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Tube amps
Tube amps
Not all tube amps are good amps.
Tube amps that only have pre amp tubes or only power tubes are not
true tube amps.
They are half solid state.
Many of the newer tube amps have pcb's.
They are difficult if not impossible to repair or mod.
So you go out and buy an all tube amp with point to point wiring and
no pcb's.
What you have now is an all tube amp that is set up the way the
factory wants it set up and it probably has cheap Chinese made tubes
along with a cold bias to allow the power tubes to last longer while
under warranty.
For those of you who are interested in good tube amps you don't have
to spend an arm and a leg for a botique amp.
Get yourself a good book on tubes and how to adjust the bias.
A properly set up amp with good quality tubes will sound and function
beautifully for years.
Every few years change the tubes, reset the bias and do a good
cleaning and you are good for another few years.
The trick to good sound and quality is knowing simple maintenance,
adjustments and using quality tubes.
Before you go out and buy that tube amp obtain the information on how
to set up and maintain the amp and it will serve you well for many
years to come.
In other words don't just jump in and buy a tube amp and expect it to
sound its best from the factory.
Learning to set the bias and change tubes is not rocket sceience.
You can learn it in a matter of minutes.
But you will need to invest a few bucks in a bias probe and a DMM.
If you don't like the sound of your tube amp change the tubes and
adjust the bias.
Pt
Not all tube amps are good amps.
Tube amps that only have pre amp tubes or only power tubes are not
true tube amps.
They are half solid state.
Many of the newer tube amps have pcb's.
They are difficult if not impossible to repair or mod.
So you go out and buy an all tube amp with point to point wiring and
no pcb's.
What you have now is an all tube amp that is set up the way the
factory wants it set up and it probably has cheap Chinese made tubes
along with a cold bias to allow the power tubes to last longer while
under warranty.
For those of you who are interested in good tube amps you don't have
to spend an arm and a leg for a botique amp.
Get yourself a good book on tubes and how to adjust the bias.
A properly set up amp with good quality tubes will sound and function
beautifully for years.
Every few years change the tubes, reset the bias and do a good
cleaning and you are good for another few years.
The trick to good sound and quality is knowing simple maintenance,
adjustments and using quality tubes.
Before you go out and buy that tube amp obtain the information on how
to set up and maintain the amp and it will serve you well for many
years to come.
In other words don't just jump in and buy a tube amp and expect it to
sound its best from the factory.
Learning to set the bias and change tubes is not rocket sceience.
You can learn it in a matter of minutes.
But you will need to invest a few bucks in a bias probe and a DMM.
If you don't like the sound of your tube amp change the tubes and
adjust the bias.
Pt
Re: Tube amps
On Tue, 29 Apr 2008 19:22:55 +1000, ARLOWE wrote:
>...If you want to mod your gear then pay a pro to do it...
> And yes I know what I am talking about.... it's been my occupation for
> many years....
The voice of vested interest speaks?
--
Tim C.
On Tue, 29 Apr 2008 19:22:55 +1000, ARLOWE wrote:
>...If you want to mod your gear then pay a pro to do it...
> And yes I know what I am talking about.... it's been my occupation for
> many years....
The voice of vested interest speaks?
--
Tim C.
Re: Tube amps
Tim C. pretended :
> On Tue, 29 Apr 2008 19:22:55 +1000, ARLOWE wrote:
>
>> ...If you want to mod your gear then pay a pro to do it...
>> And yes I know what I am talking about.... it's been my occupation for
>> many years....
>
> The voice of vested interest speaks?
Only if you're talking process control gear...I send my amp off to
someone else too....
Tim C. pretended :
> On Tue, 29 Apr 2008 19:22:55 +1000, ARLOWE wrote:
>
>> ...If you want to mod your gear then pay a pro to do it...
>> And yes I know what I am talking about.... it's been my occupation for
>> many years....
>
> The voice of vested interest speaks?
Only if you're talking process control gear...I send my amp off to
someone else too....
Re: Tube amps
"Tim C." <timchallenger@yahoo.co.uk> wrote in message
news:4ynfa6d1dtxb.numdkd968kvr$.dlg@40tude . net ...
