Coliseum Slave: simple questions / advice.

[TheBassAce]

I have the diagram the previous owner sent along with the Coliseum Slave, and it looks like he ran 2 4x12 cabs off V4 #1, 2 4x12 cabs off V4#2, and 2 cabs off the Slave, while jacking both V4s into the Slave. Is this correct?

[mckinnon audio]

  Hi there,that should work fine,each amp has a load and the slave is getting a line out from each amp's preamp.Just a word to the wise,make sure all your amps are grounded,if some/any of them are 2-prong,(ungrounded),make sure you measure the AC volts between the chassis's and flip the "ground" sw. accordingly BEFORE you plug in your signal cables.Good luck,Mel.

[TheBassAce]

Great. NOW I'm sweating! Both my 1969 Ampeg SVT and SBT are all original- right down to their two-prong AC plugs! I do, however, have a 'polarity' switch on the front panel of both. How am I to know if everything is grounded properly BEFORE I power up without a 3-prong plug? My life insurance policy against frying all my gear was to be running my entire rig thru a pair of Furman PL-PLUS II Series power conditioners BEFORE going to the wall! You wanna come out here and help me with this? 

[mckinnon audio]

  Hi there,I didn't mean to cause you to panic,it's easy.Get an AC volt meter,(analogue,digital) doesn't matter,plug your spkrs. into the amps,plug the amps into the AC,don't patch in your signal cables yet.You don't even have to turn the amps on,the gnd.is already connected on your 3-prong.Take your meter and connect it between the two chassis's and measure the AC volts,I would reference everything to the 3-prong piece of gear,flip the "polarity" sw.till you get the lowest amount of AC on the chassis,(you'll never get rid of it entirely) and measure between all the pieces in your rig.After this plug in your signal cables and you should be fine,but as a precaution measure between your rig and the PA (vocal mic,70-80 volts on the lips smarts).An expensive alternative would be to use isolation transformers on the AC.Hope this helps,didn't mean to scare or frustrate you,good luck Mel.

[TheBassAce]

I am completely inept when it comes to anything to do with electricity, voltage, and current. Yikes! If you see a bright flash and a large mushroom cloud coming from the east, that'd be my rig- blowing up!

[djc]

my 200s has the original 2 prong and if I have the polarity switch the wrong way and touch another instrument it feels like 120!
I'm used to it and just don't touch anything.  my guitarist and I trade now and then and he takes about 6 or 8 shocks to jolt his memory to not touch anything.
stupid 6-string slingers!

yes I know, I need to change that.  soon when my pile of projects gets lower.

[TheBassAce]

I am learning SO much from hanging out in these forums! I truly have NO desire to fry my vintage gear, so I plan on taking each bit of advice to heart. I appreciate the time you've all taken to help me out with my questions! Thank you SO much. Now- if I could only find a Mesa-Boogie forum... I have a 4x12 slant-front guitar cab with a crosshatch steel grille that I can't identify...

[TheBassAce]

  Hi there,I didn't mean to cause you to panic,it's easy.Get an AC volt meter,(analogue,digital) doesn't matter,plug your spkrs. into the amps,plug the amps into the AC,don't patch in your signal cables yet.You don't even have to turn the amps on,the gnd.is already connected on your 3-prong.Take your meter and connect it between the two chassis's and measure the AC volts,I would reference everything to the 3-prong piece of gear,flip the "polarity" sw.till you get the lowest amount of AC on the chassis,(you'll never get rid of it entirely) and measure between all the pieces in your rig.After this plug in your signal cables and you should be fine,but as a precaution measure between your rig and the PA (vocal mic,70-80 volts on the lips smarts).An expensive alternative would be to use isolation transformers on the AC.Hope this helps,didn't mean to scare or frustrate you,good luck Mel.

Off on a tangent here. Can you please explain the VU meter, the 'audio / 117V' switch, and the round knob on the Slave's front panel? I didn't get an owner's manual with the unit. Thank you!

[mckinnon audio]

  Hi there,the round knob is your input level control,(volume),the VU meter will show you the signal level,and I believe the "audio/117 volts" sw. is used to measure either signal input or the AC volts at the mains depending on the sw. position.It uses the same meter for two functions,not at the same time of course.Hope this is of some help,good luck,Mel.

[TheBassAce]

Hey, Mel! As always, thank you for being so helpful!

John

[mckinnon audio]

  Hi John,no prob.,just glad to help out any way that I can,good luck,Mel.

[basiklybass]

DJC; it feels like 120 volts because it is. Be careful, with your hands on your strings and your lips touching a mic, the path for the current is through your body....not a desirable condition. Small shocks can easily turn into big ones....deadly ones. A bit of sweat...a damp day...what you ate (no joke) and you could be in a bad way. I cannot be too strong in recommending that everyone with a 2 prong cord have it changed as soon as possible.

[djc]

no doubt.  it's not fun getting that through the lips.  do I have to isolate anything inside or just ground the chasis?

[mckinnon audio]

  Hi there,personally I remove the entire "polarity" circuit,the sw.,and the "death cap". I also rewire the AC mains so that the ac goes to the sw. first,then the fuse and then the trans.,this way you can change the fuse with the ac off,much safer.The downside to this is that because of the internal connection to the neon bulb in the sw.,if the fuse blows,the neon remains lit,they really don't show this very well on the schmatics.Good luck,Mel.