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Project Specific Discussions => Preamplifiers => Topic started by: promixe on July 16, 2011, 11:25:25 AM

Title: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: promixe on July 16, 2011, 11:25:25 AM
For 2012-13 updates on this project please visit my site! (http://diy.innersonix.com/)

For build/support thread on GroupDIY click HERE (http://www.groupdiy.com/index.php?topic=48695.0)

For a mini-diary of the R&D process click HERE (http://www.groupdiy.com/index.php?topic=42471.0)



Hi All,

I just finished doing preliminary testing on my THATDIP Lucidity Preamp PCB (http://diy.innersonix.com/shop/lucidity-preamp) and it seems to work great. Next step is to plug a mic in and LISTEN. =)

UPDATE: Just plugged a mic in and tested the preamp on vocals - wow... I'm actually very impressed, after having worked with Prism, Grace, Lavry stuff, this sounds damn clean, yet not "sterile" i.e. unmusical - paired to a cheap dynamic mic (Audix OM-3xb is what I immediately had access to, serious condenser testing is ahead =)

(http://diy.innersonix.com/external/innersonix_initial_lucidity_preamp_prototype.jpg)

The board features my THATDIP adapter (http://www.groupdiy.com/index.php?topic=42471.0) that utilizes THAT1570 & THAT5171 digitally controlled preamp chipset (http://thatcorp.com/1570-5171_Digital_Mic_Preamp.shtml). The board also features flexible output stage making it possible to do either balanced or single-ended out. The PCBs are very tiny - 147x36mm (1.4"x5.8") so it's easy to fit 8 of them in 1RU.

(http://diy.innersonix.com/external/innersonix_that1570_that_5171_pga2500_adapters.jpg)

I will be preparing documentation (http://diy.innersonix.com/support/documentation/lucidity-preamp) to get people started with this project. Up to 8 channels can be controlled via a single front panel controller (http://diy.innersonix.com/shop/umpc-front-panel). I have a few pilot-run PCBs for both the preamp and the controller if someone is interested.

I'm also working on a MIDI controller board (http://diy.innersonix.com/shop/umpc-midi) for the project to emulate Digidesign PRE if hooked up into Pro Tools. Also I may be making a digitally controlled minimal compressor to be inserted past the preamps - ideal for mobile recording workflow.

Is there any interest in the project? =)
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Pre [PICS]
Post by: Ptownkid on July 16, 2011, 12:30:10 PM
Radness!!!
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Pre [PICS]
Post by: spreemusik on July 16, 2011, 02:29:54 PM
How far can the controller and the preamps be apart?
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Pre [PICS]
Post by: promixe on July 16, 2011, 02:40:20 PM
How far can the controller and the preamps be apart?

I haven't tested max length yet, but the SPI bus works at 8Mhz = 125ns clock cycle. Generically speaking it's 1 ft per 1ns...
Having said that, this particular controller was designed for FRONT PANEL control (http://diy.innersonix.com/shop/umpc-front-panel) and assumed it will be in the same chassis with preamp boards (http://diy.innersonix.com/shop/lucidity-preamp). If you need a REMOTE controller it is better to use something like RS-485 over twisted pair or similar. Then we're talking 100+ ft easily done. I'm going to investigate if I can do a simple SPI to RS-485 board for this project specifically for remote use.
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Pre [PICS]
Post by: Peterson Goodwyn on July 16, 2011, 04:00:12 PM
Whoah! Awesome. I am just finishing up an 8-channel rack of MCS' 1512-based boards and I was likewise impressed by their musicality. Might embark on a rack of these next...
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Pre [PICS]
Post by: spreemusik on July 17, 2011, 04:52:25 AM
If you need a REMOTE controller it is better to use something like RS-485 over twisted pair or similar. Then we're talking 100+ ft easily done. I'm going to investigate if I can do a simple SPI to RS-485 board for this project specifically for remote use.
Yes, I really need a remote controller, and a rack of 8 pres in the piano room. That's about 20m (65ft?) of cable, so MIDI won't cut it. RS-485 sounds good.  I suppose, given a bit of time, I could devise my own controller.
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Pre [PICS]
Post by: nielsk on July 17, 2011, 08:22:02 AM
If it could use the same protocol as the Aphex 1788RC then one could use the Aphex remote (a great unit and not very expensive) and go 1,000 feet over CAT5 or +1kM over fiber w/ converters.
One could also use the free software to control using a PC...http://www.aphex.com/1788A_downloads.htm (http://www.aphex.com/1788A_downloads.htm)
As the system started using MIDI, I suspect the data protocol is based on the same format, & the basic configuration is 8x8 (8 banks of 8 channel units)
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Pre [PICS]
Post by: promixe on July 17, 2011, 11:34:30 AM
If it could use the same protocol as the Aphex 1788RC

I initially thought of using Digidesign PRE OR Aphex 1788 MIDI format, switchable. It would basically emulate either unit MIDI message wise, receive their commands, translate to SPI, my front panel controller (http://diy.innersonix.com/shop/umpc-front-panel) would grab it and talk to the actual preamps (http://diy.innersonix.com/shop/lucidity-preamp). If front panel settings are modified, send SPI to MIDI board (http://diy.innersonix.com/shop/umpc-midi), the MIDI board translates to either Aphex or PRE MIDI message and sends it out... Kind of like that.

But the initial idea was to control these preamps via Ethernet (http://diy.innersonix.com/designs/oscar) with anything that has a HTML5 compatible browser (i.e. iPad, laptop, etc.)

(http://diy.innersonix.com/external/innersonix_umpc_web_interface_prototype.jpg)

You would basically connect the preamp to your LAN (http://diy.innersonix.com/designs/oscar), it would use Bonjour to set up itself and find other units and have unified interface (kind of like above) for, say, 64 channels of clean goodness. =)
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Pre [PICS]
Post by: promixe on July 17, 2011, 02:49:19 PM
Aphex remote (a great unit and not very expensive)

It is a good unit, BUT $1299 seems a bit steep for me personally, compared to the DIY nature of the project it would control... Then its protocol would need to be reverse-engineered, which assumes I'd have to obtain a unit somehow. =) Therefore I am interested in making my own version of DIY RCU (http://diy.innersonix.com/designs/oscar) for these preamps, then it would be a sub-$300-400 remote, much more affordable, with similar features, and a lot of time would be saved by just implementing my own protocol to suit what I have already coded for the front panel controller (http://diy.innersonix.com/shop/lucidity-preamp) (picture below).

(http://diy.innersonix.com/external/innersonix_initial_umpc_prototype.jpg)

I don't know availability of which additional PCB (MIDI (http://diy.innersonix.com/shop/umpc-midi), Remote, PSU (http://diy.innersonix.com/shop/umpc-psu-v1), Metering, Compressor) would make this project more desirable for people to undertake. Also, there is a lot to think about in terms of how to interconnect everything (the logical part of it, i.e. what is master/slave at what level, etc.).

