Schematic wanted

M

Meat Plow

Guest
Peavey MX VTX 1x12 combo amp.

This is my amp and had been sitting for a year or so. When I switched
the standby rocker to low I heard a mild pop from the speaker and
after that just a faint amount of signal from the guitar out the
speaker. Plus the status led doesn't light. I've never had problems
and the tubes are a matched quad Philips 7591a JAN/NOS with low hours.

I'm sure the B+ is missing, the tubes don't heat other than the
filaments. And I probably don't really and absolutely need the
schematic but would like to have one on hand regardless.
 
Meat Plow wrote:
Peavey MX VTX 1x12 combo amp.

This is my amp and had been sitting for a year or so. When I switched
the standby rocker to low I heard a mild pop from the speaker and
after that just a faint amount of signal from the guitar out the
speaker. Plus the status led doesn't light. I've never had problems
and the tubes are a matched quad Philips 7591a JAN/NOS with low hours.

I'm sure the B+ is missing, the tubes don't heat other than the
filaments. And I probably don't really and absolutely need the
schematic but would like to have one on hand regardless.
Click to expand...

FWIW....Peavey sent me a schematic for my original Deuce amp but that
was 15 years ago now. Might want to check with them though, to see if
they still supply schematics, if you have no luck here. :)


Update....did a quick google and ran across the following:

http://music-electronics-forum.com/t10035/

Following the link one of the participants posted resulted in the following:

http://www.ampix.org/thumbnails.php?album=38&page=16
 
Meat Plow wrote:
Peavey MX VTX 1x12 combo amp.

This is my amp and had been sitting for a year or so. When I switched
the standby rocker to low I heard a mild pop from the speaker and
after that just a faint amount of signal from the guitar out the
speaker. Plus the status led doesn't light. I've never had problems
and the tubes are a matched quad Philips 7591a JAN/NOS with low hours.

I'm sure the B+ is missing, the tubes don't heat other than the
filaments. And I probably don't really and absolutely need the
schematic but would like to have one on hand regardless.
Click to expand...

whoops...sorry sent wrong url in last message. Should have been this one:

http://www.ampix.org/displayimage.php?album=search&cat=0&pos=1
 
On Thu, 27 Aug 2009 09:25:27 -0700, propman
<propman@nowhere.cam>wrote:

Meat Plow wrote:
Peavey MX VTX 1x12 combo amp.

This is my amp and had been sitting for a year or so. When I switched
the standby rocker to low I heard a mild pop from the speaker and
after that just a faint amount of signal from the guitar out the
speaker. Plus the status led doesn't light. I've never had problems
and the tubes are a matched quad Philips 7591a JAN/NOS with low hours.

I'm sure the B+ is missing, the tubes don't heat other than the
filaments. And I probably don't really and absolutely need the
schematic but would like to have one on hand regardless.


FWIW....Peavey sent me a schematic for my original Deuce amp but that
was 15 years ago now. Might want to check with them though, to see if
they still supply schematics, if you have no luck here. :)


Update....did a quick google and ran across the following:

http://music-electronics-forum.com/t10035/

Following the link one of the participants posted resulted in the following:

http://www.ampix.org/thumbnails.php?album=38&page=16
Click to expand...
Odd I didn't see this site when i googled it

http://www.ampix.org/albums/userpics/10003/PV_MX_VTX.pdf

Thanks much.
 
On Thu, 27 Aug 2009 09:32:57 -0700, propman
<propman@nowhere.cam>wrote:

Meat Plow wrote:
Peavey MX VTX 1x12 combo amp.

This is my amp and had been sitting for a year or so. When I switched
the standby rocker to low I heard a mild pop from the speaker and
after that just a faint amount of signal from the guitar out the
speaker. Plus the status led doesn't light. I've never had problems
and the tubes are a matched quad Philips 7591a JAN/NOS with low hours.

