sunn collisum super model t?

[kupervaser]

Thanx guys,

The only way is to look at the circuit, but that is not really my cup of tea, so I will have to bring it to a tech.

[kupervaser]

I contacted Conrad with the question. Here is what he wrote:

OK, this amplifier is obviously a prototype of the second version of the
Model T amp. (second generation) I was not with the company at the time
but the Coliseum series was doing very well and I think they might have
wanted to capitalize on that name. The front panel is weird for sure.
There was a Model T Super that was introduced around March 1979. Most
Sunn users of the Model T prefer the 1st generation Model T which does not
have the midrange switch.

[kupervaser]

Does anyone know whether this amp can simply be rewired for the 240V for europe? Because I heard such a thing.
If yes what should be done?

Thanx in advance,

[Isaac]

A quick glance at the schematic (http://sunn.ampage.org/site/schematics/modelt.gif) indicates that it is possible to rewire the amp for 240v operation. I'll let those with more tube amp experience weigh in with a definitive answer.

[kupervaser]

Yeah I think I understand it now. It is probably easy to change it to 240, however are there any other parts to be replaced or maybe a fuse or everything can stay the same?

[mckinnon audio]

   Hi there,the AC tranny has 2 primary windings that are the same,one has a Black wire and a Black/White wire,and the other has a Brown wire and a Brown/White wire,In North America they are hooked up in parallel for 120 Volt operation.For 220 Volt,you have to hook them up in series,here's how to do it,leave the Black wire on the switch and cut/unsolder the Brown wire from the switch,seperate the Black/White and the Brown/White wires and solder the Brown wire to the Black/White wire,the Brown/White wire goes to the White.Your windings are now in series with the Black wire being the AC hot and the Brown/White being the AC Neutral.Since you'll be running 220 VAC now,you can halve the size of your AC Mains fuse.Good luck,Mel.

[kupervaser]

So, this amplifier looks very original from inside, no doubt. The Super T has been put there by someone, so it is a Coliseum Model T amplifier of the second generation. At this moment the power cord has been cut off and on the inside i see both of the 1K resistors on the hum balance together with the hum balance pot burned down. I already got the resistors and the hum balance pot and the cord. First of all I will measure the transformer winding which goes to the heaters of the power tubes to see whether the transformer is still good. If that will work out I will rewire the transformer for European net and start troubleshooting. 
Will post updates here.

[Isaac]

   Hi there,the AC tranny has 2 primary windings that are the same,one has a Black wire and a Black/White wire,and the other has a Brown wire and a Brown/White wire,In North America they are hooked up in parallel for 120 Volt operation.For 220 Volt,you have to hook them up in series,here's how to do it,leave the Black wire on the switch and cut/unsolder the Brown wire from the switch,seperate the Black/White and the Brown/White wires and solder the Brown wire to the Black/White wire,the Brown/White wire goes to the White.Your windings are now in series with the Black wire being the AC hot and the Brown/White being the AC Neutral.Since you'll be running 220 VAC now,you can halve the size of your AC Mains fuse.Good luck,Mel.

That's exactly what I thought. Thanks for confirming it, Mel.

As the cord has been cut off, I'd make a point to replace it with a European style cord. Additionally, won't the 220/240 be too much voltage for the pilot light?

[kupervaser]

Yes will replace the power cord with the European one. llAh pilot light, good point I have no idea. Anyone?

[mckinnon audio]

  Hi there,sorry forgot about the pilot light !! You can either put a "dropping resistor" in series with the neon to bring the Volts down to 120V,or replace it with a higher voltage one.If it's inside the switch,try the resistor approach,that way you can keep the switch,good luck,Mel.

[loudthud]

You just connect the wire for the pilot light to the junction of the Brown and Black/White wires from the transformer. The thing everybody forgot was the circuit breaker. You need to find a 3.5 amp replacement breaker or install a 3.5 amp fuse. And you must remove the Death Cap and disconnect the convienence outlet. It's best to take the amp to someone qualified to perform the conversion in your country.

[mckinnon audio]

  Kudos,Loudthud,I completely forgot about the gnd.cap and the 120v accessory outlet !! As usual you didn't miss a thing,good eyes !! Mel

[kupervaser]

Which one is the death cap?
Is it the C14 on the schematic, 0,047 / 1000V?
How should it be removed? I understand all the danger and high voltages, but I am willing to die for this amplifier. No seriously, I am repairing this amplifier with someone else who has 40 years of experience in general electronics, only not in the guitar tube amplifiers. And I listen to you guys a lot.

Why should the accessory outlet be disconnected?

[kupervaser]

Found another burnt resistor, R36 on the schematic.