Cooper CS106/108+1 mod

[Jim Gilchrist]

My friend and neighbor Evan Mater has come up with a balanced line level post-eq, pre-fader direct output mod for Cooper 106+1 and 108+1 mixers.

The mod replaces one of the op-amps on each channel strip, replacing that with a more modern device. It consists of a small board that is soldered to the main channel strip board in place of the old component. The original unbalanced post-fader channel direct output 1/4" TS connector is replaced by a TRS connector. The effects I/O loop isn't used for this mod. The output level is fixed, but you can specify a level when the mod is done. Channel strips are removable as if they were stock thanks to Andy Cooper's original design.  I've seen the first boards Evan's done and the mod is very elegant.

I plan to get my 106+1 done later this summer.

Best regards,

Jim

[studiomprd]

and the cost per module is

[Jim Gilchrist]

If I understand this correctly your friend Evan is 'converting' the "insert" output, which from Cooper is a post fader and eq output with a TS (Tip and Sleeve) connector, to a pre fader post eq output utilizing a TRS (Tip Ring Sleeve) connector.  

If that's correct then you would end up with two TRS outputs from your Cooper, one pre fader and eq, and the other pre fader post eq.

Personally I enjoy the flexibility of my Cooper to be able to send playback to the PA via the "insert" output and ny utilizing the "out" line output I can continue to send it to my recorder after I've killed the playback to the speakers, say in the situation where a 'thumper' is involved in a scene.  If I had this modification done, I would lose the ability to work in that manner.

This also dredges up the conversation of your iso tracks being eq'd or not eq'd.  As I've spoken about many times before I'm of the opinion your iso tracks should be unaffected by the production mixer, this in order to allow the post production folks the full spectrum of your original recording to deal with, and not your eq'd track.

Again the argument is that if your iso track contained the same eq as your 'mixed' tracks then they would cut in seamlessly, while true in theory, if there is that much of a difference in eq'd quality between your mixed track and the iso track I believe there's a bigger problem.  I believe that when your mixed tracks are played in conjunction with your iso tracks of the same mic, the differences should be subtle, not grossly obvious.

Always nice to have options and I'm not saying this modification wouldn't be of value to some, just not to me.

Look before you leap,

RVD

Richard,

No conversion is involved. A new circuit is added to each channel strip. The TS post fader channel direct output was removed on the first board Evan did. It was replaced with a TRS connector per the user's wishes.

You can specify that the output is post-eq or pre-eq if you like. He's not converting the effects I/O loop, it remains undisturbed. A component on each channel strip that is of an obsolete design and phase reverses when clipped is replaced with a more modern device, and a second balanced output is created. You can choose to maintain both the channel direct output and the effects loop if you choose, and route these new prefader direct outputs to the pair of 7 pin Touchels if you like, though I would guess it will cost more to do so. The design of the board does allow for this.

What the mod does is give you a pre-fader output that is both balanced and hotter than the pre-fader output you can get by bridging the effects loop, which is about 20 dB lower than the mains output and unbalanced as well.

Since Evan is the guy Andy refers folks to for repairs and modifications on the East Coast, is the US distributor for Audio, Ltd and a good friend I don't feel the need to look before I leap.

Best regards,

Jim

Edit was to sign the post!

[Jim Gilchrist]

and the cost per module is

Can't resist:

Contact the manufacturer: http://www.varkaudio.com/contact-us.htm

Seriously. I don't know. Evan mentioned a number, but I don't recall. But I do remember it was reasonable.

Best regards,

Jim

[studiomprd]

while I strongly suspected it was the same "Evan", until you cleared that up, I was not certain exactly who to contact.

and my own advice applies here, especially as there are options to discuss..which would affect the actual pricing.

