HDX 192 "-10" analog inputs - ok for use 'alternate +4 inputs ?

[sbarncar]

I want to use the so-called -10 inputs on my 192 for a second tape machine that puts out +4 levels.

In the circuitry of the -10 inputs, is there anything different than the primary inputs, like more amplification before or after the trimmer?

Or are both input circuits the same, with only a trimmer factory calibrated for -10 signals and I could go ahead and use them for +4 with no worry about overload?

I would love to see at least a signal flow diagram of the 192 to confirm.


( I see I need to update my specs - now running PT HDX 12 on High Sierra )

[JFreak]

levels may be a bit hot but no harm in trying

[sbarncar]

Originally Posted by JFreak

levels may be a bit hot but no harm in trying

Thank you but I need more detail. I know it will 'work' but I really need to know if the hardware is the same path and it's just a switch selection and gain control or there's another stage of amplification involved in the -10 circuits.

If I were designing the input stages I would make them the same and use the trimmers to determine the gain structure at the factory for the two inputs.

This would make possible not having to switch cables when sourcing from two different tape machines.

[Darryl Ramm]

Come on. The box is in front of you right? Just try it.

Actually switching between -10/+4 inputs should give you a clue what is happening.

You could pull out an AD I/O card and look at it, the circuit should be (is) obvious.

[sbarncar]

Originally Posted by Darryl Ramm

Come on. The box is in front of you right? Just try it.

Actually switching between -10/+4 inputs should give you a clue what is happening.

You could pull out an AD I/O card and look at it, the circuit should be obvious.

Well I had expectations that a carefully worded post would get a more informed answer than "Come On - The box is in front of you right? Just Try it".

Do I really have to pull out test gear and probes to see at what stage the board might be clipping? I am not allowed a schematic let alone a block diagram so tracing a multi-layer board might be impossible, not to mention the stuff I might be looking for would buried deep in LSI.

once again:
I just need to know if the input circuitry on the -10 includes amplification after the input connector and BEFORE the trimmer or is it identical to the other inputs?

Why do I need to know this? I wish to use the A/B switching to select between two separate tape machines without having to go behind the rack and switch DB-25s.
if the sections are actually the same, then I can do what I wanted to do, and just adjust the trimmers and ignore the -10 designation. If there is additional amplification , then I can't and I can accept that. I am not at my workstation at the moment and am designing an installation and need to know.

This is my first post in this forum since 2013, and I was hoping for a real answer, not confrontation for my very reasonable query.

I'll wait here for someone (perhaps one of the actual designers) that actually knows the answer to my simple question.

[Darryl Ramm]

You need to stop expecting to be babied here. And as you described yourself as technical and worried about some circuit detail that nobody else cares about I'm really lost why you don't just look yourself.

Other users here just don't care about the circuit, and nobody except authorized repair centers are likely to have a circuit diagram they can just paste here or reference for you.

You don't need any test gear. You need a screwdriver. Just pull out the AD card and have a look. What are the eight big white block thingies staring you in the face. What to they do in the circuit? What's the buffer stages in front of those look like?

The designers? Of the HD I/O? They left Avid a long time ago, and Avid employees generally don't hang out here... it's a user forum.

[JFreak]

no-one is hostile here, but it's like give a guy a fish and he lives for one day and teach him to fish and he lives for years kind a thing...

[sbarncar]

So this forum is basically useless. More like a boy's club.

I don't need these insults. You guys could have handled this better. Thanks for nothing.

Again I've never seen such hostility in a forum that's supposed to help people. This is more like USENET. I'll just ask a real installer or professional.

[Darryl Ramm]

Jeez you still have not just gone and looked? Phillips screwdriver. Turn screws anti-clockwise. How else can we help you?

I would have popped out an IO card if I had a box sitting in front of me.

But this is just an 192, costs a few hundred dollars, if you have spare DigiLink capacity just grab another used 192 interface and get more inputs at whatever level you want done properly. So I'm are a loss why you are even wanting to do this, let alone getting childishly upset about what you expect other people should be doing for you.

[JFreak]

No-one is hostile here but if you really think you get tech support online same day I don't know what you're thinking...