High power combos that go intermittant
after a period of use.

If they use
an elbow jack on the amp to speaker link ,
replace with conventional, if poor manufacture.
Check the internal construction and if
poor mechanical connection at the elbow means
the shaft can turn , with pliers , when cold,
so a resistance and voltage drop, heating the plastic
disc that is all that forces a mechanical connection.
So progressively worsens, so when heated by the current,
in use, the shaft will turn with finger pressure only
rather than requiring pliers.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

On Wed, 24 Jan 2007 15:34:44 -0000, "N Cook"
wrote:

High power combos that go intermittant
after a period of use.

If they use
an elbow jack on the amp to speaker link ,
replace with conventional, if poor manufacture.
Check the internal construction and if
poor mechanical connection at the elbow means
the shaft can turn , with pliers , when cold,
so a resistance and voltage drop, heating the plastic
disc that is all that forces a mechanical connection.

You must be talking about the really cheap ones. I usually do a little
extra soldering on the ones I've used so it's not just a mechanical
connection anymore.

So progressively worsens, so when heated by the current,
in use, the shaft will turn with finger pressure only
rather than requiring pliers.

Not if you do it right.

Also, If you put a straight jack on say, an old Fender combo, you
better unplug it before you lay it on its back in the mini-van...

PS: It's called a right-angle jack. And if you're running enough
current through it to heat it up, you might want to consider Speak-ons
anyway.

-Dave

"Dave Curtis" wrote in message
...
On Wed, 24 Jan 2007 15:34:44 -0000, "N Cook"
wrote:

High power combos that go intermittant
after a period of use.

If they use
an elbow jack on the amp to speaker link ,
replace with conventional, if poor manufacture.
Check the internal construction and if
poor mechanical connection at the elbow means
the shaft can turn , with pliers , when cold,
so a resistance and voltage drop, heating the plastic
disc that is all that forces a mechanical connection.

You must be talking about the really cheap ones. I usually do a little
extra soldering on the ones I've used so it's not just a mechanical
connection anymore.

So progressively worsens, so when heated by the current,
in use, the shaft will turn with finger pressure only
rather than requiring pliers.

Not if you do it right.

Also, If you put a straight jack on say, an old Fender combo, you
better unplug it before you lay it on its back in the mini-van...

PS: It's called a right-angle jack. And if you're running enough
current through it to heat it up, you might want to consider Speak-ons
anyway.

-Dave

Dave, I think he's talking about the right angle plug #228 Switchcraft or
the even worse #220 which do really suck and can be easily damaged
and become loose enough to be intermittent. The Switchcraft #226 is
much more superior in design and reliability.

On Fri, 26 Jan 2007 10:33:00 -0600, "Elvis Kabong"
wrote:


"Dave Curtis" wrote in message
.. .
On Wed, 24 Jan 2007 15:34:44 -0000, "N Cook"
wrote:

High power combos that go intermittant
after a period of use.

If they use
an elbow jack on the amp to speaker link ,
replace with conventional, if poor manufacture.
Check the internal construction and if
poor mechanical connection at the elbow means
the shaft can turn , with pliers , when cold,
so a resistance and voltage drop, heating the plastic
disc that is all that forces a mechanical connection.

You must be talking about the really cheap ones. I usually do a little
extra soldering on the ones I've used so it's not just a mechanical
connection anymore.

So progressively worsens, so when heated by the current,
in use, the shaft will turn with finger pressure only
rather than requiring pliers.

Not if you do it right.

Also, If you put a straight jack on say, an old Fender combo, you
better unplug it before you lay it on its back in the mini-van...

PS: It's called a right-angle jack. And if you're running enough
current through it to heat it up, you might want to consider Speak-ons
anyway.

-Dave

Dave, I think he's talking about the right angle plug #228 Switchcraft or
the even worse #220 which do really suck and can be easily damaged
and become loose enough to be intermittent. The Switchcraft #226 is
much more superior in design and reliability.

I thought he was talking even cheaper (RS/china), which is why I
mentioned soldering the compression connection. I've done that to fix
a spinning tip connection. You need a hot iron and do it quick.

Yes, we both meant 'plug'.

BTW, I seen (real) cheap straight jacks where the tip or sleeve would
spin...

