Another Amek Tac Scorpion overhaul!

[bluezplaya]

Hope everyone is doing alright with their Scorpions these days. I need to recalibrate my oscillator. I think it's level is out of whack a little. I want to reset it to 0VU so I can then run it through and adjust my tape machines at 1k and be dead accurate. What would be the easiest way of doing this without expensive and fully calibrated test equipment?

 

[Noisy1]

It has been a few years since I did this.... but, I think there are small trim pots accessible via a small screwdriver from the top of the monitor channel.

Turn on the slate and measure the voltage at the mains output. Adjust the oscillator/slate trim until you are outputting 1.23V. Then, adjust the VU trim to show 0VU on the console. Finally, adjust the VU on each channel to 0VU.  Now you can use the console oscillator to adjust your tape machines to 0VU (digital should hit -18 as a zero reference).

 

[bluezplaya]

Thanks! I just got it dialed in right at 1.228. I had to borrow my neighbor's high tech DMM. My little cheap DMM was not getting it, and was not reading enough decimal points. I actually used a TRS to XLR cable and plugged out of the 1/4" oscillator output and just measured the XLR at pins 2 and 3. And now to dial in my tape machines I'll use the same with the oscillator out jack to XLR.

Thanks again,
Adam

 

[critterkllr]

IIRC this is how it's done.  Won't be able to test again for a couple of months, though.
Remove C4, C28, R55, and C34  (NOTE: R55 is probably supposed to be R54, this is what I meant that the schemo has errors, all right channel components should be even numbered, IIRC).
Then, using shielded cable with shield tied to ground on one side:
Circle 1 is where you take the signal to the ACA, Circle 2 is where it comes back to the master module so it can go to the insert and fader.  Circle 3 is where it goes to the booster and Circle 4 is where it comes back again. 

The signal goes to the TAC's monitor outs after the 47R output resistor, whether or not you use the ACA-Bo, so you'll have one more IC in your monitor path with the stock version.  If you want to monitor directly (you'll lose separate level control, but some people use external CRM systems, if so, then I think it's better to skip the ICs), you can mult the ACA-bo output direct to the monitor outs, (the ACA-Bo has two connectors per output), or use the other trafo isolated output, but your monitor would be at -6dB with respect to the main out).

Did any of you successfully add the ACA-BO to your Scorpion? I've tried and had so many problems. Had the entire thing connected and it sounded like a high pass filter at 6khz and really low volume.

So I took the booster out and just kept the ACA part. Left channel is very loud, the low end is seriously lacking and some channels are randomly only going to the right or the left when centered. It's driving me crazy.

Were there any tricks to this besides just patching it in at the correct points that were pointed out earlier by Mitsos? It seemed like it was going to be such a simple thing.

 

[critterkllr]

I'm seeing that I need to change the feedback caps and resistors in the ACA section since the Scorpion uses 10k summing resistors. I will try 5.9k for resistors and 220pf for the caps.

 

[bluezplaya]

I'd like to add this to my scorpion as well.  Let me know when you get it going and how it sounds.

 

[critterkllr]

I'd like to add this to my scorpion as well.  Let me know when you get it going and how it sounds.

I'll post a sample. I have some music I'm mixing right now. I just bounced before the mod and plan to bounce again right after.

 

[bluezplaya]

I'll post a sample. I have some music I'm mixing right now. I just bounced before the mod and plan to bounce again right after.

Have you finished mixing yet? I'd love to hear an A/B comparison.

 

[bluezplaya]

Also, I forgot to ask if anyone can recommend a drop in replacement fan for the power supply that is quiet.  I need dead quiet because I will be doing some tracking here and there in my control room.

 

[critterkllr]

Have you finished mixing yet? I'd love to hear an A/B comparison.

Not yet. Keep running into things that push it back.

 

[bluezplaya]

I need to make up some more ribbon cables. A few have gone . Does anyone have a Mouser or Digikey part number for the cable and the crimp on connectors?

 

[jensenmann]

If you can still find these ribbon wires then get as much as you can because they are no more manufactured. Of course you could DIY a solution but that´d mean a ridiculous amount of more work.

 

[Eliani]

It's just single 2.54 ribbon cable. You can still get that is grey, or colored... it's the connectors that are hard to come by I think... my cabling was swapped with new wiring, but the wrong connectors at some point...

 

[critterkllr]

I started by making a few custom cables and ended up having Best-Tronics make the rest. I recall the connectors being pretty easy to find. At least, there was a modern equivalent that was easy to find. I have all of my notes on my computer at work. If you don't hear from me by Tuesday, shoot me a PM.

 

[critterkllr]

I used Canare L-2B2AT cable (3 cables per assembly). I used the shield of each to ground. I just added an extra wire if needed to each cable assembly.  The S1001 modules use all 10 pins, so you'll need to add an extra wire. S2001 and S3101 don't use all pins though, just take a look at your schematic and customize accordingly. The connector used is Molex 22-01-2105.