I'm sure the B+ is missing, the tubes don't heat other than the
filaments. And I probably don't really and absolutely need the
schematic but would like to have one on hand regardless.


whoops...sorry sent wrong url in last message. Should have been this one:

http://www.ampix.org/displayimage.php?album=search&cat=0&pos=1
Click to expand...
Looks like an internal fuse for the B+ per the schematic. The
HI/STANDBY/LO switch rocks back and forth between taps on the
secondary to get either 262vdc or 525vdc for B+. I've seen fuses in
this situation blow because of age and no other apparent reason
specifically another amp I own a Peavey Artist 115.
 
"Meat Plow" <meat@petitmorte.net> wrote in message
news:332vhb.ar7.19.1@news.alt.net...
Peavey MX VTX 1x12 combo amp.

This is my amp and had been sitting for a year or so. When I switched
the standby rocker to low I heard a mild pop from the speaker and
after that just a faint amount of signal from the guitar out the
speaker. Plus the status led doesn't light. I've never had problems
and the tubes are a matched quad Philips 7591a JAN/NOS with low hours.
Click to expand...

Whatever tubes are in it is irrelevent. Why have you said this?



I'm sure the B+ is missing, the tubes don't heat other than the
filaments. And I probably don't really and absolutely need the
schematic but would like to have one on hand regardless.
Click to expand...


Have you measured the B+ yet? Might be a very easy fix that doesnt really
and absolutely need the schematics.
 
On Thu, 27 Aug 2009 23:28:35 +0100, "Gareth Magennis"
<gareth.magennis@virginmedia.com>wrote:

"Meat Plow" <meat@petitmorte.net> wrote in message
news:332vhb.ar7.19.1@news.alt.net...
Peavey MX VTX 1x12 combo amp.

This is my amp and had been sitting for a year or so. When I switched
the standby rocker to low I heard a mild pop from the speaker and
after that just a faint amount of signal from the guitar out the
speaker. Plus the status led doesn't light. I've never had problems
and the tubes are a matched quad Philips 7591a JAN/NOS with low hours.



Whatever tubes are in it is irrelevent. Why have you said this?
Click to expand...
Sorry you feel that way but you couldn't possibly be more incorrect.

I'm sure the B+ is missing, the tubes don't heat other than the
filaments. And I probably don't really and absolutely need the
schematic but would like to have one on hand regardless.



Have you measured the B+ yet? Might be a very easy fix that doesnt really
and absolutely need the schematics.
Click to expand...
I built my first class AB tube guitar amp back in 1972 from scrap.
Please don't insult my intelligence with your idiotic banter.
 
"Meat Plow" <meat@petitmorte.net> wrote in message
news:335a9g.rs6.19.1@news.alt.net...
On Thu, 27 Aug 2009 23:28:35 +0100, "Gareth Magennis"
gareth.magennis@virginmedia.com>wrote:


"Meat Plow" <meat@petitmorte.net> wrote in message
news:332vhb.ar7.19.1@news.alt.net...
Peavey MX VTX 1x12 combo amp.

This is my amp and had been sitting for a year or so. When I switched
the standby rocker to low I heard a mild pop from the speaker and
after that just a faint amount of signal from the guitar out the
speaker. Plus the status led doesn't light. I've never had problems
and the tubes are a matched quad Philips 7591a JAN/NOS with low hours.



Whatever tubes are in it is irrelevent. Why have you said this?

Sorry you feel that way but you couldn't possibly be more incorrect.



I'm sure the B+ is missing, the tubes don't heat other than the
filaments. And I probably don't really and absolutely need the
schematic but would like to have one on hand regardless.



Have you measured the B+ yet? Might be a very easy fix that doesnt
really
and absolutely need the schematics.


I built my first class AB tube guitar amp back in 1972 from scrap.
Please don't insult my intelligence with your idiotic banter.
Click to expand...



Maybe you could use your intelligence to measure B+ then.
 
