Shaker Desk - A/B Path Vinyl Mastering Console

[Gold]

I'm in year 12 of this build. It wasn't really a console until recently. Shaker Desk is an A/B Path console for mastering directly from open reel tape to lacquer master.  A record is a single spiral from the outside to the inside of a disc. It must be recorded in a single pass as there is no way to drop in or edit. This means that to have different settings for each song on the side you either have to change settings in the time between songs or have a separate setup. This is the purpose of an A/B path console. You can set up the A half for song 1 and the B half for song 2. When you get to song 2 you change to the B half of the console. Then you set up the A half of the console for song 3. You flip flop this way until the side is done.

The lathe automation needs to see the signal about one revolution before it gets cut. This is called the Preview Path. The signal that gets cut is called the Modulation path. This means each half is four channels. Modulation Left/Right and Preview Left/Right. Although it looks like a two channel console it is actually eight channels except for the monitoring and meters.

I've been posting the individual pieces in the appropriate sections. Until now it hasn't really been a console. Now as I'm closing in upon completion I figured I'd start this thread.

I spent the last couple of days installing the processing chain in the B half of the console and working out some kinks. I spent today listening and playing with it. I officially pronounce it a console.

The signal path for both the A and B halves are the same. Input Amplifier with source select, level adjust and process insert chain.
The process insert chain is TFEQ(Igor Sontec), Pico Compressor, Barry Porter EQ, DAOC, Maselec MLA3.
The process chain is inserted in the transfer path. The transfer path is Input Amplifier with Maselec MDS2 HF limiter permanently inserted. HPF/LPF, Elliptical EQ, Output Amplifier with level adjusters and a fader.

The Output Amplifiers feed the crossfader which can select either A, B, or Crossfade.

The monitor controller is made of two Broadcast Tools 16x2 relay switchers. One switcher is for the Modulation Path and the other is for the Preview Path. I can monitor directly from any source. Directly of the DAW D/A, 1/4" or 1/2" tape machines and two Aux positions.

I can monitor after the input amplifier for a level adjusted version of the source. I wired the Input Amplifier so that the Monitor signal is picked off before the HFL Insert and the Process Chain Insert.

You can monitor after each Output Amplifier and you can monitor after the Crossfader as the Main Out.

There is also a lathe remote.

This is the Processing Chain.

This is final face plate for the TFEQ. The BPEQ needs a final faceplate. I need to redo the center section face plates. The HPF/LPF will be removed. It is Neumann HT75's that are on their last legs. I'm going to do a stripped down HPF/LPF with only 40Hz-18dB/Oct and 16K Hz-18/dB/oct. I will locate the PCB's inside the EE chassis below it. That will open up 2RU for future expansion.

The meter panel will be redone. I've decided to use giant Weston VU meters and an RTW plasma PPM.

I spent the last couple of days installing the Processing Chain and working out the kinks. Today I got to really listen and play. It's everything I had hoped for. I'm quite pleased with the sound and functionality.

 

[ruffrecords]

Excellent project. Well done.

Cheers

Ian

 

[emrr]

So great to see this finished. 

 

[Gold]

It goes without saying that this project wouldn’t have been possible without GroupDIY. My eternal gratitude to everyone who has helped me along the way.

 

[mjrippe]

Congratulations, Paul!  I would love to come by again and see the finished product.

 

[Gold]

Congratulations, Paul!  I would love to come by again and see the finished product.

Thanks! I’m shooting for the end of June to have it complete. It might be a little optimistic but not too far off.

You are welcome to stop by and check it out though.  Invite yourself over.

I’m not going to be throwing a party as I have no way to lock down the space. If anyone wants to check it out let me know. I’m happy to show it off.

 

[Rocinante]

Wow. If you don't mind where is the Pico, and why did you pick that compressor?  (Not that there is anything wrong with it, I am just curious.

 

[Gold]

Wow. If you don't mind where is the Pico, and why did you pick that compressor?  (Not that there is anything wrong with it, I am just curious.

The Pico is the single rack space unit in the top position on the bridge. The other one is on the other side of the console.

Those were the first things to get done. They have been done for years. Although they will get new faceplates.

I wanted a clean compressor and the Pico fit the bill. The way I built it is that it’s permanently in variable attack and release mode. The controls from left to right are Attack, Release, Ratio, Threshold.

This was planned out 12 years ago. There weren’t as many projects around. I’ve never regretted my choices. A THAT VCA compressor is what I would choose today.

Same with the DAOC. It’s a one trick pony but I need that trick.

 

[Rocinante]

One last question (because I trust your opinion) are there striking differences between the Igor Sontec and Barry Porter? Do you use them both or one more than the other?

