promixe

Hi All!

I've decided to start this build/support thread hoping to compile it over time into a coherent and complete documentation for this project.

The basic support info (to be gradually expanded based on this thread's feedback) for the Lucidity Preamp is located HERE

The preamp is based on THAT1570/5171 chipset and is digitally controlled (via Front Panel interface and MIDI Remote right now, TCP/IP support is coming). A bit more info is HERE





Hopefully the early adopters who have already assembled the preamp can chime in with their experience/questions/suggestions.



Drop me a PM if you can't place an order through the WEBSITE - it's still in beta, especially for international customers.



BOM's are located here:

THATDIP Preamp v3e
UMPC Front Panel v4e
UMPC MIDI Remote v2e
UMPC PSU v1

For US customers note the "ORDER BOM" links at the bottom - this should save you guys some time! =)
Intl. customers - similar functionality is coming...
« Last Edit: August 08, 2013, 08:00:21 PM by promixe »


promixe

Re: Innersonix Lucidity Preamp (THAT1570/5171) Build/Support Thread
« Reply #1 on: May 16, 2012, 10:51:22 AM »
Essential UMPC Front Panel info:



You basically push all four buttons on the front panel, then turn on the unit and hold the buttons until the animation is over (about 2 sec. or so). Then you are in the configuration menu:

-A: Global mode of the firmware: "TH" means standalone mode for THAT5171 - use this mode when not using the MIDI Remote board and controlling the preamps directly from the Front Panel. "FP" means the Front Panel is in slave mode with a remote board attached to it acting as a master. Use this one in conjunction with the MIDI (or the upcoming Ethernet) Remote.

-B: The number of channels in the system + Connectivity Test: When in standalone mode this selects the number of channels in your build (then the firmware knows how to cycle between channels correctly). Also you can "sweep" all of the channels to check for connectivity with the THAT5171 chip. If your addressing on the preamp PCBs is done right then each channel # is going to display a dot "." next to it - this indicates that it sees the chip and can read from and write to it. If there is a "E" next to the channel # then the firmware can't talk to that chip. Either your addressing is not right, or the channel is simply not there. When the Front Panel is in Slave Mode ("FP" in menu A) this entire menu B is not available because the MIDI Remote automatically discovers number of channels sequentially upon startup. Which means that if you number (via resistor addressing - see Lucidity docs) your, say, 4 preamps #0, #1, #3, #4 then the MIDI Remote firmware is only going to discover the first two because when #2 is not responding it stops discovery and works with what it found so far.

-C: Adjustment of the displayed gain: You use this one to set the top gain value offset that your preamps have. Useful if you customized the line driver stage to boost or attenuate gain past the preamp and want the gain to visually represent this change. The bottom limit of the gain is calculated automatically by subtracting 55 steps from the top value. THAT5171 actual gain range is 13-68. If you used the values for the line driver from the schematic you set the menu C to either 70 or 75 (because the line driver has either +1.4 or +6.4 dB of gain past the preamp stage) and it is then accounted for in the UI. This is a global setting - you cannot have channel based adjustments for this one.

-D: Recall preamp state upon startup: If set to "Y" the firmware will recall all of the settings for each channel (gain, GPIO, last selected channel) when powered up. When set to "N" it will load default values (no GPIO, gain set to minimum, channel #1 is selected).

-E: Exclude GPIO from being recalled: Use actual GPIO buttons to set up a filter of which GPIO to skip recalling upon startup. Say, if you wanted to recall everything BUT the Phantom Power state (because you don't want to damage your mics on power on) just push the Phantom button and it will recall everything else but this function. This menu doesn't work if "N" is selected in menu D.

-F: Firmware version: a simple way to check the version number of UMPC Front Panel firmware.

-G: Group button behavior: When "G3" is selected the GROUP button (bottom right on the PCB) switches GPIO3 output of THAT5171. Use header H5 on the preamp PCB to utilize this function to switch custom things like an insert, etc. When "GP" is selected the GROUP button groups channel GAINS together. GPIO functions remain separate. The grouping behavior is what I call "Soft Grouping". Aphex 1788 user manual does a good job of describing this on page 33:
Quote
"..computes the modified individual channel gains in an invisible workspace that can retain over- and under-range values. This allows the unit to be able to restore the channels’ gain relationships if you reverse the direction of group gain shift after one or more channels have limited out."



To exit the config menu you reboot the unit. Hope this can get people started. Good luck! =) Questions - ask away here! =)

PS: There are a couple of known bugs in the UMPC Firmware so far. I'm waiting on more feedback on what to fix, what to improve, what to add, and they will be fixed in the next revision. Thanks!
« Last Edit: January 01, 2013, 09:19:17 PM by promixe »

okgb

Re: Innersonix Lucidity Preamp (THAT1570/5171) Build/Support Thread
« Reply #2 on: May 16, 2012, 08:16:57 PM »
Looks like nice work  , was it offered as a project ? I don't recall .
GKB Audio / Greg Boboski

Holger

Re: Innersonix Lucidity Preamp (THAT1570/5171) Build/Support Thread
« Reply #3 on: May 24, 2012, 10:29:15 AM »
My version, currently a two channel version,  easily expandable to 4 channels. Super clean, super quiet. Good work, Alex.











