Marshall JCM 2000, 1998
N_Cook
at 20V variac "mains" and temp climbs 20 deg C in 4 minutes or so.
Secondaries measure l27V, 16.3V and 2V so that side presumably ok.
DC of primaries measure 1.2R and 2.2R, would they use 2 bifilar primary
windings where stressed midpoint would show half way short and half measured
ohms?. I will poke around in the winding/ try delaminating out of curiosity
but
stock fault/ batch fault ? Other than "marinating" in paint stripper , any
tips on delaminating ?
Are replacements available from Marshall ? or a grey market source UK ? or
anyone use 2 or 3 separate Tx ? Googling Tx model
Dagnall, TXMA 00061, D2105
only shows up suspiciously low priced dollar quotes
Meat Plow
http://www.mercurymagnetics.com/pages/mainframe.htm
Should ship internationally.
--
Live Fast Die Young, Leave A Pretty Corpse
Arfa Daily
"N_Cook" <div...@tcp.co.uk> wrote in message
news:ilan3u$j8g$1...@news.eternal-september.org...
We get parts direct from Marshall. Used to be a Marshall dealer, but we are
not any more, and they still supply us with parts ok, so it must not be a
requirement. It may be that you have to be a 'legitimate' business though,
and not just 'Joe Punter'.
Arfa
N_Cook
news:rZ5ep.75494$To7....@newsfe12.ams2...
Any ball-park idea of cost for a Marshall replacement ?
Ron
I've had parts direct from Marshall also. I was never a Marshall
dealer, when you talk to their service dept, they soon suss you out as
competent or not. Great service and killer 'on hold' music on the
telephone ;)
Ron
N_Cook
laminations are apart , easy to inspect. Tomorrow I will try a 125W iron
concentrating on the central sliver of the first "E". Laid thin ptfe sheet
heat insulation under the other 3 slivers. What will be the softening
temperature of the lacquer and any guesses as to time of heat application at
the exposed end only ? At least I can monitor the other end with a
pyrommeter.
Gareth Magennis
"N_Cook" <div...@tcp.co.uk> wrote in message
news:ilas70$gc9$1...@news.eternal-september.org...
Ball park between £20 and £30 inc P&P and VAT.
N_Cook
Gareth Magennis <sound....@btconnect.com> wrote in message
news:2edep.106250$ts7....@newsfe14.ams2...
Did you leave out some zeros? 200 to 300 GBP
eg
http://www.sowter.co.uk/acatalog/SOWTER_TRANSFORMERS_CLASSIC_AMPS_15.html
Gareth Magennis
"N_Cook" <div...@tcp.co.uk> wrote in message
news:ilcnm8$t7n$1...@news.eternal-september.org...
No, I've bought quite a few Marshall transformers from Marshall, and they
are not expensive.
Arfa Daily
"N_Cook" <div...@tcp.co.uk> wrote in message
news:ilcnm8$t7n$1...@news.eternal-september.org...
I wouldn't have thought so. I would have said that Gareth's estimate was
probably not far short of the mark, based on transformers that we've ordered
from them in the past. I've always found them pretty reasonable. Just give
them a call and ask. They're a friendly enough 'family' company. Jim
Marshall's daughter did run spares. As far as I know, she still does.
Arfa
Phil Allison
"Nutcase Kook"
>
>> > Any ball-park idea of cost for a Marshall replacement ?
>
>> Ball park between £20 and £30 inc P&P and VAT.
>>
>
> Did you leave out some zeros? 200 to 300 GBP
** The Dagnall brand trannies that are fitted to modern Marshalls are all
made in India or Shi Lanka by starving children.
The design is way under sized for the job and quality is non existent.
Spares are cheap, IME.
Shame the fucking amps are not.
..... Phil
Gareth Magennis
"Arfa Daily" <arfa....@ntlworld.com> wrote in message
news:vvmep.61518$BQ7....@newsfe22.ams2...
Is that George, Arfa?
Gareth.
Arfa Daily
"Gareth Magennis" <sound....@btconnect.com> wrote in message
news:Zmqep.46314$%e2.3...@newsfe13.ams2...
Indeed it is ! :-)
They're quite close to where I live.
Arfa
Gareth Magennis
"Arfa Daily" <arfa....@ntlworld.com> wrote in message
news:_Bsep.85966$2t5....@newsfe24.ams2...
Had no idea she was part of the family!
Marshall are top of my list for spares supply and pricing, and George is
great to deal with and knows her stuff.
Gareth.
Arfa Daily
>>>
>>>
>>> Is that George, Arfa?
>>>
>>>
>>>
>>> Gareth.
>>
>> Indeed it is ! :-)
>>
>> They're quite close to where I live.