=)
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: radardoug on July 17, 2011, 04:38:00 PM
Very cool project! One thing to bear in mind, you can convert MIDI to RS485 very easily, you just have to put the signal through an RS485 interface chip at each end. Tie the chips so they only transmit or receive as appropriate at each end. It all runs off 5 volts which you could steal at each end.
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: Joelv on July 17, 2011, 10:05:11 PM
Awesome! I'm interested in 8 units for sure, possibly more. Any idea on when these will be available?
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: 12volts on July 19, 2011, 03:45:11 PM
I'm thrilled with this design/implementation. I'll have 8 boards (PGA2500) and a controller when they are available, just for starters.
Have  an ethernet controller and I'll cream my pants! Please keep us up to date with developments.

Frank B.
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: Matador on July 19, 2011, 05:40:55 PM
What about using a Microchip ENC28J60?  There's a lot of very simple PIC based web servers (a few in the sub $25 range) that include SPI:  each of your boards could run a simple web server where you could make adjustments just using the standard HTTP protocol.
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: 12volts on July 19, 2011, 06:25:59 PM
Hmmm, The PIC range is .... unreliable, the claims made in documentation don't necessarily
apply to the device .  Anything in the ATMEL range???

Frank B,
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: desun on July 20, 2011, 02:45:25 PM
Yes, interested in this, 8ch in a 1U case would be great project to do! Would be nice to have a play around with the control for these too and come up with a neat front panel design.
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: fazer on August 03, 2011, 12:22:19 PM
Very nice fit for me as well.   I have Protools and a command 8 with control for PRE 8ch.   I'm following this with great interest.    Makes a nice remote setup.

Great Job Promixe!
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: delphi on August 08, 2011, 10:49:31 PM
Count me in as an early participant to put together a 1U 8 channel version. Excellent work!
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: GnS on August 23, 2011, 12:51:02 PM
I would be in as well. Gaining and Pad On/off and P48 and Phase over MIDI would be awesome!
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: Amit on August 25, 2011, 02:26:09 AM
Nice work!
I'm in for two units, possibly four.
All the best!
/Ami
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: Moby on December 09, 2011, 12:09:12 PM
Any news? I would like to build dual unit :)
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: Nadege on December 09, 2011, 03:02:28 PM
Awsome project ! I'll be in if available .

Keep us updated !

 ;D
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: samsagaz on December 18, 2011, 09:05:45 PM
no news?
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: promixe on December 19, 2011, 01:40:20 AM
Ok, so there is some interest! =) I put the project on hold for a while but I think it is now time to resume. =)

I am starting to work on finishing up the production version of the firmware, as well as a PSU and a MIDI board for starters. What I already have:

- Finished and tested THATDIP LucidityPreamp PCBs (http://diy.innersonix.com/shop/lucidity-preamp) (that accomodates THATDIP adapters)
- Finished and tested THATDIP adapters for THAT1570/5171 chipset (http://diy.innersonix.com/shop/thatdip-adapter)
- Finished and tested controller front panel (http://diy.innersonix.com/shop/umpc-front-panel) (Universal Mic Preamp Controller - UMPC for short) with 3 buttons (48V, POLARITY, PAD)
- The actual controller chip is in beta firmware stage - finishing that up...

The UMPC controller (http://diy.innersonix.com/designs/umpc) will support THAT only mode for now (because there is a THAT based preamp PCB (http://diy.innersonix.com/shop/lucidity-preamp) already finished). PGA support (http://diy.innersonix.com/shop/pgadip-adapter) will come depending on demand, as I only have the PGA2500 adapters now, and no actual preamp boards yet. So, if someone needs PGA2500 badly, please voice your request. =)

I will provide basic documentation (http://diy.innersonix.com/support/documentation/lucidity-preamp) to get people started but would gladly accept any assistance in this matter. Thanks!

PS: To make you ponder things for a bit here is a blind shoot out (http://diy.innersonix.com/external/innersonix_lucidity_preamp_shootout_vocal1.zip) of THATDIP Lucidity Preamp (http://diy.innersonix.com/shop/lucidity-preamp) vs. Grace Design 201 (http://www.gracedesign.com/products/discontinued/discontinued.htm) and Millenia STT-1 (http://www.mil-media.com/stt-1.html) (two of the highly regarded preamps in the industry). I will be curious to know which one you think is which. =) The signal path is Neumann U149 -> passive splitter -> PREAMP level matched -> Lynx Aurora 16 A/D -> Pro Tools HD8.
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: promixe on January 11, 2012, 11:06:15 PM
A quick update:

- The PSU board (http://diy.innersonix.com/shop/umpc-psu-v1) is done.
- The new UMPC front panel controller board (http://diy.innersonix.com/shop/umpc-front-panel) is done also (features 4 buttons, channel grouping, separate configuration mode jumper, remote ID selection).
- The MIDI board (http://diy.innersonix.com/shop/umpc-midi) is done. Can be used for other MIDI controlled projects, not just UMPC (http://diy.innersonix.com/designs/umpc).

I will place an order with the PCB company as soon as I have enough $$. While I'm waiting on the PCBs, I'll work on the UMPC firmware to get to a solid beta.
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: mrcase on January 12, 2012, 07:27:31 AM
Great!
I´d be interested in 4-8 boards!!
I like the vocal1_2 track best, followed by 3 and 1...
can`t which is which since I´ve never heard either.
Congrats to this great project!!!
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: Peterson Goodwyn on January 12, 2012, 08:24:50 AM
I will provide basic documentation to get people started but would gladly accept any assistance in this matter. Thanks!

I will be glad to help with documentation when the time comes, shoot me an email.
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: promixe on February 01, 2012, 07:44:03 PM
UPDATE:

- PCBs ordered! (finally, now that the Chinese festival is over) =)
- Working on the firmware to finish new beta before the PCBs arrive. Will have grouping and remote channel ID selection through front panel interface (for Avid PRE emulation).

The new preamp PCB (http://diy.innersonix.com/shop/lucidity-preamp) has optimized split grounds with an option to stitch 'em at the PSU connector - I'm hoping this will improve EIN somewhat (the current version has -127.5dB - which is already above average pro-audio). =) There is also now an INSERT connector between the preamp and the output stage. Could be used for metering, compressor, ADC, etc...  There are a few other minor improvements.

Stay tuned. Thanks!
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: HerculesVR on February 02, 2012, 12:15:56 AM
This is evaluation board, 4-layer layout for best spec performance.

Yeap THAT1570 better than TI/BB PGA2500.
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: HerculesVR on February 02, 2012, 12:28:58 AM
UPDATE:

- PCBs ordered! (finally, now that the Chinese festival is over) =)
- Working on the firmware to finish new beta before the PCBs arrive. Will have grouping and remote channel ID selection through front panel interface (for Avid PRE emulation).

The new preamp PCB has optimized split grounds with an option to stitch 'em at the PSU connector - I'm hoping this will improve EIN somewhat (the current version has -127.5dB - which is already above average pro-audio). =) There is also now an INSERT connector between the preamp and the output stage. Could be used for metering, compressor, ADC, etc...  There are a few other minor improvements.

Stay tuned. Thanks!

You should choose good Chinese PCB factory such as chinafastprint, most low cost low quality FR-4 will reduce noise performance when high gain. For example, SYST-1141 is good at  MICPRE.

