Rewiring GK Combo to be used as stand alone cabinet?

[JordanArturo]

Hi TB'ers!

I have a technical question here and am hoping someone can help - I'm new to this.

I have a GK MB115 combo amp that one of the boards failed on it. Instead of fixing it, I'd like to convert the unit to be used with a head. It has a 15" 200w 4ohm speaker as well as a horn.

How would I go about wiring that up. Currently, the speaker and horn wires go to the preamp board.

Can I buy a premade plate with a crossover on it?


I appreciate all the help!

 

[B-string]

The horn is a piezo horn so you don't need a crossover but should solder a resistor in line with the horn. An average value of 50 ohms at 7 watt to 10 watt should work, this is so the amp does not see a purely capacitive load from the piezo horn and possibly be damaged.

 

[AstroSonic]

Under the assumption that you don't mind that you are getting a 2 cubic foot speaker enclosure in a 3 cubic foot cab (pretty light weight though), and that you will find a 200w, 4 ohm 115 useful (can't be paralleled with another cab unless the amp is stable into 2 ohms):

Add a jack plate with openings for a 1/4 inch phone jack and a speaker jack (Invalid Link Removed) Cut the required hole to the dimensions in the drawing on the items listing. install an spst toggle switch (SPST Mini Toggle Switch with Tapered Knob) in the 1/4 inch jack opening for switching the tweeter on and off. Install a female speakon jack into the large opening (it's made for this). Connect the speakon to the 15 inch driver. Run the negative lead for the tweeter to the horn. Run a wire from the other horn terminal to the switch. Wire a 47 ohm, 10w (Invalid Link Removed) resistor from the other switch terminal to the positive speak terminal. Install the jack plate with 4 wood screws. Done.

 

[JordanArturo]

Under the assumption that you don't mind that you are getting a 2 cubic foot speaker enclosure in a 3 cubic foot cab (pretty light weight though), and that you will find a 200w, 4 ohm 115 useful (can't be paralleled with another cab unless the amp is stable into 2 ohms):

Add a jack plate with openings for a 1/4 inch phone jack and a speaker jack (Invalid Link Removed) Cut the required hole to the dimensions in the drawing on the items listing. install an spst toggle switch (SPST Mini Toggle Switch with Tapered Knob) in the 1/4 inch jack opening for switching the tweeter on and off. Install a female speakon jack into the large opening (it's made for this). Connect the speakon to the 15 inch driver. Run the negative lead for the tweeter to the horn. Run a wire from the other horn terminal to the switch. Wire a 47 ohm, 10w (Invalid Link Removed) resistor from the other switch terminal to the positive speak terminal. Install the jack plate with 4 wood screws. Done.

Awesome, thank you AstroSonic! I should've been more specific, I'm thinking about starting to use a power/pre setup. The cab would mostly stay home and would be a great practice amp.

I'll give this a try and reach out to you again once I have it figured out.

 

[JordanArturo]

The horn is a piezo horn so you don't need a crossover but should solder a resistor in line with the horn. An average value of 50 ohms at 7 watt to 10 watt should work, this is so the amp does not see a purely capacitive load from the piezo horn and possibly be damaged.

Thank you, BString! I was going to ask you where I could get the parts, but AstroSonic's response covered that. You both were right on about the resistor.

I appreciate the help.