>>
>> Arfa
>
>
>
> Had no idea she was part of the family!
>
> Marshall are top of my list for spares supply and pricing, and George is
> great to deal with and knows her stuff.
>
>
> Gareth.
I've always found them very good - except when they are on stock-take !
Then, you can wait a couple of weeks for your parts ... But yes, in general,
anything you need, and very reasonably priced.
The one problem that I have got with them, is that dreadful system of
providing access to their service information. I actually find it difficult
to use, and to search, and on several occasions, have 'caught them out' with
sections of schematic that simply aren't on there. I'm sure they thought it
was a good idea to have their service info archive 'front ended' by that
Image Bank user interface, and then to give access only to registered
(=pre-approved by their service department) users, but every time I go there
to download a manual, I just find it an awkward and frustrating process.
A long time ago, I found another Marshall specialist site, and they have an
archive of pretty much everything that Marshall have ever produced, right
back to the start, arranged by 'class' and date. I always go there first to
look for service info, and treat Marshall's Image Bank as a port of last
resort. I wish, if they are basically happy to let people have service info,
they would just list everything, and let you get it on a one-click download,
as other manufacturers do. I can sort of understand that they would prefer
to have some control over who they are giving data out to in order to try to
preserve a degree of professionalism in repairs to their equipment, but
given the fact that they must know that info on every one of their products
is already out there for download by the determined searcher, it just seems
a bit 'prissy' of them to force this poorly designed service info search and
download software on their registered users. They could still restrict
registered users to a password protected area on the website, that gave
access to a simple list of all the manuals available.
Arfa
N_Cook
these days. Slipped turn at one end of a layer dropping into a lower layer,
then presumably chaffing of lacquer to marginally spot weld. Not at all
obvious "weld" point , about 80 turns from lead out of outer primary. 195
turns in all of .75mm wire for one 120V primary. Not a problem here as 240 V
use, but would be for this Tx used in USA . There is tape covering the inner
primary but not extended at the leadout point of the inner primary so first
turn of the outer primary directly crosses that point so a full short is
very likely there with a bit of normal in service vibration/ chaffing. For
240V use those 2 points are at near enough same mid-mains potential (2 tails
to options bridging point on pcb)
At least I now know how to delaminate the E/I iron laminations.
Phil Allison
"Nutcase Kook"
>
> Normal single filament winding. Normal failure mode , for slapdash wound
> Tx
> these days. Slipped turn at one end of a layer dropping into a lower
> layer,
> then presumably chaffing of lacquer to marginally spot weld.
>
> Not at all
> obvious "weld" point , about 80 turns from lead out of outer primary. 195
> turns in all of .75mm wire for one 120V primary. Not a problem here as 240
> V
> use, but would be for this Tx used in USA . There is tape covering the
> inner
> primary but not extended at the leadout point of the inner primary so
> first
> turn of the outer primary directly crosses that point so a full short is
> very likely there with a bit of normal in service vibration/ chaffing.
** The turns wound on that transformer do no move or chaff - you wanker.
Those Dagnall power transformers ( TMXA00061 etc) are made with low temp
grade enamel coating the copper and the tranny is under sized for the job it
has to do - not to mention working in a very high ambient temp from the heat
of the output valves.
As a result the windings run DAMN hot, the enamel gets soft and when two
soft spots meet under pressure you can get a short.
I have THREE dead ( internally shorted) examples of the exact same tranny
sitting here right now.
.... Phil
N_Cook
Arfa Daily
"N_Cook" <div...@tcp.co.uk> wrote in message
news:ill2ur$7hv$1...@news.eternal-september.org...
> Marshall replacement �46 , same duff construction as this one?
>
>
I would expect it to probably be a ringer for what was already in there. If
the amp is really from 1998, then duff construction or not, it ain't done
bad, and if the new one does another 13 years, it's not going to come back
on you, is it ? And, if in the intervening 13 years since it was made,
Marshall have had a lot of them fail, then maybe they've taken this up with
Dagnell, and got them to improve the situation ? I would stop agonising over
it, and just stick the new one in, and write out the hundred quid bill for
the owner ...
Arfa
Phil Allison
"N_Cook"
>
> Marshall replacement £46 , same duff construction as this one?
>
** Of course.
Only way to fix the problem is to find someone willing to rewind the
original transformer with high temp enamel wire - ie 180C rate instead of
the 120C rated stuff used by Dagnall.
Or you could fit a small fan blowing on the tranny....
..... Phil
Gareth Magennis
"Phil Allison" <phi...@tpg.com.au> wrote in message
news:8u7jc5...@mid.individual.net...
I'll go with Arfa's suggestion.
Pay the £46 and when it breaks in 13 years time, we can then re-assess the
situation.