Do you use NJM2114DD for balanced output stage? it is good colorful sound.

THATDIP adapter is good job. I dun like solder QFN package. :(
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: cyrano on February 14, 2012, 10:15:16 AM
Count me in!

This is EXACTLY what I was looking for. Can't wait  ;D
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: rmaier on February 14, 2012, 04:35:20 PM
Me too, please?

Ralph
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: promixe on February 14, 2012, 06:22:08 PM
I will have 50 channel PCBs next week, but only 16 THATDIP adapters (http://diy.innersonix.com/shop/thatdip-adapter) to start with. I will order and assemble more adapters as soon as this project generates $ (i.e. as soon as the first 16 channels are sold).

I will also have 10 PSU PCBs (http://diy.innersonix.com/shop/umpc-psu-v1) and 10 Front Panel PCBs (http://diy.innersonix.com/shop/umpc-front-panel) (each PCB controls up to 8 preamp channels) to start with.

Thanks!
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: rmaier on February 14, 2012, 07:40:47 PM
Great. Please let us know once you've worked out prices.

Ralph
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: loicm on February 15, 2012, 06:36:43 AM
Dear Promixe,


I would be glad to help on this project. I just ordered an evaluation board from THAT. I was thinking to do the same project as you ...

Here is a link for the THAT chip : http://www.thatcorp.com/datashts/DigMicPre_Seminar.pdf (http://www.thatcorp.com/datashts/DigMicPre_Seminar.pdf)

and another one for the TI chip : http://www.ti.com/product/pga2500 (http://www.ti.com/product/pga2500)

I'm in if possible for 8 preamp.

Do you plan to put all those 8 preamp on a single board ? It would be great. I can help for this if you use Eagle software for the PCB.

I send you a PM.

Best regards,
Loïc
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: rytmpoczta on February 16, 2012, 09:58:02 AM
...
PS: To make you ponder things for a bit here is a blind shoot out of THATDIP preamp (http://innersonix.com/diy/tdpre/vocal1.zip) vs. Grace Design 201 and Millenia STT-1 (two of the highly regarded preamps in the industry). I will be curious to know which one you think is which. =) The signal path is Neumann U149 -> passive splitter -> PREAMP level matched -> Lynx Aurora 16 A/D -> Pro Tools HD8.

Hello,
So tell us, which one is which in this comparision???

In my opinion:
Vocal 1_1 - Grace Design
Vocal 1_2 - Millenia
Vocal 1_3 - That
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: go4thaudio on February 16, 2012, 02:25:17 PM
If there were a generic interface such as VST I feel this project would generate a great deal of interest within the SAWstudio community.   The Appsys RGC remote gain controller has VST software that is controllable from SAW host computer and/or SAW remote applications.  I can send a link if it helps.  Of course this project is much more to my liking.  I too have been looking at THAT for a project like this but am still very novice.  Perhaps this project would be a good reason for me to learn bit banging and/or explore the Steinberg SDK.  Any news yet on price and availability for PCB's?  I would like to pass this info along to SAWstudio usergroup.
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: promixe on February 16, 2012, 04:33:55 PM
...
PS: To make you ponder things for a bit here is a blind shoot out of THATDIP Lucidity Preamp (http://diy.innersonix.com/external/innersonix_lucidity_preamp_shootout_vocal1.zip) vs. Grace Design 201 and Millenia STT-1 (two of the highly regarded preamps in the industry). I will be curious to know which one you think is which. =) The signal path is Neumann U149 -> passive splitter -> PREAMP level matched -> Lynx Aurora 16 A/D -> Pro Tools HD8.

Hello,
So tell us, which one is which in this comparision???

In my opinion:
Vocal 1_1 - Grace Design
Vocal 1_2 - Millenia
Vocal 1_3 - That

Let's not give it out to everyone just yet. =) I'm sending you a PM with what's what.
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: promixe on February 16, 2012, 04:38:45 PM
If there were a generic interface such as VST I feel this project would generate a great deal of interest within the SAWstudio community.   The Appsys RGC remote gain controller has VST software that is controllable from SAW host computer and/or SAW remote applications.  I can send a link if it helps.  Of course this project is much more to my liking.  I too have been looking at THAT for a project like this but am still very novice.  Perhaps this project would be a good reason for me to learn bit banging and/or explore the Steinberg SDK.  Any news yet on price and availability for PCB's?  I would like to pass this info along to SAWstudio usergroup.

I've been working on a universal OSC control for the preamps (http://diy.innersonix.com/designs/oscar) (and a whole lot more of other gear) through AU/VST and standalone apps. No intermediary gear will be required - just plug in your preamp into a router/hub or directly into your PCs ethernet. It's a couple of months away I think, but it's coming. =)

Help with AU/VST programming is welcome.
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: bremusound on February 22, 2012, 06:05:16 PM
I'm interested in a 8ch unit, maybe another 1-2 8ch units later... PGA preferred since i have some of those laying around...
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: promixe on February 22, 2012, 06:55:44 PM
I'm interested in a 8ch unit, maybe another 1-2 8ch units later... PGA preferred since i have some of those laying around...

I'm going to start sales with THAT1570/5171 based designs (http://diy.innersonix.com/designs/lucidity). Honestly I've been pondering the PGAs for a while and I don't really see a clear reason to design my own PGA PCBs anymore due to the following reasons:

- Igor has done it already (WIREGAIN preamp (http://www.groupdiy.com/index.php?topic=31783.0))
- THAT chipset does everything PGA does, easier to program for, I personally prefer its topology and sound to PGA. The overload feature on the PGA2500 could be replicated on the THAT chipset as well, which I will implement down the line.

I, however, do offer PGA2500-optimized high-performance DIP-28 adapters (http://diy.innersonix.com/shop/pgadip-adapter) (read about it HERE (http://www.groupdiy.com/index.php?topic=42471.msg540353#msg540353)). I have around 80 of them in stock. The main purpose of designing these adapters was DIY-friendliness, i.e. you wouldn't have to solder those SMD packages and would either use the adapters directly in your board designs or prototype with them on a breadboard. I have about 80 PGA adapters unassembled PCBs left if you are interested in using your own chips on them. If you buy over 10 pc. they would be $5/each.

(http://diy.innersonix.com/external/innersonix_pga2500_adapter.jpg)

My front panel controller (UMPC) (http://diy.innersonix.com/shop/umpc-front-panel) will initially support THAT chipset and a remote control mode (where it acts just as a display+interface, but doesn't actually send control messages to preamps; the remote board does. More on that later...). But it's in my to-do list to finish full support of up to 8 PGA2500s in a daisy-chain configuration. Stay tuned!

PS: The PCB order is going to be here any day now. I'm going to announce pricing after I test everything and am ready to sell. Thank you!
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: promixe on February 23, 2012, 07:51:05 AM
PSU

(http://diy.innersonix.com/external/innersonix_umpc_psu_v1.jpg)

Tested and working - supports up to 8 preamps (http://diy.innersonix.com/shop/lucidity-preamp) + front panel (http://diy.innersonix.com/shop/umpc-front-panel) + MIDI remote board (http://diy.innersonix.com/shop/umpc-midi). In theory should power up to 16 channels, but yet to test. It supports +48VDC phantom, +/- rails for anything bipolar (I use +/-17V for THATDIP Lucidity Preamps (http://diy.innersonix.com/designs/lucidity)), and +3.3VDC digital supply for all the control + display + relays. The digital rail is LM2676 based and could be modified to do +5VDC with a different part #. The PCB is $20USD + shipping.

