[DM]

Hi Group!! Novice question here.. I've got a Art Pro channel pre/comp/
eq.. when I engage the tube comp, there's a slight noise (hissy?)..
will replacing tubes helps? if so, which (noise-free)preamp tubes to
get? thanks inadvence!!

[Peter Wieck]

On May 10, 12:37 pm, DM wrote:
Hi Group!! Novice question here.. I've got a Art Pro channel pre/comp/
eq.. when I engage the tube comp, there's a slight noise (hissy?)..
will replacing tubes helps? if so, which (noise-free)preamp tubes to
get? thanks inadvence!!

Is the hiss continuous? And on all sources and at the same background
volume (does it vary by volume)?

Peter Wieck
Wyncote, PA

[DM]

On May 10, 9:57 am, Peter Wieck wrote:
On May 10, 12:37 pm, DM wrote:

Hi Group!! Novice question here.. I've got a Art Pro channel pre/comp/
eq.. when I engage the tube comp, there's a slight noise (hissy?)..
will replacing tubes helps? if so, which (noise-free)preamp tubes to
get? thanks inadvence!!

Is the hiss continuous? And on all sources and at the same background
volume (does it vary by volume)?

Peter Wieck
Wyncote, PA


It gets louder when I turn the Compressor knob, The Preamp has optical
and tube compressor switch.
Noise issue only on tube comp side, optical comp is smoothly quite..
is this a Tube preamp issue? thanks..

[Peter Wieck]

On May 10, 5:22 pm, DM wrote:

It gets louder when I turn the Compressor knob, The Preamp has optical
and tube compressor switch.
Noise issue only on tube comp side, optical comp is smoothly quite..
is this a Tube preamp issue? thanks..

It could be, and the cure for that might be to check various other
tubes to see if the hiss goes away. But my experience with a *hiss*
rather than either a ringing or other sorts of sporadic noises
(microphonic tubes) is that it is typically either a failed peripheral
part (such as a capacitor), or dirt on the socket or tube pins, or
the controls, or other problem, seldom (but not never) the tubes
themselves.

How old is this unit and what sort of service has it seen?

Peter Wieck
Wyncote, PA

[DM]

On May 10, 2:32 pm, Peter Wieck wrote:
On May 10, 5:22 pm, DM wrote:

It gets louder when I turn the Compressor knob, The Preamp has optical
and tube compressor switch.
Noise issue only on tube comp side, optical comp is smoothly quite..
is this a Tube preamp issue? thanks..

It could be, and the cure for that might be to check various other
tubes to see if the hiss goes away. But my experience with a *hiss*
rather than either a ringing or other sorts of sporadic noises
(microphonic tubes) is that it is typically either a failed peripheral
part (such as a capacitor), or dirt on the socket or tube pins, or
the controls, or other problem, seldom (but not never) the tubes
themselves.

How old is this unit and what sort of service has it seen?

Peter Wieck
Wyncote, PA

Less than a Week old.. it get's pretty hot too, never had a preamp
this hot?
Which Preamp (less noise) Tubes would u recommend? thanks..

[Eeyore]

DM wrote:

Hi Group!! Novice question here.. I've got a Art Pro channel pre/comp/
eq..

You mean a cheap piece of MI gear don't you ? Real 'pro' isn't just a name
that's screened on the box.


when I engage the tube comp, there's a slight noise (hissy?)..

Entirely to be expected. Tubes are noisier than solid state.


will replacing tubes helps?

Pretty unlikely. You're chasing faeries at this point.


if so, which (noise-free)preamp tubes

No such thing..


to get? thanks inadvence!!

Err, no comment.

Graham

[Eeyore]

Peter Wieck wrote:

But my experience with a *hiss* rather than either a ringing or other sorts of
sporadic noises (microphonic tubes) is that it is typically either a failed
peripheral
part (such as a capacitor)

Exactly when did you come across a hissy capacitor ?

Graham

[Eeyore]

DM wrote:

it get's pretty hot too, never had a preamp this hot?

What did you expect with a damn tube in it ?

They have these things called *heaters* (filaments to US types) you know !


Which Preamp (less noise) Tubes would u recommend? thanks..

For the typical ECC83/12AX7 used in this kind of kit the usual response is
Telefunken.

Graham

[Patrick Turner]

DM wrote:

On May 10, 9:57 am, Peter Wieck wrote:
On May 10, 12:37 pm, DM wrote:

Hi Group!! Novice question here.. I've got a Art Pro channel pre/comp/
eq.. when I engage the tube comp, there's a slight noise (hissy?)..
will replacing tubes helps? if so, which (noise-free)preamp tubes to
get? thanks inadvence!!

Is the hiss continuous? And on all sources and at the same background
volume (does it vary by volume)?

Peter Wieck
Wyncote, PA

It gets louder when I turn the Compressor knob, The Preamp has optical
and tube compressor switch.
Noise issue only on tube comp side, optical comp is smoothly quite..
is this a Tube preamp issue? thanks..

The unit should be dead quiet without line level signals present, and
despite what the other tube hating clowns tell you here on the group.

