Anyone got the schematics for a Crown XLS5000 ? I'm most interested in the
board that the mains comes in to. There's a bloody great disc something
inside a big lump of heatshrink, and serious flames shoot out of it before
every trip and fuse in the workshop goes out ...

If I bring it up on the variac, I can't get beyond about 20 volts before the
poor thing is jumping off the bench, so there's a good short on there
somewhere. I initially thought that the disc might be a big VDR that was
short, but looking up the part number on the second one that's on there for
the other half of the amp, it appears to be an inrush thermistor, so I guess
whatever is short, must be south of that ...

Arfa

You can send an email to the Crown Technical department, the usually send the schematics to you.

Dan

wrote in message
...
You can send an email to the Crown Technical department, the usually send
the schematics to you.

Dan


Cheers Dan. I'll give it a go. I have to say though that over the years,
I've only had quite limited success prying schematics out of them ...

Arfa

"Arfa Daily" wrote in message
...


wrote in message
...
You can send an email to the Crown Technical department, the usually send
the schematics to you.

Dan


Cheers Dan. I'll give it a go. I have to say though that over the years,
I've only had quite limited success prying schematics out of them ...

Arfa


Well I never ! I asked, I got. Good call, Dan ! :-)

Arfa

Arfa Daily wrote:

Anyone got the schematics for a Crown XLS5000 ? I'm most interested in the
board that the mains comes in to. There's a bloody great disc something
inside a big lump of heatshrink, and serious flames shoot out of it before
every trip and fuse in the workshop goes out ...

If I bring it up on the variac, I can't get beyond about 20 volts before the
poor thing is jumping off the bench, so there's a good short on there
somewhere. I initially thought that the disc might be a big VDR that was
short, but looking up the part number on the second one that's on there for
the other half of the amp, it appears to be an inrush thermistor, so I guess
whatever is short, must be south of that ...

** I found a nice pic:

http://www.musiker-board.de/attachme...005-jpg.84415/

The XLS series of amps use large, 240VAC rated PTCs for inrush limiting AND fault protection. Room temp resistance is a few ohms rising to over 12kohms when hot. Normally, the relay next door bridges it out soon as the DC rails come up.

The example I saw late last year was an XLS602 that would simply not switch on while the PTC was getting very hot. Like yours, you could variac it up to some extent, then the PTC detected a fault and went high.

Problem turned out to be the toroidal transformer, enamel insulation had failed in the primary winding creating shorted turns.



BTW:

Very sad to hear of George Cole's passing.



..... Phil

"Phil Allison" wrote in message
...
Arfa Daily wrote:

Anyone got the schematics for a Crown XLS5000 ? I'm most interested in
the
board that the mains comes in to. There's a bloody great disc something
inside a big lump of heatshrink, and serious flames shoot out of it
before
every trip and fuse in the workshop goes out ...

If I bring it up on the variac, I can't get beyond about 20 volts before
the
poor thing is jumping off the bench, so there's a good short on there
somewhere. I initially thought that the disc might be a big VDR that was
short, but looking up the part number on the second one that's on there
for
the other half of the amp, it appears to be an inrush thermistor, so I
guess
whatever is short, must be south of that ...

** I found a nice pic:

http://www.musiker-board.de/attachme...005-jpg.84415/

The XLS series of amps use large, 240VAC rated PTCs for inrush limiting
AND fault protection. Room temp resistance is a few ohms rising to over
12kohms when hot. Normally, the relay next door bridges it out soon as the
DC rails come up.

The example I saw late last year was an XLS602 that would simply not
switch on while the PTC was getting very hot. Like yours, you could variac
it up to some extent, then the PTC detected a fault and went high.

Problem turned out to be the toroidal transformer, enamel insulation had
failed in the primary winding creating shorted turns.



BTW:

Very sad to hear of George Cole's passing.



.... Phil


Yeah, I was very sad too, but he did have a good innings lasting until he
was 90. Dennis Waterman was still good friends with him as well. He's
looking a bit rough now, though ...

