Studiomaster Powerhouse Vision 8 , 700W mixer amp,1996

N

N_Cook

Guest
Didn't think when initially checking out, but what is the "group" slider
function,? no www user manual found.
Anyone any schematics for it ? (ps no emails to whatever this posting
apparently throughs up)
One channel clipping, then dropping out totally after a time, first problem
in preamp, imbalanced gain, second unknown pa or prea. At least possible to
swap the pa channels over it would seem , to resolve to pa or prea , if
nothing actually found.
Also what governs the fan startup, comes on at power up for 2 seconds
(presumably normal) switches off and comes on whan heated up but nothing
obviously separate from the amp/s for temp monitoring or total/channel
cutout, ie no relays, so some sort of gain control coming into play to kill
the channel.
 
On Sat, 8 Aug 2009 07:41:16 +0100, "N_Cook" <diverse@tcp.co.uk>wrote:

Didn't think when initially checking out, but what is the "group" slider
function,? no www user manual found.
Anyone any schematics for it ? (ps no emails to whatever this posting
apparently throughs up)
One channel clipping, then dropping out totally after a time, first problem
in preamp, imbalanced gain, second unknown pa or prea. At least possible to
swap the pa channels over it would seem , to resolve to pa or prea , if
nothing actually found.
Also what governs the fan startup, comes on at power up for 2 seconds
(presumably normal) switches off and comes on whan heated up but nothing
obviously separate from the amp/s for temp monitoring or total/channel
cutout, ie no relays, so some sort of gain control coming into play to kill
the channel.
Click to expand...
A group slider may refer to the aux buss group. Don't know how the fan
is governed but I'll assume it has infinite control like my
Studiomaster 700D amp. That probably gets its feedback from a sink
monted sensor, unknown where it is driven from.
 
Meat Plow <meat@petitmorte.net> wrote in message
news:31gm3i.6cj.17.9@news.alt.net...
On Sat, 8 Aug 2009 07:41:16 +0100, "N_Cook" <diverse@tcp.co.uk>wrote:

Didn't think when initially checking out, but what is the "group" slider
function,? no www user manual found.
Anyone any schematics for it ? (ps no emails to whatever this posting
apparently throughs up)
One channel clipping, then dropping out totally after a time, first
problem
in preamp, imbalanced gain, second unknown pa or prea. At least possible
to
swap the pa channels over it would seem , to resolve to pa or prea , if
nothing actually found.
Also what governs the fan startup, comes on at power up for 2 seconds
(presumably normal) switches off and comes on whan heated up but nothing
obviously separate from the amp/s for temp monitoring or total/channel
cutout, ie no relays, so some sort of gain control coming into play to
kill
the channel.


A group slider may refer to the aux buss group. Don't know how the fan
is governed but I'll assume it has infinite control like my
Studiomaster 700D amp. That probably gets its feedback from a sink
monted sensor, unknown where it is driven from.
Click to expand...

I've never seen that before, a TO220 device trackside under each pa pcb,
thermally touching the heatsink. Only 2 pins used, the B-E junction, with 2
isolated traces to the umbilical ribbon the carries the low voltage rails
and signal i/p. I wonder what is special in the 2SD1763A used for that
purpose.
 
On Sat, 8 Aug 2009 16:00:26 +0100, "N_Cook" <diverse@tcp.co.uk>wrote:

Meat Plow <meat@petitmorte.net> wrote in message
news:31gm3i.6cj.17.9@news.alt.net...
On Sat, 8 Aug 2009 07:41:16 +0100, "N_Cook" <diverse@tcp.co.uk>wrote:

Didn't think when initially checking out, but what is the "group" slider
function,? no www user manual found.
Anyone any schematics for it ? (ps no emails to whatever this posting
apparently throughs up)
One channel clipping, then dropping out totally after a time, first
problem
in preamp, imbalanced gain, second unknown pa or prea. At least possible
to
swap the pa channels over it would seem , to resolve to pa or prea , if
nothing actually found.
Also what governs the fan startup, comes on at power up for 2 seconds
(presumably normal) switches off and comes on whan heated up but nothing
obviously separate from the amp/s for temp monitoring or total/channel
cutout, ie no relays, so some sort of gain control coming into play to
kill
the channel.


A group slider may refer to the aux buss group. Don't know how the fan
is governed but I'll assume it has infinite control like my
Studiomaster 700D amp. That probably gets its feedback from a sink
monted sensor, unknown where it is driven from.