A good 12AX7 will have 2uV of noise at its input, and maybe 0.14mV at
its output
so if the signal is 0.28mV, SNR = -66dB unweighted. For best noise
results gain pot
should be after the tube, and the signal should not overload the tube to
begin with, so
you shouldn't have 1V applied to the tube input, amp up to 70V, then use
the pot to reduce that.

Without seeing the schematic, we cannot advise with any real certainty,
and its another reason to doubt the ****wit
know nothings here who advise without enough data and consideration
about what might be
really causing your problem.

Probably noise is due toa tube noisy tube.

NOS Telefunken will cost a huge amount and there is no gurantee at all
that whoever you buy from
hasn't had a couple of thousand hours from the tube, then popped it back
into its pristine
condition box for another repeat sale of New Old Stock.

NOS sales are to therefore be suspect. Try russian 12AX7 first, or try
anything first before spending big on fancy-shmancy
old german made so called NOS.

Patrick Turner.

[Peter Wieck]

On May 10, 6:02 pm, Eeyore
wrote:
Peter Wieck wrote:
But my experience with a *hiss* rather than either a ringing or other sorts of
sporadic noises (microphonic tubes) is that it is typically either a failed
peripheral
part (such as a capacitor)

Exactly when did you come across a hissy capacitor ?

Graham

In many circuits, when they leak a bit, the circuit hisses. Especially
when the leaking is heat-related. It is a remarkably common fault....
You don't do many vintage radios, do you?

Peter Wieck
Wyncote, PA

[Peter Wieck]

On May 10, 7:16 pm, Patrick Turner wrote:
DM wrote:

On May 10, 9:57 am, Peter Wieck wrote:
On May 10, 12:37 pm, DM wrote:

Hi Group!! Novice question here.. I've got a Art Pro channel pre/comp/
eq.. when I engage the tube comp, there's a slight noise (hissy?)..
will replacing tubes helps? if so, which (noise-free)preamp tubes to
get? thanks inadvence!!

Is the hiss continuous? And on all sources and at the same background
volume (does it vary by volume)?

Peter Wieck
Wyncote, PA

It gets louder when I turn the Compressor knob, The Preamp has optical
and tube compressor switch.
Noise issue only on tube comp side, optical comp is smoothly quite..
is this a Tube preamp issue? thanks..

The unit should be dead quiet without line level signals present, and
despite what the other tube hating clowns tell you here on the group.

A good 12AX7 will have 2uV of noise at its input, and maybe 0.14mV at
its output
so if the signal is 0.28mV, SNR = -66dB unweighted. For best noise
results gain pot
should be after the tube, and the signal should not overload the tube to
begin with, so
you shouldn't have 1V applied to the tube input, amp up to 70V, then use
the pot to reduce that.

Without seeing the schematic, we cannot advise with any real certainty,
and its another reason to doubt the ****wit
know nothings here who advise without enough data and consideration
about what might be
really causing your problem.

Probably noise is due toa tube noisy tube.

NOS Telefunken will cost a huge amount and there is no gurantee at all
that whoever you buy from
hasn't had a couple of thousand hours from the tube, then popped it back
into its pristine
condition box for another repeat sale of New Old Stock.

NOS sales are to therefore be suspect. Try russian 12AX7 first, or try
anything first before spending big on fancy-shmancy
old german made so called NOS.

Patrick Turner.- Hide quoted text -

- Show quoted text -

I would suggest a mil.spec. Sylvania 5751, if you can find it. Much
cheaper than a Telefunken, very low noise, and will run rings around
it under most conditions. I have never seen the appeal in the Teles
other than the yiches.

Now, if there are Chineses tubes in that thing, that would be the
problem, and I would have to apologize for steering you in any other
direction without asking that question first. Go with Patrick if you
must buy new tubes. Otherwise, gather a representative sample of
12AX7s and see where they go.

But still clean the socket and check for something loose. That the
unit is brand new does not exempt it from teething problems as these
days stuff out of China may be batch tested only if at all.

Peter Wieck
Wyncote, PA

[DM]

On May 10, 5:33 pm, Peter Wieck wrote:
On May 10, 7:16 pm, Patrick Turner wrote:





DM wrote:

On May 10, 9:57 am, Peter Wieck wrote:
On May 10, 12:37 pm, DM wrote:

Hi Group!! Novice question here.. I've got a Art Pro channel pre/comp/
eq.. when I engage the tube comp, there's a slight noise (hissy?)..
will replacing tubes helps? if so, which (noise-free)preamp tubes to
get? thanks inadvence!!

Is the hiss continuous? And on all sources and at the same background
volume (does it vary by volume)?

Peter Wieck
Wyncote, PA

It gets louder when I turn the Compressor knob, The Preamp has optical
and tube compressor switch.
Noise issue only on tube comp side, optical comp is smoothly quite..
is this a Tube preamp issue? thanks..

The unit should be dead quiet without line level signals present, and
despite what the other tube hating clowns tell you here on the group.

A good 12AX7 will have 2uV of noise at its input, and maybe 0.14mV at
its output
so if the signal is 0.28mV, SNR = -66dB unweighted. For best noise
results gain pot
should be after the tube, and the signal should not overload the tube to
begin with, so
you shouldn't have 1V applied to the tube input, amp up to 70V, then use
the pot to reduce that.

