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Shadow Hills Mono Optograph Calibraiton Help!
Old 1st November 2014
  #1
Here for the gear
 

Shadow Hills Mono Optograph Calibraiton Help!

I ended up getting 2 optographs from VK and one of the ones meters was off and ended up replacing it with a new one. I'm noticing now on the new one the compression ratios seem lower than on the other one. Does ANYONE have definitive instructions on how to calibrate these things??? Sometimes I will be running stereo into both channels and am chaining them to the dual vandergraph so I need to calibrate the mono optographs so that they match...Any help would be awesome!!
Old 1st November 2014
  #2
Gear Nut
Could you be more specific what the symptom is? Like what does it mean that the ratios sound lower?

To start, without knowing exactly what you mean, a good test is always to run a sine via two identical in the box sends to both channels (so the level will be the same coming out of the D/A). Now take two input channels in the DAW and set their inputs to the outputs of the two comps. Set all settings to the same on both comps.

Ideally if the comps are the same as far as component tolerances, the same level of signal should be coming out of each because the same level is going in. If the levels coming out are not the same then you know further investigation will be necessary.
Old 1st November 2014
  #3
Here for the gear
 

Hi,
To clarify, the signals are off. I have done some testing in the DAW as well. Both match up in Bypass, but the difference is in the compression itself. The onset of compression seems to happen much sooner on the first one where I have to turn up the compression dial on the second one pretty high to match the signal and compression and to match up on the VU Meters. There is an audible difference, for instance the compression is tighter on the first one at say 5 clicks where it may take 20 on the second one. I'm assuming these just need to be calibrated to match. Also with the new one with no signal the VU meter sits below 0 slightly but before the red 1. On the dual vandergraph and other mono optograph the needs sits on 0 where it should be. I read that it takes time to sit in, but i've let this run now and think there are some other steps that I probably need to take to calibrate the new optograph. I sent an email to shadow hills hoping for some assistance as well.
Old 1st November 2014
  #4
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nickelironsteel's Avatar
 

Send em back as for a calibrated pair done
Old 2nd November 2014
  #5
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Surely, there is a way I can calibrate these myself w/o having to send these both back. Just baffling the inconsistencies. Is this typical?
Old 2nd November 2014
  #6
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hasbeen's Avatar
Quote:
Originally Posted by The_Engineer View Post
I sent an email to shadow hills hoping for some assistance as well.
Marshall at SH is pretty quick with a response from my experience. Plus he is super detailed with info. I could never type that much in an email without great difficulty. Good luck.
Old 2nd November 2014
  #7
Gear Nut
Unfortunately, sometimes the tolerances on components are just not that tight, and you end up with units where by chance the values are at opposite ends of the allowed variation. Reading your more detailed explaination, it happened to me in the exact same fashion on my pair of Slate Dragons. It's basically impossible to use them for stereo work due to how they handle stereo sidechains - instead of picking one it's designed for true stereo detection where both units feed eachother control voltage - ordinarily a great advantage. But due to this, because Dragons behave in highly nonlinear fashions, and because they have so many interacting controls that are themselves somewhat nonlinear, I can't use them for stereo compression much at all.

However, you're in a more favorable position because S. Hills is so highly regarded, puts together such quality gear, and takes care of their customers, so the chances that they can help you are higher. This isn't to talk poorly of Slate Pro Audio, it's just a recognition that there's a difference in price and associated levels of service between the two companies. And that's fine, that's how markets work. So good luck, I hope the folks at S. Hills can help you out, as its a frustrating problem to have!

It works out okay though because it prompted me to decide to buy a proper stereo bus comp, and what slut doesn't enjoy buying more gear?
Old 2nd November 2014
  #8
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Quote:
Originally Posted by hasbeen View Post
Marshall at SH is pretty quick with a response from my experience. Plus he is super detailed with info. I could never type that much in an email without great difficulty. Good luck.
Marshall is the man! It wouldn't suprise me if you had to send it back in. Those 500 series comps from SH have 4 or 5 layers of board in there. I'm assuming they're intended to be built and disassembled in a specific order. I'd triple check with SH before diving into anything.
Old 2nd November 2014
  #9
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Just amazes me how off these 2 are from each other. I actually have the Dual Vandergraph also which is great, but I noticed going into the mono's first chained into the vandergraph gives some great compression and sounds. The last mono's I had were matching so this wasn't a problem, but there was a problem with one of the matching pairs, VU meter or opamp problem so sent it back for a replacement and now things are mismatched. What's annoying is I've sent several emails to SH w/o response, so will deal with Vintage King on getting some sort of answers. The most annoying thing is I'm in Austin, and SH is just right down the road! Tempted to drive these things up to their front door!
Old 2nd November 2014
  #10
Gear Guru
 
kafka's Avatar
I'd go ahead and do that, if I were you. One of them probably has an issue, if they're that far out.
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