UMPC - Universal Mic Preamp Controller

(http://diy.innersonix.com/external/innersonix_umpc_front_panel_v4e.jpg)

Tested and working - finishing up the firmware. The controller uC itself is going to be $25USD and the front panel PCB is $15, so as a kit = $40 + shipping. I will be doing firmware updates occasionally to support new features and/or fix bugs, so people who have purchased the UMPC chip from me before will get the new one for free and only pay for shipping or I can include it free of charge to any order they place with me.

UMPC MIDI - Remote Control Board

(http://diy.innersonix.com/external/innersonix_initial_midi_prototype.jpg)

Hardware is working but the firmware is not done yet. It will support both autonomous operation (i.e. with no front panel installed) and working in conjunction with the UMPC front panel (http://diy.innersonix.com/shop/umpc-front-panel). I want to get this out of the way quickly as I'm designing a network control system for these preamps (http://diy.innersonix.com/designs/oscar). But this board would be VERY useful for Pro Too1s people as it will see the preamps as Av1d PREs and store their data in session files for later recall. The UMPC MIDI (http://diy.innersonix.com/shop/umpc-midi) chip will be $25USD and the PCB is $10USD totalling $35USD + shipping for the whole MIDI remote control kit (http://diy.innersonix.com/shop/umpc-midi). As with the UMPC chip the same firmware upgrade scenario applies to existing customers.

Now, as far as the actual preamp: I've encountered a major design flaw in the boards I got and the workaround is not that user-friendly. Therefore I'm sending the revised layout to manufacturing this week and will order expedited shipping to get them back ASAP. I want it to be as straight-forward as possible for people to put these awesome preamps together. I want this to become a suitable DIY project for first-timers to consider and I am working hard to make this happen. =) My health has been fairly poor in the last couple of weeks and that slowed down the progress of this project considerably, but I'm slowly picking up the pace. Please bear with me. =)

QUESTION: Does anyone around here own a D1g1design (AV1D) PRE preamp or a Grace Design 802? I need to find out what heartbeat MIDI message PT sends each 8 seconds to the preamp and what message the preamp responds with. Please drop me a PM if you can help. Thank you!
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: sr1200 on February 23, 2012, 02:38:43 PM
That was such a c*ck tease man.... lol.  Been watching silently, waiting for the notice.
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: promixe on February 27, 2012, 05:37:20 AM
Some updates - http://www.groupdiy.com/index.php?topic=45035.msg602654#msg602654
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: bremusound on February 27, 2012, 07:48:23 AM
That's great news. I'm definitively in for 1-2 8ch unit packages. 8)
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: ffarrell on February 27, 2012, 09:49:47 AM
looking to buy a few boards.  any link to buy the boards?

thanks
fvf
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: promixe on February 27, 2012, 09:53:51 AM
looking to buy a few boards.  any link to buy the boards?

The only board that is 100% ready to use at the moment is the PSU (http://diy.innersonix.com/shop/umpc-psu-v1). If you are interested please PM me and specify your shipping address + how many you need. Thank you!

Otherwise please read the first post on this page carefully - the preamp boards are being redesigned and are going to be available in a couple of weeks. Stay tuned!
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: sr1200 on February 27, 2012, 09:58:51 AM
Im trying to get you the DIGI/AV1D info you were asking about now.  Hopefully have an answer for you today.

Sure wish there was a way to hook this up to my neve or 312 clones..... :)

I'm interested in hearing the pres though. I'll be down for 4-8 ch by next month.
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: promixe on February 27, 2012, 10:22:12 AM
Im trying to get you the DIGI/AV1D info you were asking about now.  Hopefully have an answer for you today.

Thank you!!!

Quote
Sure wish there was a way to hook this up to my neve or 312 clones..... :)

Actually that's coming... =) Wasn't gonna give this away that soon. =) Have been working on a relay control board to substitute the gain/atten switch on a Neve 1290. The UMPC (http://diy.innersonix.com/designs/umpc) would control it in 5dB steps. I just need some help figuring out optimal impedances once the 2nd NV stage kicks in. But more on that in a separate thread.

Quote
I'm interested in hearing the pres though. I'll be down for 4-8 ch by next month.

There is a link to a preamp shootout (http://www.groupdiy.com/index.php?topic=45035.msg590695#msg590695) between the early prototype Lucidity Preamp (http://diy.innersonix.com/designs/lucidity), Grace 201, and Millenia STT-1. Give it a listen. =)
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: sr1200 on February 27, 2012, 10:28:25 AM
OK the tech guy seems to believe there is no pulse going on besides the initialization when PT loads up. (basically 0's out the pre i guess). 

the midi implementation chart is at the back of this:
http://akmedia.digidesign.com/support/docs/PRE_Guide_v80_56123.pdf (http://akmedia.digidesign.com/support/docs/PRE_Guide_v80_56123.pdf)
but im sure you already had that stuff.

Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: promixe on February 27, 2012, 10:37:07 AM
OK the tech guy seems to believe there is no pulse going on besides the initialization when PT loads up. (basically 0's out the pre i guess). 

the midi implementation chart is at the back of this:
http://akmedia.digidesign.com/support/docs/PRE_Guide_v80_56123.pdf (http://akmedia.digidesign.com/support/docs/PRE_Guide_v80_56123.pdf)
but im sure you already had that stuff.

Look at page 15 of the Grace 802 manual - http://www.gracedesign.com/support/m802_manual_revH.pdf (http://www.gracedesign.com/support/m802_manual_revH.pdf)  - it explains the "heartbeat" part. The PRE MIDI implementation only mentions channel control protocol, not the general stuff. Hmm....  I wonder if someone could capture a minute worth of MIDI data between PT and PRE with MIDIOX or a similar tool.
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: sr1200 on February 27, 2012, 11:19:40 AM
I asked if they could set it up to see if there is something going out.  If not, i can set something up at home tonight and see if i get any results.
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: Holger on February 27, 2012, 11:53:30 AM
This is a nice project. Count me in for two channels.
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: sr1200 on February 27, 2012, 12:14:59 PM
Got a guy from Avid thats supposed to get back to me today with all the info :)
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: sr1200 on February 27, 2012, 02:05:45 PM
This is what I was sent... hopefully it helps.  I haven't done midi sysex stuff in forever and a day.

All messages are Continuous Controller(CC) messages and have a leading byte of 0xBX
where the B signifies that this is a CC message and
the X is the MIDI channel number (1-16)
--------------------------------------------------------

Rules for 3rd party developers:

1)    ProTools only supports turning off all mutes after it receives the first heartbeat

2)    Send status only works in one direction..... from ProTools to the preamp. In other words,
   ProTools is responsible for making sure its UI is in sync with the Preamp front panel.
   It does this by sending a send stautus message w/ the value 0x7f. When the preamp receives this message
   it should send the state of every element on that channel then send a send status message w/ the value 0x00.
   ProTools asks for preamp channel status sequentially. It will wait to receive the send status 0x00 message
   before it asks for status on any other channel it needs to sync with.