Without seeing the schematic, we cannot advise with any real certainty,
and its another reason to doubt the ****wit
know nothings here who advise without enough data and consideration
about what might be
really causing your problem.

Probably noise is due toa tube noisy tube.

NOS Telefunken will cost a huge amount and there is no gurantee at all
that whoever you buy from
hasn't had a couple of thousand hours from the tube, then popped it back
into its pristine
condition box for another repeat sale of New Old Stock.

NOS sales are to therefore be suspect. Try russian 12AX7 first, or try
anything first before spending big on fancy-shmancy
old german made so called NOS.

Patrick Turner.- Hide quoted text -

- Show quoted text -

I would suggest a mil.spec. Sylvania 5751, if you can find it. Much
cheaper than a Telefunken, very low noise, and will run rings around
it under most conditions. I have never seen the appeal in the Teles
other than the yiches.

Now, if there are Chineses tubes in that thing, that would be the
problem, and I would have to apologize for steering you in any other
direction without asking that question first. Go with Patrick if you
must buy new tubes. Otherwise, gather a representative sample of
12AX7s and see where they go.

But still clean the socket and check for something loose. That the
unit is brand new does not exempt it from teething problems as these
days stuff out of China may be batch tested only if at all.

Peter Wieck
Wyncote, PA- Hide quoted text -

- Show quoted text -

learn alot about preamp tubes Thanks for all the Help!!!

[west[_3_]]

"DM" wrote in message
ups.com...
On May 10, 5:33 pm, Peter Wieck wrote:
On May 10, 7:16 pm, Patrick Turner wrote:





DM wrote:

On May 10, 9:57 am, Peter Wieck wrote:
On May 10, 12:37 pm, DM wrote:

Hi Group!! Novice question here.. I've got a Art Pro channel
pre/comp/
eq.. when I engage the tube comp, there's a slight noise
(hissy?)..
will replacing tubes helps? if so, which (noise-free)preamp
tubes to
get? thanks inadvence!!

Is the hiss continuous? And on all sources and at the same
background
volume (does it vary by volume)?

Peter Wieck
Wyncote, PA

It gets louder when I turn the Compressor knob, The Preamp has
optical
and tube compressor switch.
Noise issue only on tube comp side, optical comp is smoothly quite..
is this a Tube preamp issue? thanks..

The unit should be dead quiet without line level signals present, and
despite what the other tube hating clowns tell you here on the group.

A good 12AX7 will have 2uV of noise at its input, and maybe 0.14mV at
its output
so if the signal is 0.28mV, SNR = -66dB unweighted. For best noise
results gain pot
should be after the tube, and the signal should not overload the tube
to
begin with, so
you shouldn't have 1V applied to the tube input, amp up to 70V, then
use
the pot to reduce that.

Without seeing the schematic, we cannot advise with any real
certainty,
and its another reason to doubt the ****wit
know nothings here who advise without enough data and consideration
about what might be
really causing your problem.

Probably noise is due toa tube noisy tube.

NOS Telefunken will cost a huge amount and there is no gurantee at all
that whoever you buy from
hasn't had a couple of thousand hours from the tube, then popped it
back
into its pristine
condition box for another repeat sale of New Old Stock.

NOS sales are to therefore be suspect. Try russian 12AX7 first, or try
anything first before spending big on fancy-shmancy
old german made so called NOS.

Patrick Turner.- Hide quoted text -

- Show quoted text -

I would suggest a mil.spec. Sylvania 5751, if you can find it. Much
cheaper than a Telefunken, very low noise, and will run rings around
it under most conditions. I have never seen the appeal in the Teles
other than the yiches.

Now, if there are Chineses tubes in that thing, that would be the
problem, and I would have to apologize for steering you in any other
direction without asking that question first. Go with Patrick if you
must buy new tubes. Otherwise, gather a representative sample of
12AX7s and see where they go.

But still clean the socket and check for something loose. That the
unit is brand new does not exempt it from teething problems as these
days stuff out of China may be batch tested only if at all.

Peter Wieck
Wyncote, PA- Hide quoted text -

- Show quoted text -

learn alot about preamp tubes Thanks for all the Help!!!

I doubt if a cap can give you a hiss of that sort. If you were talking about
an RF circuit, then yes, but not in an audio circuit. I can not add to
Patrick's advice, but certainly could help in discounting the charlatan's
advice.

Cordially,
west

[Peter Wieck]

On May 12, 10:29 am, "west" wrote:
"DM" wrote in message

ups.com...





On May 10, 5:33 pm, Peter Wieck wrote:
On May 10, 7:16 pm, Patrick Turner wrote:

DM wrote:

On May 10, 9:57 am, Peter Wieck wrote:
On May 10, 12:37 pm, DM wrote:

Hi Group!! Novice question here.. I've got a Art Pro channel
pre/comp/
eq.. when I engage the tube comp, there's a slight noise
(hissy?)..
will replacing tubes helps? if so, which (noise-free)preamp
tubes to
get? thanks inadvence!!

Is the hiss continuous? And on all sources and at the same
background
volume (does it vary by volume)?

