Of course the owner wants it to be as original as possible or at least
retrievable. I've convinced him that a fully bonded earth point to the
chassis is absolutely necessary for use in the UK, no getting away from
that.
Hopefully the US mains cable rubber insulation will be perished and will
need replacing anyway so would then be 3 core.
He definitely does not want the step down transformer mounted in the cab,
but external .
But if original US mains cable and US plug retained.
I'm thinking earthing coloured multistrand flexible third cable run
alongside the US cable with black heatshrink over the near-enough whole
length. The problem is what connector to use for reliable earth continuity
to the step down Tx and UK mains cable and how to make a mechanical
interlock, in effect, so the amp cannot be run without the third wire
connected.
Then what to do with the original "ground" switch ? presumably disconnect
but leave in place internally .
Do US three pin variant outlet, purpose made, step down transformers exist
in the UK, I only ever see 2 pin outlet ones. Assuming he can tolerate
swapping, but retaining with the amp, the ancient 2 pin plug.

N_Cook wrote:
Of course the owner wants it to be as original as possible or at least
retrievable. I've convinced him that a fully bonded earth point to the
chassis is absolutely necessary for use in the UK, no getting away from
that.
Hopefully the US mains cable rubber insulation will be perished and will
need replacing anyway so would then be 3 core.
He definitely does not want the step down transformer mounted in the cab,
but external .
But if original US mains cable and US plug retained.
I'm thinking earthing coloured multistrand flexible third cable run
alongside the US cable with black heatshrink over the near-enough whole
length. The problem is what connector to use for reliable earth continuity
to the step down Tx and UK mains cable and how to make a mechanical
interlock, in effect, so the amp cannot be run without the third wire
connected.
Then what to do with the original "ground" switch ? presumably disconnect
but leave in place internally .
Do US three pin variant outlet, purpose made, step down transformers exist
in the UK, I only ever see 2 pin outlet ones. Assuming he can tolerate
swapping, but retaining with the amp, the ancient 2 pin plug.

I live in Israel and have the same problem all the time. First of all, the
transformers you buy in the shops in plastic cases are junk. They are
rated in VA and sold as if that were Watts, so you never get the size you
need.

They almost never carry the ground through.

They are also autotransformers, not real transformers, so they do NOT provide
any isolation.

Luckilly we have a guy here who makes transformers. He is not cheap, but he
will make one to specification.

What you want is:

1. A True transformer (no connection of any sort to the mains,
i.e. isolation).

2. Ground carried through, i.e. the grounding pin of the 120 volt socket
is directly connected with a decent sized wire to the grounding pin
of the mains plug.

3. A easilly accessable fuse socket in the secondary (120 volt side).

4. At least 50% more than the maximum current draw rating if in real Watts
and DOUBLE if VA. Note that maximum is not always the rated value.

5. Since US equipment made in now is designed for 127 volts, not 115 or 120,
the ratio should be adjusted for a slightly higher output than 2:1
(240/130 instead of 240/120).
1950's equipment would be better off with a slightly lower ratio
(240/115 or 240/110) and heaivly motorized equipment (mentioned for
compelteness) should be lower (240/110 or 240/100 for compressors)
because of the different power factor.

BTW, if you've never done this type of work before, be careful about the
voltages, replace all the capacitors and buy yourself a large bottle of
DE-OXIT and a bunch of toothpicks (to apply it).

Geoff.


--
Geoffrey S. Mendelson N3OWJ/4X1GM
Making your enemy reliant on software you support is the best revenge.

