Metropoulos Forum

Thought I'd start a thread for this from the begining. Although most of the info can seem redundant, there are always new things and ideas that can arise.
From other threads there seems to be split ideas as to the orientation of the OT. I have noticed some of George's OT's have the orientation as seen here I believe. Is there a difference? Does it matter?
Keep in mind the OT is a 2", therefore a few extra holes in the chassis. Also note the Larry grounding, with a straight alignment under the board as Vhjunkie suggested. 2" OT, 12000 series PT from ****** Audio. Choke is a Mojo Plexi/JCM 800 3H.

One of George's builds:

I think it was Night Owl that did it in reverse (by mistake?), which is how I have my first 68 build. The one I'm breaking in now (like yours with the *****tranny's), is positioned like George's. The tranny's should be mounted on Lazy Susan's so we can rotate them to the optimal positions on the fly! Also, you should add one more of those solder lugs to grounds #1 through #4, which will make things easier and less crowded.

Yeah, thats how mine is as well from the build last year. I followed those same directions. I have the #1 and #2 lugs there as well for the grounding to the left. Total of 5 lugs. Do you mean to add another?

I mean the little tab things you solder the wires to for each ground possiton. You should have two for each ground bolt so you don't have to crowed all those ground wires on to one tab.

Strat78 wrote:I mean the little tab things you solder the wires to for each ground possiton. You should have two for each ground bolt so you don't have to crowed all those ground wires on to one tab.

Ok, gotcha.

A couple of things about the lugs:
They are easier to solder if you don't tighten them down until the end.
If you read Larry's thread(s), there should be an external tooth lockwasher between the lug(s) and the chassis.

vh junkie wrote:A couple of things about the lugs:
They are easier to solder if you don't tighten them down until the end.
If you read Larry's thread(s), there should be an external tooth lockwasher between the lug(s) and the chassis.

Even though the lugs are "toothed" already?

Yup
http://forum.metroamp.com/viewtopic.php ... 41&start=4

vh junkie wrote:Yup
http://forum.metroamp.com/viewtopic.php ... 41&start=4

Ok, on the other side(outside/up) of the chassis I have a regular brass washer between the screw and the chassis. Should that be removed, with just the screw going in first? Not a big deal I suppose, but I would suspect you want the least number of unsoldered contacts stacked there.

Screw, flatwasher(optional), chassis, external tooth LW, Lug, Lug, Nut - that's the way I read it.

Perhaps the type of lug Larry is talking about do not have the locking teeth built on. I can't think of a reason why it would matter having the extra washer with teeth other than to totally dig into the chassis to form a strong connection, still I'm going to redo all my grounds with the additional tooth washers! Great stuff!

I think that's the reason. The chassis might have oxidation on the surface. The teeth dig in to the bare metal.

On mine, I left the grounds to the preamp board a LITTLE long, and on their own lugs, so I could lift the board enough(on the pot side) to release the lug nuts. Once the nuts are off, the pot side of the board will rotate up enough to do mods on the bottom. The power amp board the same thing, but it rotates upon the tube side.

I used a Dremel around the holes.

vh junkie wrote:I think that's the reason. The chassis might have oxidation on the surface. The teeth dig in to the bare metal.

On mine, I left the grounds to the preamp board a LITTLE long, and on their own lugs, so I could lift the board enough(on the pot side) to release the lug nuts. Once the nuts are off, the pot side of the board will rotate up enough to do mods on the bottom. The power amp board the same thing, but it rotates upon the tube side.

Hey Robert, that's a good idea. This is why things that seem redundant still bring out different ideas that are usable to impove on things.