DBX 160X modifications. Advice anyone?

Hi,

I own a couple of DBX 160X's and I read about a modification to the unit involving swapping out the stock VCA with a THAT Corp VCA, and adding Jensen output transformers. Has anyone done this before? Would anyone know of the appropriate items to replace.

I think that the stock VCA is a DBX 1252(?), and I've read that a THAT 2150 would be a good replacement for that. I can't seem to find any information regarding the output transformers or suitable replacements.

Finally, would this be upgrade be worth it? I am hoping that it would give me a response that is a little more transparent and less dramatic compression artifacts, even at high compression rates.

Thank you very much for any information!

kind regards, Joel.

Bump. I have a couple of these too and would be interested in any mods. (There is a schematic in the META if anyone needs it)

My 160X has a place on the PC board for a Jensen 123-slpc output transformer, which makes it a 160XT. I had one so I stuck it in. I don't think I heard much difference, but it's now transformer-balanced on the output.

I had a couple of DBX 160X... I'm personally not a huge fan of them, and when I had mine I considered attempting some mods. But in the end I decided it wouldn't be worth the time and effort. I'd say if you like it keep it; otherwise, sell it (as I did)...

and build a GSSL or something with the money. :thumb:

I believe that the compression artefacts you refer to are much more to do with the action of the compressor as a whole - i.e. they would still be there even with a THAT corp device.

Yes, it is a "better" spec device but I think it will not do much more than improve the "technical" spec of the compressor. If this is what you want then go ahead - I think they can be pretty much dropped in.

BTW THAT corp are recommending the 2180/2181 for new designs as it offers even better specifications.

I think that the stock VCA is a DBX 1252(?), and I've read that a THAT 2150 would be a good replacement for that.

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Depends upon what sort of sound you want. The 1252 has a higher THD, but noise figures are roughly the same as the newer 2181/2180's, at least from what I've measured. Even though the THD is higher, I believe it's mostly low-order--2nd and 3rd harmonic.

I am hoping that it would give me a response that is a little more transparent and less dramatic compression artifacts, even at high compression rates.

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There are a couple of factors at play here that determine "transparency." One is the harmonic distortion of the VCA, as you may have well surmised. The other is distortion generated in the control voltage itself, and is related to the way that the level detection circuit is timed, and, if it's a DBX-type of LD circuit, the amount of biassing current it sees. If there is distortion in the CV, that distortion will be multiplied within the VCA. It then appears as pumping, hissing, and high-order artifacts. Ick.

This means that you can have a compressor whose VCA is extremely clean sounding, but still pumps and hisses when compression gets heavy. Or, it means you can have a compressor that never pumps or hisses under heavy compression settings, but still generates a pleasing harmonic distortion.

If you change the VCA out for a newer, you'll have the first type of compression. You won't really be addressing any problems that may exist in the timing circuitry. So you'll still get artifacts at high compression rates.