returns too much info on this. And I definately want to know the German word
> for someone that specializes in this, because I am definately at the point
> where I want to pay someone!

Right on; hope you find the help you're after!

--
ha

[Richard Kuschel]

>
>>I had a similar problem in my studio (located in the basement of
>>anoffice building). RF which I couldn't track down the source of. A
>>really cool guy from the electric company came down and left like
>>$200k worth of test equipment in my studio for a week (apparently he
>>was intrigued and a patron of the arts). This guy was a blessing.
>>Anyway, the test results indicated that there was a tiny current
>>probably from a walwart at about 600 milivolts (?) somewhere in the
>>building and the wiring in the building was emmitting this signal like
>>a giant antenne, ****ing up my audio. (Note, my noise suppressing
>>isolation transformer didn't help). It turned out to be a walwart for
>>an answering machine at the dry cleaner next door. They removed it and
>>my headache went away. It was quite a strange situation. BTW - the AM
>>radio trick picked up this signal all over the place.
>>
>>
>
>Wow. Excellent!
>
>
>
>
You don't need a ton of equipment to find a hum that is being radiated. A
battery operated amplifer (Pignose or one of those cute little Marshalls ) and
a single coil guitar pickup will show it up right away.
Richard H. Kuschel
"I canna change the law of physics."-----Scotty