Kalamazoo 30w bass combo 1965

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M Fowler
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Kalamazoo 30w bass combo 1965

Post by M Fowler »

Here is my Kalamazoo 30w bass combo built in 1965 per schematic that was inside the amplifier.

Wanted to document in case anyone needs to build such an amp.

Mark
Work Bench 01.JPG
Kalamazoo Bass top.JPG
Kalamazoo Bass control.JPG
Kalamazoo Bass gut.JPG
Kalamazoo Bass Schematic.JPG
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Stevem
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Re: Kalamazoo 30w bass combo 1965

Post by Stevem »

Nice!
I have worked on a few of those and it's nice that for Bass usage they chose to fix bias it while Ampeg was still in Cathode bias output stage mode with the flip tops!

I usually make that first filter node cap for the plates a 80 mfd!
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M Fowler
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Re: Kalamazoo 30w bass combo 1965

Post by M Fowler »

Recently got it back from a guitar store I was trying to sell it at but they said it was acting up so I need to see what is going on probably just a tube and I don't have any extra of these.

Mark
tubeswell
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Re: Kalamazoo 30w bass combo 1965

Post by tubeswell »

Hi Mark

Very tidy example. Interesting seeing the schematic - slight differences from the repro Bass 30 schemes I've seen on the net.

Be curious to know what sort of AC voltages you are getting at the PT secondaries (as well as the B+) if you have time.

(Maybe some of the problem is in those old(?) black sprague electrolytics in the bias supply?)

Cheers
Last edited by tubeswell on Fri Nov 03, 2017 3:55 pm, edited 2 times in total.
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M Fowler
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Re: Kalamazoo 30w bass combo 1965

Post by M Fowler »

Pete,

I can write the voltages down sure no problem.

Mark
tictac
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Re: Kalamazoo 30w bass combo 1965

Post by tictac »

Pretty cool 8)

Like a Williamson amp with tone controls....

TT
sluckey
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Re: Kalamazoo 30w bass combo 1965

Post by sluckey »

I bet the amp looks more like this schematic...

http://el34world.com/charts/Schematics/ ... bass30.pdf
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