Author Topic: coliseum slave advice wanted  (Read 3670 times)

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Offline RxJxVx

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coliseum slave advice wanted
« on: March 20, 2007, 03:54:34 am »
i plan on using my concert bass head to run a 450w 215 cabinet i've assembled, and i want to run a coliseum slave off the concert bass and use the slave to power my 1200w 412 bass cabinet.  can anyone tell me what's the best/safest input sensitivity setting to use the coliseum slave with?  the only control on teh front panel is a INPUT SENSITIVITY KNOB which can be set anywhere from .5 volts to 2.5 volts...  also, i have not been able to determine whether the coliseum slave requires a 4 or 2 ohm signal.  the slave appears to be early 70's and is marked 500w on the rear panel.  any guidance / advice appreciated.  thanks
« Last Edit: March 20, 2007, 04:23:37 pm by RxJxVx »

Offline Isaac

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Re: coliseum slave advice wanted
« Reply #1 on: March 20, 2007, 06:47:55 pm »
The input signal to the slave should be a line level signal. Run an instrument cord from the Concert's preamp out. Set the Coliseum's Input Sensitivity wherever it sounds best.

I'm not sure what you mean by "a 4 or 2 ohm signal". Signals don't come in ohms.
Isaac

Offline EdBass

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Re: coliseum slave advice wanted
« Reply #2 on: March 20, 2007, 07:36:04 pm »
i plan on using my concert bass head to run a 450w 215 cabinet i've assembled, and i want to run a coliseum slave off the concert bass and use the slave to power my 1200w 412 bass cabinet.  can anyone tell me what's the best/safest input sensitivity setting to use the coliseum slave with?  the only control on teh front panel is a INPUT SENSITIVITY KNOB which can be set anywhere from .5 volts to 2.5 volts...  also, i have not been able to determine whether the coliseum slave requires a 4 or 2 ohm signal.  the slave appears to be early 70's and is marked 500w on the rear panel.  any guidance / advice appreciated.  thanks

As Isaac said, you can't "send" ohms to a anything, ohms are a rating of impedance to current flow, not an amplifier power rating or signal strength rating.
You mentioned the power ratings of your cabinet, they will no doubt handle any unclipped signal a Coliseum can deliver and then some. But the important question is, how many ohms is the cabinet? I don't know a whole bunch about solid state Sunns, but if you have an 8 ohm 4x12, your slave will likely only produce 125-150 watts when you use it to drive your 1200 watt cabinet.

To my knowledge, Sunn never made an amp capable of 500 watts. You are probably looking at the maximum A/C power draw label.

From a recycle bin post I inadvertently responded to yesterday...

Research "Ohm's law". (Georg Simon Ohm (1789-1854) was an early electrical engineer. He published his original theory of applied voltage in 1827, and his "law" as it eventually became, is the keystone for electrical circuits).
It is interesting, pretty easy to grasp, and will give you a great overview of what's going on with your amps.

 

Offline RxJxVx

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Re: coliseum slave advice wanted
« Reply #3 on: March 21, 2007, 01:44:21 am »
 :-P

so let's say the 1200w 412 cab is 4ohms (which it in fact is)...does this mean i can actually get up to 250w out of the coliseum slave?  or will i only be able to get 200 or less since i'm running out of the concert bass?  my understanding of impedance is VERY limited, and i do plan on researching the law you've referenced.  thanks for the input you all have provided thusfar...

Offline EdBass

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Re: coliseum slave advice wanted
« Reply #4 on: March 21, 2007, 09:52:28 am »
:-P

so let's say the 1200w 412 cab is 4ohms (which it in fact is)...does this mean i can actually get up to 250w out of the coliseum slave?
I don't know the actual rating of a Coliseum slave @ 4 ohms, but I'll bet you're very close; 200-250 watts, I'd guess.
or will i only be able to get 200 or less since i'm running out of the concert bass?
The Concert’s watt rating has no bearing on the Coliseums output potential
A regular “amp” for bass or guitar (like your Concert bass) is actually an integrated amplifier, which means it’s really two amps in one box. You have a pre amp, (which generally will output around a 2 volt signal max) which drive a power amp, which is what actually drives the speakers.
A slave amp (like your Coliseum slave) is not an integrated amp, but a power amp only, and needs a pre amp to drive it. When you take a line out from the pre amp on the Concert Bass you are using the pre amp in the Concert to drive both the power amp section of the Concert AND the power amp section only Coliseum slave with that 2V +/- signal mentioned above.
Hence, the sensitivity rating on the Coliseum’s input attenuator.
my understanding of impedance is VERY limited, and i do plan on researching the law you've referenced.  thanks for the input you all have provided thusfar...
Keep on researching and asking questions, it’s not very complicated once you get a handle on the basics!

Offline RxJxVx

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Re: coliseum slave advice wanted
« Reply #5 on: March 21, 2007, 11:31:47 am »
thanks again for taking the time to read my post, and taking the time to help me out...i can't tell you enough how much i appreciate it. :-D

Offline Isaac

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Re: coliseum slave advice wanted
« Reply #6 on: March 21, 2007, 01:27:39 pm »
You could try!  :-D
Isaac

Offline RxJxVx

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Re: coliseum slave advice wanted
« Reply #7 on: March 26, 2007, 08:57:51 pm »
I APPRECIATE EVERYONE'S INPUT AND RESPONES SOOOOO MUCH THAT I AM SAYING "THANKS!!!" ONE MORE TIME...i would much rather ask some folks who know than blow up some vintage amplifiers... :wink:

Offline Isaac

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Re: coliseum slave advice wanted
« Reply #8 on: March 28, 2007, 11:29:52 am »
I couldn't agree more. I love all the old Sunn stuff, though I'm partial to the late sixties tube amps. Parts can be hard to find, too, so blowing them up is a bad choice on many levels.
Isaac