3)    The heartbeat is sent once every 8 seconds from ProTools and requires an immediate respopnse from the preamp.
   This is how ProTools determines if it is still in communication w/ the preamp at idle.

4)    ProTools currently does not use or request the version number. In a future release this may be used to upgrade
   the firmware of our PRE preamp from within ProTools.

5)   Preamp must send a "lockout off" message upon powerup if the preamp clears lockout mode when power cycled.

6)   ProTools supports an input gain range of 0 - 69db in 3db steps as defined in the Gain Table.

7)   The pad feature tells the preamp to attenuate its input gain. On PRE this is -18db and is reflected as such in
   the ProTools UI. There is currently no method of dynamically changing the UI to reflect a different amount of attenuation.

8)    Reset to defaults is a single message that causes the preamp to reset all its controls to their default settings. On
   PRE this is currently and input gain of 0db and all other controls in the "off" state. Other preamps could implement
   different default states but this may confuse a user who is used to the PRE defaults. 


---------------------------------------------------------

Gain Table:

3rd byte   gain value
-----------       -----------
0x00       00
0x01       03
0x02       06
0x03       09
0x04       12
0x05       15
0x06        18
0x07        21
0x08        24
0x09        27
0x0A        30
0x0B        33
0x0C        36
0x0D        39
0x0E        42
0x0F        45
0x10        48
0x11        51
0x12        54
0x13        57
0x14        60
0x15        63
0x16        66
0x17        69

-----------------------------------------------------------


Heartbeat   
2nd byte         3rd byte
-------------         ----------------
0x0A            0x00 = sent from ProTools, 0x7F = sent from Preamp
---------------------------------------------------------



Lockout mode
-------------
2nd byte         3rd byte
-------------         ----------------
0x0C            0x00 = off, 0x7F = on
---------------------------------------------------------




Reset To Defaults
2nd byte         3rd byte
-------------         ----------------      
0x0E            irrelevant
---------------------------------------------------------




Version Number of Preamp
2nd byte         3rd byte
-------------         ----------------
0x0F            irrelevant
---------------------------------------------------------



Mic Pre channel #1
-------------
2nd byte         3rd byte
-------------         -----------------
0x00 : Input Source      0x00 = Mic, 0x01 = Line, 0x02 = Inst
0x01 : Input Z         0x00 = 1.5K, 0x01 = 10K, 0x02 = 1.5M
0x02 : Pad         0x00 = off, 0x7F = on
0x03 : Insert         0x00 = off, 0x7F = on
0x04 : Phantom      0x00 = off, 0x7F = on
0x05 : Phase         0x00 = off, 0x7F = on
0x06 : HP Filter      0x00 = off, 0x7F = on
0x07 : Mute         0x00 = off, 0x7F = on
0x08 : Input Gain (coarse)   currently not implemented
0x09 : Input Gain (fine)   see Gain Table
0x0D : Send status      0x00 = sent from preamp, 0x7f = sent from ProTools


Mic Pre channel #2
-------------
2nd byte         3rd byte
-------------         -----------------
0x10 : Input Source      0x00 = Mic, 0x01 = Line, 0x02 = Inst
0x11 : Input Z         0x00 = 1.5K, 0x01 = 10K, 0x02 = 1.5M
0x12 : Pad         0x00 = off, 0x7F = on
0x13 : Insert         0x00 = off, 0x7F = on
0x14 : Phantom      0x00 = off, 0x7F = on
0x15 : Phase         0x00 = off, 0x7F = on
0x16 : HP Filter      0x00 = off, 0x7F = on
0x17 : Mute         0x00 = off, 0x7F = on
0x18 : Input Gain (coarse)   currently not implemented
0x19 : Input Gain (fine)   see Gain Table
0x1D : Send status      0x00 = sent from preamp, 0x7f = sent from ProTools


Mic Pre channel #3
-------------
2nd byte         3rd byte
-------------         -----------------
0x20 : Input Source      0x00 = Mic, 0x01 = Line, 0x02 = Inst
0x21 : Input Z         0x00 = 1.5K, 0x01 = 10K, 0x02 = 1.5M
0x22 : Pad         0x00 = off, 0x7F = on
0x23 : Insert         0x00 = off, 0x7F = on
0x24 : Phantom      0x00 = off, 0x7F = on
0x25 : Phase         0x00 = off, 0x7F = on
0x26 : HP Filter      0x00 = off, 0x7F = on
0x27 : Mute         0x00 = off, 0x7F = on
0x28 : Input Gain (coarse)   currently not implemented
0x29 : Input Gain (fine)   see Gain Table
0x2D : Send status      0x00 = sent from preamp, 0x7f = sent from ProTools


Mic Pre channel #4
-------------
2nd byte         3rd byte
-------------         -----------------
0x30 : Input Source      0x00 = Mic, 0x01 = Line, 0x02 = Inst
0x31 : Input Z         0x00 = 1.5K, 0x01 = 10K, 0x02 = 1.5M
0x32 : Pad         0x00 = off, 0x7F = on
0x33 : Insert         0x00 = off, 0x7F = on
0x34 : Phantom      0x00 = off, 0x7F = on
0x35 : Phase         0x00 = off, 0x7F = on
0x36 : HP Filter      0x00 = off, 0x7F = on
0x37 : Mute         0x00 = off, 0x7F = on
0x38 : Input Gain (coarse)   currently not implemented
0x39 : Input Gain (fine)   see Gain Table
0x3D : Send status      0x00 = sent from preamp, 0x7f = sent from ProTools


Mic Pre channel #5
-------------
2nd byte         3rd byte
-------------         -----------------
0x40 : Input Source      0x00 = Mic, 0x01 = Line, 0x02 = Inst
0x41 : Input Z         0x00 = 1.5K, 0x01 = 10K, 0x02 = 1.5M
0x42 : Pad         0x00 = off, 0x7F = on
0x43 : Insert         0x00 = off, 0x7F = on
0x44 : Phantom      0x00 = off, 0x7F = on
0x45 : Phase         0x00 = off, 0x7F = on
0x46 : HP Filter      0x00 = off, 0x7F = on
0x47 : Mute         0x00 = off, 0x7F = on
0x48 : Input Gain (coarse)   currently not implemented
0x49 : Input Gain (fine)   see Gain Table
0x4D : Send status      0x00 = sent from preamp, 0x7f = sent from ProTools


Mic Pre channel #6
-------------
2nd byte         3rd byte
-------------         -----------------
0x50 : Input Source      0x00 = Mic, 0x01 = Line, 0x02 = Inst
0x51 : Input Z         0x00 = 1.5K, 0x01 = 10K, 0x02 = 1.5M
0x52 : Pad         0x00 = off, 0x7F = on
0x53 : Insert         0x00 = off, 0x7F = on
0x54 : Phantom      0x00 = off, 0x7F = on
0x55 : Phase         0x00 = off, 0x7F = on
0x56 : HP Filter      0x00 = off, 0x7F = on
0x57 : Mute         0x00 = off, 0x7F = on
0x58 : Input Gain (coarse)   currently not implemented
0x59 : Input Gain (fine)   see Gain Table
0x5D : Send status      0x00 = sent from preamp, 0x7f = sent from ProTools