Though the small fan idea is a good one IMHO. Might extend that period to
26 years or more.
Gareth.
Phil Allison
"Gareth Magennis"
"Phil Allison"
>
>> "Nutcase Kook"
>>>
>>> Marshall replacement �46 , same duff construction as this one?
>>>
>>
>> ** Of course.
>>
>> Only way to fix the problem is to find someone willing to rewind the
>> original transformer with high temp enamel wire - ie 180C rate instead of
>> the 120C rated stuff used by Dagnall.
>>
>> Or you could fit a small fan blowing on the tranny....
>
>
** Makes you as big a fucking halfwit as he is.
> Pay the �46 and when it breaks in 13 years time,
** HUH ???
What sort of madness makes do you think the problem has a 13 year delay
built in ??????
That POS tranny can fail in the first few hours of use !!!
Only has to overheat enough to soften the enamel on the wire - and overheat
it surely will cos it is not correctly sized ( in terms of VA rating) for
the job it has to do.
..... Phil
Arfa Daily
"Phil Allison" <phi...@tpg.com.au> wrote in message
news:8u7pif...@mid.individual.net...
>
> "Gareth Magennis"
> "Phil Allison"
>>
>>> "Nutcase Kook"
>>>>
>>>> Marshall replacement £46 , same duff construction as this one?
>>>>
>>>
>>> ** Of course.
>>>
>>> Only way to fix the problem is to find someone willing to rewind the
>>> original transformer with high temp enamel wire - ie 180C rate instead
>>> of the 120C rated stuff used by Dagnall.
>>>
>>> Or you could fit a small fan blowing on the tranny....
>>
>>
>> I'll go with Arfa's suggestion.
>
> ** Makes you as big a fucking halfwit as he is.
I wonder what that makes you then, Philip ? Actually, don't answer that. We
all already know that you are a half-baked twat ... :-)
Arfa
Phil Allison
"Arfa Daily"
** Please come to Sydney - Arfa.
Just buy a one way ticket, cos that is all you will need.
Go straight to Circular Quay from Mascot airport and then into any pub with
your stupid, whiny pommy voice and tell everyone there all your brilliant
thoughts.
The sharks in Sydney harbour will be picking your bones by nightfall.
..... Phil
N_Cook
What is the point of CE "compliance" testing etc if 2 layers of lacquer to
resist 120V av . At one time, before CE marking, all these Tx tails had
extra sleeving over them to avoid this problem.
Gareth Magennis
"Phil Allison" <phi...@tpg.com.au> wrote in message
news:8u7pif...@mid.individual.net...
That may be more of a problem in the heat of Shark Infested Sydney than the
cold wet miserable UK, otherwise I would be changing these transformers all
the time and I am not.
I say again I think the fan idea is a good cheap easy solution, but not one
I personally would bother with, though Mr Cook may rise and eyebrow or two
of interest.
Gareth.
>
>
Arfa Daily
"N_Cook" <div...@tcp.co.uk> wrote in message
news:iln7t6$kj3$1...@news.eternal-september.org...
What indeed? agreed. Unfortunately, that's just the world that we live in
now. Long ago, I gave up trying to change the situation, got over it, and
just got on with making a living ...
Put the new tranny in, write up the bill, and move on to the next one :-)
Arfa
Arfa Daily
"Phil Allison" <phi...@tpg.com.au> wrote in message
news:8u8120...@mid.individual.net...
You do have a vivid imagination, Philip. The last place on earth I would
want to go, is anywhere you are. Stupid person ... :-)
Arfa
Phil Allison
"Gareth Magennis"
>
>
>>> I'll go with Arfa's suggestion.
>>
>> ** Makes you as big a fucking halfwit as he is.
>
>>> Pay the £46 and when it breaks in 13 years time,
>>
>> ** HUH ???
>>
>> What sort of madness makes do you think the problem has a 13 year delay
>> built in ??????
>>
>> That POS tranny can fail in the first few hours of use !!!
>>
>> Only has to overheat enough to soften the enamel on the wire - and
>> overheat it surely will cos it is not correctly sized ( in terms of VA
>> rating) for the job it has to do.
>
>
> the cold wet miserable UK,
** So it is always " cold wet and miserable " INSIDE a venue in summer
plus INSIDE a Marshall valve amp playing " Death Metal " riffs to hundreds
of head bangers in the UK - is it ??
God, what a fuckwit you are.
>> I say again I think the fan idea is a good cheap easy solution,
** The easy and engineering wise final solution is the re-wind I suggested.
Fuck head.
.... Phil
Gareth Magennis
Just gone through my database.
From February 2005 to present I have replaced 2 mains transformers and 2
Output transformers in JCM2000's.
If there was a particular problem with JCM2000 mains TX's in the UK I would
have expected rather more than this.