I've never seen that before, a TO220 device trackside under each pa pcb,
thermally touching the heatsink. Only 2 pins used, the B-E junction, with 2
isolated traces to the umbilical ribbon the carries the low voltage rails
and signal i/p. I wonder what is special in the 2SD1763A used for that
purpose.
Click to expand...
On our Mackie aux buss is referred to as 'group',

As far as the 220 devices go the BE junction resistance probably has
the desirable thermo electronic properties the engineers were after.
I've seen it in many other amps using different package devices
including TO-18 and TO-92 eitther fitted into a hole in the sink,
clamped, or just touched with a blob of thermal paste. However these
were used for PA bias but also are temp sensing like the fan driver.

Same goes for my SCS 700 watt MOSFET amp. Infinite control fan and
temp sensored driven. Good for bass guitar final since the fan noise
is controlled. I used a Crown Microtech 1000 but band members
complained its one speed fan sounded like a microwave oven running.
And my BGW 700w was much the same. Guess both were designed to
be off stage unlike the SCS and Studio.

We have a few Wharfedale PAs that the fan always idles at a noticeable
RPM but increases with demand. And a 2008 Behringer powered 12ch mixer
where the fan acts the same as your Studio.
 
N_Cook wrote:
Meat Plow <meat@petitmorte.net> wrote in message
news:31gm3i.6cj.17.9@news.alt.net...
On Sat, 8 Aug 2009 07:41:16 +0100, "N_Cook" <diverse@tcp.co.uk>wrote:

Didn't think when initially checking out, but what is the "group" slider
function,? no www user manual found.
Anyone any schematics for it ? (ps no emails to whatever this posting
apparently throughs up)
One channel clipping, then dropping out totally after a time, first
problem
in preamp, imbalanced gain, second unknown pa or prea. At least possible
to
swap the pa channels over it would seem , to resolve to pa or prea , if
nothing actually found.
Also what governs the fan startup, comes on at power up for 2 seconds
(presumably normal) switches off and comes on whan heated up but nothing
obviously separate from the amp/s for temp monitoring or total/channel
cutout, ie no relays, so some sort of gain control coming into play to
kill
the channel.

A group slider may refer to the aux buss group. Don't know how the fan
is governed but I'll assume it has infinite control like my
Studiomaster 700D amp. That probably gets its feedback from a sink
monted sensor, unknown where it is driven from.


I've never seen that before, a TO220 device trackside under each pa pcb,
thermally touching the heatsink. Only 2 pins used, the B-E junction, with 2
isolated traces to the umbilical ribbon the carries the low voltage rails
and signal i/p. I wonder what is special in the 2SD1763A used for that
purpose.


You need to be talking to Graham Stevenson (Eeyore) I think he designed it.
Click to expand...

Ron
 
On Sat, 08 Aug 2009 16:38:30 +0100, Ron
<ron@lunevalleyaudio.com>wrote:

N_Cook wrote:
Meat Plow <meat@petitmorte.net> wrote in message
news:31gm3i.6cj.17.9@news.alt.net...
On Sat, 8 Aug 2009 07:41:16 +0100, "N_Cook" <diverse@tcp.co.uk>wrote:

Didn't think when initially checking out, but what is the "group" slider
function,? no www user manual found.
Anyone any schematics for it ? (ps no emails to whatever this posting
apparently throughs up)
One channel clipping, then dropping out totally after a time, first
problem
in preamp, imbalanced gain, second unknown pa or prea. At least possible
to
swap the pa channels over it would seem , to resolve to pa or prea , if
nothing actually found.
Also what governs the fan startup, comes on at power up for 2 seconds
(presumably normal) switches off and comes on whan heated up but nothing
obviously separate from the amp/s for temp monitoring or total/channel
cutout, ie no relays, so some sort of gain control coming into play to
kill
the channel.

A group slider may refer to the aux buss group. Don't know how the fan
is governed but I'll assume it has infinite control like my
Studiomaster 700D amp. That probably gets its feedback from a sink
monted sensor, unknown where it is driven from.


I've never seen that before, a TO220 device trackside under each pa pcb,
thermally touching the heatsink. Only 2 pins used, the B-E junction, with 2
isolated traces to the umbilical ribbon the carries the low voltage rails
and signal i/p. I wonder what is special in the 2SD1763A used for that
purpose.


You need to be talking to Graham Stevenson (Eeyore) I think he designed it.

Ron
Click to expand...
Yeah don't talk to us lowly nincompoops about something someone else
designed.
 