Here are my cable notes for the S1001 cables as well as the 3 cables used for the S4001 Master section:


S1001 Input Cable
Molex 22-01-2105 / Molex 22-01-2105
Length - 13"
Pin 1 - Signal A-1
Pin 2 - Signal A-2
Pin 3 - Ground/Sleeve A
Pin 4 - Signal B-1
Pin 5 - Signal B-2
Pin 6 - Ground/Sleeve B
Pin 7 - Ground/Sleeve C
Pin 8 - Singal C-1
Pin 9 - Signal C-2
Pin 10 - Signal C-3

S4001 Master 1
Molex 22-01-2105 / Molex 22-01-2105
Length 13”
Pin 1 - Ground/Sleeve A
Pin 2 - Signal A
Pin 3 - Ground/Sleeve B
Pin 4 - Signal B
Pin 5 - Ground/Sleeve C
Pin 6 - Signal C
Pin 7 - Ground/Sleeve D
Pin 8 - Signal D-1
Pin 9 - Signal D-2
Pin 10 - Signal D-3

S4001 Master 2
Molex 22-01-2105 / Molex 22-01-2105
Length - 16"
Pin 1 - Ground/Sleeve A
Pin 2 - Signal A
Pin 3 - Ground/Sleeve B
Pin 4 - Signal B
Pin 5 - Ground/Sleeve C
Pin 6 - Signal C
Pin 7 - Ground/Sleeve D
Pin 8 - Signal D-1
Pin 9 - Signal D-2
Pin 10 - Signal D-3

S4001 Master 3
Molex 22-01-2105 / Molex 22-01-2105
Length - 22"
Pin 1 - Signal
Pin 2 - Signal
Pin 3 - Signal
Pin 4 - Signal
Pin 5 - Signal
Pin 6 - Signal
Pin 7 - Signal
Pin 8 - Signal
Pin 9 - Signal
Pin 10 - Signal

 

[Noisy1]

You don't have to use ribbon cable. I use Mogami console wire when I need to  replace a broken cable. I often use a guitar pick on its side to push the wire into the connectors. For single broken connections on a ribbon I strip the Mogami out of its shield and just take one of the wires. Then, cut back the offending inop ribbon. Finally, just push the single Mogami into place. Works great.

 

[audiogeeks1]

The connectors are still made (by AMP I believe). You can get them at Mouser, Digikey, etc.  The ribbon is also just standard ribbon cable, but notched at the ends so there is a solid piece of insulation left after the connector.  You can use shielded cable, but the console would potentially benefit more from circuit modifications.

 

[tmuikku]

sorry offtopic, but i think people in this thread can give educated answer.

How is the mechanical structure in the scorpion, is it possible to hacksaw for example 30 channel console into a 16 channel one? Could you say it is doable or not doable?

thanks

 

[bluezplaya]

If anyone is interested in having their TAC Scorpion channels modified, you should consider GRS Systems in California. I just emailed with them and they're pricing is OUT OF THIS WORLD! Here's what Geoff quoted me:

"Thanks Adam,

The channel strip upgrade is a $525 upgrade ($7,500 special price for 16 channels) with the new mic preamp card & custom IC's, new balanced line input & output transformers and associated new line driver circuitry, new potentiometers, new switches, new upgraded capacitors with adjusted / corrected values, and with the EQ system upgrade / & quasi-parametric control modifications.

The entire upgrade is a complete upgrade package that is meant to be installed into a Scorpion I or II console that has like upgraded modifications to the master and groups, modified to work with the input channel changes and the transformer balanced line outputs. The console send / receive console circuitry is also upgraded to special balanced line output/input circuitry with new line driver IC circuitry.

The same channel modifications are available without the input & output transformers, but with new, high-speed, hi-performance IC drivers. The cost is $313, ($4,500 special price for 16 channels).

However, this is only a part of the complete console system upgrade and will not function correctly in a standard, unmodified console. We do a complete 16 input console upgrade, rebuild and restoration for $12, 797 with the transformer version; $9.797 without the input / output transformers.

These changes only work with a completely upgraded and modified console. So this is why we do not offer these services for individual channel as they will not perform correctly in an unmodified console.

I hope this is clearer. And if you have any questions about this, please let me know.

Thank you.

Best regards,

Geoff Edwards, MSEE
Audio Design Engineer
Studio Systems & Technologies"

 

[Eliani]

If anyone is interested in having their TAC Scorpion channels modified, you should consider GRS Systems in California. I just emailed with them and they're pricing is OUT OF THIS WORLD! Here's what Geoff quoted me:

"Thanks Adam,

The channel strip upgrade is a $525 upgrade ($7,500 special price for 16 channels) with the new mic preamp card & custom IC's, new balanced line input & output transformers and associated new line driver circuitry, new potentiometers, new switches, new upgraded capacitors with adjusted / corrected values, and with the EQ system upgrade / & quasi-parametric control modifications.

The entire upgrade is a complete upgrade package that is meant to be installed into a Scorpion I or II console that has like upgraded modifications to the master and groups, modified to work with the input channel changes and the transformer balanced line outputs. The console send / receive console circuitry is also upgraded to special balanced line output/input circuitry with new line driver IC circuitry.

The same channel modifications are available without the input & output transformers, but with new, high-speed, hi-performance IC drivers. The cost is $313, ($4,500 special price for 16 channels).

However, this is only a part of the complete console system upgrade and will not function correctly in a standard, unmodified console. We do a complete 16 input console upgrade, rebuild and restoration for $12, 797 with the transformer version; $9.797 without the input / output transformers.

These changes only work with a completely upgraded and modified console. So this is why we do not offer these services for individual channel as they will not perform correctly in an unmodified console.

I hope this is clearer. And if you have any questions about this, please let me know.

Thank you.

Best regards,

Geoff Edwards, MSEE
Audio Design Engineer
Studio Systems & Technologies"

That's ridiculous!! For $313 a channel I will gladly recap and re-seat some ic's!! That's just plain stupid...

$12.000 dollar for the transformer upgrade? Are those made from solid gold?!