Metro JTM45 Build

Jimy · Post by **Jimy** » Fri Mar 17, 2006 12:09 pm

I did a little work on the amp last night and took a couple more pics. After I installed the board the other day, I realized that the ground wire in the corner (the one that comes off the cathode of the first gain stage) was supposed to be connected to the ground lug under the board. (To anyone else building this kit it should be pointed out that this needs to be done as part of step 11 even though it isn't mentioned in the instructions until step 13.) So I lifted up the board and installed the ground wire and, while I was in there, I shortened up the green input wires, which I'd cut a bit too long originally. Dropping the board in is a little tricky to do correctly and I can see now why George recommends populating the board after it's installed. My only concern with that approach is that one of the under-board connections could come loose while you're soldering a component to the upper side of the turret. I have to say I'm not really crazy about this method of construction. It gives a really neat appearance but, from a maintenance and repair point of view, it's a bit problematic. I suppose that's why Marshall moved away from it in their later amps. Anyway, I finally got the board in place the way I wanted and made a few connections. Next up is wiring the preamp sockets.

Flames1950 · Post by **Flames1950** » Fri Mar 17, 2006 3:58 pm

Oh man, you're so close to firing it up I can taste it.........

BashCoder · Post by **BashCoder** » Sat Mar 18, 2006 6:06 am

That's looking like a reference-quality build, Jimy. You are going to LOVE that amp!! Great job, and great pics!

Flames1950 · Post by **Flames1950** » Sat Mar 18, 2006 7:21 am

Is it done yet?? Are you deaf??? Are your family, friends and neighbors rueing the day you discovered www.metroamp.com ????
And if you're like the rest of us....when are you building the next one???

Jimy · Post by **Jimy** » Sat Mar 18, 2006 12:06 pm

Not quite there yet but I believe today will be the day...

I got the preamp sockets done last night. All I need to do is wire the pots and attach the power cord. Then it's on to testing and, hopefully, some beautiful noise.

I've never yet had an amp work on the first power up so expect some trouble shooting questions from me later today.

The next amp is already in the works. It's gonna be an early Tweed Twin clone. After that I'm thinking I need a 12000 series...

Jimy · Post by **Jimy** » Sat Mar 18, 2006 7:33 pm

HOLY CRAP!

This amp is a thing of beauty! Complex tone, versatility, and, oh yes, it IS loud. I can't believe it fired up and worked perfectly on the first try. That's never happened to me before. I credit George's excellent instructions... and all the folks who caught my .01uf capacitor mistake. Anyway, did I mention the amp kicks butt? Jumpered channels is definitely the way to go... lots of variety there. I've got to go try some other guitars and a couple pedals. More later...

He, he, he, he, he, he, he, he...

bvmjethead · Post by **bvmjethead** » Sat Mar 18, 2006 10:51 pm

We will not be hearing from Jimy for a while...

BashCoder · Post by **BashCoder** » Sun Mar 19, 2006 12:42 am

Jimy wrote:I can't believe it fired up and worked perfectly on the first try. That's never happened to me before.

I knew it would, and almost said that this morning, but I didn't want to jinx you!

I think that any build that clean will fire up, first time.

neikeel · Post by **neikeel** » Mon Mar 20, 2006 7:02 am

[quote="Jimy"] My only concern with that approach is that one of the under-board connections could come loose while you're soldering a component to the upper side of the turret. I have to say I'm not really crazy about this method of construction. It gives a really neat appearance but, from a maintenance and repair point of view, it's a bit problematic. I suppose that's why Marshall moved away from it in their later amps. Anyway, I finally got the board in place the way I wanted and made a few connections.[quote="Jimy"]

I have to agree. I have had a wire drop on my JTM45 board and my JTM45/100 causing fire up problems

. My 50 watter with visible links - with a 350 degree wrap around the lower half of the turret had no such problems

. Maybe because I used buss wire and insulation I did not wedge the wire in tight enough and when I dropped the components in and soldered I dislodged them.

Lessons learned, will not do on next build.

Looks great, glad it sounds as good as it looks

.