I saw every episode of Minder that was ever made. They all had very clever
'play on words' titles, and the first two series were actually quite dark
stories. They didn't think it was going to last beyond that, but the comedy
element was deliberately ramped up in the third series by the interaction
between Cole and Waterman, and it became an overnight success. I just loved
the character Arthur Daley for the wicked sense of comic timing and the
malapropism he employed. And of course, it was made by Euston Films, the
absolute kings of drama made in London.

Back to the crown. The transformers in this 5000 model are truly massive
torroidals, and I'm leaning towards suspecting shorted turns on the primary
of the one on the bad channel. The inrush thermistors are the size of penny
toffees - the biggest I've ever seen. From the sheet of flame that shot out
of this one and the number of bench fuses that blew, the short must be right
on top of the thermistor. The fact that you can only get to about 20 v of AC
input before the variac is jumping off the bench, also makes me think
shorted primary.

Unfortunately, it's not an easy task to get to the secondary side of the
PSU, as it's one of those two-board constructions, where one power amp is
stacked on top of the other, and all of the bridges and filter caps for both
amps are, needless-to-say, on the bottom board where you can't get to
anything.

Before going to all of the trouble to get the top board out to see if I can
unplug the tranny secondaries, I'm waiting on the shop getting in touch with
the owner to give him an estimate of what it might cost, depending on what I
find. I'm not sure what the spares position for Crown stuff is like here in
the UK, if it needed a tranny ...

Arfa

Arfa Daily wrote:



I just loved
the character Arthur Daley for the wicked sense of comic timing and the
malapropism he employed.


** Like: " The world is your lobster... "


Unfortunately, it's not an easy task to get to the secondary side of the
PSU, as it's one of those two-board constructions, where one power amp is
stacked on top of the other, and all of the bridges and filter caps for both
amps are, needless-to-say, on the bottom board where you can't get to
anything.

* You could snip the leads for the main secondary ( leaving the CT) and join them again if the tranny proves OK.


Before going to all of the trouble to get the top board out to see if I can
unplug the tranny secondaries, I'm waiting on the shop getting in touch with
the owner to give him an estimate of what it might cost, depending on what I
find. I'm not sure what the spares position for Crown stuff is like here in
the UK, if it needed a tranny ...

** Out of curiosity, I stripped down the tranny from that XLS602. Internal shorts in large toroidals are very rare, especially with no other fault.

The whole thing was rough as guts, with a wound core made from dozens of off- cuts of steel strip tacked welded together and bits of cloth tape covering the edges. Normal toroidal cores are precison made and have moulded plastic covers covering all sharp edges, where the primary is wound.

The twin 120/240 primary was bi-filar wound placing 120VAC between every adjacent turn, a dodgy practice at best and fatal if the enamel coating ever gets damaged.


.... Phil

"Phil Allison" wrote in message
...
Arfa Daily wrote:



I just loved
the character Arthur Daley for the wicked sense of comic timing and the
malapropism he employed.


** Like: " The world is your lobster... "


Unfortunately, it's not an easy task to get to the secondary side of the
PSU, as it's one of those two-board constructions, where one power amp is
stacked on top of the other, and all of the bridges and filter caps for
both
amps are, needless-to-say, on the bottom board where you can't get to
anything.

* You could snip the leads for the main secondary ( leaving the CT) and
join them again if the tranny proves OK.


Hadn't thought of that. I've got schematics for the thing, so shouldn't be
too hard to identify which wires are what. The primary is on a plug that's
easy to get to, and all is well with that pulled off, so nothing else on the
input board is the problem.




Before going to all of the trouble to get the top board out to see if I
can
unplug the tranny secondaries, I'm waiting on the shop getting in touch
with
the owner to give him an estimate of what it might cost, depending on
what I
find. I'm not sure what the spares position for Crown stuff is like here
in
the UK, if it needed a tranny ...

** Out of curiosity, I stripped down the tranny from that XLS602. Internal
shorts in large toroidals are very rare, especially with no other fault.