[Jim Gilchrist]

Richard,

The insert circuit remains stock. The channel direct output is still on the board, but on the first mixer modified, the owner chose to replace the connector for that output when he had the mod done with the new balanced prefader output. Speaking for myself, I'm planning to get the mod done as follows:

1.) Add the new circuit board to each channel strip that creates the balanced line level prefader output. I plan to have the board fabricated to create that output at about 4 dB below the level that it would be at the console mains. I'm on the fence regarding pre or post-eq, although I've been told it's my choice I'm unsure if that's possible to go pre-eq without some custom work.

2.) Have the additional op-amps in the eq circuits updated.

3.) Route the new balanced prefader outputs to a TRS connector that would replace the TS connector for the postfader channel direct outputs that are stock on the console.

4.) Reroute those postfader channel direct outputs to the mono Nagra 7 pin Tuschel connector since I use them quite a bit for playback situations like the one you outlined earlier, for a talent cue situation, etc. It's a fairly simple matter to built a little breakout box to have the individual postfader channel direct outputs available from the 7 pin Tuschel and it's also work I'm capable of doing myself. Since I no longer own a recorder capable of using the functions built into that connection, I plan to disable them in favor of the versatility the change I propose offers.

As I recall, you've got a 108 so this scheme might not fit what you need but I'm also still coming up with what will work for me. What appeals to me is getting out of the in-between level available as a prefader output by bridging the insert I/O, which is typically about 20 to 22 dB below the mains output for a single channel. That will get me away from using the mic preamps on a firewire interface that I can afford (incidentally also the one I own), along with a bunch of residual noise, grounding issues and so on.

Two things to note are that a channel strip with this mod will work when put into any other 106 or 108 (and both the insert loop and postfader channel direct out will be available) and a channel strip without this mod will work in a mixer with the mod (other than the modified output connection for the balanced prefader out that replaces the unbalanced post fader connector on a stock mixer). I'm getting confused myself but there is no change to the capabilities of the channel strip, an additional output is added. Andy provided for a number of extra connections between each channel strip and the mixer in his original design, a feature I'm now glad to have paid for in my original purchase.

When Evan spoke with Andy before he began designing the mod, Andy pointed out that the architecture of the 208 had the prefader channel direct post-EQ so it was assumed that 106 and 108 users would want that since that's what Andy was urged to do when he added the prefader balanced output mod for the 208 by the owners of those mixers.

I've gone on too long with this reply, but having spoken with Evan recently, your point is well-taken and on the next batch of boards, a jumper will be added to convert the new balanced output from pre-eq to post-eq rather than as a custom option for pre-eq.

I've also been told that the mod is $175.00 per channel strip plus shipping and any custom options you might require.

With warm regards,

Jim

[David Waelder]

Andy provided for a number of extra connections between each channel strip and the mixer in his original design, a feature I'm now glad to have paid for in my original purchase.

It is a marvelously adaptable piece of gear.

As a sidebar, I note that I've been feeding two recorders out of the Nagra tuchels for some time now. There are a number of pins that are not used and available for other schemes. I first had Neil Stone wire up a line out to the tuchels so I could feed my PD4 along with a Nagra. Then, when everything switched over to hard drive recorders, I had the feed to the Nagra redone to provide standard line level. (Regrettably, Neil was no longer available but LSC accomplished the task for me.)

One does need a routing box to send the appropriate signals to each connected recorder but that's a minor expense balanced against having the side of the mixer free of connection clutter and also having the regular line outs available for another purpose.

David Waelder

[Jim Gilchrist]

It is a marvelously adaptable piece of gear.

As a sidebar, I note that I've been feeding two recorders out of the Nagra tuchels for some time now. There are a number of pins that are not used and available for other schemes. I first had Neil Stone wire up a line out to the tuchels so I could feed my PD4 along with a Nagra. Then, when everything switched over to hard drive recorders, I had the feed to the Nagra redone to provide standard line level. (Regrettably, Neil was no longer available but LSC accomplished the task for me.)

One does need a routing box to send the appropriate signals to each connected recorder but that's a minor expense balanced against having the side of the mixer free of connection clutter and also having the regular line outs available for another purpose.

David Waelder

Future-proofed to an extent I've only just begun to appreciate.

Best regards,

Jim