Best Opamps to replace TL072's in TAC Scorpion-II

[Matt Syson]

Hi
Get the master and aux modules recapped and cleaned first.
If your monitors are connected and not humming, don't bother balancing them.
Balancing the main outs could be good but again if you have no problem and your setup is pretty 'static' you probably don't need to do these either.
Auxes may be better balanced as it would save messing about when connecting different gear. Using a SSM2142, DRV134 or THAT1646 chip with the very small handful of components (basically 4 capacitors and a couple of resistors) would add the balance to an output. To be useful as a balanced out it MUST have a 'transformer like' characteristic where it automatically keeps the level out constant even if you short hot OR cold to ground (unbalanced). The above chips do that.
For a few extra output amplifiers you don't need to mess with the supply.
A proper power supply 'upgrade' should mean bigger heatsinks and transformer as other efforts are just 'fiddling around'.
Matt S

[jensenmann]

Manufacturer´s datasheets contain circuit examples, have a look here:
http://www.ti.com/lit/ds/sbos094a/sbos094a.pdf
http://www.analog.com/static/importe...ts/SSM2142.pdf
http://www.thatcorp.com/datashts/THA..._Datasheet.pdf

[heavyllegas]

Hi
I recently bought a tac scorpion console used.
And I would like to upgrade.

I wonder where I can buy the opamps:
BurrBrown OPA1642 fet
National LME49720NA

truth there are so many models which are not purchased

I appreciate your help
regards


moises villegas
heavyllegas@hotmail.com

[donnie7]

moises villegas,
You have a lot of work to do. The upgrade is no small thing. Your capacitors being replaced (recapped) are much more important than replacing the opamps. You can Google whatever you need. Proceed with CAUTION ! Season's Greetings.

[Samuelito]

Hi moises,

You can get them either at Digikey or at Mouser, but be aware that you'll need the adapter for the OPA1642, the .1 uf mono ceramic caps and of course a new power supply to make the board run with those IC's.

GRS will help you with this.

Or you can go to AML get the kit for the scorpion, recap both PSU and console and be happy with it.

Maybe you can upgrade U5 with LT1358's and live with same PSU.. Don't know really.

Someone else can answer this??





Sam

[heavyllegas]

Originally Posted by Samuelito

Hi moises,

You can get them either at Digikey or at Mouser, but be aware that you'll need the adapter for the OPA1642, the .1 uf mono ceramic caps and of course a new power supply to make the board run with those IC's.

GRS will help you with this.

Or you can go to AML get the kit for the scorpion, recap both PSU and console and be happy with it.

Maybe you can upgrade U5 with LT1358's and live with same PSU.. Don't know really.

Someone else can answer this??





Sam

Then I change the TL072 serve by OPA1642AID.
because I need other psu?

[heavyllegas]

The truth change the TL072's thought by eq OPA1642
TL072 fader and the LME49720NA

none of this will work?

[Samuelito]

Hi Moises,

Like Jim Williams said, the bottle neck of the channel srtips is the U1 position (preamp).

I suggest you go first to Audio Maintenance and get the preamp kit for the s1000 modules that comes with a full recap and explanation on how to upgrade the U1 position.
Recap also the s2000 et s3000 modules.
For the master fader (s4000) you can recap it and/or mod it. I sent it to Jim and he has done a great job with mine. Just think how you will be using the board... only for the preamps or are you going to be monitoring and maybe summing, through the master module.

And don't forget to recap your PSU, is the heart of your board.

This will give you time with your hands on the board and you will start understanding what you want and what you don't want to do with this console.

Good modding!!





Sam

[heavyllegas]

I want to use the console to mix songs.
then will move forward slowly with AML kits for preamps

I would also like to improve the sound console equalizer

thanks sam

[Steele]

Originally Posted by Jim Williams

Hi Donnie!

Did you try out the amps I suggested before?

Avoid OP275's in the EQ circuit as they have too much bias current and will make the frequency pots scratch. Use either a high beta opamp like the LT1352 or a fet input opamp like OP2134. OP2604's may require extra psu bypassing and prehaps some local phase margine tweaks to stabilize. I also like AD825's mounted on a Brown Dog adaptor.

I like the LT1358's in the fader amp position of the 4001 inputs. You can remove all the coupling caps in that section if you use this opamp. It's also very good in the stereo sum amp position as noise is reduced and loop gain increases for lower buss distortion and better clarity when bussing a large number of inputs.

Jim Williams
Audio Upgrades

Yea, listen to Jim. I've always upgraded my gear and jim is one of my references. With my Scorpion II I went thru everything. One thing different, I put LME49720's in U5. No more caps.

[heavyllegas]

Originally Posted by Jim Williams

I believe AML has sub boards for replacing the SSM2015 chip. In recent years new devices have been released that would be a fine addition to the Scorpion.

In the stereo sum stage of the 4000 module I use the National LME49720NA. That is a very low noise opamp with huge open loop gain at 10k hz. That will clean up a stereo mix quite well. Coupling caps can be yanked out, those are precision devices.

In the S1000/1001 inputs, the new BurrBrown OPA1642 fet opamp is a winner in the EQ section, very low bias current (no pot scratch) and very low 5 nv noise. Use LME49720 for the fader amp and remove all the el caps there.

good afternoon

My last question:
-The LME49720 NA in U5 not need upgrade PSU?
-What amp could replace the TL072 (U2, U3, U4). not requiring upgrade psu?
-What brand of OPAmps would have to buy? (texas Instruments or other brand)


Thank you very much.