On Sat, 29 Aug 2009 00:19:34 +0100, "Gareth Magennis"
<gareth.magennis@virginmedia.com>wrote:

"Meat Plow" <meat@petitmorte.net> wrote in message
news:335a9g.rs6.19.1@news.alt.net...
On Thu, 27 Aug 2009 23:28:35 +0100, "Gareth Magennis"
gareth.magennis@virginmedia.com>wrote:


"Meat Plow" <meat@petitmorte.net> wrote in message
news:332vhb.ar7.19.1@news.alt.net...
Peavey MX VTX 1x12 combo amp.

This is my amp and had been sitting for a year or so. When I switched
the standby rocker to low I heard a mild pop from the speaker and
after that just a faint amount of signal from the guitar out the
speaker. Plus the status led doesn't light. I've never had problems
and the tubes are a matched quad Philips 7591a JAN/NOS with low hours.



Whatever tubes are in it is irrelevent. Why have you said this?

Sorry you feel that way but you couldn't possibly be more incorrect.



I'm sure the B+ is missing, the tubes don't heat other than the
filaments. And I probably don't really and absolutely need the
schematic but would like to have one on hand regardless.



Have you measured the B+ yet? Might be a very easy fix that doesnt
really
and absolutely need the schematics.


I built my first class AB tube guitar amp back in 1972 from scrap.
Please don't insult my intelligence with your idiotic banter.




Maybe you could use your intelligence to measure B+ then.
Click to expand...
Maybe you could measure your intelligence in single digits.
 
"Meat Plow" <meat@petitmorte.net> wrote in message
news:3381lm.v4e.17.2@news.alt.net...
On Sat, 29 Aug 2009 00:19:34 +0100, "Gareth Magennis"
gareth.magennis@virginmedia.com>wrote:


"Meat Plow" <meat@petitmorte.net> wrote in message
news:335a9g.rs6.19.1@news.alt.net...
On Thu, 27 Aug 2009 23:28:35 +0100, "Gareth Magennis"
gareth.magennis@virginmedia.com>wrote:


"Meat Plow" <meat@petitmorte.net> wrote in message
news:332vhb.ar7.19.1@news.alt.net...
Peavey MX VTX 1x12 combo amp.

This is my amp and had been sitting for a year or so. When I switched
the standby rocker to low I heard a mild pop from the speaker and
after that just a faint amount of signal from the guitar out the
speaker. Plus the status led doesn't light. I've never had problems
and the tubes are a matched quad Philips 7591a JAN/NOS with low hours.



Whatever tubes are in it is irrelevent. Why have you said this?

Sorry you feel that way but you couldn't possibly be more incorrect.



I'm sure the B+ is missing, the tubes don't heat other than the
filaments. And I probably don't really and absolutely need the
schematic but would like to have one on hand regardless.



Have you measured the B+ yet? Might be a very easy fix that doesnt
really
and absolutely need the schematics.


I built my first class AB tube guitar amp back in 1972 from scrap.
Please don't insult my intelligence with your idiotic banter.




Maybe you could use your intelligence to measure B+ then.

Maybe you could measure your intelligence in single digits.
Click to expand...


Now you're sounding like a 12 year old.
 
Meat Plow wrote:
On Sat, 29 Aug 2009 00:19:34 +0100, "Gareth Magennis"
gareth.magennis@virginmedia.com>wrote:


"Meat Plow" <meat@petitmorte.net> wrote in message
news:335a9g.rs6.19.1@news.alt.net...

On Thu, 27 Aug 2009 23:28:35 +0100, "Gareth Magennis"
gareth.magennis@virginmedia.com>wrote:


"Meat Plow" <meat@petitmorte.net> wrote in message
news:332vhb.ar7.19.1@news.alt.net...

Peavey MX VTX 1x12 combo amp.

This is my amp and had been sitting for a year or so. When I switched
the standby rocker to low I heard a mild pop from the speaker and
after that just a faint amount of signal from the guitar out the
speaker. Plus the status led doesn't light. I've never had problems
and the tubes are a matched quad Philips 7591a JAN/NOS with low hours.



Whatever tubes are in it is irrelevent. Why have you said this?

Sorry you feel that way but you couldn't possibly be more incorrect.



I'm sure the B+ is missing, the tubes don't heat other than the
filaments. And I probably don't really and absolutely need the
schematic but would like to have one on hand regardless.



