MQ1 schematics

[human74]

Hi Ted, is it possible to have the schematics of joemeek mq1? I bought one on ebay but it doesn´t power on. Despite of not being a tech guy it would be a major help. Thank you for your time and attention. Hugo.

[Ted Fletcher]

I have sent the circuit diagrams to your email address.

[human74]

Uau Mr. Ted Fletcher! Thank you so much for your kindness and quick answer. Saying that you are an inspiration is something that you must be used to, but i´ll say it anyway. Thankful for your availability and for not being “industry standard”. I wish you all the best. Hugo.

(I´ve sent this message directly to your email on the 10th, but decided to post it anyway, just in case you missed it)

[human74]

Hi Ted once more. I want to rack the MQ1. It is working already, just needed some solder and tlc. What would be a correct external power supply for it. I see in the schematics 12 volt unreg., but a PC power supply is regulated, so i´m confused. Does the MQ1 regulate onboard? Could i use an unregulated 12VDC 1Amp psu? Would 1 amp be sufficient? Thank you for your time and attention. Hugo.

[Ted Fletcher]

The MQ1 has a very sophisticated regulator/power supply on-board. This power supply creates 13-0-13V for the audio and 48V for the phantom power.

So 12 volts DC at 1 amp from a regulated supply should be fine; you can try it from an unregulated 12V supply, it will not hurt anything, but a regulated supply might be best.

[human74]

Great! I ´m so impressed by your quick answers. Thank you so much.

[saxvoice78]

Hi Ted, I just found this forum and am quite interested in the MQ1 schematics. I am looking at racking my MQ1 and I would find it very useful to have a wiring diagram of the 26 way cable that connects the the front interface with the rear board. The rear board has one button to activate the +48V Phantom Power and 4 TRS sockets, plus the connector for the XLR input cable, so is it just the case of soldering each wire from the 26 way cable to a number of TRS/XLR sockets and a switch? Thanks in advance.

Regards

ANDREA

[Ted Fletcher]

Sorry to be a spoil-sport…. I’m afraid the only info have on the MQ1 is the circuit diagram, which does not help very much. I’m afraid the documentation on the interconnections got lost in one of my moves. Apologies.

If you do not have the circuit diagram, pls email me at [email protected] and I will email it back to you.

[saxvoice78]

Thanks Ted, yeah, I’d love to see the circuit diagram, I’ll drop an email to the email address you gave me. As regards the cable diagram, that’s no problem! If you look at the small PCB against a bright light you can see some kinda ‘paths’ going from the connecting pins of the cable to various places on the board, like the sockets, the switch and so on. Do you think that this is a good way to make a reasonable guess as to how the cable is wired or is it just a ridiculous idea destined to fail miserably?

[Ted Fletcher]

That’s the way I would do it!

The MQ1 was an interesting design; the audio circuitry is excellent, the problems we had in design were all to do with the power supply. There were also some screening issues….. The interference to the audio can be really bad because the audio circuitry is fitted inside the computer. Nowadays these problems are much better understood.

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