The whole thing was rough as guts, with a wound core made from dozens of
off- cuts of steel strip tacked welded together and bits of cloth tape
covering the edges. Normal toroidal cores are precison made and have
moulded plastic covers covering all sharp edges, where the primary is
wound.

That's interesting. If this turns out to be the tranny, and the owner goes
ahead - assuming we can get one, of course - I will try to find the time to
have a look. Over the last couple of years, I've had probably three or four
large toroidals with shorted primaries, so maybe there's some Chinese
factory churning out cheapies like the one you saw, virtually made from
scrap ...


The twin 120/240 primary was bi-filar wound placing 120VAC between every
adjacent turn, a dodgy practice at best and fatal if the enamel coating
ever gets damaged.

Yes, not a good practice for sure. I suppose though that it's hard to find a
way to wind a twin primary on a toroidal core where you're trying to keep
the profile low, and a similar level of core coupling from both windings.
Much easier when you have a traditional E-I core and can have two primaries
stacked on top of one another, I guess

Arfa


... Phil

Arfa Daily wrote:


** Out of curiosity, I stripped down the tranny from that XLS602. Internal
shorts in large toroidals are very rare, especially with no other fault.

The whole thing was rough as guts, with a wound core made from dozens of
off- cuts of steel strip tacked welded together and bits of cloth tape
covering the edges. Normal toroidal cores are precison made and have
moulded plastic covers covering all sharp edges, where the primary is
wound.

That's interesting. If this turns out to be the tranny, and the owner goes
ahead - assuming we can get one, of course - I will try to find the time to
have a look. Over the last couple of years, I've had probably three or four
large toroidals with shorted primaries, so maybe there's some Chinese
factory churning out cheapies like the one you saw, virtually made from
scrap ...


** The transformer maker used in the XLS series is:

" NRE Electrical Manufacturing Co Ltd ".

www.fsnre.com


( I posted the same details here on December 10,2014 )

BTW:

Is it possible the company is being run by a Mr Dai Lee ??




.... Phil

google images


https://www.google.com/search?site=i...ring+schematic

On Saturday, August 8, 2015 at 1:11:53 PM UTC-4, wrote:
google images


https://www.google.com/search?site=i...ring+schematic

oooooooooooooooooooooooooooo


https://www.google.com/search?site=i...lCki_FhustM%3A

"Arfa Daily" wrote in message ...

Anyone got the schematics for a Crown XLS5000 ? I'm most interested in the
board that the mains comes in to. There's a bloody great disc something
inside a big lump of heatshrink, and serious flames shoot out of it before
every trip and fuse in the workshop goes out ...

If I bring it up on the variac, I can't get beyond about 20 volts before the
poor thing is jumping off the bench, so there's a good short on there
somewhere. I initially thought that the disc might be a big VDR that was
short, but looking up the part number on the second one that's on there for
the other half of the amp, it appears to be an inrush thermistor, so I guess
whatever is short, must be south of that ...

Arfa






Hey guess what? Today I received a Crown XLS 602. (a baby by comparison)
And guess what? The mains Transformer is open circuit.

This TX is marked "NRE Electronics Manufacturing Co Ltd.
08/2006"

Dunno if that makes it from the same source or not.



Cheers,


Gareth.

"Gareth Magennis" wrote in message
...


"Arfa Daily" wrote in message ...

Anyone got the schematics for a Crown XLS5000 ? I'm most interested in the
board that the mains comes in to. There's a bloody great disc something
inside a big lump of heatshrink, and serious flames shoot out of it before
every trip and fuse in the workshop goes out ...

If I bring it up on the variac, I can't get beyond about 20 volts before
the
poor thing is jumping off the bench, so there's a good short on there
somewhere. I initially thought that the disc might be a big VDR that was
short, but looking up the part number on the second one that's on there
for
the other half of the amp, it appears to be an inrush thermistor, so I
guess
whatever is short, must be south of that ...

Arfa






Hey guess what? Today I received a Crown XLS 602. (a baby by
comparison)
And guess what? The mains Transformer is open circuit.