Geoffrey S. Mendelson wrote in message
...
N_Cook wrote:
Of course the owner wants it to be as original as possible or at least
retrievable. I've convinced him that a fully bonded earth point to the
chassis is absolutely necessary for use in the UK, no getting away from
that.
Hopefully the US mains cable rubber insulation will be perished and will
need replacing anyway so would then be 3 core.
He definitely does not want the step down transformer mounted in the
cab,
but external .
But if original US mains cable and US plug retained.
I'm thinking earthing coloured multistrand flexible third cable run
alongside the US cable with black heatshrink over the near-enough whole
length. The problem is what connector to use for reliable earth
continuity
to the step down Tx and UK mains cable and how to make a mechanical
interlock, in effect, so the amp cannot be run without the third wire
connected.
Then what to do with the original "ground" switch ? presumably
disconnect
but leave in place internally .
Do US three pin variant outlet, purpose made, step down transformers
exist
in the UK, I only ever see 2 pin outlet ones. Assuming he can tolerate
swapping, but retaining with the amp, the ancient 2 pin plug.

I live in Israel and have the same problem all the time. First of all, the
transformers you buy in the shops in plastic cases are junk. They are
rated in VA and sold as if that were Watts, so you never get the size you
need.

They almost never carry the ground through.

They are also autotransformers, not real transformers, so they do NOT
provide
any isolation.

Luckilly we have a guy here who makes transformers. He is not cheap, but
he
will make one to specification.

What you want is:

1. A True transformer (no connection of any sort to the mains,
i.e. isolation).

2. Ground carried through, i.e. the grounding pin of the 120 volt socket
is directly connected with a decent sized wire to the grounding pin
of the mains plug.

3. A easilly accessable fuse socket in the secondary (120 volt side).

4. At least 50% more than the maximum current draw rating if in real Watts
and DOUBLE if VA. Note that maximum is not always the rated value.

5. Since US equipment made in now is designed for 127 volts, not 115 or
120,
the ratio should be adjusted for a slightly higher output than 2:1
(240/130 instead of 240/120).
1950's equipment would be better off with a slightly lower ratio
(240/115 or 240/110) and heaivly motorized equipment (mentioned for
compelteness) should be lower (240/110 or 240/100 for compressors)
because of the different power factor.

BTW, if you've never done this type of work before, be careful about the
voltages, replace all the capacitors and buy yourself a large bottle of
DE-OXIT and a bunch of toothpicks (to apply it).

Geoff.


--
Geoffrey S. Mendelson N3OWJ/4X1GM
Making your enemy reliant on software you support is the best revenge.

All original inside except one resistor. 1964 Twin Reverb. I see US 3 pin
outlet auto transformers are available.
But owner wants to retain the moulded , sorry molded, 2 pin plug. All I can
think of is making a 2 part shroud that fits overe the existing plug and
includes a third earthing pin to mate with the 3 pin outlet, also retaining
polarisation for added safety (assuming anyone rewiring the UK main plug in
the future , wires it correctly).
Third wire under heatshrink and bonded to the chassis mounted 110V outlet ,
removing the PK and replacing with a bolt and lock nut/star washer inside.
Some sort of shrouding over the earth /chassis bond and exposed stub of
wire.
I'll try and convince him to go for isolating rather than auto but the
original 2 pin plug plus grounding pin union problem remains.

I really want to be able to condemn the mains lead. But the internal exposed
sheathing looks fine, how to non-destructively check for internally mangled
insulation or wiring filaments inside the cable strain relief?

On 6/30/2011 6:24 AM, N_Cook wrote:
I really want to be able to condemn the mains lead.

You could, of course, tell him to take it elsewhere
because you're not going to be involved in him killing
himself.

Jeff


--
"Everything from Crackers to Coffins"

I see Jeffrey A offers a good solution, same as what I'd generally tell a
friend, even.

If the amp is so valuable to him, he should have it insured and not be using
it.. and buy a display case to protect it.

A proper step-down isolating transformer (not auto transformer buck types)
would allow 120VAC operation, just the way it was made.
Amp and guitar isolated.

As long as the users of the amp don't plug in any line-operated
accessories/equipment (patch to mixers etc) the amp should operate
flawlessly.
Any accessories (pedals etc) added between the guitar and amp should be
battery powered only.
Battery only.
No exceptions.

So.. a 5-6A? capacity (see the amp's fuse rating) 240 to 120 step-down
isolation transformer (no 3/third wire BS for the amp) with only 1 single,
2-blade 120VAC outlet.
The single 120VAC outlet is a factor because idiots will start plugging more
crap into it.