Mic Pre channel #7
-------------
2nd byte         3rd byte
-------------         -----------------
0x60 : Input Source      0x00 = Mic, 0x01 = Line, 0x02 = Inst
0x61 : Input Z         0x00 = 1.5K, 0x01 = 10K, 0x02 = 1.5M
0x62 : Pad         0x00 = off, 0x7F = on
0x63 : Insert         0x00 = off, 0x7F = on
0x64 : Phantom      0x00 = off, 0x7F = on
0x65 : Phase         0x00 = off, 0x7F = on
0x66 : HP Filter      0x00 = off, 0x7F = on
0x67 : Mute         0x00 = off, 0x7F = on
0x68 : Input Gain (coarse)   currently not implemented
0x69 : Input Gain (fine)   see Gain Table
0x6D : Send status      0x00 = sent from preamp, 0x7f = sent from ProTools



Mic Pre channel #8
-------------
2nd byte         3rd byte
-------------         -----------------
0x70 : Input Source      0x00 = Mic, 0x01 = Line, 0x02 = Inst
0x71 : Input Z         0x00 = 1.5K, 0x01 = 10K, 0x02 = 1.5M
0x72 : Pad         0x00 = off, 0x7F = on
0x73 : Insert         0x00 = off, 0x7F = on
0x74 : Phantom      0x00 = off, 0x7F = on
0x75 : Phase         0x00 = off, 0x7F = on
0x76 : HP Filter      0x00 = off, 0x7F = on
0x77 : Mute         0x00 = off, 0x7F = on
0x78 : Input Gain (coarse)   currently not implemented
0x79 : Input Gain (fine)   see Gain Table
0x7D : Send status      0x00 = sent from preamp, 0x7f = sent from ProTools
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: sr1200 on February 27, 2012, 04:47:57 PM
My vote:
1) THAT
2) GRACE
3) MILLENIA
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: 12volts on February 27, 2012, 06:04:39 PM
This is what I was sent... hopefully it helps.  I haven't done midi sysex stuff in forever and a day.

All messages are Continuous Controller(CC) messages and have a leading byte of 0xBX
where the B signifies that this is a CC message and
the X is the MIDI channel number (1-16)
--------------------------------------------------------

Rules for 3rd party developers:

1)    ProTools only supports turning off all mutes after it receives the first heartbeat

2)    Send status only works in one direction..... from ProTools to the preamp. In other words,
   ProTools is responsible for making ... et al ...   


Doncha just love this site? A mine of information.
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: promixe on February 27, 2012, 06:11:42 PM
Heartbeat   
2nd byte         3rd byte
-------------         ----------------
0x0A            0x00 = sent from ProTools, 0x7F = sent from Preamp
---------------------------------------------------------

Lockout mode
-------------
2nd byte         3rd byte
-------------         ----------------
0x0C            0x00 = off, 0x7F = on
---------------------------------------------------------

Reset To Defaults
2nd byte         3rd byte
-------------         ----------------      
0x0E            irrelevant
---------------------------------------------------------

Version Number of Preamp
2nd byte         3rd byte
-------------         ----------------
0x0F            irrelevant
---------------------------------------------------------

You are THE MAN!!! =) Precisely what I needed! Thank you!

Also I had a question about implementing grouping on my UMPC. There are two ways of doing this:

1st is hard limiting gains - i.e. if the gain range is 20-75dB and, say, you group channel #1 and #2. #1's gain is 30 and and #2's gain is 45 (i.e. 15 dB apart). As you decrease #2's gain it stops at 35dB (because channel #1 is hit with its lowest gain limit - 20). Same applies when you increase channel #1's gain, it stops at 60, because channel #2 is hit its upper boundary of 75.

2nd way is "soft limiting" gains - i.e. it permits full gain range on every grouped channel and channels that are at their limits just stay there retaining the offset relative to the channel being currently modified. I.e. in the scenario above you can decrease channel #2 all the way to 20 and channel #1 will stay at 20 during the 15 steps of #2's gain decrease. As you increase #2's gain it goes back up to 35 before channel #1 starts moving upwards in sync with #2's changes. This way is much harder to implement than the 1st way, but I need opinions whether it's worth it and is much more useful than the 1st way in real-world practical scenarios. I hope it's clear the way I described it. =)

Thanks!
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: promixe on February 27, 2012, 06:42:22 PM
   ProTools is responsible for making sure its UI is in sync with the Preamp front panel.
   It does this by sending a send stautus message w/ the value 0x7f. When the preamp receives this message
   it should send the state of every element on that channel then send a send status message w/ the value 0x00.

AND

Quote
Heartbeat   
2nd byte         3rd byte
-------------         ----------------
0x0A            0x00 = sent from ProTools, 0x7F = sent from Preamp
---------------------------------------------------------


AND THEN AGAIN

Quote

Mic Pre channel #1
-------------
2nd byte         3rd byte
-------------         -----------------
.........
0x0D : Send status      0x00 = sent from preamp, 0x7f = sent from ProTools

Is it just me or is there a contradiction? Anyway, this isn't hard to reverse engineer the correct way from here. =)
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: sr1200 on February 27, 2012, 07:42:00 PM
the way i understood it, the heartbeat comes FROM protools and the individual channels are responding in sequence.  So a pulse goes out, and the pre responds from 1-8  with the correct responses... my question is if you only do a 4 channel unit... what happens to the missing 4 channels responses?  Thats going to be something to try.
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: promixe on February 27, 2012, 07:49:13 PM
the way i understood it, the heartbeat comes FROM protools and the individual channels are responding in sequence.  So a pulse goes out, and the pre responds from 1-8  with the correct responses... my question is if you only do a 4 channel unit... what happens to the missing 4 channels responses?  Thats going to be something to try.

Nothing happens - it will just ignore it (as well as Input Z, source, Mute, and HPF messages). It will respond to whatever it has capabilities to respond, which are determined dynamically at startup.

The question above was about the description contradicting itself saying that PT send 0x7F message to PRE, and below it says it sends 0x00 message to PRE. And then the other way around again. =) But I will figure that out - this info is enough for me to continue. Thanks!