> On Tue, 29 Apr 2008 19:22:55 +1000, ARLOWE wrote:
>
>>...If you want to mod your gear then pay a pro to do it...
>> And yes I know what I am talking about.... it's been my occupation for
>> many years....
>
> The voice of vested interest speaks?
>
More likely the voice of reason. Capacitors retain their charge for quite a
while after the power has been shut off. If they are shorted out that
current is released.
"Tim C." <timchallenger@yahoo.co.uk> wrote in message
news:4ynfa6d1dtxb.numdkd968kvr$.dlg@40tude . net ...
> On Tue, 29 Apr 2008 19:22:55 +1000, ARLOWE wrote:
>
>>...If you want to mod your gear then pay a pro to do it...
>> And yes I know what I am talking about.... it's been my occupation for
>> many years....
>
> The voice of vested interest speaks?
>
More likely the voice of reason. Capacitors retain their charge for quite a
while after the power has been shut off. If they are shorted out that
current is released.
Re: Tube amps
Don Freeman wrote:
> "Tim C." <timchallenger@yahoo.co.uk> wrote in message
> news:4ynfa6d1dtxb.numdkd968kvr$.dlg@40tude . net ...
>
>>On Tue, 29 Apr 2008 19:22:55 +1000, ARLOWE wrote:
>>
>>
>>>...If you want to mod your gear then pay a pro to do it...
>>>And yes I know what I am talking about.... it's been my occupation for
>>>many years....
>>
>>The voice of vested interest speaks?
>>
>
>
> More likely the voice of reason. Capacitors retain their charge for quite a
> while after the power has been shut off. If they are shorted out that
> current is released.
>
>
That assumes that the guy knows how to safely discharge the filter caps in the
first place.
He's also talking about biasing your own amp. Most amps do NOT provide
adjustment outside of the chassis, even if you do have a probe (and my probe
doesn't give plate voltage, I have to sneak in other wires with the pins when I
work on an amp that does have external bias adjustment). This means you're
working on a live circuit with several hundred volts lurking inside. There's
been some "yeah, but it probably won't kill you" comments made. Best not to
find out!!!
Lots of things can go wrong. Novices should NOT go poking around inside of a
tube amp chassis! It's simple risk analysis. Some tech time is cheaper than a
casket.
TRUE story on how I almost made a BIG mistake...
I bought a Univox U-1061 4x6L6GC 105W bass amp that the previous owner had
screwed with. I was running it with two output tubes at the time. I opened the
chassis for the first time, to look for bonehead circuit changes by the previous
owner (yup, they were there, but that's another discussion).
Now, some power supplies have a resistor in them that will drain the voltage
down in a matter of minutes. So I carefully check the voltage from chassis to
the + point of the bank of filter resistors, thinking that could be the case. I
get a zero reading.
Safe to proceed, right? NO WAY. As a safety precaution (holding the
polycarbonate insulated handle, with tip already touching chassis ground) I put
a screwdriver across the point from ground to filter caps. BIG GNARLY BLUE SPARK.
Damn, I'm glad I pay attention to safety issues! I then noticed that one of my
meter probes were not fully seated in the the meter. A later reading told me
that I could've been bitten by 720V!
Other guys have instinctively grabbed a chassis as it was teetering or falling
from a bench, and been hit with B+. Or just made a move that had no rhyme or
reason.
And these are guys who KNOW what they are doing.
Novices: Learn basic electronics and all safety issues before even thinking of
opening a tube chassis!
Don Freeman wrote:
> "Tim C." <timchallenger@yahoo.co.uk> wrote in message
> news:4ynfa6d1dtxb.numdkd968kvr$.dlg@40tude . net ...
>
>>On Tue, 29 Apr 2008 19:22:55 +1000, ARLOWE wrote:
>>
>>
>>>...If you want to mod your gear then pay a pro to do it...
>>>And yes I know what I am talking about.... it's been my occupation for
>>>many years....
>>
>>The voice of vested interest speaks?
>>
>
>
> More likely the voice of reason. Capacitors retain their charge for quite a
> while after the power has been shut off. If they are shorted out that
> current is released.
>
>
That assumes that the guy knows how to safely discharge the filter caps in the
first place.
