FEELER: API style console (Toft ATB complete rebuild)

[Floti]

Yeah, that‘s the idea. I have already designed the submaster modules too, but I want to make sure the input modules work before I move forward.

 

[warpie]

Cool, I was just wondering...

Wouldn't be a better option to sell the atb and use the funds to make a frame exactly the way you want it? Just thinking out loud really

 

[Floti]

It is a possibility, of course. As I said, this just evolved from a small mod to going crazy. I‘m also thinking about building myself a full console, but I don‘t want to spend so much time with designing and doing the metalwork, plus it‘s not going to be cheap. The ATB has enough features in a small size, and that‘s really cool. If thi works, I‘ll be happy with that. But who knows, maybe in some time I end up building myself a console...

 

[qmp audio]

just checking in to see if you had any luck w/ your channel pcbs.  Did you ever get them working?

 

[Floti]

Hi! I have been REALLY busy and have had no time to move on with this project. I have an almost finished input card sitting since really long and hope I can finish and test it soon. I guess it should work, since I´ve double checked everything 10.000 times, but there´s always the stupid thing that you can´t see until it´s too late. I´ll keep my fingers crossed. I´ll surely come back here and let you know if it works once I´m done.

Also if you want to I can send you one pcb and you can try it yourself.

 

[qmp audio]

Floti,  I would be happy to do some testing!  Ill send a pm

 

[qmp audio]

Hey Floti!  I know you’re very busy.  I just wanted to mention a few things as I’m thinking about them:

1.  What is your plan to handle the XLRF on the PCB?  It doesn't seem clear to me at first glance.
2. What version of Toft to you have?  Mine is a 2.5 with direct outs added as a 1/4” output on each channel.  I know older versions did not have direct outs.
My confusion comes from the plan to route preamp outs to a db25 on the digital IO card area.  My thoughts would be to route this to each channels existing direct out jack.  Or are you already doing that somewhere else?

 

[Floti]

My toft is also a late version and has the direct outs. The preamp out doesn‘t go to the connectors on the back of the toft, you need to wire a mic cable in there and send it out through the digital card location in the chassis. My idea was to use a couple of multi cores and have all the channels half normaled on a patchbay. The patchbay would then return to the insert returns on the back of the toft. That way the insert point is balanced, and not unbalanced like in the original toft. Shouldnt you need a preamp out, you could just wire the preamp out on the pcb to the insert return, but I guess we all want to have inserts on our console...

The direct out is the output after the insert and after the second 2623 transformer. So, you have a preamp output where you can just use your preamps as preamps and send your signal balanced using a 2623 to some outboard equipment or your recorder. Then you have your insert return that goes to the fader where you can attenuate your signal or add 6db gain and then the signal can go out again through the direct output again balanced with a second 2623, exactly the same topology as an original API 528/536 card or the CAPI VP28. Before being balanced by the second transformer the signal can be sent to the buses.

Hope it makes it easier to understand.

 

[qmp audio]

Thanks!  yes, this makes your intent much clearer.    all parts have arrived,  I'm going to do some studying and start getting the pcb built up for testing.

one note:  I plan to use this CAPI pcb with INA134 for the balanced line receivers.  This way I can swap back and forth w/ a 2520 for testing,  and not have the dip8 socket installed.
http://capi-gear.com/catalog/product_info.php?cPath=71_73&products_id=435

 

[Floti]

You can of course use those pcbs from CAPI, but it would make the build more complicated. This pcb would replace the 2520, but the circuit around it would remain, and you would need to do the CMRR adjustment on the insert return and on the tape return. If you use the INAs soldered directly in my pcb you can leave out all the components that I marked with a red X on the pdf I sent you, and no adjustments would be necessary. Either way is fine, but if you are going to go with CMRR and all of that, then I would just use 2520s.

 

[Floti]

Just an updated version of the schematic.

 

[Floti]

Hi again to everyone following this post!

I´ve been working very inconsistently on this project but I´m happy to report that now I have a finished product, at least for the input boards. They are working just fine and I think they sound amazing!

They the be dropped in place of the original channel boards of the toft and basically convert your toft channels into an API 528 module with a Trident style EQ and a 325 style booster for the monitor inputs! Only two functions in the Toft are not present: I got rid of the Aux 5-6 to Mon and this switch selects now if the EQ goes PRE or POST insert. I also got rid of the Invert Line/MON switch on the preamp section to have a pad for the mic input. The insert point is now balanced unlike the original toft input. You have the choice in the board of using a simple pot or a stepped gain switch on the preamp. The costs for all the components to build a channel should be around 250-270€.

I´m working on finishing the submaster and master modules too.

Should you guys have interest on building some boards for your toft, just let me know. I don´t know yet how much they would cost, but surely not much! Write me at [email protected] for more info!

 

[Floti]

The finished board

 

[qmp audio]

Excellent work.  You know i'm in for a couple buckets.

 

[darkus]

Interested in these pcb's! Do you have plans to do busses 1-8 and master section too? The 2 bus disappointed me the most with my Toft

 

[Floti]

Hi! Sure! Both the submaster and master pcb are advanced in the design, but I wanted to have the final input pcb before moving on. The input cards are now in their final version with some add ons that would surely bring a lot to the overall sound and functionality.

 

[jawilkes84]

This is absolutely brilliant! I am very interested in replacing the Master board ASAP then gradually swapping out channels.
How close are you to a finished product ?

 

[Floti]

Hi! Thanks for the comment!
The input channel PCBs are done and they work just fine. I'm finishing the submaster modules, see  the schematic attached as pdf.

 

[Denyle Guitars]

Count me in for input channels & master, possibly group channels.

 

[Fsharpminor]

Im very interested in this as well!