If the user has any problems (likely to be self-induced), he can take it up
with the manufacturer of the isolation transformer..
and he should be informed of this, as his only option.

Or.. pull the amp chassis out of the case, and install a properly grounded
240VAC amp chassis in it's place.

--
Cheers,
WB
..............


"N_Cook" wrote in message
...
Of course the owner wants it to be as original as possible or at least
retrievable. I've convinced him that a fully bonded earth point to the
chassis is absolutely necessary for use in the UK, no getting away from
that.
Hopefully the US mains cable rubber insulation will be perished and will
need replacing anyway so would then be 3 core.
He definitely does not want the step down transformer mounted in the cab,
but external .
But if original US mains cable and US plug retained.
I'm thinking earthing coloured multistrand flexible third cable run
alongside the US cable with black heatshrink over the near-enough whole
length. The problem is what connector to use for reliable earth continuity
to the step down Tx and UK mains cable and how to make a mechanical
interlock, in effect, so the amp cannot be run without the third wire
connected.
Then what to do with the original "ground" switch ? presumably disconnect
but leave in place internally .
Do US three pin variant outlet, purpose made, step down transformers exist
in the UK, I only ever see 2 pin outlet ones. Assuming he can tolerate
swapping, but retaining with the amp, the ancient 2 pin plug.

Jeffrey Angus wrote in message
...
On 6/30/2011 6:24 AM, N_Cook wrote:
I really want to be able to condemn the mains lead.

You could, of course, tell him to take it elsewhere
because you're not going to be involved in him killing
himself.

Jeff


--
"Everything from Crackers to Coffins"


A possible face-saving route. Release the tethered 2 part mains cable strain
relief, bend the cable back and forth at that strain point enough times and
let the owner feel the floppy section. Then 3 core can go in place.

In article , "N_Cook"
wrote:

Jeffrey Angus wrote in message
...
On 6/30/2011 6:24 AM, N_Cook wrote:
I really want to be able to condemn the mains lead.

You could, of course, tell him to take it elsewhere
because you're not going to be involved in him killing
himself.

Jeff


--
"Everything from Crackers to Coffins"


A possible face-saving route. Release the tethered 2 part mains cable strain
relief, bend the cable back and forth at that strain point enough times and
let the owner feel the floppy section. Then 3 core can go in place.

Doesn't sound like you, deliberately sabotaging and destroying
customer-owned equipment, as a means of coercion. Either set it up the
way the customer wants, or walk away from the job based on your safety
concerns.

In article , N_Cook wrote:
Of course the owner wants it to be as original as possible or at least
retrievable. I've convinced him that a fully bonded earth point to the
chassis is absolutely necessary for use in the UK, no getting away from
that.
Hopefully the US mains cable rubber insulation will be perished and will
need replacing anyway so would then be 3 core.
He definitely does not want the step down transformer mounted in the cab,
but external .
But if original US mains cable and US plug retained.
I'm thinking earthing coloured multistrand flexible third cable run
alongside the US cable with black heatshrink over the near-enough whole
length. The problem is what connector to use for reliable earth continuity
to the step down Tx and UK mains cable and how to make a mechanical
interlock, in effect, so the amp cannot be run without the third wire
connected.
Then what to do with the original "ground" switch ? presumably disconnect
but leave in place internally .
Do US three pin variant outlet, purpose made, step down transformers exist
in the UK, I only ever see 2 pin outlet ones. Assuming he can tolerate
swapping, but retaining with the amp, the ancient 2 pin plug.

Don't you Brits use a 110 Volt (center tapped) system for construction
site power tools? On a lot of '60s vintage transformer powered tube
gear, the only connection between either side of the power cord to chassis
ground* was a small filter cap. So the amp may be perfectly happy running
that way as neither side of the power line was expected to be ground.
And, if something goes wrong, at 60 volts or so, it should keep your
customer from killing himself.