He's also talking about biasing your own amp. Most amps do NOT provide
adjustment outside of the chassis, even if you do have a probe (and my probe
doesn't give plate voltage, I have to sneak in other wires with the pins when I
work on an amp that does have external bias adjustment). This means you're
working on a live circuit with several hundred volts lurking inside. There's
been some "yeah, but it probably won't kill you" comments made. Best not to
find out!!!
Lots of things can go wrong. Novices should NOT go poking around inside of a
tube amp chassis! It's simple risk analysis. Some tech time is cheaper than a
casket.
TRUE story on how I almost made a BIG mistake...
I bought a Univox U-1061 4x6L6GC 105W bass amp that the previous owner had
screwed with. I was running it with two output tubes at the time. I opened the
chassis for the first time, to look for bonehead circuit changes by the previous
owner (yup, they were there, but that's another discussion).
Now, some power supplies have a resistor in them that will drain the voltage
down in a matter of minutes. So I carefully check the voltage from chassis to
the + point of the bank of filter resistors, thinking that could be the case. I
get a zero reading.
Safe to proceed, right? NO WAY. As a safety precaution (holding the
polycarbonate insulated handle, with tip already touching chassis ground) I put
a screwdriver across the point from ground to filter caps. BIG GNARLY BLUE SPARK.
Damn, I'm glad I pay attention to safety issues! I then noticed that one of my
meter probes were not fully seated in the the meter. A later reading told me
that I could've been bitten by 720V!
Other guys have instinctively grabbed a chassis as it was teetering or falling
from a bench, and been hit with B+. Or just made a move that had no rhyme or
reason.
And these are guys who KNOW what they are doing.
Novices: Learn basic electronics and all safety issues before even thinking of
opening a tube chassis!
Re: Tube amps
On Apr 30, 3:46 pm, Jim <j...@askmebeforeyousend . com > wrote:
> Novices: Learn basic electronics and all safety issues before even thin=
king of
> opening a tube chassis!- Hide quoted text -
>
> - Show quoted text -
Did you ever grab a leaking spark plug wire while the car is running?
Ouch!
Thousands of volts!
You are still alive.
Amperes kill.
Not volts.
Pt
On Apr 30, 3:46 pm, Jim <j...@askmebeforeyousend . com > wrote:
> Novices: Learn basic electronics and all safety issues before even thin=
king of
> opening a tube chassis!- Hide quoted text -
>
> - Show quoted text -
Did you ever grab a leaking spark plug wire while the car is running?
Ouch!
Thousands of volts!
You are still alive.
Amperes kill.
Not volts.
Pt
Re: Tube amps
Pt <peatea@yahoo . com > wrote:
> On Apr 30, 3:46 pm, Jim <j...@askmebeforeyousend . com > wrote:
>
>> Novices: Learn basic electronics and all safety issues before even
>> thinking of opening a tube chassis!- Hide quoted text -
>>
>> - Show quoted text -
>
>
> Did you ever grab a leaking spark plug wire while the car is running?
> Ouch!
> Thousands of volts!
> You are still alive.
> Amperes kill.
> Not volts.
>
> Pt
From the point of view of human physiology, that's just wrong.
Car batteries are capable of delivering pretty high currents. Ever hear
of anyone being killed by one?
The body presents a certain resistance path to ground at a given entry
point. Even if a source is *capable* of delivering a sufficient current
level, it has to have enough voltage to actually *provide* that level of
current through the resistance path presented by the body.
You might want to take a look at this:
* en.wikipedia.org/wiki/Electric_shock
Given what's known about the physiology of electric shocks (and the
advice given here and elsewhere from people who regularly work on amps),
I'd say it's pretty irresponsible to minimize the risks.
Pt <peatea@yahoo . com > wrote:
> On Apr 30, 3:46 pm, Jim <j...@askmebeforeyousend . com > wrote:
>
>> Novices: Learn basic electronics and all safety issues before even
>> thinking of opening a tube chassis!- Hide quoted text -
>>
>> - Show quoted text -
>
>
> Did you ever grab a leaking spark plug wire while the car is running?
> Ouch!
> Thousands of volts!
> You are still alive.
> Amperes kill.
> Not volts.
>
> Pt
From the point of view of human physiology, that's just wrong.
Car batteries are capable of delivering pretty high currents. Ever hear
of anyone being killed by one?