RMAA frequency response and noise, Fireface UC at 192kHz:




promixe

Re: Innersonix Lucidity Preamp (THAT1570/5171) Build/Support Thread
« Reply #4 on: May 24, 2012, 07:37:14 PM »
WOW!!! Howcome I've missed this thread's notifications...?! %] Anyway, this is so cool to see, Holger - you're the 1st official builder of this design! Well done!

Are you using it on any recordings yet? Do you have any preamps to compare it with (transformerless solid-state types)?

Holger

Re: Innersonix Lucidity Preamp (THAT1570/5171) Build/Support Thread
« Reply #5 on: May 25, 2012, 04:39:40 AM »
Alex, haven't used them yet. And no, I can't compare them to other transformerless solid state pres because I don't have any.
I was just curious how a modern digitally controlled preamp would perform compared to my other iron/DOA/tube pres, that's why I decided to jump on this project.
And from what I've heard so far this pre amp is clear and quiet.

12volts

Re: Innersonix Lucidity Preamp (THAT1570/5171) Build/Support Thread
« Reply #6 on: May 25, 2012, 11:32:56 AM »
Hi folks,
I am a builder of these pre-amps. I'm aiming for 8 channels in a 1U case - I haven't got as far as the case yet but most of boards are built and tested the idea is doable.
A pre-amp and controller were initially built just to try them out. Now, I've seen/heard most popular pre amps over the years in my workshop, and I'm fairly critical, but
I am impressed by this implementation of the THAT chip set. Only tried it on acoustic recording but the reactions have all been favourable (ie build me a 2/4 channel rig)
Hardware aside, the embedded software in the front panel controller is intuitive, I can't wait to try the promised meter bridge and the promised TCP/IP control - I'll cream
my pants if/when that appears. Photo's to follow ...


Frank B.
« Last Edit: May 28, 2012, 05:44:02 AM by 12volts »

i3j0rn

Re: Innersonix Lucidity Preamp (THAT1570/5171) Build/Support Thread
« Reply #7 on: June 02, 2012, 05:46:43 AM »
Is it possible to control the preamplifiers gain via Midi Control Change messages?

promixe

Re: Innersonix Lucidity Preamp (THAT1570/5171) Build/Support Thread
« Reply #8 on: June 02, 2012, 10:55:55 AM »
Is it possible to control the preamplifiers gain via Midi Control Change messages?

Yes, please take a look at THIS - starting at page 17 it details how to set up the preamp to be controlled via Pro Tools (or any other MIDI host, but without native UI for it). Pages 41-44 detail the MIDI implementation.

Basically UMPC MIDI Remote Firmware complies with the above implementation except:
  • It ignores LINE/INST source messages, because the Lucidity preamps only have MIC inputs
  • It ignores impedance messages, because Lucidity preamps have a constant non-switchable ~2k4 input impedance
  • It ignores HPF messages, because it's not implemented in Luciditiy, however, the INSERT header on the PCB could be used to implement an HPF in between the preamp and the line driver, and then be switched remotely via INSERT MIDI command.
  • MUTE is not implemented either and is ignored

The MIDI and Front Panel boards should actually be the easiest to build, in comparison to the PSU and Lucidity Preamp boards. The system could also be built using ONLY the MIDI Remote (and no Front Panel) or JUST the Front Panel and no MIDI Remote, or both could be used. It is pretty flexible in this regard.

I recommend building the Front Panel board anyway, because one can test the preamps with it (it has a test mode in the menu that checks connectivity of each channel and lets you know visually which channels it cannot communicate with, so you can narrow down a problem). It also narrows the scope of a problem, should one occur, to your build box, and not your computer (in case of MIDI control) and makes troubleshooting easier.
« Last Edit: December 23, 2012, 01:34:29 PM by promixe »

zebra50

Re: Innersonix Lucidity Preamp (THAT1570/5171) Build/Support Thread
« Reply #9 on: June 02, 2012, 11:28:42 AM »
This is awesome stuff!
Ribbon microphone services
http://www.xaudia.com
Microphone blog


ArnauTS

Re: Innersonix Lucidity Preamp (THAT1570/5171) Build/Support Thread
« Reply #10 on: June 02, 2012, 11:36:38 AM »
This is awesome stuff!
+1 really interesting. Hope i can build some soon
if you can have it all, stop in the middle

i3j0rn

Re: Innersonix Lucidity Preamp (THAT1570/5171) Build/Support Thread
« Reply #11 on: June 21, 2012, 03:52:32 PM »
I received the boards today. All parts in stock...
Great!
« Last Edit: June 21, 2012, 05:17:37 PM by i3j0rn »

i3j0rn

Re: Innersonix Lucidity Preamp (THAT1570/5171) Build/Support Thread
« Reply #12 on: June 22, 2012, 11:07:58 AM »
Is it a mistake in the BOM?
In the mouser references you suggested:
The preamp 33 pF poly (C22) are rated for 1000V.
Also the  preamp C20, C21 poly caps are 150 pF instead of 180pF.

is it ok to use them?



promixe

Re: Innersonix Lucidity Preamp (THAT1570/5171) Build/Support Thread
« Reply #13 on: June 22, 2012, 11:15:26 AM »
Is it a mistake in the BOM?
In the mouser references you suggested:
The preamp 33 pF poly (C22) are rated for 1000V.
Also the  preamp C20, C21 poly caps are 150 pF instead of 180pF.

is it ok to use them?