Peter Wieck
Wyncote, PA

It gets louder when I turn the Compressor knob, The Preamp has
optical
and tube compressor switch.
Noise issue only on tube comp side, optical comp is smoothly quite..
is this a Tube preamp issue? thanks..

The unit should be dead quiet without line level signals present, and
despite what the other tube hating clowns tell you here on the group.

A good 12AX7 will have 2uV of noise at its input, and maybe 0.14mV at
its output
so if the signal is 0.28mV, SNR = -66dB unweighted. For best noise
results gain pot
should be after the tube, and the signal should not overload the tube
to
begin with, so
you shouldn't have 1V applied to the tube input, amp up to 70V, then
use
the pot to reduce that.

Without seeing the schematic, we cannot advise with any real
certainty,
and its another reason to doubt the ****wit
know nothings here who advise without enough data and consideration
about what might be
really causing your problem.

Probably noise is due toa tube noisy tube.

NOS Telefunken will cost a huge amount and there is no gurantee at all
that whoever you buy from
hasn't had a couple of thousand hours from the tube, then popped it
back
into its pristine
condition box for another repeat sale of New Old Stock.

NOS sales are to therefore be suspect. Try russian 12AX7 first, or try
anything first before spending big on fancy-shmancy
old german made so called NOS.

Patrick Turner.- Hide quoted text -

- Show quoted text -

I would suggest a mil.spec. Sylvania 5751, if you can find it. Much
cheaper than a Telefunken, very low noise, and will run rings around
it under most conditions. I have never seen the appeal in the Teles
other than the yiches.

Now, if there are Chineses tubes in that thing, that would be the
problem, and I would have to apologize for steering you in any other
direction without asking that question first. Go with Patrick if you
must buy new tubes. Otherwise, gather a representative sample of
12AX7s and see where they go.

But still clean the socket and check for something loose. That the
unit is brand new does not exempt it from teething problems as these
days stuff out of China may be batch tested only if at all.

Peter Wieck
Wyncote, PA- Hide quoted text -

- Show quoted text -

learn alot about preamp tubes Thanks for all the Help!!!

I doubt if a cap can give you a hiss of that sort. If you were talking about
an RF circuit, then yes, but not in an audio circuit. I can not add to
Patrick's advice, but certainly could help in discounting the charlatan's
advice.

Cordially,
west



- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -

Yo, twit. I repeat, you don't get out much, do you? And you say you
have "... built amps with 6550s and El-34s...."? From a cookbook or
kit no doubt, not from understanding the circuits or components.

Examples. Dynaco ST-70... there are two (2) 0.1uF caps. If either one
of them has a temperature-related leak problem... such that the
leakage is threshold-related, you will get a low-pop---- hiss-to-decay-
to-silence as it cycles. On the PAS (as we are discussing pre-amps),
the 0.05uF cap on the phono-board can have the same effect, although
usually without cycling . Seen it, done it, fixed it. Hey, I had one
70 cross my bench that as long as I kept the voltage at 110V or less,
everything was fine. The moment it went into the line, (121V at its
home-location),
*pop*HISSssssss................................... ....................*pop*HISSssssssss.
Caps. 45 YO caps, but caps none-the-less.

I have seen near-as-many "impossible, it can't do that" situations and
conditions come across my bench as so-called 'typical' ones. And I am
always ready for something new to happen that I have never seen
before.

Peter Wieck
Wyncote, PA

[west[_3_]]

"Peter Wieck" wrote in message
ups.com...
On May 12, 10:29 am, "west" wrote:
"DM" wrote in message

ups.com...





On May 10, 5:33 pm, Peter Wieck wrote:
On May 10, 7:16 pm, Patrick Turner wrote:

DM wrote:

On May 10, 9:57 am, Peter Wieck wrote:
On May 10, 12:37 pm, DM wrote:

Hi Group!! Novice question here.. I've got a Art Pro channel
pre/comp/
eq.. when I engage the tube comp, there's a slight noise
(hissy?)..
will replacing tubes helps? if so, which (noise-free)preamp
tubes to
get? thanks inadvence!!

Is the hiss continuous? And on all sources and at the same
background
volume (does it vary by volume)?

Peter Wieck
Wyncote, PA

It gets louder when I turn the Compressor knob, The Preamp has
optical
and tube compressor switch.
Noise issue only on tube comp side, optical comp is smoothly
quite..
is this a Tube preamp issue? thanks..

The unit should be dead quiet without line level signals present,
and
despite what the other tube hating clowns tell you here on the
group.

A good 12AX7 will have 2uV of noise at its input, and maybe 0.14mV
at
its output
so if the signal is 0.28mV, SNR = -66dB unweighted. For best noise
results gain pot
should be after the tube, and the signal should not overload the
tube
to
begin with, so
you shouldn't have 1V applied to the tube input, amp up to 70V,
then
use
the pot to reduce that.

Without seeing the schematic, we cannot advise with any real
certainty,
and its another reason to doubt the ****wit
know nothings here who advise without enough data and
consideration
about what might be
really causing your problem.

Probably noise is due toa tube noisy tube.

