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K 150-7 [message #14025]

Sun, 11 July 2010 03:11

willc68
Messages: 15
Registered: May 2010
Location: philly

Junior Member

I recently aquired a k 150-7 2x12 combo and it is functioning well in almost every way with one exception being a loud popping noise when the amp is turned on or off. This is not the normal bassy pop that I hear with my other kustom amps this is loud and more of a piercing sound. Also the amp seems to make this almost exact sound about one an hour or hour and a half when just running at an idle. I have never encountered this before and was wondering if this is some indication of a problem to come or nothing to worry about? -will

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Re: K 150-7 [message #14028 is a reply to message #14025]

Sun, 11 July 2010 09:36

rodak
Messages: 511
Registered: October 2001
Location: Georgia

Senior Member

I have the same problem with my K150 2x10. I get the "thump", plus the loud "pop" when turning it on, and a pop when turning it off. I don't think mine does it after it's been turned on.

www.combo-organ.com

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Re: K 150-7 [message #14036 is a reply to message #14025]

Mon, 12 July 2010 05:56

stevem
Messages: 4733
Registered: June 2004
Location: NY

Senior Member

These amps use many modlex silp on type connectors to make the hook ups between boardsand they
may just need to cleanded and have the tops of the male portion of the connector pins re-spread to ingage the female section better.
bad connections lead to high resistance which puts the amp on the edge of ocscilating at power up, while running and at turn off.

Another possibilty is that one or more of the Tantalum type caps on one of the boards is going bad and drifting in value.

For a test out I would unplug both main connectors from each
preamp board and power the amp on which will leave just the output driver board and the efefcts board working and see/hear if you still get the act up problems.

One preamp board feeds thru the other so you can only leave the top channel board unpluged and do the test again.
If you do not hear the problem you have then pinned down the top channel as the problem.

[Updated on: Mon, 12 July 2010 05:58]

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Re: K 150-7 [message #14049 is a reply to message #14036]

Mon, 12 July 2010 22:22

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

Senior Member

Stevenm, I think you are confusing their amps with the K150-2 amps. The K150-7 and K150-8 didn't use the connector plugs.
pleat

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Re: K 150-7 [message #14052 is a reply to message #14025]

Tue, 13 July 2010 06:24

stevem
Messages: 4733
Registered: June 2004
Location: NY

Senior Member

Your right, thanks I read the post too fast to note that.
In that case you need to check for bad solder connections on the boards by taping around with a wood dowel. make sure the 2 screw down connection points on the top of the two big can filters clamped on the bottom of the amp are tight,and as I posted before any of those tantalum type electrolytic caps are fair game also.

If I had to guess by apply the info that you gave about the time factor which relates to heat, I would say your problem lies on the output stage driver board.
You can apply some low heat from a hair dryer to see if that board acts up.

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Re: K 150-7 [message #17146 is a reply to message #14025]

Mon, 04 June 2012 15:31

corim53
Messages: 4
Registered: September 2011

Junior Member

I have a 150-7 as well, my question is that the overall sound seems a little scratchy. I have dialed out the reverb and trem to get a very clean tone and it still sounds a bit scratchy or like a mild distorion is on. ( I am using a low volume setting) Is this just typical of these amps? thanks

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Re: K 150-7 [message #17147 is a reply to message #14025]

Mon, 04 June 2012 16:39

chicagobill
Messages: 2005
Registered: April 2003

Senior Member

No, these amps should sound very clean with no distortion. Have you tried the amp plugged into a different set of speakers?

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Re: K 150-7 [message #17148 is a reply to message #14025]

Mon, 04 June 2012 19:08

Kustom_Bart
Messages: 601
Registered: October 2010
Location: Greenville, MichiGUN

Senior Member

Every K150-7 that I have ever owned has the Kustom Thump when you turn it on and off. Thump Thump every time.

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Re: K 150-7 [message #17149 is a reply to message #14025]

Tue, 05 June 2012 07:05

stevem
Messages: 4733
Registered: June 2004
Location: NY

Senior Member

Yes, but the amp should not intermitanly thump once its on.
More than likly its solder connection, a cap in the 8 volt + and - regulator section or in the driver/output board, and or a transistor anywhere in the amp!

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Re: K 150-7 [message #17150 is a reply to message #17149]

Tue, 05 June 2012 10:47

Kustom_Bart
Messages: 601
Registered: October 2010
Location: Greenville, MichiGUN

Senior Member

Correct, once on it should not thump like that, bad solider joint maybe, bad cap? I am no tech but it is somewhere that it is making it lose voltage and gain it back just like turning it off then back on really quick.

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