No mistake - that's what I use in my pres here. It's usually hard to find a smaller voltage rated WIMA of this capacitance (33pF) in stock, and since they are the same physical size and are not electrolytic it should be suitable for this application. As long as C22 is faster (smaller value) than the main two feedback caps (C20/C21) there shouldn't be any problem. If you measure the WIMA 150pF actual capacitance with a DMM they sometime come close to 220pF which is actually good for this line driver stage. =)

promixe

Re: Innersonix Lucidity Preamp (THAT1570/5171) Build/Support Thread
« Reply #14 on: June 22, 2012, 11:19:26 AM »
Also, make sure that you solder the uC socket on the front panel BEFORE the LED 7-segment display on the opposite side. Otherwise it's impossible to assemble. =)

Another important thing: You should cut pin 7 of the LM2676 before you solder it to the PCB (or after you solder, doesn't really matter except that it's easier to do before soldering). Pin 7 is the on/off pin, rightmost one if you are looking at the front of the package (closest to C21), and if it is left connected to the PCB the reg will go into standby mode and not output anything. Took me a bit to trace, and I will fix this with the next revision of the PCB. =)

Also, to make the bipolar rails as symmetrical as possible you should match R4/R6 and R3/R5 with a DMM as close as possible. Not the absolute resistance values but just so these pairs match each other's values as tight as possible. Not a requirement, but I think it helps.

i3j0rn

Re: Innersonix Lucidity Preamp (THAT1570/5171) Build/Support Thread
« Reply #15 on: June 22, 2012, 03:22:16 PM »
THanks for the advises.

Almost finnished!

Btw the red Omron switches were out of stock with a very long delay. I took this model instead http://www2.mouser.com/ProductDetail/Omron-Electronics/B3W-9000-RG2N/?qs=EHIUIbu4Vmga69L8Ovky9BEPnglzbO77
in the same serie...
It's a two led model (red/green). I was hoping to make it work as a single red switch by letting the green led unused. Do you think it could work. I've looked at the documentation but I  can't be sure...

« Last Edit: June 22, 2012, 03:35:21 PM by i3j0rn »

promixe

Re: Innersonix Lucidity Preamp (THAT1570/5171) Build/Support Thread
« Reply #16 on: June 22, 2012, 03:47:09 PM »
Btw the red Omron switches were out of stock with a very long delay. I took this model instead http://www2.mouser.com/ProductDetail/Omron-Electronics/B3W-9000-RG2N/?qs=EHIUIbu4Vmga69L8Ovky9BEPnglzbO77
in the same serie...
It's a two led model (red/green). I was hoping to make it work as a single red switch by letting the green led unused. Do you think it could work. I've looked at the documentation but I  can't be sure...

Yes, it should work. You have to find the right legs for the RED color (test with a battery+resistor) and cut off the GREEN legs and then orient it the right way prior to soldering to the PCB. Just take your time with this one and pay close attention to how to solder it in the right way. But I don't see a reason it shouldn't work. =)

i3j0rn

Re: Innersonix Lucidity Preamp (THAT1570/5171) Build/Support Thread
« Reply #17 on: June 22, 2012, 04:57:04 PM »
Perfect! Thanks!



Soldering DONE.
Tomorrow Wiring...



promixe

Re: Innersonix Lucidity Preamp (THAT1570/5171) Build/Support Thread
« Reply #18 on: June 22, 2012, 08:02:12 PM »
Looks good!

FIY, the UMPC Firmware chips - the one with the white marking (ATMega48) goes to the MIDI Remote board and the one without the marking (ATMega88) goes into the Front Panel.

Also, before you plug in the PSU: you need to insulate all four regulators on the PSU from the heatsinks and each other. Make sure they are not touching neither the heatsinks nor the other regs, because all of their thermal pads are at different voltage potentials and shorting them together would not be a good thing. =)

What else?... I really gotta find time and throw a basic manual of the UMPC Firmware, because there are quite a few useful features inside the setup menu, but:

EDIT: UMPC Firmware info has been relocated to the 2nd post of this thread.
« Last Edit: December 23, 2012, 01:35:47 PM by promixe »

i3j0rn

Re: Innersonix Lucidity Preamp (THAT1570/5171) Build/Support Thread
« Reply #19 on: June 24, 2012, 12:12:14 PM »
Wiring DONE! Ready for testing!
Before I do something wrong... :P

On the preamp board:
Do I live J3 and J4 open?

Midi/Front panel board:
There is a two pin header labeled "prog" on the midi board do I have to connect it to the Front panel?

Also, before you plug in the PSU: you need to insulate all four regulators on the PSU from the heatsinks and each other.
What should I use to do that? Plastic film?

Thanks again for your support.


 

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