Have you measured the B+ yet? Might be a very easy fix that doesnt
really
and absolutely need the schematics.


I built my first class AB tube guitar amp back in 1972 from scrap.
Please don't insult my intelligence with your idiotic banter.




Maybe you could use your intelligence to measure B+ then.


Maybe you could measure your intelligence in single digits.
base32 ?
Click to expand...
 
On Sat, 29 Aug 2009 15:13:53 +0100, "Gareth Magennis"
<gareth.magennis@virginmedia.com>wrote:

"Meat Plow" <meat@petitmorte.net> wrote in message
news:3381lm.v4e.17.2@news.alt.net...
On Sat, 29 Aug 2009 00:19:34 +0100, "Gareth Magennis"
gareth.magennis@virginmedia.com>wrote:


"Meat Plow" <meat@petitmorte.net> wrote in message
news:335a9g.rs6.19.1@news.alt.net...
On Thu, 27 Aug 2009 23:28:35 +0100, "Gareth Magennis"
gareth.magennis@virginmedia.com>wrote:


"Meat Plow" <meat@petitmorte.net> wrote in message
news:332vhb.ar7.19.1@news.alt.net...
Peavey MX VTX 1x12 combo amp.

This is my amp and had been sitting for a year or so. When I switched
the standby rocker to low I heard a mild pop from the speaker and
after that just a faint amount of signal from the guitar out the
speaker. Plus the status led doesn't light. I've never had problems
and the tubes are a matched quad Philips 7591a JAN/NOS with low hours.



Whatever tubes are in it is irrelevent. Why have you said this?

Sorry you feel that way but you couldn't possibly be more incorrect.



I'm sure the B+ is missing, the tubes don't heat other than the
filaments. And I probably don't really and absolutely need the
schematic but would like to have one on hand regardless.



Have you measured the B+ yet? Might be a very easy fix that doesnt
really
and absolutely need the schematics.


I built my first class AB tube guitar amp back in 1972 from scrap.
Please don't insult my intelligence with your idiotic banter.




Maybe you could use your intelligence to measure B+ then.

Maybe you could measure your intelligence in single digits.



Now you're sounding like a 12 year old.
Click to expand...
Sorry, had to put it in a context you'd understand.
 
"Meat Plow" <meat@petitmorte.net> wrote in message
news:33830q.v4e.17.10@news.alt.net...
On Sat, 29 Aug 2009 15:13:53 +0100, "Gareth Magennis"
gareth.magennis@virginmedia.com>wrote:


"Meat Plow" <meat@petitmorte.net> wrote in message
news:3381lm.v4e.17.2@news.alt.net...
On Sat, 29 Aug 2009 00:19:34 +0100, "Gareth Magennis"
gareth.magennis@virginmedia.com>wrote:


"Meat Plow" <meat@petitmorte.net> wrote in message
news:335a9g.rs6.19.1@news.alt.net...
On Thu, 27 Aug 2009 23:28:35 +0100, "Gareth Magennis"
gareth.magennis@virginmedia.com>wrote:


"Meat Plow" <meat@petitmorte.net> wrote in message
news:332vhb.ar7.19.1@news.alt.net...
Peavey MX VTX 1x12 combo amp.

This is my amp and had been sitting for a year or so. When I
switched
the standby rocker to low I heard a mild pop from the speaker and
after that just a faint amount of signal from the guitar out the
speaker. Plus the status led doesn't light. I've never had problems
and the tubes are a matched quad Philips 7591a JAN/NOS with low
hours.



Whatever tubes are in it is irrelevent. Why have you said this?

Sorry you feel that way but you couldn't possibly be more incorrect.



I'm sure the B+ is missing, the tubes don't heat other than the
filaments. And I probably don't really and absolutely need the
schematic but would like to have one on hand regardless.



Have you measured the B+ yet? Might be a very easy fix that doesnt
really
and absolutely need the schematics.


I built my first class AB tube guitar amp back in 1972 from scrap.
Please don't insult my intelligence with your idiotic banter.