This TX is marked "NRE Electronics Manufacturing Co Ltd.
08/2006"

Dunno if that makes it from the same source or not.



Cheers,


Gareth.



Certainly the same as Phil's one. I don't know who made the one in my '5000.
There's nothing I can immediately see to identify it, but there may be
something when it's out - if of course the owner goes ahead. It's going to
need a pair of spanners big enough to take off tractor wheel nuts ... :-)

Arfa

"Arfa Daily" wrote in message ...



"Gareth Magennis" wrote in message
...


"Arfa Daily" wrote in message ...

Anyone got the schematics for a Crown XLS5000 ? I'm most interested in the
board that the mains comes in to. There's a bloody great disc something
inside a big lump of heatshrink, and serious flames shoot out of it before
every trip and fuse in the workshop goes out ...

If I bring it up on the variac, I can't get beyond about 20 volts before
the
poor thing is jumping off the bench, so there's a good short on there
somewhere. I initially thought that the disc might be a big VDR that was
short, but looking up the part number on the second one that's on there
for
the other half of the amp, it appears to be an inrush thermistor, so I
guess
whatever is short, must be south of that ...

Arfa






Hey guess what? Today I received a Crown XLS 602. (a baby by
comparison)
And guess what? The mains Transformer is open circuit.

This TX is marked "NRE Electronics Manufacturing Co Ltd.
08/2006"

Dunno if that makes it from the same source or not.



Cheers,


Gareth.



Certainly the same as Phil's one. I don't know who made the one in my '5000.
There's nothing I can immediately see to identify it, but there may be
something when it's out - if of course the owner goes ahead. It's going to
need a pair of spanners big enough to take off tractor wheel nuts ... :-)

Arfa





The customer said it had been in storage the past 2 years. He fired it up
today and it blew all the main fuses in his gaff.
So sounds like it may have been short like yours and Phil's, then blew open.



Gareth.

"Gareth Magennis" wrote in message ...



"Arfa Daily" wrote in message ...



"Gareth Magennis" wrote in message
...


"Arfa Daily" wrote in message ...

Anyone got the schematics for a Crown XLS5000 ? I'm most interested in the
board that the mains comes in to. There's a bloody great disc something
inside a big lump of heatshrink, and serious flames shoot out of it before
every trip and fuse in the workshop goes out ...

If I bring it up on the variac, I can't get beyond about 20 volts before
the
poor thing is jumping off the bench, so there's a good short on there
somewhere. I initially thought that the disc might be a big VDR that was
short, but looking up the part number on the second one that's on there
for
the other half of the amp, it appears to be an inrush thermistor, so I
guess
whatever is short, must be south of that ...

Arfa






Hey guess what? Today I received a Crown XLS 602. (a baby by
comparison)
And guess what? The mains Transformer is open circuit.

This TX is marked "NRE Electronics Manufacturing Co Ltd.
08/2006"

Dunno if that makes it from the same source or not.



Cheers,


Gareth.



Certainly the same as Phil's one. I don't know who made the one in my '5000.
There's nothing I can immediately see to identify it, but there may be
something when it's out - if of course the owner goes ahead. It's going to
need a pair of spanners big enough to take off tractor wheel nuts ... :-)

Arfa





The customer said it had been in storage the past 2 years. He fired it up
today and it blew all the main fuses in his gaff.
So sounds like it may have been short like yours and Phil's, then blew open.



Gareth.





Er, except customers tend to lie a lot.

He may have tried to boot several times with various size fuses/paper clips
etc.


Gareth.

The customer said it had been in storage the past 2 years. He fired it up
today and it blew all the main fuses in his gaff.
So sounds like it may have been short like yours and Phil's, then blew
open.



Gareth.





Er, except customers tend to lie a lot.

He may have tried to boot several times with various size fuses/paper
clips etc.


Gareth.