NOS Telefunken will cost a huge amount and there is no gurantee at
all
that whoever you buy from
hasn't had a couple of thousand hours from the tube, then popped
it
back
into its pristine
condition box for another repeat sale of New Old Stock.

NOS sales are to therefore be suspect. Try russian 12AX7 first, or
try
anything first before spending big on fancy-shmancy
old german made so called NOS.

Patrick Turner.- Hide quoted text -

- Show quoted text -

I would suggest a mil.spec. Sylvania 5751, if you can find it. Much
cheaper than a Telefunken, very low noise, and will run rings around
it under most conditions. I have never seen the appeal in the Teles
other than the yiches.

Now, if there are Chineses tubes in that thing, that would be the
problem, and I would have to apologize for steering you in any other
direction without asking that question first. Go with Patrick if you
must buy new tubes. Otherwise, gather a representative sample of
12AX7s and see where they go.

But still clean the socket and check for something loose. That the
unit is brand new does not exempt it from teething problems as these
days stuff out of China may be batch tested only if at all.

Peter Wieck
Wyncote, PA- Hide quoted text -

- Show quoted text -

learn alot about preamp tubes Thanks for all the Help!!!

I doubt if a cap can give you a hiss of that sort. If you were talking
about
an RF circuit, then yes, but not in an audio circuit. I can not add to
Patrick's advice, but certainly could help in discounting the
charlatan's
advice.

Cordially,
west



- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -

Yo, twit. I repeat, you don't get out much, do you? And you say you
have "... built amps with 6550s and El-34s...."? From a cookbook or
kit no doubt, not from understanding the circuits or components.

Examples. Dynaco ST-70... there are two (2) 0.1uF caps. If either one
of them has a temperature-related leak problem... such that the
leakage is threshold-related, you will get a low-pop---- hiss-to-decay-
to-silence as it cycles. On the PAS (as we are discussing pre-amps),
the 0.05uF cap on the phono-board can have the same effect, although
usually without cycling . Seen it, done it, fixed it. Hey, I had one
70 cross my bench that as long as I kept the voltage at 110V or less,
everything was fine. The moment it went into the line, (121V at its
home-location),

*pop*HISSssssss................................... ....................*pop*H
ISSssssssss.
Caps. 45 YO caps, but caps none-the-less.

I have seen near-as-many "impossible, it can't do that" situations and
conditions come across my bench as so-called 'typical' ones. And I am
always ready for something new to happen that I have never seen
before.

Peter Wieck
Wyncote, PA

I could understand your embarrassment. Don't take it so hard.

west

[Gerry[_2_]]

On May 10, 8:33 pm, Peter Wieck wrote:

But still clean the socket and check for something loose.

How would you recommend cleaning a socket? I've got an amp that gets
fairly noisy with hissing and occasional popping, and the EL84 tubes
seem rather loose in the sockets. Moving them around in the sockets
seems to make the noise go away temporarily. I've tried spraying the
sockets with contact cleaner, but that didn't seem to help. Pushing
the tubes back down helps for a little while, but they seem to work
their way back out to their loose state after a while.

Gerry

[jaap[_2_]]

Gerry schreef:
On May 10, 8:33 pm, Peter Wieck wrote:

But still clean the socket and check for something loose.

How would you recommend cleaning a socket? I've got an amp that gets
fairly noisy with hissing and occasional popping, and the EL84 tubes
seem rather loose in the sockets. Moving them around in the sockets
seems to make the noise go away temporarily. I've tried spraying the
sockets with contact cleaner, but that didn't seem to help. Pushing
the tubes back down helps for a little while, but they seem to work
their way back out to their loose state after a while.

Gerry


The spray solution is intended for removing light oxidation from
undamaged surfaces and leaves a protective film to protect against
further oxidation. You best apply modest quantities and wipe off excess
fluid. Tobacco stores sell pipe cleaners (cotton on a wire) which are
useful to get inside the pinholes.

Once a contact has been damaged by arcing you better replace the
complete socket. The same goes for low quality sockets used in the past.

Jaap

[Eeyore]

Gerry wrote:

On May 10, 8:33 pm, Peter Wieck wrote:

But still clean the socket and check for something loose.

How would you recommend cleaning a socket? I've got an amp that gets
fairly noisy with hissing and occasional popping, and the EL84 tubes
seem rather loose in the sockets. Moving them around in the sockets
seems to make the noise go away temporarily. I've tried spraying the
sockets with contact cleaner, but that didn't seem to help. Pushing
the tubes back down helps for a little while, but they seem to work
their way back out to their loose state after a while.

Several posters in rec.audio.pro swear by Caig De-oxit.

Graham

[Patrick Turner]

Gerry wrote:

On May 10, 8:33 pm, Peter Wieck wrote:

But still clean the socket and check for something loose.

How would you recommend cleaning a socket? I've got an amp that gets
fairly noisy with hissing and occasional popping, and the EL84 tubes
seem rather loose in the sockets. Moving them around in the sockets
seems to make the noise go away temporarily. I've tried spraying the
sockets with contact cleaner, but that didn't seem to help. Pushing
the tubes back down helps for a little while, but they seem to work
their way back out to their loose state after a while.