Maybe you could use your intelligence to measure B+ then.

Maybe you could measure your intelligence in single digits.



Now you're sounding like a 12 year old.

Sorry, had to put it in a context you'd understand.
Click to expand...


You're still sounding like a 12 year old, I'm afraid.
 
On Sat, 29 Aug 2009 15:25:35 +0100, "Gareth Magennis"
<gareth.magennis@virginmedia.com>wrote:

"Meat Plow" <meat@petitmorte.net> wrote in message
news:33830q.v4e.17.10@news.alt.net...
On Sat, 29 Aug 2009 15:13:53 +0100, "Gareth Magennis"
gareth.magennis@virginmedia.com>wrote:


"Meat Plow" <meat@petitmorte.net> wrote in message
news:3381lm.v4e.17.2@news.alt.net...
On Sat, 29 Aug 2009 00:19:34 +0100, "Gareth Magennis"
gareth.magennis@virginmedia.com>wrote:


"Meat Plow" <meat@petitmorte.net> wrote in message
news:335a9g.rs6.19.1@news.alt.net...
On Thu, 27 Aug 2009 23:28:35 +0100, "Gareth Magennis"
gareth.magennis@virginmedia.com>wrote:


"Meat Plow" <meat@petitmorte.net> wrote in message
news:332vhb.ar7.19.1@news.alt.net...
Peavey MX VTX 1x12 combo amp.

This is my amp and had been sitting for a year or so. When I
switched
the standby rocker to low I heard a mild pop from the speaker and
after that just a faint amount of signal from the guitar out the
speaker. Plus the status led doesn't light. I've never had problems
and the tubes are a matched quad Philips 7591a JAN/NOS with low
hours.



Whatever tubes are in it is irrelevent. Why have you said this?

Sorry you feel that way but you couldn't possibly be more incorrect.



I'm sure the B+ is missing, the tubes don't heat other than the
filaments. And I probably don't really and absolutely need the
schematic but would like to have one on hand regardless.



Have you measured the B+ yet? Might be a very easy fix that doesnt
really
and absolutely need the schematics.


I built my first class AB tube guitar amp back in 1972 from scrap.
Please don't insult my intelligence with your idiotic banter.




Maybe you could use your intelligence to measure B+ then.

Maybe you could measure your intelligence in single digits.



Now you're sounding like a 12 year old.

Sorry, had to put it in a context you'd understand.



You're still sounding like a 12 year old, I'm afraid.
Click to expand...
You're afraid of what?
 
"Meat Plow" <meat@petitmorte.net> wrote in message
news:332vhb.ar7.19.1@news.alt.net...
Peavey MX VTX 1x12 combo amp.

This is my amp and had been sitting for a year or so. When I switched
the standby rocker to low I heard a mild pop from the speaker and
after that just a faint amount of signal from the guitar out the
speaker. Plus the status led doesn't light. I've never had problems
and the tubes are a matched quad Philips 7591a JAN/NOS with low hours.

I'm sure the B+ is missing, the tubes don't heat other than the
filaments. And I probably don't really and absolutely need the
schematic but would like to have one on hand regardless.
Click to expand...



Here's an idea or two (for a typical 6L6 / EL34 push pull circuit):

First you really should assume that one or more output tubes may be faulty.
So turning on the amp and seeing if any of them get hot while they melt the
OPT is probably best avoided.
Remove all the output valves and you can then easily measure the HT on the
Anodes and G2's as well as the bias voltage (perhaps using a Variac to
slowly ramp up the voltages). With the amp off and the HT discharged you
can then measure the integrity of the output stage by measuring the presence
of all the G2 and Grid resistors, again from the output sockets. You can
also check both anode pairs are connected, the cathodes all grounded
(perhaps via low ohm resistors) and that the OPT primary is present between
the appropriate Anodes, again all from the output sockets. You can measure
separately each half of the OPT primary via its HT connection and the
oputput sockets to check for possible shorted windings. Check the presence
or not of the secondaries at the speaker jack socket. You might also check
that no secondary winding has any connection to the primary.