That would be my feeling. It would seem that when these trannies fail on the
primary, they do it in style. The one in this 5000 is *so* short-circuit, it
blew the fuse in the mains lead plugtop, the fuse in the bench input lead
where it plugs into the heavy duty extension cable, and the fuse in the
extension plugtop. Oh yes, and it popped the breaker in the consumer unit as
well. I've had a few mains shorts over the years, but I can't remember one
that has ever taken out three mains fuses in series, *and* the breaker. Just
goes to show how slow the breaker is though, compared to the cartridge fuses
in the plugs. But then I suppose it is over twice their rating, at 30 amps
....

Arfa

Gareth Magennis wrote:



The customer said it had been in storage the past 2 years. He fired it up
today and it blew all the main fuses in his gaff.
So sounds like it may have been short like yours and Phil's, then blew open.


** Hmmm - that should not happen.

However, if the amp worked even for a few seconds, the chunky relay next to the PTC closes and bridges it out. If the primary shorted out after that, it is possible the relay contacts became instantly welded closed.

The fault current could then trip the breaker in the 30A ring mains and easily blow any fuse fitted inside power plug.

A subsequent attempt to switch on the amp would result another huge surge and maybe make a track on the PSU board vaporise.

BTW:

IIRC, the secondary voltages and currents are printed on the side of the tranny. The tranny is about 800VA and it ought to be possible to have one made that is close to the same size and ratings for an acceptable cost.


.... Phil

On Thursday, August 13, 2015 at 5:51:55 AM UTC+1, Phil Allison wrote:
Gareth Magennis wrote:



The customer said it had been in storage the past 2 years. He fired it up
today and it blew all the main fuses in his gaff.
So sounds like it may have been short like yours and Phil's, then blew open.


** Hmmm - that should not happen.

However, if the amp worked even for a few seconds, the chunky relay next to the PTC closes and bridges it out. If the primary shorted out after that, it is possible the relay contacts became instantly welded closed.

The fault current could then trip the breaker in the 30A ring mains and easily blow any fuse fitted inside power plug.

A subsequent attempt to switch on the amp would result another huge surge and maybe make a track on the PSU board vaporise.

BTW:

IIRC, the secondary voltages and currents are printed on the side of the tranny. The tranny is about 800VA and it ought to be possible to have one made that is close to the same size and ratings for an acceptable cost.


... Phil



They are. 74/0/74 and 18.3/0/18.3


Cheers,


Gareth.

Gareth Magennis wrote:



Hey guess what?
Today I received a Crown XLS 602.
And guess what?
The mains Transformer is open circuit.

This TX is marked "NRE Electronics Manufacturing Co Ltd.
08/2006"

Dunno if that makes it from the same source or not.


** It's exactly the same as the one I described as "rough as guts".



.... Phil

"Phil Allison" wrote in message
...
Gareth Magennis wrote:



Hey guess what?
Today I received a Crown XLS 602.
And guess what?
The mains Transformer is open circuit.

This TX is marked "NRE Electronics Manufacturing Co Ltd.
08/2006"

Dunno if that makes it from the same source or not.


** It's exactly the same as the one I described as "rough as guts".



... Phil


The owner has decided to 'go for it' so the owner of the shop that it came
in through has gone ahead and ordered in the replacement that was offered at
100 GBP. Should be here this week sometime. While we're on slave amps,
anyone following this thread got the schematic for an Alto Mac 2.2 ? Very
odd fault. Both channels work just fine for a while, then all of a sudden,
one channel starts to indicate 'clip' with the level control just a gnat's
bollock above zero. There seems to be a dual opamp involved in the clip
detect circuit, but before going round in circles trying to see what's
happening and why, it would be handy to have a schematic to see how the clip
detect circuit is designed and what its inputs are. I'll put a new post up
as well to catch anyone that's not following this discussion.