Gerry

Get yourself an awl. This is simply a 3mm dia steel spike with wooden
handle used for
all sorts of general hole making in leather work.

This can be CAREFULLY used to reach down into the pin holes in a socket
and to bend the pin grippers together where they have become spread over
time and constant
movement and in-outing of tubes.

Sometimes you have to file/grind the round awl point flat to fit into a
slot beside a
pin gripper but most 9 pin sockets allow a normal awl entry.
Don't apply too much bend force because if the socket is ceramic it can
crack,
and then then you have to replace the socket.

If you have a greasy socket from whatever you have sprayed all over it,
use a tooth brush and white spirit
to disolve/dilute it and let the gunk drip through internally where it
is unlikely to harm anything
before it re-dries again and could be wiped clean.
Often a bit of a scrub can remove polution which might be allowing small
lekage currents across the socket.

Let the amp dry right out after cleaning before re-tubing.

Check solder joints to wires to the sockets by applying a small dab of
new solder to each
tag of each socket, and any suspect dry joint will become good again.
Maybe go over all the joints everywhere if you are keen.
Sometimes resistors can be intermittent, and finding which one can be
tiring,
but try all this first, and if noise continues, you need to check
further.
Dodgy resistaors sometimes can be found with a resistance meter across
end to end
and with slight movement of the resistor body you get an OL or open
circuit reading,
or from where its supposed to be connected to; I had a bias setting R in
an amp last week, soldered in
by an incompetent tech person and for years the amp had given troubles
with bias failure.

Then when re-inserting tubes, just press straight in with minimal
rocking side to side,
but makes sure all pins go into a pin gripper, not down between
a gripper and the plastic/ceramic because such a joint won't conduct
properly.

Old sockets made with flat brass sheet pin grippers set up between two
sandwiched layers of
thin bakelite should be all replaced with McMurdo tube sockets.

Such a fix usually lasts OK unless you keep replacing tubes, or
accidently
bend them over in their sockets.

Patrick Turner.

[Peter Wieck]

On May 13, 6:48 am, Gerry wrote:
On May 10, 8:33 pm, Peter Wieck wrote:

But still clean the socket and check for something loose.

How would you recommend cleaning a socket? I've got an amp that gets
fairly noisy with hissing and occasional popping, and the EL84 tubes
seem rather loose in the sockets. Moving them around in the sockets
seems to make the noise go away temporarily. I've tried spraying the
sockets with contact cleaner, but that didn't seem to help. Pushing
the tubes back down helps for a little while, but they seem to work
their way back out to their loose state after a while.

Gerry

OK... socket cleaning 101:

a) some cheap sockets that have been annealed by heat over many years
may be cleaned to oblivion and will never get tight or remain tight.
So, start with the premise that the sockets are still in reasonably
good shape.
b) understand that you will have to get under the chassis and tighten
the pin-clamps in some cases as the cause of the problem is not
(directly) dirt or oxidation but that the clamps are simply loose.

With that in mind, obtain a fine Jeweler's File of the correct
diameter of the pins in question (tapered files may be used with great
care). Get the finest pitch you can, more than anything else it will
be a "polishing file" (#6 grade), about the equivalent of 600-grit wet/
dry paper (and get a file-cleaning card while you are there).

http://www.2spi.com/catalog/tools/smtool8.shtml
http://www.kassoy.com/benchtools/files01.html
http://www.findingking.com/storefron...022&c=10038063

Clean the sockets lightly and carefully. Do not overdo it.

RINSE the cleaned socket with a non-residue cleaner. You want _ALL_
the filings to be out of there.

Get underneath the chassis and with a fine needle-nose plier, riffler
or dental tool (and if you can talk your dentist into saving you a set
of worn out (to him) picks, you will never regret it), tighten each
set of clamps without squashing them. REMEMBER: THE BASE METAL WILL BE
ANNEALED AND SO VERY SOFT.

That should do it.

The problem with the spray-deoxidants and the non-abraisive scrapings
is that they do not really address the loose clampsor the grooves worn
into the clamps by the tube pins.

It also helps to lightly touch up the tube pins themselves with a flat-
file to roughen the surface a wee-tiny bit. This enhances the friction
when they are installed which in turn helps make better contact.
Again, use the FINEST file.

Once again, use a non-residue cleaner to rinse everything down after
cleaning.

Peter Wieck
Wyncote, PA

[DM]

Wanna hear some opinion on the Following tubes setup;

V1 Preamp - Penta Labs/Shuguang 12AX7
V2 Compressor - Mullard 12AT7WA
V3 EQ - Penta Labs/Shuguang 12AT7

Thanks!!!

[Peter Wieck]

On May 14, 11:11 pm, DM wrote:
Wanna hear some opinion on the Following tubes setup;

V1 Preamp - Penta Labs/Shuguang 12AX7
V2 Compressor - Mullard 12AT7WA
V3 EQ - Penta Labs/Shuguang 12AT7

Thanks!!!

Lose the Chinese tubes and you will be fine. China is perfectly
capable of making a legitmate tube, and as it happens, a certain
number of its tubes happen to be legitimate if only by accident.
Unless you have hundreds to choose from thereby allowing you to cull
for the half-dozen good ones per hundred.

