Sony MX-20 discrete mixer interesting bass loss

[lawsonfeltman]

Hey y'all, I have an interesting issue and I wonder if you could shine some light...

So I picked up this rad little 8X4 mixer for a great deal, and I was thinking I'll use it to make drum busses and and other combo busses.

The interesting issue is that all 4 XLR buss outputs have an extremely treble-heavy sound with absolutely no bass at all. My initial thought was caps gone bad...

I have opened her up for a look inside, and it's quite beautiful point to point construction. To get a look at the XLR outs would require a complete disassembly, removing 24+ pots, etc, which I don't really want to get into...

but, the good news is that I can take the bus outputs from the RCA jacks and get nice beefy full sound... So for the time being I'm using the unbalanced outputs.

Just curious as to why the balanced XLR outs are so tinny sounding in comparison.

Do you think it's a capacitor issue?

 

[bouldersoundguy]

Is the device you're connecting it to balanced or unbalanced? If it's all four and the sound is degraded in the same way I would suspect something common to all of them, like a power supply problem or your cabling configuration.

 

[lawsonfeltman]

Is the device you're connecting it to balanced or unbalanced? If it's all four and the sound is degraded in the same way I would suspect something common to all of them, like a power supply problem or your cabling configuration.

I had been plugging into a Tascam 388 with a balanced XLR-TRS cable from the MX-20... Your question led me to double check the 388 manual and sure enough the 1/4" line inputs are unbalanced. I'm going to try XLR-XLR into the Mic input on the 388 because the manual says it'll handle both mics and balanced lines. I'll let you know if that works.

As far as the power supply, knock on wood everything has been a ok thus far.

Thanks for your idea

 

[delfman]

hello...i also own a sony mx20...do you happen to have the manual or better yet the service manual??? i would like to get this thing up and running, thanks

 

[The Ghost of FM]

hello...i also own a sony mx20...do you happen to have the manual or better yet the service manual??? i would like to get this thing up and running, thanks

The member you're quoting has 7 posts here and hasn't posted in over 6 months. Odds are he's not still visiting this forum to answer your question.

There is this on-line,

Sony MX-20 Service Manual, Analog Alley Manuals

... though its 15 bucks to download it. Short of an ebay hunt, I doubt you'll find much else.

luck.



Cheers!

 

[The Ghost of FM]

Is the device you're connecting it to balanced or unbalanced? If it's all four and the sound is degraded in the same way I would suspect something common to all of them, like a power supply problem or your cabling configuration.

I'd suspect an impedance mismatch as to why the bass it all gone on the op's Sony unit. Sony has made some weird-ass mics over the years and that mixer was likely made to accommodate those mics in particular. So, there's likely nothing wrong with his mixer beyond its engineered design.



Cheers!

 

[bouldersoundguy]

Yeah, it's just about old enough.