*Ground came from somewhere else, as the gear was floating at 1/2 the
power voltage at high impedance. (Made working on transistor circuits
with an old tube 'scope a learning experience. First lesson: always
hook up the ground lead first).

Mark Zenier
Googleproofaddress(account:mzenier provider:eskimo domain:com)

"Wild Bull**** Artist


A proper step-down isolating transformer (not auto transformer buck types)
would allow 120VAC operation, just the way it was made.
Amp and guitar isolated.

** But that is NOT how such amps work in the USA.

http://www.webphix.com/schematic%20h...b763_schem.pdf

Note the switch and the 0.047uF cap in the AC line to the amp - this is
the " polarity switch" and it connects the chassis to one or other side of
the AC supply via the cap. Users are meant to select the less noisy
position, which equates to the neutral conductor.

To duplicate this set up , the isolation stepdown tranny must have one side
of its secondary linked to the supply ground.

The only thing left " un-American " then is the frequency of 50Hz - which
WILL cause the power tranny to get rather hot.


As long as the users of the amp don't plug in any line-operated
accessories/equipment (patch to mixers etc) the amp should operate
flawlessly.

** It will work fine even with them - you posturing ass.


Any accessories (pedals etc) added between the guitar and amp should be
battery powered only.
Battery only.
No exceptions.

** Total lunacy.

The amp will always be safer if the chassis is grounded.


So.. a 5-6A? capacity (see the amp's fuse rating)


** A 300VA isolation stepdown tranny would be plenty.


..... Phil

Speaking of bull****:

.... and the whores you rode in on.

You know all of this because you personally designed or reviewed/approved
every ****in piece of audio-related equipment that any idiot may attempt to
attach to an amp.


Well, it seems you haven't.. or you might have a GD clue.. many PROPER
isolation transformers DO have a side to ground thru a high-value resistor.

Wow.. a transformer that generates heat? You complete dumbass.
Overheat - NO.

Use all the space you need to list all the electrical devices that DON'T
generate heat.


Shame how so many OPs post entirely in meaningless generalisations.
Means that is how they are thinking too.

..... Always BITCHING UNBALANCED Phil


--
Cheers,
WB
..............


"Phil Allison" wrote in message
...

"Wild Bull**** Artist


A proper step-down isolating transformer (not auto transformer buck
types) would allow 120VAC operation, just the way it was made.
Amp and guitar isolated.

** But that is NOT how such amps work in the USA.

http://www.webphix.com/schematic%20h...b763_schem.pdf

Note the switch and the 0.047uF cap in the AC line to the amp - this is
the " polarity switch" and it connects the chassis to one or other side
of the AC supply via the cap. Users are meant to select the less noisy
position, which equates to the neutral conductor.

To duplicate this set up , the isolation stepdown tranny must have one
side of its secondary linked to the supply ground.

The only thing left " un-American " then is the frequency of 50Hz - which
WILL cause the power tranny to get rather hot.


As long as the users of the amp don't plug in any line-operated
accessories/equipment (patch to mixers etc) the amp should operate
flawlessly.

** It will work fine even with them - you posturing ass.


Any accessories (pedals etc) added between the guitar and amp should be
battery powered only.
Battery only.
No exceptions.

** Total lunacy.

The amp will always be safer if the chassis is grounded.


So.. a 5-6A? capacity (see the amp's fuse rating)


** A 300VA isolation stepdown tranny would be plenty.


.... Phil

Returning to plan A. What I think of as a lawnmower connector, 2 part outer
shell. Just space to mould in the existing US plug and fix in a third pin.
All demountable leaving the original cable and plug untouched, if so
required. Then either black nylon spiral wrap or heatshrink over the green
wire along the original cable. Satisfying the original brief but would be a
lot cheaper for him just having 2 core cable replaced with 3 core and 3 pin
plug, retained in the cab for any , unlikely, future USA based user.