Gareth.
N_Cook
For balance I got a quote from proper tx winders Majestic , just down the
road
http://www.transformers.uk.com/brochure.pdf
for a one off , custom/semicustom build from scratch , to specified V & A of
the 3 secondaries. Somewhere between 50 and 70 GBP plus VAT plus carriage,
about 2 week turn around
Phil Allison
"Nutcase Kook "
>
> For balance I got a quote from proper tx winders Majestic , just down the
> road
> http://www.transformers.uk.com/brochure.pdf
> for a one off , custom/semicustom build from scratch , to specified V & A
> of
> the 3 secondaries. Somewhere between 50 and 70 GBP plus VAT plus carriage,
> about 2 week turn around
** That is a very reasonable price.
But did you ask them to make a new tranny with the exact same stack size and
through chassis design as the Dagnall ones ??
Were they offering you a custom toroidal tranny by any chance??
..... Phil
Phil Allison
"Gareth Magennis is an utter ASS "
>>
>>>
>>>>> I'll go with Arfa's suggestion.
>>>>
>>>> ** Makes you as big a fucking halfwit as he is.
>>>
>>>>> Pay the £46 and when it breaks in 13 years time,
>>>>
>>>> ** HUH ???
>>>>
>>>> What sort of madness makes do you think the problem has a 13 year delay
>>>> built in ??????
>>>>
>>>> That POS tranny can fail in the first few hours of use !!!
>>>>
>>>> Only has to overheat enough to soften the enamel on the wire - and
>>>> overheat it surely will cos it is not correctly sized ( in terms of VA
>>>> rating) for the job it has to do.
>>>
>>>
>>> That may be more of a problem in the heat of Shark Infested Sydney than
>>> the cold wet miserable UK,
>>
>>
>> ** So it is always " cold wet and miserable " INSIDE a venue in
>> summer plus INSIDE a Marshall valve amp playing " Death Metal " riffs
>> to hundreds of head bangers in the UK - is it ??
>>
>> God, what a fuckwit you are.
>>
>>
>>>> I say again I think the fan idea is a good cheap easy solution,
>>
>>
>> ** The easy and engineering wise final solution is the re-wind I
>> suggested.
>>
>
** Go shove you stupid fucking database up you stupid fat arse !!
Engineering facts are F A C T S !!
You pathetic, pommy DUMBASS !!
.... Phil
Gareth Magennis
My facts are real life experience long term test facts. Can't get a lot
more factual than that, eh Phil.
Gareth.
Phil Allison
"Gareth Magennis"
** Bullshit stats YOU INVENTED are not engineering facts !!
YOU GOD ALMIGHTY KNOW NOTHING POMMY CUNT
---------------------------------------------------------------------------
Those same Port Jackson sharks would eat YOU for breakfast !!
Arfa Daily
"Phil Allison" <phi...@tpg.com.au> wrote in message
news:8u95sg...@mid.individual.net...
>
************* hey LooK pHILeeP -
>>> ** I cAn do asTeRiskS and CAPItalS and eXClamaTION MARKS TOO !!! <<<<
>>> ***
** <> ***
Never mind Gareth. Clearly he's either pissed or off his barmy head again,
so with any luck, the dopey twat will stagger to the edge of the harbour and
fall in himself, to be gobbled up by those naughty sharks ... :-)
Arfa
Michael A. Terrell
Or he'll run into an angry bunch of sheep, in no mood for his sexual
advances...
--
You can't fix stupid. You can't even put a Band-Aid™ on it, because it's
Teflon coated.
Arfa Daily
"Michael A. Terrell" <mike.t...@earthlink.net> wrote in message
news:GuGdnWIqArZxQ-LQ...@earthlink.com...
Or perhaps he'll get his head stomped on by an irate kangaroo ...
Arfa
> --
> You can't fix stupid. You can't even put a Band-AidT on it, because it's
> Teflon coated.
Michael A. Terrell
Go Kanagroo, go!!!
--
You can't fix stupid. You can't even put a Band-Aid™ on it, because it's
Teflon coated.
William Sommerwerck
Disembowelment from a kick is more likely.
Herbivores are more dangerous than carnivores.
N_Cook
mount of the fan to solder a solder tag then that bolted to the fan.
Setting fan at 20 degrees to the horizontal and cutting and fitting a
shroud from that red impregnated cardboard stuff to direct the flow into one
side , up, over top and back out the other side between windings and bobbin.
As secondary side gets hotter than primary , fan positioned mainly on that
side
Air flow checked using a joss stick. Perhaps next time using some DC from
the amp rather than bridge rect and cap off the heater supply as light
current drops in the diodes bring it down to less than 9V . Retained the
template for the shroud for the next one of these to attend to.