Studiomaster Powerhouse Vision 8 , 700W mixer amp,1996
N_Cook
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.
N_Cook
news:31gm3i....@news.alt.net...
> 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.
Ron
Ron
Arfa Daily
> On Sat, 08 Aug 2009 16:38:30 +0100, Ron
> <r...@lunevalleyaudio.com>wrote:
> 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
Ron
a yatter in MSN) or in the pro.live-sound group. Hope he`s ok.
Ron
Geo
>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
Arfa Daily
"Geo" <hw9j...@dea.spamcon.org> wrote in message
news:ojtt75tb1j93qc22a...@4ax.com...
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
Jamie
You talking about Eye-Snore?
I think he was just in a couple of days ago.
chezma...@aol.com
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
N_Cook
news:8621fc4e-f5d9-4ced...@t13g2000yqt.googlegroups.com...
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/
N_Cook
main combined ps and thermal board in place, DC voltages on con3
80,0.2(�),15,0,0
-80,16.6($),0,0,0 (*)
* has 0.6V ac, and � 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.
N_Cook
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
robertn...@gmail.com
I need the user manual for stidomaster powerhouse vision 8 , anybody can help me!? THANKS!
dulciep...@gmail.com
dulciep...@gmail.com
dulcie...@yahoo.co.uk