I have inherited a large Carlsboro Hornet Custom 35w amp with twin 12” 20w celestion speakers.
It works well, tremelo, presence, etc.it has one fault…it just dies after 10 or 15 minutes use.
I really need a schematic, but I can’t find this model !
willing to pay for a circuit diagram, and would appreciate any advice re the caps!
Mike, Hinckley, Leics,Uk
i can send a pic if required!!
It works well, tremelo, presence, etc.it has one fault…it just dies after 10 or 15 minutes use.
I really need a schematic, but I can’t find this model !
willing to pay for a circuit diagram, and would appreciate any advice re the caps!
Mike, Hinckley, Leics,Uk
i can send a pic if required!!
Picures are always helpful and there's some good ones of the circuitry in this link:
https://www.ssguitar.com/index.php?topic=4559.0
The advice would probably be to start by replacing all the electrolytic capacitors, especially the large power supply ones.
https://www.ssguitar.com/index.php?topic=4559.0
The advice would probably be to start by replacing all the electrolytic capacitors, especially the large power supply ones.
It appears that original drawings were lost during a change of ownership.
You may reach someone with the required knowledge by posting in the Live Sound: Instruments and Amps section of the forum.
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You may reach someone with the required knowledge by posting in the Live Sound: Instruments and Amps section of the forum.
If you click on the Report button at bottom left, you can ask a moderator to move your thread there.
Done.
Can you isolate the dc power to the amp. If needed, cut the traces on the pcb right after C23 and C24.
Switch on the amp and measure the voltage over these caps, C23 and C24.
Leave the meter connected and wait for some time.
If the voltage drops; then probably there is a problem with one or both caps.
If not, switch all off and remake the traces on the pcb.
Switch on the amp and measure the voltage over these caps.
Leave the meter connected and wait for another while or until it gets silent.
If the voltages do not change, measure the violtages on the IC's. Should be around + and - 15V.
If they differ to much. like 6V or 2V, then either there is a bad Chip (IC 1 and.or 2) or the circuit that powers the chips has a problem.
Maybe an electrolytic.
And maybe there is bad powertransistor. Check if they get HOT.
Let's see what's going on now.
Switch on the amp and measure the voltage over these caps, C23 and C24.
Leave the meter connected and wait for some time.
If the voltage drops; then probably there is a problem with one or both caps.
If not, switch all off and remake the traces on the pcb.
Switch on the amp and measure the voltage over these caps.
Leave the meter connected and wait for another while or until it gets silent.
If the voltages do not change, measure the violtages on the IC's. Should be around + and - 15V.
If they differ to much. like 6V or 2V, then either there is a bad Chip (IC 1 and.or 2) or the circuit that powers the chips has a problem.
Maybe an electrolytic.
And maybe there is bad powertransistor. Check if they get HOT.
Let's see what's going on now.
It's a pretty simple circuit, so it shouldn't be too hard to draw it out, but really the first thing to do is find out if it's the preamp or power amp that's dying. Funnily enough I live only a few miles from where Carlsboro were based, and they were extremely helpful on the few occasions I rang with any queries about repairs. It's a shame they no longer exist, it was decently made gear.
Drawing circuits out is a bit of a pain, but it's a skill that's very much worth learning.
Curious if it has thermal cutoff switch.
Outputs might be getting hot.
Does it have thermal sensor mounted near outputs.
Likely one side of main wiring wired to thermal switch
Could be dried up thermal grease for transistor mounting.
Or bias drifted a little hot.
Outputs might be getting hot.
Does it have thermal sensor mounted near outputs.
Likely one side of main wiring wired to thermal switch
Could be dried up thermal grease for transistor mounting.
Or bias drifted a little hot.