On Fri, 1 Jul 2011 08:15:55 +0100, "N_Cook" wrote:

Returning to plan A. What I think of as a lawnmower connector, 2 part outer
shell. Just space to mould in the existing US plug and fix in a third pin.
All demountable leaving the original cable and plug untouched, if so
required. Then either black nylon spiral wrap or heatshrink over the green
wire along the original cable. Satisfying the original brief but would be a
lot cheaper for him just having 2 core cable replaced with 3 core and 3 pin
plug, retained in the cab for any , unlikely, future USA based user.

Since the owner wants the amp to be at least retrievable then why not
un-solder the old cord, coil it uo, and store it inside the amp.
Re-wire witha grounded cord. Then if he ever wants to return the thing
to stock someone can remove the cord from inside the amp and solder
it back in place. Probably my suggestion will not please your customer
though, you must have already suggested this.
Eric

On Fri, 01 Jul 2011 11:53:24 +1000, Phil Allison wrote:

"Wild Bull**** Artist


A proper step-down isolating transformer (not auto transformer buck
types) would allow 120VAC operation, just the way it was made. Amp and
guitar isolated.

** But that is NOT how such amps work in the USA.

http://www.webphix.com/schematic%20h...ticheaven.com/
fenderamps/twin_reverb_ab763_schem.pdf

Note the switch and the 0.047uF cap in the AC line to the amp - this
is the " polarity switch" and it connects the chassis to one or other
side of the AC supply via the cap. Users are meant to select the less
noisy position, which equates to the neutral conductor.

To duplicate this set up , the isolation stepdown tranny must have one
side of its secondary linked to the supply ground.

The only thing left " un-American " then is the frequency of 50Hz -
which WILL cause the power tranny to get rather hot.


As long as the users of the amp don't plug in any line-operated
accessories/equipment (patch to mixers etc) the amp should operate
flawlessly.

** It will work fine even with them - you posturing ass.


Any accessories (pedals etc) added between the guitar and amp should be
battery powered only.
Battery only.
No exceptions.

** Total lunacy.

The amp will always be safer if the chassis is grounded.


So.. a 5-6A? capacity (see the amp's fuse rating)


** A 300VA isolation stepdown tranny would be plenty.


.... Phil

Why be a prick? Are your Ewes not in heat?





--
Live Fast Die Young, Leave A Pretty Corpse

On Fri, 01 Jul 2011 13:21:14 +1000, Phil Allison wrote:

"Wild Bull**** Artist"

We know you are.



--
Live Fast Die Young, Leave A Pretty Corpse

Mark Zenier wrote in message
...
In article , N_Cook wrote:
Of course the owner wants it to be as original as possible or at least
retrievable. I've convinced him that a fully bonded earth point to the
chassis is absolutely necessary for use in the UK, no getting away from
that.
Hopefully the US mains cable rubber insulation will be perished and will
need replacing anyway so would then be 3 core.
He definitely does not want the step down transformer mounted in the cab,
but external .
But if original US mains cable and US plug retained.
I'm thinking earthing coloured multistrand flexible third cable run
alongside the US cable with black heatshrink over the near-enough whole
length. The problem is what connector to use for reliable earth
continuity
to the step down Tx and UK mains cable and how to make a mechanical
interlock, in effect, so the amp cannot be run without the third wire
connected.
Then what to do with the original "ground" switch ? presumably disconnect
but leave in place internally .
Do US three pin variant outlet, purpose made, step down transformers
exist
in the UK, I only ever see 2 pin outlet ones. Assuming he can tolerate
swapping, but retaining with the amp, the ancient 2 pin plug.

Don't you Brits use a 110 Volt (center tapped) system for construction
site power tools? On a lot of '60s vintage transformer powered tube
gear, the only connection between either side of the power cord to chassis
ground* was a small filter cap. So the amp may be perfectly happy running
that way as neither side of the power line was expected to be ground.
And, if something goes wrong, at 60 volts or so, it should keep your
customer from killing himself.

*Ground came from somewhere else, as the gear was floating at 1/2 the
power voltage at high impedance. (Made working on transistor circuits
with an old tube 'scope a learning experience. First lesson: always
hook up the ground lead first).

