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BiAmp [message #21803]

Tue, 04 November 2014 00:24

Iowa Boy
Messages: 767
Registered: June 2014

Senior Member

I saw a Kustom VIII biamp power amp listed on Ebay the other day and was wondering what it is. Is there any practical application for this with the vintage equipment?

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Re: BiAmp [message #21804 is a reply to message #21803]

Tue, 04 November 2014 06:21

stevem
Messages: 4733
Registered: June 2004
Location: NY

Senior Member

It' is two power amps and a electronic crossover in one unit.
It coluld be drivin off of any Kustom amp that has a monitor or recording, or slave output Jack on the rear but some of these outputs are very hot so adjusting the bi amps in put levels for the low and high amp would need to done carfully!

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Re: BiAmp [message #21805 is a reply to message #21803]

Tue, 04 November 2014 10:38

Iowa Boy
Messages: 767
Registered: June 2014

Senior Member

Sounds like it could cause more problems then benefits..........so what was its purpose then?

Is there any way of wiring a meter of some kind into this so you tell if you were running too hot?

Update.....picked up a K300-5 PA head last night in really good condition......it is so quiet it makes my other amp heads sound bad. And power....oh yeah.....lots of it. Reverb of course doesn't work but tank is there and will check it out later today. Power switch is missing the blue cover but light still works so will fabricate something to make it look better. Only set me back $150 and T&R only has one small tear that will be easy to fix. Well Stevem we have all the amp heads now......just have to get my additional speakers for the other two cabinets I bought couple weeks back and we can start rewiring that K400B-5 head to be the slave unit for this one like we talked about awhile back.

Just pulled chassis out of cabinet and found two surprises.....wiring schematic and the button to the on/off switch. Re-glued the switch back together and its now on and light comes on but thinking since the plastic....cheap switch....is so fragile, I'll but a toggle switch in the back since I am replacing the power cord as well.

[Updated on: Tue, 04 November 2014 12:19]

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Re: BiAmp [message #21806 is a reply to message #21805]

Tue, 04 November 2014 14:11

fieldflower
Messages: 71
Registered: July 2004
Location: Sweden

Member

Iowa Boy wrote on Tue, 04 November 2014 16:38

Sounds like it could cause more problems then benefits..........so what was its purpose then?

The 2 amps have a crossover so that one amp gets all the low frequencies and the other get all the high frequencies.
This enables feeding a bass speaker and a high frequency speaker and letting them work the best since they only have to take care of the frequencies they work best with.
A modern PA system basically, but I guess in mono still.

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Re: BiAmp [message #21809 is a reply to message #21803]

Wed, 05 November 2014 06:18

stevem
Messages: 4733
Registered: June 2004
Location: NY

Senior Member

Right you are our friend from Sweden!
The metal face switches really are not fragile ,it's just that after 40 years like any plastic they out gas and dry up and then get weak and snap much like that dash board does on your 1971 car!

[Updated on: Wed, 05 November 2014 06:23]

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Re: BiAmp [message #21811 is a reply to message #21803]

Wed, 05 November 2014 09:40

Iowa Boy
Messages: 767
Registered: June 2014

Senior Member

I stand corrected on the plastic switch....still a poor choice in my book.....but 40 plus years in understandable. WoW man, you still driving a '71? Pinto or Maverick? You definitely need to be charging for what you know about Kustom equipment. Smile

So question still stands......is this biamp worth buying? I definitely have the speaker capability....crossover really isn't needed unless I decide to use those two sirens in the cabinets that I just purchased. The crossovers for those equals almost half of what they are asking for this biamp.

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Re: BiAmp [message #21812 is a reply to message #21803]

Wed, 05 November 2014 16:25

fieldflower
Messages: 71
Registered: July 2004
Location: Sweden

Member

Not sure if the crossover is possible to disconnect (or set to zero/infinite frequency for one of the amps)..?
If not it becomes a problem instead of a feature since neither jack will give You the full tone when connecting only one speaker.
You can select the bass-only jack or the bass-less jack, but not get full tone.

And running only 1 speaker of course means only using a portion of the effect since one amp simply isn't used at all.

But like I said - I just don't know if the crossover is possible to set to full tone...

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Re: BiAmp [message #21813 is a reply to message #21803]

Wed, 05 November 2014 19:47

Iowa Boy
Messages: 767
Registered: June 2014

Senior Member

Things seem a little murky here. So do you take the left and right channel out of the PA amp and plug it into the input jacks on this biamp and then run from the outputs on this amp to your speakers? Also, I am guessing that if you have a set of horns, then you run straight off of this biamp to the horns as well. Guessing that since there are (2) 100 watt amps inside this, one amp to woofers, other to horns.....if you didn't want to connect horns you just don't plug them in and still would get the 100 watts from the one amp...correct? So does this biamp increase your wattage overall? Like I said earlier, I don't know anything about these things. Thanks

[Updated on: Wed, 05 November 2014 19:50]

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Re: BiAmp [message #21814 is a reply to message #21813]

Wed, 05 November 2014 22:22

pleat
Messages: 1452
Registered: June 2004
Location: Belding, Mi

Senior Member

The Kustom Bi-Amp slave amp came in two versions. The, VIII, and the XII model.
The VIII Bi-Amp has two amplifiers and a three position electronic crossover. Crossover points are 500HZ 800HZ and 1000HZ.

Both amps are driven by a mixer.

The VIII low or bass amp is 130 watts into a 4 ohm total load.
The Horn or High pass amp is 70 watts into 8 ohms.

The big brother XII Bi-Amp has the same three position electronic crossover, and has three 130 watt RMS amps into 4 ohm total load for each amp. It is designed that two of the amps are driving the low or bass section. The third amp is driving the horn or high freq horns.

A conventional PA system, the passive crossover is in the speaker cabinet in a two way speaker cabinet. Passive crossovers can soak up a ton of power from the power amp that is driving both the low frequency woofer and the high or horn section.
If the amp is driven to distortion, you hear the distortion in both the horns and the woofers.
The object of Bi amping a PA system is electronically divide the frequency into two distinct frequency paths before the signals go to each amplifier. So if the low frequency amp is driven to distortion, the horn amp remains clean and clear.
In general a bi-amp PA system compared with a conventional PA. the bi-amp system will be 3 dB louder with the same total wattage. To gain that 3dB in a conventional system, you'd have to double the power amp wattage.

pleat

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