Once the output stage has been thus checked, and thus your OPT protected,
you could sub in a known good set of output valves and, (perhaps running up
slowly with a Variac) see if the amp now works, confirming whether your
original set of valves are faulty. If your amp has a Fender style Power Amp
In jack, this is a good place to inject the signal to properly test the
output stage.

Notice that at no point was the make and model of output tubes mentioned.
If you have subbed the 6L6's for 7591's you just need to measure at the
(different) appropriate pins, and replace with the same type if necessary.


Now you could check the preamp section by injecting a signal. If no signals
appear at the output socket grids (output valves removed again), the preamp
is broken. Or you could use the now tested output stage to monitor the
preamp. Swap all the preamp valves with known good ones. Check there is
HT on every preamp valve Anode. Follow the injected signal from tube to
tube and see where it disappears. Tap with a wooden or plastic object to
see if you have any dry joints etc etc etc.






But I'm sure you know all this stuff already.
 
On Sat, 29 Aug 2009 17:06:02 +0100, "Gareth Magennis"
<gareth.magennis@virginmedia.com>wrote:

"Meat Plow" <meat@petitmorte.net> wrote in message
news:332vhb.ar7.19.1@news.alt.net...
Peavey MX VTX 1x12 combo amp.

This is my amp and had been sitting for a year or so. When I switched
the standby rocker to low I heard a mild pop from the speaker and
after that just a faint amount of signal from the guitar out the
speaker. Plus the status led doesn't light. I've never had problems
and the tubes are a matched quad Philips 7591a JAN/NOS with low hours.

I'm sure the B+ is missing, the tubes don't heat other than the
filaments. And I probably don't really and absolutely need the
schematic but would like to have one on hand regardless.




Here's an idea or two (for a typical 6L6 / EL34 push pull circuit):

First you really should assume that one or more output tubes may be faulty.
So turning on the amp and seeing if any of them get hot while they melt the
OPT is probably best avoided.
Remove all the output valves and you can then easily measure the HT on the
Anodes and G2's as well as the bias voltage (perhaps using a Variac to
slowly ramp up the voltages). With the amp off and the HT discharged you
can then measure the integrity of the output stage by measuring the presence
of all the G2 and Grid resistors, again from the output sockets. You can
also check both anode pairs are connected, the cathodes all grounded
(perhaps via low ohm resistors) and that the OPT primary is present between
the appropriate Anodes, again all from the output sockets. You can measure
separately each half of the OPT primary via its HT connection and the
oputput sockets to check for possible shorted windings. Check the presence
or not of the secondaries at the speaker jack socket. You might also check
that no secondary winding has any connection to the primary.

Once the output stage has been thus checked, and thus your OPT protected,
you could sub in a known good set of output valves and, (perhaps running up
slowly with a Variac) see if the amp now works, confirming whether your
original set of valves are faulty. If your amp has a Fender style Power Amp
In jack, this is a good place to inject the signal to properly test the
output stage.

Notice that at no point was the make and model of output tubes mentioned.
If you have subbed the 6L6's for 7591's you just need to measure at the
(different) appropriate pins, and replace with the same type if necessary.


Now you could check the preamp section by injecting a signal. If no signals
appear at the output socket grids (output valves removed again), the preamp
is broken. Or you could use the now tested output stage to monitor the
preamp. Swap all the preamp valves with known good ones. Check there is
HT on every preamp valve Anode. Follow the injected signal from tube to
tube and see where it disappears. Tap with a wooden or plastic object to
see if you have any dry joints etc etc etc.






But I'm sure you know all this stuff already.
Click to expand...

Yeh and I really don't know why you would waste your time with such a
juvenile entity as myself.

I replaced the 1amp fuse between the bridge and the B+ secondary and
all is well. Didn't bother taking voltages or other tests.

Oh and I forgot to mention I worked for a company that did Roland,
Yamaha and Peavey warranty to name a few. I have a file cabinet full
of service literature for Peavey gear just not the MX-VTX.

