Amps in series [message #19759] |
Thu, 19 December 2013 19:42 |
Gplayer56
Messages: 7 Registered: November 2013
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Junior Member |
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Hey all, I have two KB200 amps. I would like to run them in series. Is that possible? I know in my younger years, we had something plugged into something, running two amps... Can anyone help me out here?
Thanks!
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Re: Amps in series [message #19760 is a reply to message #19759] |
Thu, 19 December 2013 22:43 |
chicagobill
Messages: 2006 Registered: April 2003
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Senior Member |
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Series implies that you want to run the output of one amp into the input of the second amp. Is this what you are thinking of?
There is no good way that I know of to do this safely with two Kustom amps.
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Re: Amps in series [message #19787 is a reply to message #19759] |
Sat, 21 December 2013 02:03 |
Kustom_Bart
Messages: 601 Registered: October 2010 Location: Greenville, MichiGUN
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Senior Member |
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Actually now that I think about it, the better way to get more power is to test your speaker cabinets and see how many ohm's each of them are, if they are both 16 ohm cabs hook both cabs to one head to get full power from it and you would be doing the same thing as hooking two heads together.
To do this you have to make sure that you cabinets are 16ohms each as your head will only want an 8 ohm load max. By giving it an 8 ohm total load you will get the full power instead of half power when using one cabinet. to do this if it only has one speaker output use a Y jack to run a cable to each cabinet. It is the same thing as using 2 heads two heads at 100w = 200w with an 8ohm total load, one head with two 16ohm cabs hooked to it = 200w @ 8 ohm total load.
To test the ohms of the cabinet plug a speaker cable into the input jack of the cab and use a multimeter and turn it to the ohm setting and touch one probe to the tip of the jack and the other to the sleeve and it should give you a reading around 12ohms or so if it is a 16 ohm cabinet. Test them both and it they are both 16 ohm load, Y them to the output of the head and it is 200w instead of 100w with double the air moving. By using half the ohm rating you only get half power from the head.
[Updated on: Sat, 21 December 2013 11:51] Report message to a moderator
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Re: Amps in series [message #19792 is a reply to message #19791] |
Sat, 21 December 2013 14:17 |
pleat
Messages: 1454 Registered: June 2004 Location: Belding, Mi
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Senior Member |
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First off, I think Kustom Bart is thinking a K100-1 or K100-2 head that runs a max of 8 Ohms. The K200 series runs 100 watt into a 4 ohm total load cabinet(s).
A K400 has two K200 power amps in one chassis and each amp still runs a max of 4 ohms per amp. The only 3x15 cabinet that was offered with 4 cabinets is the K400-5 PA system that uses the siren horns. 3x15 cabs with all paper speakers, kustom offered the 400 with only two cabinets, or 4 of the 2x15 cabinets.
Getting back to the original question of running two amps together, each amp runs 4 ohms total, and we don't know what kind or impedance of the cabinets are. Impedance of the cabinets will determine output gain but that's not a question we need to be concerned with.
Addressing the post of excessive hum. If both amps power cords were changed to the 3 prong grounded cables, and the death cap removed on both. I would have to ask, were both switches wired the same when the cables were replaced, and were the power switches in the same positon when turned on. (Example both switches turned to the right)and using the same AC outlet? Were the ground side of RCA jacks making a good connection, they sometimes get corosion from lack of use.
Looking at the power amps schematic the RCA jack is tapped at a point between the first part of the power amp and that trace point goes to the speaker output further down the circuit.
I'm not a amp tech, but I didn't see why it would not work. Wish I had two K200's to try it myself.
pleat
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Re: Amps in series [message #19794 is a reply to message #19759] |
Sat, 21 December 2013 21:59 |
chicagobill
Messages: 2006 Registered: April 2003
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Senior Member |
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When two amps have grounded power cords, their chassis' are connected together via the power cords. When you connect the two amps with an audio cable, there are two separate ground paths, which will cause what is called a ground loop.
The first thing I try is to either lift one power cord ground by using one of those 3-prong to 2-prong adapters, or by using an audio cable that has the ground connection unhooked at one end.
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