Mark Zenier
Googleproofaddress(account:mzenier provider:eskimo domain:com)



Site transformers , tend to be bright yellow and start at 1000VA, so an
appreciable weight and industrial size connectors.

"N_Cook" schreef in bericht
...
Of course the owner wants it to be as original as possible or at least
retrievable. I've convinced him that a fully bonded earth point to the
chassis is absolutely necessary for use in the UK, no getting away from
that.
Hopefully the US mains cable rubber insulation will be perished and will
need replacing anyway so would then be 3 core.
He definitely does not want the step down transformer mounted in the cab,
but external .
But if original US mains cable and US plug retained.
I'm thinking earthing coloured multistrand flexible third cable run
alongside the US cable with black heatshrink over the near-enough whole
length. The problem is what connector to use for reliable earth continuity
to the step down Tx and UK mains cable and how to make a mechanical
interlock, in effect, so the amp cannot be run without the third wire
connected.
Then what to do with the original "ground" switch ? presumably disconnect
but leave in place internally .
Do US three pin variant outlet, purpose made, step down transformers exist
in the UK, I only ever see 2 pin outlet ones. Assuming he can tolerate
swapping, but retaining with the amp, the ancient 2 pin plug.



IMHO the only way to solve all the problems that has been risen, is finding
a good, fully insulated 50Hz to 60 Hz converter. That way you can ground the
enclosure of the converter as well as one side of the 60Hz output. An
American outlet that matches the Fender plug can be build in the converter
so you do not need to modify that Fender at all. No need to say that the
converter has to provide a clean 60Hz sine wave as well as enough power to
satisfy the Fender all of the time.

petrus bitbyter

"petrus bitbyter"

IMHO the only way to solve all the problems that has been risen, is
finding a good, fully insulated 50Hz to 60 Hz converter. That way you can
ground the enclosure of the converter as well as one side of the 60Hz
output. An American outlet that matches the Fender plug can be build in
the converter so you do not need to modify that Fender at all. No need to
say that the converter has to provide a clean 60Hz sine wave as well as
enough power to satisfy the Fender all of the time.


** Massively silly idea.

50Hz to 60Hz sine wave converters capable of 300VA at 120 Volts AC are not "
off the shelf " items.

One would have to be custom built and there is simply no need.

Just use a normal 240/120 step down transformer and ground one side of the
secondary - perfectly safe and legal.

If there is any concern about how warm the tranny in the Fender Twin is
getting, just place a small fan behind the amp.

My god you ****wits here know how to complicate simple matters.



..... Phil

"Phil Allison" schreef in bericht
...

"petrus bitbyter"

IMHO the only way to solve all the problems that has been risen, is
finding a good, fully insulated 50Hz to 60 Hz converter. That way you can
ground the enclosure of the converter as well as one side of the 60Hz
output. An American outlet that matches the Fender plug can be build in
the converter so you do not need to modify that Fender at all. No need to
say that the converter has to provide a clean 60Hz sine wave as well as
enough power to satisfy the Fender all of the time.


** Massively silly idea.

50Hz to 60Hz sine wave converters capable of 300VA at 120 Volts AC are not
" off the shelf " items.

One would have to be custom built and there is simply no need.

Just use a normal 240/120 step down transformer and ground one side of the
secondary - perfectly safe and legal.

If there is any concern about how warm the tranny in the Fender Twin is
getting, just place a small fan behind the amp.

My god you ****wits here know how to complicate simple matters.



.... Phil



You may be right, you may be wrong but I got 60Hz trannies fried on 50Hz
mains. I'd take no risk with a - at least in the owners eye - precious
Fender.

petrus bitbyter

petrus bitbyter wrote:
You may be right, you may be wrong but I got 60Hz trannies fried on 50Hz
mains. I'd take no risk with a - at least in the owners eye - precious
Fender.

It's not SUPPOSED to happen, but it does. A properly spec'ed 60Hz transformer
will happily work on 50Hz, right at the edge of where it was supposed to
be run. (20% overload)

However, quite often things sold in the US were not spec'ed properly, they
were designed to work at 60Hz, without a big change in frequency or current
draw.