"Meat Plow" <meat@petitmorte.net> wrote in message
news:31guea.kd6.17.3@news.alt.net...
On Sat, 08 Aug 2009 16:38:30 +0100, Ron
ron@lunevalleyaudio.com>wrote:

N_Cook wrote:
Meat Plow <meat@petitmorte.net> wrote in message
news:31gm3i.6cj.17.9@news.alt.net...
On Sat, 8 Aug 2009 07:41:16 +0100, "N_Cook" <diverse@tcp.co.uk>wrote:

Didn't think when initially checking out, but what is the "group"
slider
function,? no www user manual found.
Anyone any schematics for it ? (ps no emails to whatever this posting
apparently throughs up)
One channel clipping, then dropping out totally after a time, first
problem
in preamp, imbalanced gain, second unknown pa or prea. At least
possible
to
swap the pa channels over it would seem , to resolve to pa or prea ,
if
nothing actually found.
Also what governs the fan startup, comes on at power up for 2 seconds
(presumably normal) switches off and comes on whan heated up but
nothing
obviously separate from the amp/s for temp monitoring or total/channel
cutout, ie no relays, so some sort of gain control coming into play to
kill
the channel.

A group slider may refer to the aux buss group. Don't know how the fan
is governed but I'll assume it has infinite control like my
Studiomaster 700D amp. That probably gets its feedback from a sink
monted sensor, unknown where it is driven from.


I've never seen that before, a TO220 device trackside under each pa pcb,
thermally touching the heatsink. Only 2 pins used, the B-E junction,
with 2
isolated traces to the umbilical ribbon the carries the low voltage
rails
and signal i/p. I wonder what is special in the 2SD1763A used for that
purpose.


You need to be talking to Graham Stevenson (Eeyore) I think he designed
it.

Ron

Yeah don't talk to us lowly nincompoops about something someone else
designed.
Click to expand...
Where's Graham gone lately ? Used to enjoy some of his design insights, and
also his tendency to suddenly fly off the handle occasionally !! :)

C'mon Graham - bet you're still lurking - we all luv ya really ...

Arfa
 
On Sat, 8 Aug 2009 18:06:43 +0100, "Arfa Daily"
<arfa.daily@ntlworld.com>wrote:

"Meat Plow" <meat@petitmorte.net> wrote in message
news:31guea.kd6.17.3@news.alt.net...
On Sat, 08 Aug 2009 16:38:30 +0100, Ron
ron@lunevalleyaudio.com>wrote:

N_Cook wrote:
Meat Plow <meat@petitmorte.net> wrote in message
news:31gm3i.6cj.17.9@news.alt.net...
On Sat, 8 Aug 2009 07:41:16 +0100, "N_Cook" <diverse@tcp.co.uk>wrote:

Didn't think when initially checking out, but what is the "group"
slider
function,? no www user manual found.
Anyone any schematics for it ? (ps no emails to whatever this posting
apparently throughs up)
One channel clipping, then dropping out totally after a time, first
problem
in preamp, imbalanced gain, second unknown pa or prea. At least
possible
to
swap the pa channels over it would seem , to resolve to pa or prea ,
if
nothing actually found.
Also what governs the fan startup, comes on at power up for 2 seconds
(presumably normal) switches off and comes on whan heated up but
nothing
obviously separate from the amp/s for temp monitoring or total/channel
cutout, ie no relays, so some sort of gain control coming into play to
kill
the channel.

A group slider may refer to the aux buss group. Don't know how the fan
is governed but I'll assume it has infinite control like my
Studiomaster 700D amp. That probably gets its feedback from a sink
monted sensor, unknown where it is driven from.


I've never seen that before, a TO220 device trackside under each pa pcb,
thermally touching the heatsink. Only 2 pins used, the B-E junction,
with 2
isolated traces to the umbilical ribbon the carries the low voltage
rails
and signal i/p. I wonder what is special in the 2SD1763A used for that
purpose.


You need to be talking to Graham Stevenson (Eeyore) I think he designed
it.

Ron

Yeah don't talk to us lowly nincompoops about something someone else
designed.

Where's Graham gone lately ? Used to enjoy some of his design insights, and
also his tendency to suddenly fly off the handle occasionally !! :)

C'mon Graham - bet you're still lurking - we all luv ya really ...
Click to expand...
Haven't seen him since for a month or so. I think he gets dragged
into here via xpost more often than not.
 