But when they set out to make decent tubes from sand & metal to
finished product, their costs are as high as anyone else and they lose
their competitive advantage.

Peter Wieck
Wyncote, PA

[west[_4_]]

beside, any logical thinker could see the BS because if true, you would have
mentioned these trumped up specifics up front. Indeed, memorizing the values
and part numbers. Do you take us all for idiots? Now you understand what I
meant by the King's war on the disingenuous.

west

"west" wrote in message
news:t1s1i.4108$yy6.3143@trnddc05...

"Peter Wieck" wrote in message
ups.com...
On May 12, 10:29 am, "west" wrote:
"DM" wrote in message

ups.com...





On May 10, 5:33 pm, Peter Wieck wrote:
On May 10, 7:16 pm, Patrick Turner
wrote:

DM wrote:

On May 10, 9:57 am, Peter Wieck wrote:
On May 10, 12:37 pm, DM wrote:

Hi Group!! Novice question here.. I've got a Art Pro
channel
pre/comp/
eq.. when I engage the tube comp, there's a slight noise
(hissy?)..
will replacing tubes helps? if so, which
(noise-free)preamp
tubes to
get? thanks inadvence!!

Is the hiss continuous? And on all sources and at the same
background
volume (does it vary by volume)?

Peter Wieck
Wyncote, PA

It gets louder when I turn the Compressor knob, The Preamp has
optical
and tube compressor switch.
Noise issue only on tube comp side, optical comp is smoothly
quite..
is this a Tube preamp issue? thanks..

The unit should be dead quiet without line level signals
present,
and
despite what the other tube hating clowns tell you here on the
group.

A good 12AX7 will have 2uV of noise at its input, and maybe
0.14mV
at
its output
so if the signal is 0.28mV, SNR = -66dB unweighted. For best
noise
results gain pot
should be after the tube, and the signal should not overload the
tube
to
begin with, so
you shouldn't have 1V applied to the tube input, amp up to 70V,
then
use
the pot to reduce that.

Without seeing the schematic, we cannot advise with any real
certainty,
and its another reason to doubt the ****wit
know nothings here who advise without enough data and
consideration
about what might be
really causing your problem.

Probably noise is due toa tube noisy tube.

NOS Telefunken will cost a huge amount and there is no gurantee
at
all
that whoever you buy from
hasn't had a couple of thousand hours from the tube, then popped
it
back
into its pristine
condition box for another repeat sale of New Old Stock.

NOS sales are to therefore be suspect. Try russian 12AX7 first,
or
try
anything first before spending big on fancy-shmancy
old german made so called NOS.

Patrick Turner.- Hide quoted text -

- Show quoted text -

I would suggest a mil.spec. Sylvania 5751, if you can find it.
Much
cheaper than a Telefunken, very low noise, and will run rings
around
it under most conditions. I have never seen the appeal in the
Teles
other than the yiches.

Now, if there are Chineses tubes in that thing, that would be the
problem, and I would have to apologize for steering you in any
other
direction without asking that question first. Go with Patrick if
you
must buy new tubes. Otherwise, gather a representative sample of
12AX7s and see where they go.

But still clean the socket and check for something loose. That the
unit is brand new does not exempt it from teething problems as
these
days stuff out of China may be batch tested only if at all.

Peter Wieck
Wyncote, PA- Hide quoted text -

- Show quoted text -

learn alot about preamp tubes Thanks for all the Help!!!

I doubt if a cap can give you a hiss of that sort. If you were talking
about
an RF circuit, then yes, but not in an audio circuit. I can not add to
Patrick's advice, but certainly could help in discounting the
charlatan's
advice.

Cordially,
west



- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -

Yo, twit. I repeat, you don't get out much, do you? And you say you
have "... built amps with 6550s and El-34s...."? From a cookbook or
kit no doubt, not from understanding the circuits or components.

Examples. Dynaco ST-70... there are two (2) 0.1uF caps. If either one
of them has a temperature-related leak problem... such that the
leakage is threshold-related, you will get a low-pop---- hiss-to-decay-
to-silence as it cycles. On the PAS (as we are discussing pre-amps),
the 0.05uF cap on the phono-board can have the same effect, although
usually without cycling . Seen it, done it, fixed it. Hey, I had one
70 cross my bench that as long as I kept the voltage at 110V or less,
everything was fine. The moment it went into the line, (121V at its
home-location),


*pop*HISSssssss................................... ....................*pop*H
ISSssssssss.
Caps. 45 YO caps, but caps none-the-less.

I have seen near-as-many "impossible, it can't do that" situations and
conditions come across my bench as so-called 'typical' ones. And I am
always ready for something new to happen that I have never seen
before.

Peter Wieck
Wyncote, PA

I could understand your embarrassment. Don't take it so hard.

west

[Peter Wieck]

You are an idiot. Note the interpolations.

On May 15, 1:12 pm, "west" wrote:

beside, any logical thinker could see the BS because if true, you would have
mentioned these trumped up specifics up front.