How's Amps, Ed?

I've got an intermittent Randall with a(nother) glued-on back, a
2X50watt Marshall to bias, and a sick MusicMan... CYA!

I need more benches!
(actually, I just need to clean a few more off ;o)

-Dave

"Dave Curtis" wrote in message
...
On Fri, 26 Jan 2007 10:33:00 -0600, "Elvis Kabong"
wrote:


"Dave Curtis" wrote in message
.. .
On Wed, 24 Jan 2007 15:34:44 -0000, "N Cook"
wrote:

High power combos that go intermittant
after a period of use.

If they use
an elbow jack on the amp to speaker link ,
replace with conventional, if poor manufacture.
Check the internal construction and if
poor mechanical connection at the elbow means
the shaft can turn , with pliers , when cold,
so a resistance and voltage drop, heating the plastic
disc that is all that forces a mechanical connection.

You must be talking about the really cheap ones. I usually do a little
extra soldering on the ones I've used so it's not just a mechanical
connection anymore.

So progressively worsens, so when heated by the current,
in use, the shaft will turn with finger pressure only
rather than requiring pliers.

Not if you do it right.

Also, If you put a straight jack on say, an old Fender combo, you
better unplug it before you lay it on its back in the mini-van...

PS: It's called a right-angle jack. And if you're running enough
current through it to heat it up, you might want to consider Speak-ons
anyway.

-Dave

Dave, I think he's talking about the right angle plug #228 Switchcraft or
the even worse #220 which do really suck and can be easily damaged
and become loose enough to be intermittent. The Switchcraft #226 is
much more superior in design and reliability.

I thought he was talking even cheaper (RS/china), which is why I
mentioned soldering the compression connection. I've done that to fix
a spinning tip connection. You need a hot iron and do it quick.

Yes, we both meant 'plug'.

BTW, I seen (real) cheap straight jacks where the tip or sleeve would
spin...

How's Amps, Ed?

I've got an intermittent Randall with a(nother) glued-on back, a
2X50watt Marshall to bias, and a sick MusicMan... CYA!

I need more benches!
(actually, I just need to clean a few more off ;o)

-Dave

Sheeks Dave, you *would* have to ask. Here's the rundown:

Just finished doing all I can do with a Marshall Model 2000 250watt lead head
that I think the owner stressed the OT years ago by sticking 20amp automotive
fuses for the external fuse holders even though there is at least an internal fuse
to blow in case of that idiocy. Not only that and even though EL34s can handle
the B+ the customer doesn't want to pay to have 6550s in it. But what happens
every now and then, the protection diodes short and blows the mains fuse.
I keep telling him this is going to happen when he cranks it since the OT seems
out of whack. On the primary, I'm getting 57mH on one side and 68mH on the other.
The output signal looks wacky too. What a shame. The amp is rare and the owner
went and abused it. Can you imagine how much Mercury Magnetics would charge
to rebuild the OT?

Also restoring a BF Twin Reverb head that was under water during Katrina.
The fiberboard was like a roller coaster so I'm having to replace it with a
Mojo one. Reinstalling all of the blue Moldeds and any resistors not out of
tolerance and any pots that still turn. Took the PT apart to let it dry out and
found that it had some sort of tar substance in it which means to me it must
be waterproof, so I'm assuming all of the transformers are ok, that is until
I fire it up once finished reassembling.

Just finished the HOSE amp version 1 (High Output Single Ended).
High B+, switchable to 5AR4 or 5U4, one 6550 and two paralleled
12AX7s with gain, master and treb, mid, bass controls. Got it up
to 17 watts even though the OT specifies 15 watts.

Just starting HOSE version 2: low output SE amp into an interstage
transformer to a pair of EL34s. Hope I can get that wonderful tone
of an SE amp preserved and amplified into a push-pull output to
be loud enough for bigger gigs and not having to mic for a gig.
Might turn out to be the best of both worlds - that sweet SE tone,
yet loud enough to gig with and with more than just having a single
tone pot. Considering installing a low output OT to also a low watt
speaker for the practice amp/studio volume of a just a SE amp
and making it switchable to either that or to the interstage transformer.