I had a wonderful Phase Linear 400 watt per channel amp I had to sell when I
left the US because their transformers were well known not to be able to
stand 50Hz. :-(

Geoff.

--
Geoffrey S. Mendelson N3OWJ/4X1GM
Making your enemy reliant on software you support is the best revenge.

On Sun, 3 Jul 2011 14:54:05 +0000 (UTC), "Geoffrey S. Mendelson"
wrote:

However, quite often things sold in the US were not spec'ed properly, they
were designed to work at 60Hz, without a big change in frequency or current
draw.

I had a wonderful Phase Linear 400 watt per channel amp I had to sell when I
left the US because their transformers were well known not to be able to
stand 50Hz. :-(

It's fairly easy to build a 50Hz to 60Hz switching inverter. Start
with a 230V 50Hz power supply that produces 330VDC. Then run the
330VDC through a 60Hz chopper to get a 330VDC peak-to-peak square
wave. If your xformer is fails to appreciate square waves and
converts the harmonic energy into heat, then something more
sophisticated, like a step approximated sine wave switcher can replace
the chopper.

Well, maybe this is overkill (and inefficient):
http://www.hzfrequencyconverter.com

Also, I just downloaded the Phase Linear 400 schematic:
http://www.schematicsunlimited.com/download.php?manu=phase-linear&file=phase-linear-400-power-amplifier-schematic.pdf
and found that the xformer is just a full wave center tapped single
winding (other than the winding running the pilot lights). You could
possibly have found a 50Hz replacement for something that simple or
deviced another +75v/-75v power source. Oh well, too late.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On 7/2/2011 11:42 PM, Phil Allison wrote:
My god you ****wits here know how to complicate simple matters.

Yeah but that's half the fun.

I'm thinking of a nice motor-generator set with a
common armature. ;-)

And a nice roll around cabinet. Tolex covering of
course with shiny brass fittings.

Jeff


--
"Everything from Crackers to Coffins"

"Geoffrey S. Mendelson"

I had a wonderful Phase Linear 400 watt per channel amp I had to sell when
I
left the US because their transformers were well known not to be able to
stand 50Hz.


** That is utter bull**** !!

I have personally seen 120 VAC Phase Linear 400s, here in Sydney running on
a step down tranny and doing fine.




...... Phil

"petrus bitbyter"
"Phil Allison"

IMHO the only way to solve all the problems that has been risen, is
finding a good, fully insulated 50Hz to 60 Hz converter. That way you
can ground the enclosure of the converter as well as one side of the
60Hz output. An American outlet that matches the Fender plug can be
build in the converter so you do not need to modify that Fender at all.
No need to say that the converter has to provide a clean 60Hz sine wave
as well as enough power to satisfy the Fender all of the time.


** Massively silly idea.

50Hz to 60Hz sine wave converters capable of 300VA at 120 Volts AC are
not " off the shelf " items.

One would have to be custom built and there is simply no need.

Just use a normal 240/120 step down transformer and ground one side of
the secondary - perfectly safe and legal.

If there is any concern about how warm the tranny in the Fender Twin is
getting, just place a small fan behind the amp.

My god you ****wits here know how to complicate simple matters.


You may be right,

** Of course I am - thouasands of examples prove it.


but I got 60Hz trannies fried on 50Hz mains.

** Yawnnnnnnn....


..... Phil

"Jeff Liebermann"

It's fairly easy to build a 50Hz to 60Hz switching inverter.

** ********.

Start
with a 230V 50Hz power supply that produces 330VDC. Then run the
330VDC through a 60Hz chopper to get a 330VDC peak-to-peak square
wave.

** What that produces is a 165 volts of DC.

Dickhead.