Have a great life.
 
"Meat Plow" <meat@petitmorte.net> wrote in message
news:338gtc.t98.19.1@news.alt.net...
On Sat, 29 Aug 2009 17:06:02 +0100, "Gareth Magennis"
gareth.magennis@virginmedia.com>wrote:


"Meat Plow" <meat@petitmorte.net> wrote in message
news:332vhb.ar7.19.1@news.alt.net...
Peavey MX VTX 1x12 combo amp.

This is my amp and had been sitting for a year or so. When I switched
the standby rocker to low I heard a mild pop from the speaker and
after that just a faint amount of signal from the guitar out the
speaker. Plus the status led doesn't light. I've never had problems
and the tubes are a matched quad Philips 7591a JAN/NOS with low hours.

I'm sure the B+ is missing, the tubes don't heat other than the
filaments. And I probably don't really and absolutely need the
schematic but would like to have one on hand regardless.




Here's an idea or two (for a typical 6L6 / EL34 push pull circuit):

First you really should assume that one or more output tubes may be
faulty.
So turning on the amp and seeing if any of them get hot while they melt
the
OPT is probably best avoided.
Remove all the output valves and you can then easily measure the HT on the
Anodes and G2's as well as the bias voltage (perhaps using a Variac to
slowly ramp up the voltages). With the amp off and the HT discharged you
can then measure the integrity of the output stage by measuring the
presence
of all the G2 and Grid resistors, again from the output sockets. You
can
also check both anode pairs are connected, the cathodes all grounded
(perhaps via low ohm resistors) and that the OPT primary is present
between
the appropriate Anodes, again all from the output sockets. You can
measure
separately each half of the OPT primary via its HT connection and the
oputput sockets to check for possible shorted windings. Check the
presence
or not of the secondaries at the speaker jack socket. You might also
check
that no secondary winding has any connection to the primary.

Once the output stage has been thus checked, and thus your OPT protected,
you could sub in a known good set of output valves and, (perhaps running
up
slowly with a Variac) see if the amp now works, confirming whether your
original set of valves are faulty. If your amp has a Fender style Power
Amp
In jack, this is a good place to inject the signal to properly test the
output stage.

Notice that at no point was the make and model of output tubes mentioned.
If you have subbed the 6L6's for 7591's you just need to measure at the
(different) appropriate pins, and replace with the same type if necessary.


Now you could check the preamp section by injecting a signal. If no
signals
appear at the output socket grids (output valves removed again), the
preamp
is broken. Or you could use the now tested output stage to monitor the
preamp. Swap all the preamp valves with known good ones. Check there is
HT on every preamp valve Anode. Follow the injected signal from tube to
tube and see where it disappears. Tap with a wooden or plastic object to
see if you have any dry joints etc etc etc.






But I'm sure you know all this stuff already.


Yeh and I really don't know why you would waste your time with such a
juvenile entity as myself.

I replaced the 1amp fuse between the bridge and the B+ secondary and
all is well. Didn't bother taking voltages or other tests.

Oh and I forgot to mention I worked for a company that did Roland,
Yamaha and Peavey warranty to name a few. I have a file cabinet full
of service literature for Peavey gear just not the MX-VTX.

Have a great life.
Click to expand...




Yes, you love telling us all about yourself and your gear, don't you.

I seem to recall a recent post by Mr N. Cook about rewinding pickups for a
AB Landola guitar he had for repair. You posted 2 links to pictures of
YOUR guitars and then went on to tell us all what projects YOU are doing
now.
In this thread you first boasted unecessarily about YOUR fancy JAN tube
replacements, then told us YOU'VE been building amps from scrap for
centuries, and now that YOU did loads of warranty work and have filing
cabinets full of schematics.

If you are such a techical Wizard, why then did you need to post here asking
for schematics and boasting about yourself, when the only problem was a
blown fuse?

I could probably find lots more examples of your sad posts, but I really
can't be arsed.



Good day, Sir.
 