Apart from the sad fact that you are not a 'logical thinker', anyone
who had spent any time at all with tube components, especially vintage
components that have been around the block a few times would have
experienced such hiss, and known of its various causes. And anyone who
has been around a bit will have seen even new components experience
teething problems such that certain checks are done as a matter of
course. So, citing specifics is generally required only to slap down
the inexperienced ignorant such as you. And I picked Dynaco circuits
as they are nearly universal across the hobby and well understood by
perhaps tens of thousands... though not you. But I have seen the same
in Scott, Fisher, and even Audio Research tube components from the
same causes. You really do need to get out more.

Indeed, memorizing the values
and part numbers.

Lemme see, what are there, perhaps a total of 3 non-electrolytic cap
values in the Dynaco ST-70 and what 6, 7 for the PAS-3? How much of a
trick of memorization is that after the 20th one has crossed the
bench?

Do you take us all for idiots?

No, only you and your "King" as referenced below.

Now you understand what I
meant by the King's war on the disingenuous.

And it took you how long to come up with this tripe? You have
obviously lost sleep over it or you would have left well-enough
alone.

Peter Wieck
Wyncote, PA

[west[_4_]]

"Peter Wieck" wrote in message
oups.com...
You are an idiot. Note the interpolations.

On May 15, 1:12 pm, "west" wrote:

beside, any logical thinker could see the BS because if true, you would
have
mentioned these trumped up specifics up front.

Apart from the sad fact that you are not a 'logical thinker', anyone
who had spent any time at all with tube components, especially vintage
components that have been around the block a few times would have
experienced such hiss, and known of its various causes. And anyone who
has been around a bit will have seen even new components experience
teething problems such that certain checks are done as a matter of
course. So, citing specifics is generally required only to slap down
the inexperienced ignorant such as you. And I picked Dynaco circuits
as they are nearly universal across the hobby and well understood by
perhaps tens of thousands... though not you. But I have seen the same
in Scott, Fisher, and even Audio Research tube components from the
same causes. You really do need to get out more.

Indeed, memorizing the values
and part numbers.

Lemme see, what are there, perhaps a total of 3 non-electrolytic cap
values in the Dynaco ST-70 and what 6, 7 for the PAS-3? How much of a
trick of memorization is that after the 20th one has crossed the
bench?

Do you take us all for idiots?

No, only you and your "King" as referenced below.

Now you understand what I
meant by the King's war on the disingenuous.

And it took you how long to come up with this tripe? You have
obviously lost sleep over it or you would have left well-enough
alone.

Peter Wieck
Wyncote, PA

You should have cut your losses and suck it up while you were only a bit
behind. You will do anything to support your lies. I notice a glaring trait
of yours is to accuse someone of the very misgivings that you are guilty of.
The projection is obvious.
About me loosing sleep? I believe that the majority of Rats know that you
are a genuine cyber-stalker. Stalkers are the ones who loose sleep, consumed
with the negative emotions about how to get even with someone.
You do have a huge advantage over me and that is you are not afraid to make
a complete ass out of yourself.

UOOC

[Peter Wieck]

On May 15, 7:13 pm, "west" wrote:
"Peter Wieck" wrote in message

oups.com...





You are an idiot. Note the interpolations.

On May 15, 1:12 pm, "west" wrote:

beside, any logical thinker could see the BS because if true, you would
have
mentioned these trumped up specifics up front.

Apart from the sad fact that you are not a 'logical thinker', anyone
who had spent any time at all with tube components, especially vintage
components that have been around the block a few times would have
experienced such hiss, and known of its various causes. And anyone who
has been around a bit will have seen even new components experience
teething problems such that certain checks are done as a matter of
course. So, citing specifics is generally required only to slap down
the inexperienced ignorant such as you. And I picked Dynaco circuits
as they are nearly universal across the hobby and well understood by
perhaps tens of thousands... though not you. But I have seen the same
in Scott, Fisher, and even Audio Research tube components from the
same causes. You really do need to get out more.

Indeed, memorizing the values
and part numbers.

Lemme see, what are there, perhaps a total of 3 non-electrolytic cap
values in the Dynaco ST-70 and what 6, 7 for the PAS-3? How much of a
trick of memorization is that after the 20th one has crossed the
bench?

Do you take us all for idiots?

No, only you and your "King" as referenced below.

Now you understand what I
meant by the King's war on the disingenuous.

And it took you how long to come up with this tripe? You have
obviously lost sleep over it or you would have left well-enough
alone.

Peter Wieck
Wyncote, PA

You should have cut your losses and suck it up while you were only a bit
behind. You will do anything to support your lies. I notice a glaring trait
of yours is to accuse someone of the very misgivings that you are guilty of.
The projection is obvious.
About me loosing sleep? I believe that the majority of Rats know that you
are a genuine cyber-stalker. Stalkers are the ones who loose sleep, consumed
with the negative emotions about how to get even with someone.
You do have a huge advantage over me and that is you are not afraid to make
a complete ass out of yourself.

UOOC- Hide quoted text -

- Show quoted text -

Thank you, Timmee, for your excellent analysis. Now, when you get a
life, please check back in. Until then, concentrate on curing your
'congestion'.

Peter Wieck
Wyncote, PA