The body presents a certain resistance path to ground at a given entry
point. Even if a source is *capable* of delivering a sufficient current
level, it has to have enough voltage to actually *provide* that level of
current through the resistance path presented by the body.
You might want to take a look at this:
* en.wikipedia.org/wiki/Electric_shock
Given what's known about the physiology of electric shocks (and the
advice given here and elsewhere from people who regularly work on amps),
I'd say it's pretty irresponsible to minimize the risks.
Re: Tube amps
On Apr 30, 7:52 pm, "RichL" <rpleav...@yahoo . com > wrote:
> I'd say it's pretty irresponsible to minimize the risks.-
Of course it is and people should not stick their hands in to places
where they don't belong.
But like I said before it is not rocket sceience.
Educate yourself on the subject.
This doesn't mean you should know Ohms or Watts laws, it means to know
where the capacitors are and how to discharge them if necessary.
Too many people believe that amps will kill them.
Have you ever heard of someone being killed working on guitar amps?
I'm sure it has happened but it is rare.
You can also drown in a bathtub.
Pt
On Apr 30, 7:52 pm, "RichL" <rpleav...@yahoo . com > wrote:
> I'd say it's pretty irresponsible to minimize the risks.-
Of course it is and people should not stick their hands in to places
where they don't belong.
But like I said before it is not rocket sceience.
Educate yourself on the subject.
This doesn't mean you should know Ohms or Watts laws, it means to know
where the capacitors are and how to discharge them if necessary.
Too many people believe that amps will kill them.
Have you ever heard of someone being killed working on guitar amps?
I'm sure it has happened but it is rare.
You can also drown in a bathtub.
Pt
Re: Tube amps
Pt presented the following explanation :
> On Apr 30, 7:52 pm, "RichL" <rpleav...@yahoo . com > wrote:
>
>> I'd say it's pretty irresponsible to minimize the risks.-
>
> Of course it is and people should not stick their hands in to places
> where they don't belong.
True...like bear traps.
> But like I said before it is not rocket sceience.
Not wrong, but not intirely true. Rocket Science includes the use of
electricity.....:)
> Educate yourself on the subject.
I have. Over 3 years of study and many more in prractice.
> This doesn't mean you should know Ohms or Watts laws, it means to know
> where the capacitors are and how to discharge them if necessary.
Mate, that is wrong. Working safely on any eqipment that is mains
powered requires that the person doing the work understands how
electricity works. So you do need to know Ohm's Law, Coulomb's Law,
Lenz's Law, Farady's Law, Your In-laws, L.A. Law,Long Arm of the Law
and all of the other laws that relate to electricty.
This is the point...If you don't know how electricity works how would
you even know when you were in danger??? You can't see the stuff...you
can only measure it by sensor. It takes a realitively high level of
knowlege just to use the test gear...
> Too many people believe that amps will kill them.
I would say they were correct. Ok, there is a bit more to it, but in
general they are right.
> Have you ever heard of someone being killed working on guitar amps?
no, but I do know of cases where people have been killed by TVs and
stereo equipment.
> I'm sure it has happened but it is rare.
> You can also drown in a bathtub.
I almost drowned in a gin bottle.
>
> Pt
Pt presented the following explanation :
> On Apr 30, 7:52 pm, "RichL" <rpleav...@yahoo . com > wrote:
>
>> I'd say it's pretty irresponsible to minimize the risks.-
>
> Of course it is and people should not stick their hands in to places
> where they don't belong.
True...like bear traps.
> But like I said before it is not rocket sceience.
Not wrong, but not intirely true. Rocket Science includes the use of
electricity.....:)
> Educate yourself on the subject.
I have. Over 3 years of study and many more in prractice.
> This doesn't mean you should know Ohms or Watts laws, it means to know
> where the capacitors are and how to discharge them if necessary.
Mate, that is wrong. Working safely on any eqipment that is mains
powered requires that the person doing the work understands how
electricity works. So you do need to know Ohm's Law, Coulomb's Law,
Lenz's Law, Farady's Law, Your In-laws, L.A. Law,Long Arm of the Law
and all of the other laws that relate to electricty.
