New Amp Day: 1977 Marshall 2104 JMP Master Volume Lead, 50W 2X12″ Combo in Fawn

Just looking at that title makes me tired, what a long name.  But not as tired as my back after hauling it to the curb in Williamsburg, where Main Drag Music did right by me – in fact, they took better pictures than I ever could, so here they are:

 

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4 of the original control knobs needed new caps, so we just popped those off and put modern repros on there.  Swapped out the power cord and tubes, and shielded the high input wire going to the first tube grid, to prevent frequency oscillations.  They did killer work, both inputs sound just as they should, and even the cleans have a 3D quality to them that other Marshalls I’ve played failed to have.

These originally came with Blackbacks or at least Celestions for sure, the Fanes date from around the same time but were definitely added in 1984. I know because both still have the red inventory stickers on them from ’84, ha!  These late 70s Fanes can blow the doors off as you can imagine, but they sound so good that they’re staying in there.  Word is that they’re not similar to the Fanes found in some Hiwatt cabs of that era, which makes sense what with how the overdrive retains a sense of self.

Here’s an interesting tidbit.  Check out the serial number:

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See how it ends with a “J”? That means that the chassis was built in 1977, according to this article:

https://reverb.com/news/how-to-date-a-marshall-amp#modelserialdate1969-1983

And the serial numbers on the original iron – both the power and output Drake transformers are within the date range for 1977:

http://marstran.com/Transformer%20Codes.htm

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https://legendarytones.com/marshall-shoppers-guide-2/

http://solodallas.com/the-vintage-marshall-guide

Those are good sources showing that 1977 was the first year for the rocker switches instead of the toggles (although Canada kept the toggles).  For some reason, my amp retains the EL34 power tubes, which I like since I find the headroom and clarity to be improved, which is a bit easier transition for me, coming from the Fender Blackface world.  Plus I believe in 1977 they still used mustard caps instead of the square caps.  Didn’t take internal pics to confirm, but I’m not going to monkey around inside the chassis at this point since it sounds so good, ha.

Suffice to say, there are a few internal and external differences from your typical JCM 800 Model 2204 50W head that is so synonymous with 80s Metal, but hey, this late 70s JMP is more alike than not with that eventual configuration, especially compared to the vertical input early 80s versions.  Well, with the massive exception of using an open back 2X12 combo cab of course!

Anyhow, this is an amazing sounding amp.  Of course it can rock, but it is also far more versatile than I expected.  It really cleans up beautifully as well, but when you crank it, man, that’s the business.

 

Edit:

Just noticed that the Ohm selector was on 16 ohms, but the Fanes are 4 ohms each and wired in series.  Oops.  Moved the jumper to 8 ohms and all is well.  Don’t want to blow those tubes, or definitely not those transformers!
That threw me for a loop for a bit, since my Pro Reverb runs off a 4 ohm tap, but the speakers are 8 ohms each and wired in parallel.  After looking at this, I got it all figured out!
And right before the end of 2016, Here is the Fryette Power Station 2.  With this, I can dime everything on the Marshall in the Low Input channel for the rage AND keep the low end.  Man, sounds great.  So here are my amps at the end of the year.  Happy New Year!
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Edit – RonW on TGP hooked me up with this period correct handle and mounting hardware and caps and all that – man, looks like it has lived on this amp forever!

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I thought I had to get the chassis off to replace the handle. I was wrong. But hey since I had it off, I took a look at the tubes – one of the 12AX7 tubes was a JJ so I replaced it with a NOS RCA greyplate. And take a look – a few things replaced here and there but for the most part you can see it was from the mustard cap era:

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Still sounds killer! Tried it with my ES-335 today, and I love how I can control that feedback perfectly now that the PS2 brings the rage down to respectable levels.

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