Well, maybe this is overkill (and inefficient):
http://www.hzfrequencyconverter.com

** ROTFL !!


Also, I just downloaded the Phase Linear 400 schematic:
http://www.schematicsunlimited.com/download.php?manu=phase-linear&file=phase-linear-400-power-amplifier-schematic.pdf
and found that the xformer is just a full wave center tapped single
winding (other than the winding running the pilot lights). You could
possibly have found a 50Hz replacement for something that simple or
deviced another +75v/-75v power source.


** The amp works just fine on a standard step down tranny.

Just like 99% of all amps made for 60 Hz power.



...... Phil

On Mon, 4 Jul 2011 12:17:12 +1000, "Phil Allison"
wrote:

It's fairly easy to build a 50Hz to 60Hz switching inverter.

** ********.

Correction. It's fairly easy for *me* to build a 50 to 60Hz switching
inverter.

Start
with a 230V 50Hz power supply that produces 330VDC. Then run the
330VDC through a 60Hz chopper to get a 330VDC peak-to-peak square
wave.

** What that produces is a 165 volts of DC.

Oops. I forgot it was for UK power. US power is 117Vrms
Pk-to-peak is 2 * 1.414 * 117Vrms = 330 V Pk-to-pk
Double that for UK power.

Dickhead.

Judging by your typical acerbic remarks, I'll consider that a relative
compliment.

Well, maybe this is overkill (and inefficient):
http://www.hzfrequencyconverter.com

** ROTFL !!

Well, it is a bit large, noisy, inefficient, expensive, messy, and
overkill. But, it will do the job.

One could probably just slow down a 60Hz gasoline portable generator
to run at 50Hz, but that would be too easy. I don't think the
generator noise will be heard over the music belched by the typical
Fender guitar amp.

Also, I just downloaded the Phase Linear 400 schematic:
http://www.schematicsunlimited.com/download.php?manu=phase-linear&file=phase-linear-400-power-amplifier-schematic.pdf
and found that the xformer is just a full wave center tapped single
winding (other than the winding running the pilot lights). You could
possibly have found a 50Hz replacement for something that simple or
deviced another +75v/-75v power source.

** The amp works just fine on a standard step down tranny.
Just like 99% of all amps made for 60 Hz power.

The xformers that burn up are the one's that are operating close to
saturation at 60Hz. That's usually near maximum rated xformer load.
Run those on 50Hz, the core saturates and gets hot. The same xformer,
run with a much smaller load, works just fine.



--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

"Jeff Liebermann" wrote in message
...
On Mon, 4 Jul 2011 12:17:12 +1000, "Phil Allison"
wrote:

It's fairly easy to build a 50Hz to 60Hz switching inverter.

** ********.

Correction. It's fairly easy for *me* to build a 50 to 60Hz switching
inverter.

** Grandiose bull****.



Start
with a 230V 50Hz power supply that produces 330VDC. Then run the
330VDC through a 60Hz chopper to get a 330VDC peak-to-peak square
wave.

** What that produces is a 165 volts of DC.

Oops. I forgot it was for UK power.


** You forgot about the DC component - among other crucial errors.

Dickhead.


Judging by your typical acerbic remarks, I'll consider that a relative
compliment.

** No it ain't - ****head.



Well, maybe this is overkill (and inefficient):
http://www.hzfrequencyconverter.com

** ROTFL !!

Well, it is a bit large, noisy, inefficient, expensive, messy, and
overkill. But, it will do the job.

** Totally INSANE.

Like you.


One could probably just slow down a 60Hz gasoline portable generator
to run at 50Hz, but that would be too easy.

** Other way around - dickwad.



Also, I just downloaded the Phase Linear 400 schematic:

** The amp works just fine on a standard step down tranny.
Just like 99% of all amps made for 60 Hz power.


The xformers that burn up are the one's that are operating close to
saturation at 60Hz.

** FFS - I know the actual amplifiers.

YOU do not.

**** OFFFFFFFFFFFFFFFFFF



..... Phil

A couple of clinchnuts instead of the one closure fixing, for a now
2-section Black & Decker lawnmower connector and looks almost professional.
Earthing pin set into the side , black epoxied and shrouded over, not quite
so pro looking.