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Old 07-13-2019, 07:30 AM   #41
Khron
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Default Re: Mackie CR4 monitors

Here's a silly thought - any chance there's room on the backplate to mount the transformer on the outside, using the same mounting holes? Going by the photo, there should be.

That way, you'd just have to lengthen the five wires (mains in, sec-0-sec) - might need to drill one extra hole (or two) though - and ideally add a rubber / plastic bushing, to protect the wire insulation.
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Old 09-14-2019, 11:28 AM   #42
Xebozone
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Default Re: Mackie CR4 monitors

Hello,

My speakers suffered the same issues as is common with these around the internet.
The article linked earlier in this thread helped me identify the Zener diode (1N4742A - 12V 1W) that caused the issues.

I replaced it with a beefier one (1N5349 - 12V 5W) and cut the mute pin of the amplifier chip (TDA7265). My speakers were cracking and silent, and after, they worked great.

A few months later, the powered speaker started to go silent. After cooling down, it worked again. I noted that some of the PCB is cracked and blackened as typical with these speakers (perhaps due to the thermal expansion and contraction). I had to bypass the cracks in my board by soldering some wires across the cracks and it's working again... for now.

In that linked article above, the writer of the article mentions making a cheap circuit to bypass the poorly designed "shunt regulator". I'm interested in implementing his solution, but there is no mention in that article about how to wire-in the solution.

I'm certainly no electronics expert, so it would be appreciated if someone with some knowledge could take a look at the photos and schematic from that article and advise how to complete/wire-in the circuit replacement. What needs to be removed from the circuit (if anything)?

Thanks for your time!
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Old 11-13-2019, 07:31 AM   #43
decayed.cell
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Default Re: Mackie CR4 monitors

So I have no sound out my CR4's and I went ahead and replaced all the diodes and the resistors, as well as all the electrolytic capacitors except the big 4700uF ones. However now I'm getting approximately 16V, -16V, +6V, +16V on the four measurement points rather than -20V, -12V, +12V and +20V. Anyone know what to do now?
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