This is the point...If you don't know how electricity works how would
you even know when you were in danger??? You can't see the stuff...you
can only measure it by sensor. It takes a realitively high level of
knowlege just to use the test gear...
> Too many people believe that amps will kill them.
I would say they were correct. Ok, there is a bit more to it, but in
general they are right.
> Have you ever heard of someone being killed working on guitar amps?
no, but I do know of cases where people have been killed by TVs and
stereo equipment.
> I'm sure it has happened but it is rare.
> You can also drown in a bathtub.
I almost drowned in a gin bottle.
>
> Pt
Re: Tube amps
ARLOWE expounded in news:mn.0b687d8533297697.90583@nose.picker . com :
> Pt presented the following explanation :
>> On Apr 30, 7:52 pm, "RichL" <rpleav...@yahoo . com > wrote:
>>
>>> I'd say it's pretty irresponsible to minimize the risks.-
>>
>> Of course it is and people should not stick their hands in to places
>> where they don't belong.
>
> True...like bear traps.
>
>> But like I said before it is not rocket sceience.
..
>> Have you ever heard of someone being killed working on guitar amps?
>
> no, but I do know of cases where people have been killed by TVs and
> stereo equipment.
>>
>> Pt
The warning was issued, ppl here have read it, and that
should be enough. I think Pt's point is simply that some
dwell too much on "scaring" instead of educating ppl
on what they need to know (or pointing them to resources).
Not that my experience is any proof, but I as a kid I
was able to gain the necessary basic knowledge and
safely survived all kinds of TV set repairs. If a kid
can do it, others here can as well.
The worst thing that ever happened to me was the
cut I got from touching a (temperature) hot tube
and cutting my hand on something sharp as I
instinctively pulled it away.
The thing I find most fascinating is that most ppl are
more willing to overlook ppl doing their own home
wiring-- but when it comes to tube amps, everyone
starts with the UPPERCASE messages.
Snark.
** Posted from * w w w .teranews . com **
ARLOWE expounded in news:mn.0b687d8533297697.90583@nose.picker . com :
> Pt presented the following explanation :
>> On Apr 30, 7:52 pm, "RichL" <rpleav...@yahoo . com > wrote:
>>
>>> I'd say it's pretty irresponsible to minimize the risks.-
>>
>> Of course it is and people should not stick their hands in to places
>> where they don't belong.
>
> True...like bear traps.
>
>> But like I said before it is not rocket sceience.
..
>> Have you ever heard of someone being killed working on guitar amps?
>
> no, but I do know of cases where people have been killed by TVs and
> stereo equipment.
>>
>> Pt
The warning was issued, ppl here have read it, and that
should be enough. I think Pt's point is simply that some
dwell too much on "scaring" instead of educating ppl
on what they need to know (or pointing them to resources).
Not that my experience is any proof, but I as a kid I
was able to gain the necessary basic knowledge and
safely survived all kinds of TV set repairs. If a kid
can do it, others here can as well.
The worst thing that ever happened to me was the
cut I got from touching a (temperature) hot tube
and cutting my hand on something sharp as I
instinctively pulled it away.
The thing I find most fascinating is that most ppl are
more willing to overlook ppl doing their own home
wiring-- but when it comes to tube amps, everyone
starts with the UPPERCASE messages.
Snark.
** Posted from * w w w .teranews . com **
Re: Tube amps
Charmed Snark wrote:
> The warning was issued, ppl here have read it, and that
> should be enough. I think Pt's point is simply that some
> dwell too much on "scaring" instead of educating ppl
> on what they need to know...
Ok, so I won't stick my 12AX7 in my mouth.
Is there somewhere else I should stick it?
Lumpy
In Your Ears for 40 Years
w w w .LumpyMusic . com
Charmed Snark wrote:
> The warning was issued, ppl here have read it, and that
> should be enough. I think Pt's point is simply that some
> dwell too much on "scaring" instead of educating ppl
> on what they need to know...
Ok, so I won't stick my 12AX7 in my mouth.
Is there somewhere else I should stick it?
Lumpy
In Your Ears for 40 Years
w w w .LumpyMusic . com
Re: Tube amps
"Lumpy" <lumpy@digitalcartography . com > wrote in message
news:680gs7F2r07vdU1@mid.individual . net ...