"Meat Plow" <meat@petitmorte.net> wrote in message
news:332vhb.ar7.19.1@news.alt.net...
Peavey MX VTX 1x12 combo amp.

This is my amp and had been sitting for a year or so. When I switched
the standby rocker to low I heard a mild pop from the speaker and
after that just a faint amount of signal from the guitar out the
speaker. Plus the status led doesn't light. I've never had problems
and the tubes are a matched quad Philips 7591a JAN/NOS with low hours.

I'm sure the B+ is missing, the tubes don't heat other than the
filaments. And I probably don't really and absolutely need the
schematic but would like to have one on hand regardless.
Click to expand...





Hmmm, sounds of pennies dropping - you didn't perchance happen to buy a
matched quad of 7591 valves and plug them into your amp meant for 6L6
without first rewiring the sockets?
 
On Sat, 29 Aug 2009 22:15:44 +0100, "Gareth Magennis"
<gareth.magennis@virginmedia.com>wrote:

"Meat Plow" <meat@petitmorte.net> wrote in message
news:332vhb.ar7.19.1@news.alt.net...
Peavey MX VTX 1x12 combo amp.

This is my amp and had been sitting for a year or so. When I switched
the standby rocker to low I heard a mild pop from the speaker and
after that just a faint amount of signal from the guitar out the
speaker. Plus the status led doesn't light. I've never had problems
and the tubes are a matched quad Philips 7591a JAN/NOS with low hours.

I'm sure the B+ is missing, the tubes don't heat other than the
filaments. And I probably don't really and absolutely need the
schematic but would like to have one on hand regardless.






Hmmm, sounds of pennies dropping - you didn't perchance happen to buy a
matched quad of 7591 valves and plug them into your amp meant for 6L6
without first rewiring the sockets?
Click to expand...
Do you have some mental issues?

http://www.vacuumtubes.com/6l6.html

Scroll down to the 7581a/KT66 paragraph.

Yes I know before you whine about it I incorrectly labeled them as
7591a only because the amp had been stored for a couple years
and I had forgotten the exact number.

However both are pinned the same and have like characteristics.

All this aside, the amp was stored in working condition. Taken out of
storage and promptly blew the HV fuse. Fuse was replaced, amp was
load tested for an hour at 50% output and passed with flying colors.

Now, be a good boy and piss off.
 
"Meat Plow" <meat@petitmorte.net> wrote in message
news:33ans3.uri.19.1@news.alt.net...
On Sat, 29 Aug 2009 22:15:44 +0100, "Gareth Magennis"
gareth.magennis@virginmedia.com>wrote:


"Meat Plow" <meat@petitmorte.net> wrote in message
news:332vhb.ar7.19.1@news.alt.net...
Peavey MX VTX 1x12 combo amp.

This is my amp and had been sitting for a year or so. When I switched
the standby rocker to low I heard a mild pop from the speaker and
after that just a faint amount of signal from the guitar out the
speaker. Plus the status led doesn't light. I've never had problems
and the tubes are a matched quad Philips 7591a JAN/NOS with low hours.

I'm sure the B+ is missing, the tubes don't heat other than the
filaments. And I probably don't really and absolutely need the
schematic but would like to have one on hand regardless.






Hmmm, sounds of pennies dropping - you didn't perchance happen to buy a
matched quad of 7591 valves and plug them into your amp meant for 6L6
without first rewiring the sockets?

Do you have some mental issues?

http://www.vacuumtubes.com/6l6.html

Scroll down to the 7581a/KT66 paragraph.

Yes I know before you whine about it I incorrectly labeled them as
7591a only because the amp had been stored for a couple years
and I had forgotten the exact number.

However both are pinned the same and have like characteristics.

All this aside, the amp was stored in working condition. Taken out of
storage and promptly blew the HV fuse. Fuse was replaced, amp was
load tested for an hour at 50% output and passed with flying colors.

Now, be a good boy and piss off.
Click to expand...



7591A: http://tdsl.duncanamps.com/show.php?des=7591A
6L6: http://tdsl.duncanamps.com/show.php?des=6L6


Different pinouts.
 
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