Mercury Magnetics

[hunter]

Heija,

Anyone in here ever replaced a stock 50W or 100W Marshall the PT, OT or Choke by Mercury Magnetics ones?

Any experiences welcome!

CJ

[Rob Stobbs]

On another forum that I am regularly viewing, nobody has a bad word to say for Mercury Products. One Guy in particular was positively raving about them very recently. 8)

[jpfamps]

I've used several Mercury Magnetics transformers in a variety of amps including Marshalls, with good results, although I do know that one quite large US amp manufacturer stopped using MM due to QC problems.

However they aren't cheap to get to the UK, and unless I am told that only MM will do, I usually use other transformers.

I wouldn't bother changing the choke unless it had expire (very rare).

The main sonic advantage to using a MM mains transformer is that they provide a variety of B+ voltages so you can get the correct plate voltage in your amp. e.g. mid-late 70s JMP 50 Marshalls run with around 380 VDC on the plates, whereas most repro mains transformers will give a B+ around 480 VDC.

The OT is the transformer which will make the most difference.

Personally I've had as good or better results, certainly for Fender amps, with Mojotone repro OTs. These are made exactly like the originals, stick wound on paper bobbins, and are much cheaper than MM. They are also available in the UK from Allparts so you don't have shipping/ import duty to pay.

[Dragoneti]

I have replaced the OT of both my TSL60 and later the DSL50 as it became my main amp (using the same ot from the tsl60 as its the same between the two) with a mercury one, axiom MAR-50 i think is the model.

The difference it made to both amps was the same, a tighter feel, more balsy and more 3d, an overall improvement to both amps (when i removed the ot from my tsl i rememberd why i was so satisfied with the swap at the beggining)

hope i helped!

Stelios

[hunter]

Good info everyone. Thanks for the Mojotone tip!

Actually I was trying a JVM410 recently and I think it's a prefect amp with regards to features and switching options. Those 6 programs on the footswitch where you can for each chose a channel, a mode, reverb on/off, loop on/off and master 1 or 2 makes it an extremely versatile beast, really awesome.

The basic sound is good, but when I compare it to the Bog, it's missing balls and meat around the bones, if you know what I mean. I do think that some more iron could do the trick here, as the transformers seem a bit on the skinny side for a 100W amp.

If you order an OT from either Mojo or Mercury, would it matter whether it's 230V or 120V or is that only relevant on the PT?

[Dragoneti]

OT are the same for every country's voltage, it only applies to the PT which sould be orderd accordigly. Yeah i think the jvm should benefit from a mercury as all modern marshalls do!

I think some people in the jvm forum have made the switch and posted positive results.

As i know that you like some 80s hard rock (judging by your clips) how do you find the jvm? (i'm tempted for an another head...once again :P)

[hunter]

As i know that you like some 80s hard rock (judging by your clips) how do you find the jvm? (i'm tempted for an another head...once again :P)

Well I find it really good. It has so many sounds, it's unbelieveable. It also gives me that VM flavour that I was missing a bit with those snarling upper mids and thick and spanking palm mutes.

It's just lacking that little bit extra in oomph/punch and 3D-ness, which I believe could be fixed with a Transformer swap. Ideally it would be PT and OT, but that's a bit much $$.

[Dragoneti]

Ah i have a feeling that a jvm will be added to my collection soon (unless i go with a jcm800 reissue... :P)

I would go first with the OT swap and latter on if still necessery the choke and PT.

Btw the OT swap is a very easy task to do, no need for a tech to do it, it is just a matter of unpluging a set of cables (with connectors just like in speaker cabs) and unscreawing four bolts, replace the OT and reconnect the cables and voila! :)

In both marshallampforum and jvm forum there are guides on how to do it. I took me about 15 minutes from start to finish (includind taking the amp form its head case on and off).

Just do not touch the caps in there (there are lethal voltages in there even when the amp is off for days), stick to the OT side of the amp.

[HTH AMPS]

I've installed quite a few Mercury Magnetics transformers and haven't once been disappointed.  The difference in price is significant if you're a punter buying just one piece though. 

I haven't tried every transformer manufacturer out there, but I do know that what I've tried from MM has all been great.

Give them an email and tell them what amp you're thinking of upgrading and what your expectations are - they're a good bunch of guys and won't steer you wrong.

[jpfamps]

Ah i have a feeling that a jvm will be added to my collection soon (unless i go with a jcm800 reissue... :P)

I would go first with the OT swap and latter on if still necessery the choke and PT.

Btw the OT swap is a very easy task to do, no need for a tech to do it, it is just a matter of unpluging a set of cables (with connectors just like in speaker cabs) and unscreawing four bolts, replace the OT and reconnect the cables and voila! :)

In both marshallampforum and jvm forum there are guides on how to do it. I took me about 15 minutes from start to finish (includind taking the amp form its head case on and off).

Just do not touch the caps in there (there are lethal voltages in there even when the amp is off for days), stick to the OT side of the amp.

Er the OT is connected to the filter caps via the primary centre tap (otherwise the amp wouldn't work....). I would always advise ensuring you filter caps are discharged when fiddling inside an amp.