Arfa Daily wrote:
"Meat Plow" <meat@petitmorte.net> wrote in message
news:31guea.kd6.17.3@news.alt.net...
On Sat, 08 Aug 2009 16:38:30 +0100, Ron
ron@lunevalleyaudio.com>wrote:

N_Cook wrote:
Meat Plow <meat@petitmorte.net> wrote in message
news:31gm3i.6cj.17.9@news.alt.net...
On Sat, 8 Aug 2009 07:41:16 +0100, "N_Cook" <diverse@tcp.co.uk>wrote:

Didn't think when initially checking out, but what is the "group"
slider
function,? no www user manual found.
Anyone any schematics for it ? (ps no emails to whatever this posting
apparently throughs up)
One channel clipping, then dropping out totally after a time, first
problem
in preamp, imbalanced gain, second unknown pa or prea. At least
possible
to
swap the pa channels over it would seem , to resolve to pa or prea ,
if
nothing actually found.
Also what governs the fan startup, comes on at power up for 2 seconds
(presumably normal) switches off and comes on whan heated up but
nothing
obviously separate from the amp/s for temp monitoring or total/channel
cutout, ie no relays, so some sort of gain control coming into play to
kill
the channel.

A group slider may refer to the aux buss group. Don't know how the fan
is governed but I'll assume it has infinite control like my
Studiomaster 700D amp. That probably gets its feedback from a sink
monted sensor, unknown where it is driven from.

I've never seen that before, a TO220 device trackside under each pa pcb,
thermally touching the heatsink. Only 2 pins used, the B-E junction,
with 2
isolated traces to the umbilical ribbon the carries the low voltage
rails
and signal i/p. I wonder what is special in the 2SD1763A used for that
purpose.


You need to be talking to Graham Stevenson (Eeyore) I think he designed
it.

Ron
Yeah don't talk to us lowly nincompoops about something someone else
designed.

Where's Graham gone lately ? Used to enjoy some of his design insights, and
also his tendency to suddenly fly off the handle occasionally !! :)

C'mon Graham - bet you're still lurking - we all luv ya really ...

Arfa


Come to think of it, I havent seen him online lately (we sometimes have
Click to expand...
a yatter in MSN) or in the pro.live-sound group. Hope he`s ok.

Ron
 
On Sat, 08 Aug 2009 13:33:01 -0400, Meat Plow <meat@petitmorte.net> wrote:


Haven't seen him since for a month or so. I think he gets dragged
into here via xpost more often than not.
Click to expand...
He was posting in sci.e.d on the 7th.

--
Geo
 
"Geo" <hw9j-s5hw@dea.spamcon.org> wrote in message
news:eek:jtt75tb1j93qc22a7ga59go3qolve07h8@4ax.com...
On Sat, 08 Aug 2009 13:33:01 -0400, Meat Plow <meat@petitmorte.net> wrote:


Haven't seen him since for a month or so. I think he gets dragged
into here via xpost more often than not.

He was posting in sci.e.d on the 7th.

--
Geo
Click to expand...
Perhaps he's just got tired of talking to us lowly menders ... You know what
these design boys are like ... :) Come to think of it though, I'm sure I
saw a reply from him in one of the threads on here a coupla weeks back.

Arfa
 
Arfa Daily wrote:

"Geo" <hw9j-s5hw@dea.spamcon.org> wrote in message
news:eek:jtt75tb1j93qc22a7ga59go3qolve07h8@4ax.com...

On Sat, 08 Aug 2009 13:33:01 -0400, Meat Plow <meat@petitmorte.net> wrote:



Haven't seen him since for a month or so. I think he gets dragged
into here via xpost more often than not.

He was posting in sci.e.d on the 7th.

--
Geo


Perhaps he's just got tired of talking to us lowly menders ... You know what
these design boys are like ... :) Come to think of it though, I'm sure I
saw a reply from him in one of the threads on here a coupla weeks back.

Arfa


You talking about Eye-Snore?
Click to expand...

I think he was just in a couple of days ago.
 
