Horn test cab sold on so thread over thanks

[jhk]

Is there a simple test for relative non experts to find out whether the horn in a peavey 4X10 tvx bass cab is not working or the attenuator/pot does not work,resulting in same thing.
I don`t want to replace the wrong piece is the real crux of the matter.

I have a small circuit tester ............ will that be of any use?

all answers welcome

Edited August 25, 2008 by jhk

[bass_ferret]

Probably. Lots of horn tweeters used in bass amps can be a bit delicate IME. You could try putting the meter across the terminals on the horn but I'm not really an expert on this sort of thing so dont know whether you should put a 9v battery across the jack terminals as well. Putting a 9V battery across a woofer is usual to check its working but dont know about tweeters.

[escholl]

the easiest way should just be to connect another amplifier (like a hifi amp or similar) across the terminals of the tweeter. put some material through the amp, and starting with the volume on the test amp all the way down, slowly start to turn it up. if you get past about 10% of the way up and you still can't hear anything, then the tweeter's gone. if you can hear the material coming through it, then it's not the tweeter.

the fact there's no crossover won't hurt the tweeter in this test scenario as long as you keep the volume fairly quiet and don't go trying to max it out or anything silly

[jhk]

I`ve tried your suggestion and hey presto,at least I know the horn works.
So the problem is within the circuit board or components.I`ve run the tester over the components and the one marked

T.I 15 OhF 5%
MEA 200VDC

is not letting any signal or circuit go through!
is that the crossover?

can i get diagrams or specific components from peavey?

Edited July 22, 2008 by jhk

[stevie]

[quote name='jhk' post='245625' date='Jul 22 2008, 07:33 PM']I`ve tried your suggestion and hey presto,at least I know the horn works.
So the problem is within the circuit board or components.I`ve run the tester over the components and the one marked

T.I 15 OhF 5%
MEA 200VDC

is not letting any signal or circuit go through!
is that the crossover?

can i get diagrams or specific components from peavey?[/quote]

Would that be 15 uF? Sound like a film cap. Can you measure capacitance with your meter? To confirm that it's not working, bypass it with some wire - keep the volume low, obviously. It would be very unusual for a 200V filmcap to go in an HF circuit. It's a bit difficult to troubleshoot blind at this distance but I'll try to help (although I'm only here now and then). If the crossover uses an L-pad (like a volume control), chances are that's what's gone.

[escholl]

[quote name='stevie' post='245687' date='Jul 22 2008, 09:21 PM']It would be very unusual for a 200V filmcap to go in an HF circuit....If the crossover uses an L-pad (like a volume control), chances are that's what's gone.[/quote]

+1

[muzzer]

+1 also

Though it sounds like the component you're talking about is probably a 150 microfarad non-polarised capacitor.
It's being used as a simple "crossover" to reduce low frequencies going to the HF horn. You won't be able to measure this using the "ohms" scale on multimeter as they block DC current and only let through higher frequencies.
Sounds to me more its more likely the HF pad or level control is likely to be at fault.

The level control will have at least two terminals or wires going to it, you should be able to read a change in resistance when you turn the control (or a fixed resistance if you measure across the outer 2 contacts of a 3 terminal control - either outside terminal should be variable to the middle one).

Hope that makes more sense than how it reads

Anyway, if you get an open-circuit across across any of the connections it's probably blown - you should be able to just short across it to bypass this if you don't mind the horn at full-blast all the time.

HTH

Steve