Soon there will be pics on Dave Moore's website. That's still in process.

Have fun,

Ed

Not actually required as a mechanical problems on a Marshall "Valvestate"
VS65R. But I cannot find any details on the main components , ready for next
time, or for anyone else coming across them , any pointers ?

Marshall T65 and its compliment T64A (curiously one suffixed A only), TOP66
package
Motorola MJF 22 , also marked R91, TO220 package, not found on Motorola site

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

N Cook wrote:

Not actually required as a mechanical problems on a Marshall "Valvestate"
VS65R. But I cannot find any details on the main components , ready for next
time, or for anyone else coming across them , any pointers ?

Marshall T65 and its compliment T64A (curiously one suffixed A only), TOP66
package Motorola MJF 22 , also marked R91, TO220 package, not found on
Motorola site

TOP66 ? Do you mean TO-220 ?

Resistors in TO-220 packages are not unknown. Possibly low inductance low ohms
type. What's the function - and marking ?

Graham

Eeyore wrote in message
...


N Cook wrote:

Not actually required as a mechanical problems on a Marshall
"Valvestate"
VS65R. But I cannot find any details on the main components , ready for
next
time, or for anyone else coming across them , any pointers ?

Marshall T65 and its compliment T64A (curiously one suffixed A only),
TOP66
package Motorola MJF 22 , also marked R91, TO220 package, not found on
Motorola site

TOP66 ? Do you mean TO-220 ?

Resistors in TO-220 packages are not unknown. Possibly low inductance low
ohms
type. What's the function - and marking ?

Graham





The package that plastic 2N3055 come in like TIP3055, probably something
like Marshall badged TIP3055/TIP2955 output pair

N Cook wrote:

Eeyore wrote in message
N Cook wrote:

Not actually required as a mechanical problems on a Marshall
"Valvestate" VS65R. But I cannot find any details on the main components ,
ready for
next time, or for anyone else coming across them , any pointers ?

Marshall T65 and its compliment T64A (curiously one suffixed A only),
TOP66 package Motorola MJF 22 , also marked R91, TO220 package, not found
on
Motorola site

TOP66 ? Do you mean TO-220 ?

Resistors in TO-220 packages are not unknown. Possibly low inductance low
ohms type. What's the function - and marking ?

Graham


The package that plastic 2N3055 come in like TIP3055, probably something
like Marshall badged TIP3055/TIP2955 output pair

Oddball devices.

My big Motorola Power Devices manual lists nothing like it ! The MJFs have fully
isolated packages btw. Is that the case here ?

Graham

Eeyore wrote in message
...


N Cook wrote:

Eeyore wrote in message
N Cook wrote:

Not actually required as a mechanical problems on a Marshall
"Valvestate" VS65R. But I cannot find any details on the main
components ,
ready for
next time, or for anyone else coming across them , any pointers ?

Marshall T65 and its compliment T64A (curiously one suffixed A
only),
TOP66 package Motorola MJF 22 , also marked R91, TO220 package, not
found
on
Motorola site

TOP66 ? Do you mean TO-220 ?

Resistors in TO-220 packages are not unknown. Possibly low inductance
low
ohms type. What's the function - and marking ?

Graham


The package that plastic 2N3055 come in like TIP3055, probably something
like Marshall badged TIP3055/TIP2955 output pair

Oddball devices.

My big Motorola Power Devices manual lists nothing like it ! The MJFs have
fully
isolated packages btw. Is that the case here ?

Graham



It was actually MJF122, the centre spine of the retaining clip had messed
up the surface of the package and obscured the 1 , so plenty of info on that
one

N Cook wrote:

It was actually MJF122, the centre spine of the retaining clip had messed
up the surface of the package and obscured the 1 , so plenty of info on that
one

Complement is MJF127.

That's a fully isolated TO-220 package though ! Quite different to TIP3055.

Graham

Eeyore wrote in message
...


N Cook wrote:

It was actually MJF122, the centre spine of the retaining clip had
messed
up the surface of the package and obscured the 1 , so plenty of info on
that
one

Complement is MJF127.

That's a fully isolated TO-220 package though ! Quite different to
TIP3055.

