Wiring Diagram for 2" Metroamp EL 34 OT

mightymike · Post by **mightymike** » Sat Dec 02, 2006 10:16 am

Metro 2" EL 34 OT that justs arrived has different colors than the diagram for the 2" in the store.

Here's what color wires I have:

Primary side is ------red, brown and blue

Secondarys is -------Orange, Black, Yellow, and Green.

This OT looks very familiar to George's KT66 JTM 45/100 OT
That one had the primary side with:
Blue, and Brown for primarys to v5,v6
And the Secondary side was:

black common to speaker

and the orange, yellow , green were the 4,8, and 16 ohm taps respectively

Are both of these Metroamp 2" Ots using the same wire color scheme?

Post by **VelvetGeorge** » Sat Dec 02, 2006 10:43 am

it's the same code as the jtm 45 OT:

http://store.metroamp.com/product_info. ... cts_id=271

But watch the brown and blue primary. Heyboer likes to reverse the phase on these. I have it corrected on the next run.

VG

mightymike · Post by **mightymike** » Mon Dec 04, 2006 5:38 am

OK then:

Primarys:

Blue primary goes to V5 pin3

Red = CT

Brown primary goes to V6 pin3

Secondarys:

Black Speaker
4ohm yellow
8 ohm green
16 Orange

Thanks,
Mike

mightymike · Post by **mightymike** » Wed Dec 06, 2006 4:53 am

Update:

I just installed this in a SLP reissue, and wow is it mean and ballsy.
It was a tight fit, but I made sure there's enough room for fat bottles.
It has a 67 board that George loaded and someone else installed.

Very agressive,no Ice Pic, and cleans up well.
I almost hope the guy takes his time paying me so I can have fun playing it some more.

It's a fun amp, and I'm not easily impressed.

Bad Kitty · Post by **Bad Kitty** » Wed Dec 06, 2006 5:51 am

So would you say that it's a must have as far as the reissues?

Mike

mightymike · Post by **mightymike** » Wed Dec 06, 2006 7:33 am

Absolutely! The OT is the Heart of an Amp.
A pretty PTP board with name brand NOS parts won't make a crappy
tranny sound good. He already put a Sozo Metro 67 board in, but now this tranny is getting the most out of what that new board was trying to do. He was going for Page tone.

Right now this amp has a meaner bottom end than Back and Black, and that high filtered tight bottom end like a really good metal Face, but with nicer smoother highs than most metal faces.

If I was going for Page tone, I would lower the filtering on this to 67 spec.
Right now it's a little too aggressive, but you can allways roll of the volume a little, until you get the 4 caps needed to convert.

It close.

I know some people who would give a right tooth for Marhsall this agressive. It's one of thee most aggressive Marshalls I've ever heard.
I has one of the meanest bottom ends of any I've heard.

mightymike · Post by **mightymike** » Wed Dec 06, 2006 10:17 am

I plotted out his Power section while playing Good Times Bad times.
And he can get some really great Page tone by lowering his wall voltage slightly. Some good VH at 112ac/450dc, some great Page at 470 -472.
Nailed the lead tone for good times, and the lower valtage made the filters not work so hard. it put it over the top. Tamed the agressiveness so it sound more like Zep and less like ACDC.

If it were my amp, I'd probably just buy a variac instead of lower the filering. A couple volts does a lot. different ways to skin a cat.
Even if you're using it to supply a steady 120 it's better than the wall.

As it stands he could go all the way down to 110 wall AC and still maintain 3.02/and 3.08 on V1s heaters pins to ground. where he would have 445 Plates. some say you can go down to 2.8, but I'm keeping it above 3.

then up from there to 120

Wall AC ---------Heater on V1 pin 9 and 4&5--------DC Plate Voltage

110 ---------------- 3.02/3.05 ------------------------445 DC

113.2 --------- 3.04/.3.07 -------- 455 DC

115.1 -------------------3.06/3.09 ----------------461 DC

116.2 ------------------3.08/3.12 ------- 465 DC

117.7 ------------------3.11/3.15 ----------------470 DC

119.3 -------------------3.15/3.2 --------------- 475 DC

120 ------------------ 3.17/3.22 ---------------477 DC

Metal Handles · Post by **Metal Handles** » Mon Dec 11, 2006 8:21 pm

I need some help if you guys don't mind. I just got the 100 watt package deal (listed as the 1200 series option on the bare bones kit). I ordered it with '67 super bass specs, so it came with the 2" Drake style output. The numbers on the label are "100-OT HTS-7338 9960641". It's all black and has the red/blue/brown and yellow/green/orange/black wiring set up.

The mounting hole spacing is 3 1/4" square on the tranny, but the chassis is 3 1/4" X 3 1/8". Am I crazy?
Or how is the best way to mod this? Round file the tranny tabs? Or do I have the wrong one, maybe the JTM 45/100 tranny?

mightymike · Post by **mightymike** » Tue Dec 12, 2006 6:06 am

Make sure you have it turned the right way.
Bell cover facing left and right, not front and back for early 67.

Then if it's still off, What I would do is lay the chassis down, and set the tranny how it would go. Then mark it, and use a drill bit to elongate the holes just enough, or drill new holes outright.

You'll probably end up using 2 existing holes and only widen the other 2 by 1/8 inch each. You'll find out what you have, once you lay it on there. This way the washer will cover the slighty widened holes, and once the tranny is isntalled, it would look perfect.

Just make sure you don't crowd your tubes. I put a KT66 or a Fat Bottle 6ca7 in the nearest tube socket just to make sure it clears (with tube retainer installed), before drilling.

Use oil on the bit, so it doesn't dull, and wear safety goggles.

Metal Handles · Post by **Metal Handles** » Tue Dec 12, 2006 12:22 pm

Thanks MightyMike. Your review of this transformer sounds really good, I hope I hear the same thing with this amp. Plus a little early Billy Gibbons and clean Hendrix.

Modding the holes was easy enough, I took a round chainsaw blade file to the holes and didn't have to work long at all to get the brass bolts through.

Thanks for the tips. I'll need a few more before I'm done I'm sure.

mightymike · Post by **mightymike** » Tue Dec 12, 2006 6:46 pm

Anytime.
Glad to help.