 

[Gold]

are there striking differences between the Igor Sontec and Barry Porter? Do you use them both or one more than the other?

They sound different from each other. They are both what I would consider clean. No strong character just passing through the box.

The Igor Sontec was built using polystyrene caps and the Fred Forssell 993 FET  DOA’s.  I describe the sound as Yacht Rock. Kind of a soft focus sound. It is meant to replace the Quad Eight EQ’s I currently use for broad soft sound. It sounds softer than a real Sontec. A real Sontec has some bite to it.

The Barry Porter is M/S only. I’m using the first generation Kirkwood M/S boards as the I/O. That’s one major difference to a stock build.  The other thing about my Barry Porter is that I used C0G ceramics in the tuning circuits. I tried some PP caps which I imagine most use. They sounded good but the C0G’s have a unique thing going on. I guess subtle but significant  to me. I really like them. The opamps in the  SVF made a big difference in the sound as well.  Those were carefully chiosen. The opamps in the tuning circuits of the Igor Sontec didn’t make much of a difference.  The summing amp had a major influence in the sound though.

I’m just getting this up and running. I  haven’t explored them yet.  It’s a chicken and egg issue. You have to have something built to be able to evaluate it and find strengths and weaknesses. Now I can get down to some serious listening. I’m sure I’ll have to develop new techniques with the new equipment. I’ve been using basically the same rig for close to 20 years. I won’t use the new rig until I feel comfortable with it. If I have to think about the equipment when I’m working I’m starting out behind the eight ball.  That’s to be avoided at all costs.

The  Igor Sontec  can have a much wider bandwidth than the BPEQ. The BPEQ is the more surgical and the Sontec is more broad generally speaking.

There will be a third EQ. A four band shelving EQ. I haven’t figured out what that’s going to be yet.

 

[Winston OBoogie]

This is really great to see Paul    Must've been an almost unbelievable amount of graft involved to get here... But she's a console alright!

Thanks for documenting & posting

 

[Squeaky]

Great to see your work and inspiring!

 

[Gold]

This is really great to see Paul    Must've been an almost unbelievable amount of graft involved to get here... But she's a console alright!

Thanks for documenting & posting

It makes no financial sense to build this. It was tremendously expensive no matter how you count. I include the shop in the expense because the shop was built  to make the console.  I couldn’t get anywhere near what it cost to make out of it.  The hourly rate will go up though.  I will enjoy working on it which is also important.

It is the most elaborate A/B path console ever built AFAIK. The Grundman consoles don’t have as many processing choices or separate HFL’s or a bunch of other stuff .

 

[boji]

Wow, just wow!!!!  Thank you for sharing Gold. Love it. 100% bespoke-looking.  Each piece likey deserves its own breakdown.
If you ever have to pull one for service, please take some inside shots for us and add it to this thread?

Thanks again, super inspiring!

 

[Gold]

If you ever have to pull one for service, please take some inside shots for us and add it to this thread?

Here  you go
https://groupdiy.com/index.php?topic=27972.760

https://groupdiy.com/index.php?topic=26585.1500

I can post some pictures of  the Input and Output Amplifiers and the monitor controller

 

[boji]

Awesome. Thank you! Please, post as much as you care to! 

It is the most elaborate A/B path console ever built AFAIK

I don't doubt it.  Many questions.

 

[Gold]

Here are some shots of one of the Output Amplifiers. Both the Input and Output amplifiers use JLM DiNGO boards. They are a Line receiver and a Line Driver with adjustable gain. There is a 5K bridged T Shallco attenuator between the receiver and driver. +/- 11dB in 0.5dB steps. The fader is a TKD 2500. I had P&G RF-15's as the fader before this. The RF-15's had significant and varying series resistance when at the top of the throw. One deck had 200Ω series resistance at the top of the throw. Unacceptable! The inputs are AC coupled and the outputs are DC coupled.

 

[Gold]

This is the Monitor Controller. It has a full H pad attenuator with a 10K input impedance and a 5K output impedance. It's 12 decks.
It controls two Broadcast Tools 16x2 relay switchers for source select. The monitor is either passive or can switch over to a Wayne Kirkwood M/S board for various flavors of Mono and M/S.

 

[boji]

Holy smokes those stacked rotary switches!!!   

Excited to see your use of din rail gear too... I never seen it before in diy audio and always wondered...why not?

Happy you decided to share your amazing work.  Thank you!

 

[Gold]

Here is an Input Amplifier installed. Everything can be pulled from the rack with audio and power connected. The Input Amplifier is the same as the Output Amplifier except it has Source Select instead of a fader. It also has the relays for the Process Chain Insert.