On Aug 8, 8:41 am, "N_Cook" <dive...@tcp.co.uk> wrote:
Didn't think when initially checking out, but what is the "group" slider
function,? no www user manual found.
Anyone any schematics for it ? (ps no emails to whatever this posting
apparently throughs up)
One channel clipping, then dropping out totally after a time, first problem
in preamp, imbalanced gain, second unknown pa or prea. At least possible to
swap the pa channels over it would seem , to resolve to pa or prea , if
nothing actually found.
Also what governs the fan startup, comes on at power up for 2 seconds
(presumably normal) switches off and comes on whan heated up but nothing
obviously separate from the amp/s for temp monitoring or total/channel
cutout, ie no relays, so some sort of gain control coming into play to kill
the channel.
Click to expand...
glad to see we are not alone got similar problem,have run studiomaster
vision 8 for 12months no prob but have suspected fan not doing its
stuff. summertime is hot here so used external fan just to be
sure,However--- big prob occured running just one guitar in practice
session, unit suddenly lost digital display, developed loud squeal
from both speakers, master straight to off, peak red lights showing
max!! then nothing.
tried powering up again same result.
have carried out detailed inspection, all pcb's ok visually.ribbon
cables and pins good,transformer seems ok but I'm not sure what value
outputs I should be measuring at each pin??
would really appreiciate any help
 
<chezmarkhams@aol.com> wrote in message
news:8621fc4e-f5d9-4ced-95e2-5c78067365fa@t13g2000yqt.googlegroups.com...
On Aug 8, 8:41 am, "N_Cook" <dive...@tcp.co.uk> wrote:
Didn't think when initially checking out, but what is the "group" slider
function,? no www user manual found.
Anyone any schematics for it ? (ps no emails to whatever this posting
apparently throughs up)
One channel clipping, then dropping out totally after a time, first
problem
in preamp, imbalanced gain, second unknown pa or prea. At least possible
to
swap the pa channels over it would seem , to resolve to pa or prea , if
nothing actually found.
Also what governs the fan startup, comes on at power up for 2 seconds
(presumably normal) switches off and comes on whan heated up but nothing
obviously separate from the amp/s for temp monitoring or total/channel
cutout, ie no relays, so some sort of gain control coming into play to
kill
the channel.
Click to expand...
glad to see we are not alone got similar problem,have run studiomaster
vision 8 for 12months no prob but have suspected fan not doing its
stuff. summertime is hot here so used external fan just to be
sure,However--- big prob occured running just one guitar in practice
session, unit suddenly lost digital display, developed loud squeal
from both speakers, master straight to off, peak red lights showing
max!! then nothing.
tried powering up again same result.
have carried out detailed inspection, all pcb's ok visually.ribbon
cables and pins good,transformer seems ok but I'm not sure what value
outputs I should be measuring at each pin??
would really appreiciate any help

I've not got the schematic but I've found you can run it stripped down.
Disconnect the 2 pa and all the ribbon cables except the one between the ps
one, via small rear panel and up to the mixer. To check for any mixer
problems, removing display and memory stuff, monitor output by phones.
It looks, not done so yet, that you can then plug in one amp at a time , or
swap around , to localise single channel problem to one ch or the other in
pa or mixer section.
There seems to be odd power rails , +/65V main power rails and a pair of
+/79V.
I have some monitored voltages at the pa headers, will get back to it today


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/
 
With pa's and mixer removed and Conn3 and conn4 ribbons removed, so just the
main combined ps and thermal board in place, DC voltages on con3
80,0.2(Ł),15,0,0
-80,16.6($),0,0,0 (*)

* has 0.6V ac, and Ł has 0.2Vac on it with 400Hz input and 0db bar
registered on the meter
$, 16.6V via 100R to base of thermal monitor TO220 ,to test point T12 ,
obviously drops down to Vbe , with pa in place

T10 for the other amp TP

The 0.6V ac also on that pin of conn4, clear and balanced , unlike
originally with all connected, very marked signal imbalance. There was a
problem with the "group" slider , but maybe not the cause of original
problem. I will next try with swapped pas in place, then display board if
all seems well.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/
 
Previous 2x5 header volts viewed/monitored at pins , starting from main caps
end

At 75 percent or less of mains voltage both red LED "fault" lights light,
gives some sort of check of functioning.
I don't know what temperature is required to activate the yellow LEDs and
channel/channels ? shutdown, but presumably greater than 90 deg c

With PAs loose(on nylon standoff only, not nutted down) in the amp , make
sure there is insulation between both sets of live heatsinks.
You can monitor signal in of the PA at R11 , R9 end.
Monitoring output and T12 TP, increasing the heatsink temp with hot air gun
and fan off. No change in output level up to 90 deg C.
With fan connected , fan comes on (at T12) with Vbe between 0.61 and 0.62
and temp between about 45 and 55 degree C (the "thermal" Tr is underneath),
dropping to 0.52 or so at 90 deg C. Both channels checked like this


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/
 
Hello to everybody!
I need the user manual for stidomaster powerhouse vision 8 , anybody can help me!? THANKS!
 
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