> Charmed Snark wrote:
>> The warning was issued, ppl here have read it, and that
>> should be enough. I think Pt's point is simply that some
>> dwell too much on "scaring" instead of educating ppl
>> on what they need to know...
>
> Ok, so I won't stick my 12AX7 in my mouth.
> Is there somewhere else I should stick it?
>
>
Will....NOT....Reply......will NOT reply......will NOT Reply...
(Whew, the temptation has left the building.)
Don
Drinkin' yer beers for 40 years..
w w w .cosmoslair . com /photos/Misc/DownAndOut.jpg
> Lumpy
>
> In Your Ears for 40 Years
> w w w .LumpyMusic . com
>
>
>
"Lumpy" <lumpy@digitalcartography . com > wrote in message
news:680gs7F2r07vdU1@mid.individual . net ...
> Charmed Snark wrote:
>> The warning was issued, ppl here have read it, and that
>> should be enough. I think Pt's point is simply that some
>> dwell too much on "scaring" instead of educating ppl
>> on what they need to know...
>
> Ok, so I won't stick my 12AX7 in my mouth.
> Is there somewhere else I should stick it?
>
>
Will....NOT....Reply......will NOT reply......will NOT Reply...
(Whew, the temptation has left the building.)
Don
Drinkin' yer beers for 40 years..
w w w .cosmoslair . com /photos/Misc/DownAndOut.jpg
> Lumpy
>
> In Your Ears for 40 Years
> w w w .LumpyMusic . com
>
>
>
Re: Tube amps
Pt wrote:
> On Apr 30, 3:46 pm, Jim <j...@askmebeforeyousend . com > wrote:
>
>
>>Novices: Learn basic electronics and all safety issues before even thinking of
>>opening a tube chassis!- Hide quoted text -
>>
>>- Show quoted text -
>
>
>
> Did you ever grab a leaking spark plug wire while the car is running?
> Ouch!
> Thousands of volts!
> You are still alive.
> Amperes kill.
> Not volts.
>
> Pt
A tube amp has enough current at high enough voltage to kill you dead! Saying
otherwise is not only stupid, but potentially lethal advice.
Pt wrote:
> On Apr 30, 3:46 pm, Jim <j...@askmebeforeyousend . com > wrote:
>
>
>>Novices: Learn basic electronics and all safety issues before even thinking of
>>opening a tube chassis!- Hide quoted text -
>>
>>- Show quoted text -
>
>
>
> Did you ever grab a leaking spark plug wire while the car is running?
> Ouch!
> Thousands of volts!
> You are still alive.
> Amperes kill.
> Not volts.
>
> Pt
A tube amp has enough current at high enough voltage to kill you dead! Saying
otherwise is not only stupid, but potentially lethal advice.
Re: Tube amps
"Jim" <jim@askmebeforeyousend . com > wrote in message
news:AeSdnQxxZ7t82oTVnZ2dnUVZ_uydnZ2d@isomediainc...
>
> A tube amp has enough current at high enough voltage to kill you dead!
As opposed to the other types of killing? <G>
"Jim" <jim@askmebeforeyousend . com > wrote in message
news:AeSdnQxxZ7t82oTVnZ2dnUVZ_uydnZ2d@isomediainc...
>
> A tube amp has enough current at high enough voltage to kill you dead!
As opposed to the other types of killing? <G>
Re: Tube amps
On Thu, 1 May 2008 09:43:34 -0700, Don Freeman wrote:
> "Jim" <jim@askmebeforeyousend . com > wrote in message
> news:AeSdnQxxZ7t82oTVnZ2dnUVZ_uydnZ2d@isomediainc...
>>
>> A tube amp has enough current at high enough voltage to kill you dead!
>
> As opposed to the other types of killing? <G>
Can you be half-dead more than twice?
--
Tim C.
On Thu, 1 May 2008 09:43:34 -0700, Don Freeman wrote:
> "Jim" <jim@askmebeforeyousend . com > wrote in message
> news:AeSdnQxxZ7t82oTVnZ2dnUVZ_uydnZ2d@isomediainc...
>>
>> A tube amp has enough current at high enough voltage to kill you dead!
>
> As opposed to the other types of killing? <G>
Can you be half-dead more than twice?
--
Tim C.
