Metropoulos Forum

needed to drill new holes for the trannies. Getting them in place was not as easy as I thought.
I figured trannies hardware would not be included so I already had bought 5mm bolts/nuts, with double large washers.

I wanted to leave as less untwisted wire as possible...

At this point I gave Nik a shout about the bias wiring and half-power switch and he sent me the temporary layout. I realised I had to desolder all the bias resistors and change the position. I was lucky since I had just enough lead to do it clean.

Left 8-Ohm tap unslodered for the NFB wire...

Pentode-Triode Switch
Loads of wires in there...

Now this is where I kinda had to stop.
The kit is a bit different compared to the Metro instructions and I wanted to be careful. The manual says I have to connect some wires that will be connected to the turret board, but my board is already wired so I had to check back and forth between manual and ceriatone layout to spot the differences. But I think I'm gonna need Nik's help on this...

Anyway, I've seen some amp guts pics where the PT primaries are twisted as well so I wanted to do the same between the power switch and the fuse holder. Also the pilot light is wired to the heaters pins on V7.

Outstanding !
Will you be incorporating Larry's grounding scheme ?

JimiJames wrote:Outstanding !
Will you be incorporating Larry's grounding scheme ?

I was thinking about that... I don't have extra ground lugs for now and I haven't checked which holes I could use on the chassis yet.

Xmas is close and I'll be out of town in a few days so... I was a bit anxious to hear this thing

I was looking at this:
http://forum.metroamp.com/viewtopic.php?f=45&t=31328" onclick="window.open(this.href);return false;

Do you think something is changing with the external bias pot?

Now that I remember, I have some eye-let terminals, but they're for 6mm holes. It could be a temporary solution... if I still have enough wire...

Really neat looking job! Since you want to twist as much as possible twist your ot secondaries too.

clean looking build

Alright. Nik told me the 'new' layout he gave me was only a reference for wiring the biast test points and the half-power switch.

The rest is just like the layout on ceriatone website:

So now, looking at this thread again:
http://forum.metroamp.com/viewtopic.php?f=45&t=31328" onclick="window.open(this.href);return false;

Can anyone tell me which wires for which point? or at least fill in?

In that picture at the very bottom I see:

point 1)
- input jacks ch 1
- input jacks ch 2
- V1 cathodes
- what's the other wire?

point 2)
- normal Vol pot
- bright vol pot
- V2 cathodes
- pre-amp filter cap (which in my case is on the board and already soldered to the ceriatone on-board buss wire)

point 3)
- mids pot
- presence pot
- output jacks. Mine it soldered on the V5 ground lug as per manual.
- F6 filter cap ground? Can anyone tell me the reason?

point 4)
- bias pot. Mine is in between the power tubes and it's sharing the ground lug with the bias test points. It would be a mess to deconstruct now...
- Bias 0 from PT. Mine is already cut and soldered to the F6 ground lug with the heaters CT.
Should I really extend the lead and move it here?
- F2 cap ground, I'll have to cut the buss wire and remove the existing lug for this one. just to avoid confusion..

point 5)
- just the bridge rectifier.

Is this all correct?
And can I use the transformers bolts?

The point 1 "other wire" is the heater center tap. It is better not to use transformer bolts for grounding.

Yeah, get away from the transformer to ground.

It is beautiful. The only thing I would say that I don't like is the heater having the big loop out at every tube. Better to go straight across the tubes there, but hey, that is a great looking build that is over the top on clean work. Good job!