Arfa

Just start a new thread Arf. Itt is damn hard enough for peopple to keep track of **** without having two separate isssues in threads not specificallty named hat they should be named. If =you do, I won't rip you a new ******** hole, we got Phil to take care of that.

but seriously seriously here, I almost NEVER had an actual bad power traansformer almost in my life. I had one in a Zenith TV that started getting open connections. First was to the CRT filamentm whichg I fixed by wrapping a wire around the flyback core to get about 22 volts peak to peak which is about 6 volts RMS. Then another linee come loose and it was tjhe center tap for the +/- 24V or whatever fed the vertical, and was on th same wire as the return for the 130 volt lin. It sent the picture offf ceneter and the centering control of course did not work. ALL the currnet pulled by the 130 volt line was going through one of the vertical output transistors. this was another of the myriad of TVs that nobody else could fix. That was my specialty.

But that sounds interesting. Question is, is it distorting ? There are a couple of different ways to implement a clipping detector. If it is actually detecting a ifference between the input and output of the power amp there are several possibilities. High frequency oscillation is possible. Loss of bias couldd do it.

Start a thread, I am not going to **** this all up. This thread is for this, make that thread for that. See you there.

Arfa Daily wrote:


While we're on slave amps,
anyone following this thread got the schematic for an Alto Mac 2.2 ? Very
odd fault. Both channels work just fine for a while, then all of a sudden,
one channel starts to indicate 'clip' with the level control just a gnat's
bollock above zero. There seems to be a dual opamp involved in the clip
detect circuit, but before going round in circles trying to see what's
happening and why, it would be handy to have a schematic to see how the clip
detect circuit is designed and what its inputs are.


** The schem of the 2.3 should be very close:

http://www.mediafire.com/view/bmotmj..._manual+8.jpg#

The Alto MAC amps have basically copied early QSC models like the USA850 and 900. Changes include use of a toroidal transformer, flat pack output transistors and SMD for all the small signal stuff.

The topology is very odd with output transistor collectors all tied to chassis ground while the DC rails swing with output signal. Speaker drive comes from the PSU centre points for each channel and the usual driver transistors have simply been eliminated. The short circuit protection scheme is weird too.

Advantages are a low parts count, cheap to make and will not pass DC current into a speaker under fault conditions.

The clip LED is driven by U2-B (half an NE5532 supplying drive to the output stage) via a diode bridge and also triggers the clipping limiter (U1A) via R26 to ground.


.... Phil

"Phil Allison" wrote in message
...
Arfa Daily wrote:


While we're on slave amps,
anyone following this thread got the schematic for an Alto Mac 2.2 ? Very
odd fault. Both channels work just fine for a while, then all of a
sudden,
one channel starts to indicate 'clip' with the level control just a
gnat's
bollock above zero. There seems to be a dual opamp involved in the clip
detect circuit, but before going round in circles trying to see what's
happening and why, it would be handy to have a schematic to see how the
clip
detect circuit is designed and what its inputs are.


** The schem of the 2.3 should be very close:

http://www.mediafire.com/view/bmotmj..._manual+8.jpg#

The Alto MAC amps have basically copied early QSC models like the USA850
and 900. Changes include use of a toroidal transformer, flat pack output
transistors and SMD for all the small signal stuff.

The topology is very odd with output transistor collectors all tied to
chassis ground while the DC rails swing with output signal. Speaker drive
comes from the PSU centre points for each channel and the usual driver
transistors have simply been eliminated. The short circuit protection
scheme is weird too.

Advantages are a low parts count, cheap to make and will not pass DC
current into a speaker under fault conditions.

The clip LED is driven by U2-B (half an NE5532 supplying drive to the
output stage) via a diode bridge and also triggers the clipping limiter
(U1A) via R26 to ground.


.... Phil


Thanks for that, Phil. Much appreciated. Odd how it works for a short while.
Before having the schematic, I gave everything in the area a good dousing
with freezer when it failed, but nothing really that I would say was very
positive. Maybe - and it *was* a maybe - the 5532 was a bit sensitive, but
it was inconclusive. I did notice that when it was wrong, the waveform on
pin 7 I think it was, was much bigger than 'normal' and the output TRs on
that side got quite hot quite quickly.

I'll try and find time to get another look today or tomorrow with the
benefit of your schematic. Thanks again

Arfa