How do I know tubes are getting old?

[MD]

My high freqs are dropping off
10k -2db
12k -4db etc

Happens on both channels though (maybe this is how the amp works
normally? I checked the Stereophile specs and it should be much better
than this. Also - I have checked on 3 different speakers)

[Sander deWaal]

MD > said:

>My high freqs are dropping off
>10k -2db
>12k -4db etc
>
>Happens on both channels though (maybe this is how the amp works
>normally? I checked the Stereophile specs and it should be much better
>than this. Also - I have checked on 3 different speakers)


Depending on the circuitry (local and global feedback), tube wear will
be compensated for to a reasonable amount.
After that, power will drop, and high frequencies may well be
affected.

Try a fresh set of tubes!

--

"Audio as a serious hobby is going down the tubes."
- Howard Ferstler, 25/4/2005

[Arny Krueger]

"Sander deWaal" > wrote in message

> MD > said:
>
>> My high freqs are dropping off
>> 10k -2db
>> 12k -4db etc

What amp?

Droppingm c Compared to what?

>> Happens on both channels though (maybe this is how the
amp
>> works normally? I checked the Stereophile specs and it
>> should be much better than this. Also - I have checked
on 3
>> different speakers)

> Depending on the circuitry (local and global feedback),
tube
> wear will be compensated for to a reasonable amount.

Agreed.

> After that, power will drop, and high frequencies may well
be
> affected.

IME, its the low frequencies that go first. But, the high
frequencies aren't far behind.

> Try a fresh set of tubes!

Agreed.

[Howard Ferstler]

Sander deWaal wrote:
>
> MD > said:
>
> >My high freqs are dropping off
> >10k -2db
> >12k -4db etc
> >
> >Happens on both channels though (maybe this is how the amp works
> >normally? I checked the Stereophile specs and it should be much better
> >than this. Also - I have checked on 3 different speakers)

> Depending on the circuitry (local and global feedback), tube wear will
> be compensated for to a reasonable amount.
> After that, power will drop, and high frequencies may well be
> affected.
>
> Try a fresh set of tubes!

Try a modern amp.

Howard Ferstler

[Mike Gilmour]

"MD" > wrote in message
...
> My high freqs are dropping off
> 10k -2db
> 12k -4db etc
>
> Happens on both channels though (maybe this is how the amp works normally?
> I checked the Stereophile specs and it should be much better than this.
> Also - I have checked on 3 different speakers)

Suggest you post to rec.audio.tubes with information about your amp.

Mike

[Sander deWaal]

"Mike Gilmour" > said:


>Suggest you post to rec.audio.tubes with information about your amp.


He would get the same answer from me there, and a 300+ line diatribe
from Patrick Turner ;-)

--

"Audio as a serious hobby is going down the tubes."
- Howard Ferstler, 25/4/2005

[west]

"Sander deWaal" > wrote in message
...
> "Mike Gilmour" > said:

> He would get the same answer from me there, and a 300+ line diatribe
> from Patrick Turner ;-)

> "Audio as a serious hobby is going down the tubes."
> - Howard Ferstler, 25/4/2005

I think you used the wrong word (diatribe). A diatribe is a bitter, abusive
criticism. I think you meant a 333+ line of solid information. What
percentage of Patrick's tube knowledge do you propose, you have, honestly.
west

[Sander deWaal]

"west" > said:


>> He would get the same answer from me there, and a 300+ line diatribe
>> from Patrick Turner ;-)


>I think you used the wrong word (diatribe). A diatribe is a bitter, abusive
>criticism. I think you meant a 333+ line of solid information. What
>percentage of Patrick's tube knowledge do you propose, you have, honestly.
>west


Trouble identifying a smiley, mr. West?
First you franticly attack John Stewart, and now you're coming after
me? Think I'm an easier target?

PS. I'm not interested in a dick contest with Patrick or anyone else.
Patrick and I have a very good e-mail relationship, and none of your
petty little attempts at trolling will change that.
He knows *exactly* how I think about him (which is very favorable,
BTW).

PPS. Any progress on that 833 amp yet?

--

"Audio as a serious hobby is going down the tubes."
- Howard Ferstler, 25/4/2005

[Arny Krueger]

"west" > wrote in message
m
> "Sander deWaal" > wrote in message
> ...
>> "Mike Gilmour" > said:
>
>> He would get the same answer from me there, and a 300+
line
>> diatribe from Patrick Turner ;-)
>
>> "Audio as a serious hobby is going down the tubes."
>> - Howard Ferstler, 25/4/2005
>
> I think you used the wrong word (diatribe). A diatribe is
a
> bitter, abusive criticism. I think you meant a 333+ line
of
> solid information. What percentage of Patrick's tube
knowledge
> do you propose, you have, honestly. west

I liked Patrick the best when he got mellow one day over on
the Aussie audio newsgroup and admitted that more than
anything else he liked building audio gear for people for
fun and profit, and that he built tubed gear because that
was where the money is.

[[email protected]]

Yes, it is, or certainly can be, because it looks nice and also sounds
good. Boy Arny, is that ever a crime!

But for the original poster's question, I would run tests on the amp
with the current installed tubes and with new ones, no more than a
audio oscillator, preferably a nice benchworthy one like a HP. or of
course even a stinky peecee with a buffer such as is described in the
current AudioXPress, a noininductive resistor, which for most tube amps
can be a small one for only a few dollars, and a DMM accurate from 20
to 20 kHz. Hardly more than a hundred bucks worth of stuff!

[west]

If I called you a fat Eskimo, would you get offended? Why? The truth brings
out the best and worse in people. In you case it showed you ugly personality
and possibly the need for more roughage in your diet.

"Sander deWaal" > wrote in message
...
> "west" > said:
>
>
> >> He would get the same answer from me there, and a 300+ line diatribe
> >> from Patrick Turner ;-)
>
>
> >I think you used the wrong word (diatribe). A diatribe is a bitter,
abusive
> >criticism. I think you meant a 333+ line of solid information. What
> >percentage of Patrick's tube knowledge do you propose, you have,
honestly.
> >west
>
>
> Trouble identifying a smiley, mr. West?
> First you franticly attack John Stewart, and now you're coming after
> me? Think I'm an easier target?
>
> PS. I'm not interested in a dick contest with Patrick or anyone else.
> Patrick and I have a very good e-mail relationship, and none of your
> petty little attempts at trolling will change that.
> He knows *exactly* how I think about him (which is very favorable,
> BTW).
>
> PPS. Any progress on that 833 amp yet?
>
> --
>
> "Audio as a serious hobby is going down the tubes."
> - Howard Ferstler, 25/4/2005

[Sander deWaal]

"west" > said:

>If I called you a fat Eskimo, would you get offended? Why? The truth brings
>out the best and worse in people. In you case it showed you ugly personality
>and possibly the need for more roughage in your diet.

Get help, dude. Soon.

--

"Audio as a serious hobby is going down the tubes."
- Howard Ferstler, 25/4/2005