What about the grouping implementation question above?
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: sr1200 on February 27, 2012, 07:59:31 PM
ahhh i see what youre gettin at there.... yeah a typo... should i let avid know? lol :evil grin:
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: promixe on March 01, 2012, 12:57:35 AM
=)

UPDATE: As I'm about to order the revised THATDIP Lucidity Preamp boards (http://diy.innersonix.com/shop/lucidity-preamp) I have a question. The entire system (preamp / front panel controller / remote boards) was initially designed around a 12-pin (2x6) interconnect (header+cable). But recently, while looking for a suitable cable assemblies and bulk ribbon cable supplies, I realized that oddly enough the industry standards are either 10-pin or 14-pin IDC interconnects... Why did they skip on 12-pin? Have no clue. But I decided to base my whole design on a 10-pin IDC connectors because they just turn up in searches a lot more, i.e. are more available to a general DIY crowd. =)

That leads to the question at hand. I have 10 remote MIDI boards (http://diy.innersonix.com/shop/umpc-midi) and 10 UMPC front panel PCBs (http://diy.innersonix.com/shop/umpc-front-paneli) with the old 12-pin headers on them. Would people here be opposed to purchasing these and soldering the cables between them manually (i.e. bypassing the 12-pin headers)? I will post detailed graphical explanation on how to do that. The reason is that I, quite frankly, don't have enough cash to reorder the MIDI and Front Panel boards with the new 10-pin standard headers until I generate some sales of the existing stuff I have. The end-user functionality of the design is completely unaffected by this header mismatch issue.

I can discount the front panel and the MIDI PCB price because of this inconvenience. Please let me know whether or not this is a huge issue for the DIY people here. =)

Thanks!
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: promixe on March 01, 2012, 08:49:30 AM
As I'm working on the MIDI remote board (http://diy.innersonix.com/shop/umpc-midi) I'm running into some undocumented protocol quirks... After implementing the basics described by sr1200 on page 3 (http://www.groupdiy.com/index.php?topic=45035.msg603379#msg603379) I still can't get PT to recognize my device. It appears that PT is also sending a 0xA1 0x00 0x00 message along with the heartbeat message, which contradicts their 0xBx status byte format and isn't documented anywhere. And my proper heartbeat response is not pleasing PT as it keeps telling me there isn't a preamp connected to it... =\

sr1200, maybe you could relay this message to your contact at Av1d and ask for more information? Otherwise I have to go through THIS (http://www.avid.com/US/partners/developer-program/AudioPlugin) and I already smell a dead end there... =)

Thank you!!!

UPDATE: Looks like I got it to recognize my MIDI board finally. It seems that MIDI-OX (my MIDI monitor program) takes exclusive control of my computer's MIDI IN port and while displaying all incoming messages nicely it doesn't let PT see them. =) But the 0xA1 messages from PT are still there and I don't know their purpose. Back to work... Oh, first some sleep. =)
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: promixe on March 04, 2012, 05:46:28 AM
UPDATE: Revised PCBs are ordered - huge thanks to Frank (12volts)! Should be here in about a week and a half. =)

Also, I redesigned the preamp and MIDI boards so that they can work with up to 16 (!!!) channels in a single chassis. I'm still working on the firmware to make this happen, but the idea is that in PT you select that you have TWO preamps connected on consecutive MIDI channels, even though the physical connection is just to a single UMPC MIDI board. It recognizes which MIDI channel should talk to which group of preamp channels inside a single rack. Basically PT thinks you have 2 Av1d PREs, but you actually have one 16-channel custom-brewed super-clean goodness. =)

And I'm beginning to work on the metering system for this project that will be able to send the levels over the network into a remote control app (OSX / iOS first, Linux / Win with help from others) through my upcoming OSCAR (OSC Audio Remote) design (http://diy.innersonix.com/designs/oscar). It'll be a little while until it's in beta, but hopefully the MIDI remote (http://diy.innersonix.com/shop/umpc-midi) can sustain your happiness for a while. =)

I also ran some tests on the current boards I have and the EIN has improved a bit over previous versions of the preamp - it is now -128dBu @75dB gain with 150Ohm termination, 20-20k BW, flat weighted. Pretty high-end if you ask me. But I have a question about this if anyone knows what FFT size the industry uses to measure the EIN. I use very large FFT size (131072+) but have noticed that if I decrease it to 32768 or less the EIN figure improves dramatically (up to 3dB), which makes this a theoretically noiseless preamp on paper with -131dBu EIN (the thermal noise floor of the terminating resistor that is). =)))

More updates to come.
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: promixe on March 04, 2012, 02:18:15 PM
As a side note: I just randomly visited THAT's website and they've just released 5173 digital chip (http://thatcorp.com/5173_Digital_Preamplifier_Controller_ICs.shtml)!!! It appears to be 5171's smaller variant with 3dB steps and 5x5 QFN24 package. The specs are really good, very similar to 5171 especially at higher gains. Hmm.. =) Let's see how much it costs...

Looking at the datasheet (http://thatcorp.com/datashts/THAT_5173_Datasheet.pdf), however, there are some major differences on the digital side, both good and not so. The cool feature is that they now support GPIO changes on zero-crossings, in addition to gain. But to take advantage of this the GPIO switching has to be a lot faster than what relays offer... Another cool thing is that the gain now DIRECTLY matches the PT MIDI protocol described on page 3 here. =) The thing I don't dig as much though is that it is now daisy-chainable, and not addressable as the 5171 is. It is basically controlled the same way PGA2500 is. The SPI addressing is a major convenience to me personally, as I can minimize SPI traffic significantly and the code is cleaner that way. But daisy-chained fashion is not a complete deal breaker, just not my personal preference. =)

But I suspect it will be about 1/3 cheaper than the 5171, if not more. We'll see. =)
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: loicm on March 12, 2012, 05:17:24 AM
Dear Promixe,

Quote
if anyone knows what FFT size the industry uses to measure the EIN. I use very large FFT size (131072+) but have noticed that if I decrease it to 32768 or less the EIN figure improves dramatically (up to 3dB), which makes this a theoretically noiseless preamp on paper with -131dBu EIN (the thermal noise floor of the terminating resistor that is). =)))

I think you should integrate the signal up to 20 KHz in your FFT. If you increase the size of the FFT, you will get the noise of the high frequency. This will lead to poor results. 
It's normal that the noise change according to the bandwith of your analysis.

To do a FFT, you define a temporal window and the number of point in this window (the size I guess in your software).
This number of point will give you the bandwidth of the analysis. If you increase this value you will get the high frequency in the spectrum.
The more point you have in the FFT, the more high frequency and noise you will get in your spectrum.
The noise is the integration of the spectrum curve. I think you should integrate up to 20 KHz for this measurement.

Also the EIN change a lot according to the gain you have. There is an ANSI recommendation to make the measurement.
http://us.sonici.com/ctrldocs/ResearchPapers/5000445.C-IsEINAnAdequateMeasureofACN.pdf

Also, it is very important to terminate the input.

EIN = max gain + 22~22k hz bandwidth RMS S/N


All resistors generate noise from thermal agitation. A mic pre will also add
voltage and current noise. But an open input is like a very high resistance,
and high resistance generates giant noise.

If you short input pin 2 to pin 3 you will just measure the pres voltage noise mostly. If you use a standard resistor like 150 ohms you will measure the resistor noise as well as the pre voltage and current noise. There will be a limit no matter how quiet the pre is.

An example...

a very quiet 1nV/sqrt Hz EIN density pre will contribute about the same random noise component as a 50 ohm resistor. So with a 150 ohm load connected it actually makes most of the noise rather than the pre.

To get input spectral noise density measure output RMS, divide by gain,
then divide by SQRT of frequency range (sqrt 20kHZ=141). You must band limit the signal you are measuring to get meaningful results.