Graham



That was the small Motorola one, that I misread

The Marshall badged ones are probably like these 2, original specs, for the
archives, both are the right TIP35/TIP3055 type packages

T64 = BDV64C
T65 = BDV65C
eg
Part Number = BDV65C
Manufacturer Name = Various
Description = Darlington, PowerDarlington, Power
BDV65C
Si
npn
125W
140V
120V
5V
12A
150C
-
-
2000T
PHI
TO218-2

OR


T65 NPN silicon darlington power transistor. Complementary epitaxial base
transistors in monolithic darlington circuit for audio output stages and
general amplifier and switching applications. Magnatec Inc

ABSOLUTE MAXIMUM RATINGS (T = 25°C unless otherwise stated)
case
T64 T65
-120V 120V
V Collector - Base Voltage (Open Emitter)
CBO
-120V 120V
Collector - Emitter Voltage (Open Base)
V
CEO
-5V 5V
Emitter - Base Voltage (Open Collector)
V
EBO
12A
Collector Current (d.c)
I
C
20A
Peak Collector Current
I
CM
0.5A
Base Current (d.c)
I
B
125W
Total Power Dissipation up to T = 25°C
P
tot
mb
-65 to 150°C
Storage Temperature Range
T
stg
150°C
Maximum Junction Temperature

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

N Cook wrote:
Eeyore wrote in message
...

N Cook wrote:

It was actually MJF122, the centre spine of the retaining clip had
messed
up the surface of the package and obscured the 1 , so plenty of info on
that
one
Complement is MJF127.

That's a fully isolated TO-220 package though ! Quite different to
TIP3055.
Graham



That was the small Motorola one, that I misread

The Marshall badged ones are probably like these 2, original specs, for the
archives, both are the right TIP35/TIP3055 type packages

T64 = BDV64C
T65 = BDV65C
eg
Part Number = BDV65C
Manufacturer Name = Various
Description = Darlington, PowerDarlington, Power
BDV65C
Si
npn
125W
140V
120V
5V
12A
150C
-
-
2000T
PHI
TO218-2

OR


T65 NPN silicon darlington power transistor. Complementary epitaxial base
transistors in monolithic darlington circuit for audio output stages and
general amplifier and switching applications. Magnatec Inc

ABSOLUTE MAXIMUM RATINGS (T = 25°C unless otherwise stated)
case
T64 T65
-120V 120V
V Collector - Base Voltage (Open Emitter)
CBO
-120V 120V
Collector - Emitter Voltage (Open Base)
V
CEO
-5V 5V
Emitter - Base Voltage (Open Collector)
V
EBO
12A
Collector Current (d.c)
I
C
20A
Peak Collector Current
I
CM
0.5A
Base Current (d.c)
I
B
125W
Total Power Dissipation up to T = 25°C
P
tot
mb
-65 to 150°C
Storage Temperature Range
T
stg
150°C
Maximum Junction Temperature

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/



Marshall are quite happy to supply semiconductor spares and have a very
helpful service dept - once you get through to them!

Ron(UK)

--
Lune Valley Audio
Public Address Systems
Hire Sales Maintenance
www.lunevalleyaudio.com

On 17 feb, 18:19, Eeyore
wrote:
N Cook wrote:
Eeyore wrote in message
N Cook wrote:

Not actually required as a mechanical problems on a Marshall
"Valvestate" VS65R. But I cannot find any details on the main components ,
ready for
next time, or for anyone else coming across them , any pointers ?

Marshall T65 and its compliment T64A (curiously one suffixed A only),
TOP66 package Motorola MJF 22 , also marked R91, TO220 package, not found
on
Motorola site

TOP66 ? Do you mean TO-220 ?

Resistors in TO-220 packages are not unknown. Possibly low inductance low
ohms type. What's the function - and marking ?

Graham

The package that plastic 2N3055 come in like TIP3055, probably something
like Marshall badged TIP3055/TIP2955 output pair

Oddball devices.

My big Motorola Power Devices manual lists nothing like it ! The MJFs have fully
isolated packages btw. Is that the case here ?

Graham

el t65 y el 64 son darlington. buscalos como bdv65 y bdv64 reemplazo
tip142 tip147. para el mjf122 el tip120 o 122

alexis cid de chile