One problem you will get using a simple meter...it's likely that most of the noise you measure will be hum harmonics rather than random noise (hiss) so you may get much poorer results than expected.

Here is a good thread about this : http://www.gearslutz.com/board/geekslutz-forum/598851-how-can-i-measure-ein.html

And this from RANE :

EIN. Equivalent Input Noise or Input Referred Noise
What is tested? Equivalent input noise, or input referred noise, is how noise is spec'd on mixing consoles, standalone mic preamps and other signal processing units with mic inputs. The problem in measuring mixing consoles (and all mic preamps) is knowing ahead of time how much gain is going to be used. The mic stage itself is the dominant noise generator; therefore, the output noise is almost totally determined by the amount of gain: turn the gain up, and the output noise goes up accordingly. Thus, the EIN is the amount of noise added to the input signal. Both are then amplified to obtain the final output signal.

For example, say your mixer has an EIN of -130 dBu. This means the noise is 130 dB below a reference point of 0.775 volts (0 dBu). If your microphone puts out, say, -50 dBu under normal conditions, then the S/N at the input to the mic preamp is 80 dB (i.e., the added noise is 80 dB below the input signal). This is uniquely determined by the magnitude of the input signal and the EIN. From here on out, turning up the gain increases both the signal and the noise by the same amount.

How is it measured? With the gain set for maximum and the input terminated with the expected source impedance, the output noise is measured with an rms voltmeter fitted with a bandwidth or weighting filter.

Required Conditions. This is a spec where test conditions are critical. It is very easy to deceive without them. Since high-gain mic stages greatly amplify source noise, the terminating input resistance must be stated. Two equally quiet inputs will measure vastly different if not using the identical input impedance. The standard source impedance is 150 ohms. As unintuitive as it may be, a plain resistor, hooked up to nothing, generates noise, and the larger the resistor value the greater the noise. It is called thermal noise or Johnson noise (after its discoverer J. B. Johnson, in 1928) and results from the motion of electron charge of the atoms making up the resistor. All that moving about is called thermal agitation (caused by heat -- the hotter the resistor, the noisier).

The input terminating resistor defines the lower limit of noise performance. In use, a mic stage cannot be quieter than the source. A trick which unscrupulous manufacturers may use is to spec their mic stage with the input shorted -- a big no-no, since it does not represent the real performance of the preamp.

The next biggie in spec'ing the EIN of mic stages is bandwidth. This same thermal noise limit of the input terminating resistance is a strong function of measurement bandwidth. For example, the noise voltage generated by the standard 150 ohm input resistor, measured over a bandwidth of 20 kHz (and room temperature) is -131 dBu, i.e., you cannot have an operating mic stage, with a 150 ohm source, quieter than -131 dBu. However, if you use only a 10 kHz bandwidth, then the noise drops to -134 dBu, a big 3 dB improvement. (For those paying close attention: it is not 6 dB like you might expect since the bandwidth is half. It is a square root function, so it is reduced by the square root of one-half, or 0.707, which is 3 dB less).

Since the measured output noise is such a strong function of bandwidth and gain, it is recommended to use no weighting filters. They only complicate comparison among manufacturers. Remember: if a manufacturer's reported EIN seems too good to be true, look for the details. They may not be lying, only using favorable conditions to deceive.

Correct: EIN = -130 dBu, 22 kHz BW, max gain, Rs = 150 ohms

Wrong: EIN = -130 dBu


I'm still in the project ! I will do some measurement with the spectrum analyzer we have here.

Best regards,
Loïc
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: promixe on March 22, 2012, 03:44:11 PM
UPDATE: The boards are ready to go. I'm in the process of preparing initial documentation/BOMs for everything and putting them up on my website (http://diy.innersonix.com/) (which will hopefully launch this week).

The DIP adapters will be BTO (Built To Order) for a while to gain momentum, so there will be a delay of several days between receiving an order and shipping them out.

- DIP adapters (http://diy.innersonix.com/shop/product-category/dip-adapters) are $40/ea
- Lucidity Preamp Channel PCBs (http://diy.innersonix.com/shop/lucidity-preamp) are $20/ea  (and $15/ea if you order over 7pc.)
- UMPC Front Panel Kit (http://diy.innersonix.com/shop/umpc-front-panel) (PCB+uC) is $40  (single kit needed for 1-8 channels)
- UMPC MIDI Remote (http://diy.innersonix.com/shop/umpc-midi) (PCB+uC) is $35 (single kit needed for 1-16 channels)
- PSU v1 PCB (http://diy.innersonix.com/shop/umpc-psu-v1) is $20. Customers ordering 8 or more channels will get the PSU board for free (while I have this edition of the PSU board in stock).

There are various configurations possible: MIDI remote only (headless, i.e. black front panel), MIDI + Front Panel, Front Panel only with no MIDI, etc...

I will post links to BOMs ASAP. In general, to build the preamp channel it's around $30 in additional components here in the US for top quality, most expensive being relays. You could build it for less if you wanted to. So, the full cost of a single channel is around $95 or less (with PCB, DIP adapter, remaining components).

If you would like to place an order please PM me with your shipping address and what you would like to order and I'll send you my Paypal address and a quote. Thanks!

More to come!...
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: promixe on March 29, 2012, 12:01:40 AM
The new preamp boards are beautiful in white! =)

(http://diy.innersonix.com/2012/imgp0468o.jpg)

BOM's are up online:

THATDIP Preamp v3e (https://docs.google.com/spreadsheet/ccc?key=0Arcfz39vu47bdE9ZbXRZOHdTQ19VWHIxLXVycHdMR0E)
UMPC Front Panel v4e (https://docs.google.com/spreadsheet/ccc?key=0Arcfz39vu47bdDVseFM0bHJXYWFqNUF5dU1ISFdUVVE)
UMPC MIDI Remote v2e (https://docs.google.com/spreadsheet/ccc?key=0Arcfz39vu47bdDJBd1FmT1RCZjI5QjJNSW5LYjFuLUE)
UMPC PSU v1 (https://docs.google.com/spreadsheet/ccc?key=0Arcfz39vu47bdHJRUllZVjlKZXZhbUd4LXFFdlRVY3c)

For US customers note the "ORDER BOM" links at the bottom - this should save you guys some time! =)
Intl. customers - similar functionality is coming...

Basic documentation is coming up ASAP.. +)
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: Holger on March 29, 2012, 11:43:33 AM
Wonderful...
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: mrcase on March 30, 2012, 06:29:58 AM
indeed! looks great! you`ll get an order from me soon.
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: promixe on May 16, 2012, 10:57:39 AM
For 2012 update on this project please visit my site! (http://diy.innersonix.com/)

For build/support thread click HERE (http://www.groupdiy.com/index.php?topic=48695.0)



Thank you all for your participation in this thread!
Title: Re: THATDIP Preamp - THAT1570/5171 Digitally Controlled Mic Pre [PICS]
Post by: rmaier on May 16, 2012, 10:47:33 PM
Congratulations on your site and on getting things to this point - this looks like a fabulous project, and I'll be in touch with an order as soon as time and finances permit. Very much looking forward to hearing how things come together for people working on these.