[BUILD] Innersonix Lucidity Preamp (THAT1570/5171) Build/Support Thread

[i3j0rn]

Hi.
I haven't been here for a long time but I would like to thank you again for your great work!
I I'm still amazed about how clean and precise the sound of this preamplifier is. I did some more tests with a friend of mine. He use Neve, Uad, millenia, etc preamps on his studio. We both agreed: this preamp sound great! (He also was more than interrested in the Tcp-ip remote option). We have tried a lot of quality preamps before. Choosing the right tool is always a matter of taste but once your ears have tasted quality stuf you don't want to go back. So when you plug your favorite microphone on a new preamp you instantaneously know if it's gonna do the job or not.
This little preamp has everything someone should expect from a high quality piece of hardware.

Greatings from the French Alps.

Jonathan.

 

[i3j0rn]

Hi,

Is one UPS enough to power eight preamps? I guess the UPS needs some modification to work with European 220V?

No modification is needed. You just have to choose the right transformer... I used a 220V to 2X 25v/1.6A for my four channel preamp.

 

[promixe]

I found the Boms, if those are the actual ones. Still missing the cutout info though...
http://www.groupdiy.com/index.php?topic=45035.msg607977#msg607977

Yes, these are the latest BOMs. The dimensions for the Front Panel PCB can be looked at HERE. Both the LED display and the encoder are centered vertically on the PCB (i.e. are at ~18.5mm from either top or bottom edge of the PCB).

PS: Jonathan, that's a nice review about Lucidity, thank you! =) Yes, it does sound ridiculously high-end in many applications and if one already owns a pair or more of vintage preamps then Lucidity could not only inexpensively increase the channel count of one's setup, but also could bring a whole lot of versatility to it.

PPS: I'm currently working on a 4-channel Lucidity rig for a client of mine, will post pictures, sounds, and more info here as soon as it's ready. =)

Thank you all!

 

[delphi]

Hi Promixe,

I had to put my 8 channel 1U build plus FPC/MC on hold but now I have time over the Christmas break I have now resumed. All 8 channels are now populated as well as the FPC and MC and PSU.

What is purpose of H5 - I have just soldered in a 2 pin male header - do I need to jumper this closed?

YOu also kindly shipped me two of your 4 channel stacked jack boards - I cant find the stacked jacks that fit the board - can you give me spec/part number.

I am assuming L1 thru' L8 are the same inductor for EMI/RFI suppression as on the input of the Lucidity. the 3 capacitors for each output are obviously the same for each of the 4 channels. Am I correct in assuming I can use 470pf COGs across the two inductors and then 220pf from each line to ground? IN other words can you tell me the value of C1, C3 and C2 please.

Thanks

 

[promixe]

Hi Brian,

I'm glad you're progressing on your build! =)

What is purpose of H5 - I have just soldered in a 2 pin male header - do I need to jumper this closed?

H5 is not a jumper but a +3.3V CMOS logic output header from the 5171 chip. It links to its GPIO3 output and you use this output for a multitude of applications, such as switching an Insert in and out. In other words you would route the signal from H5 to a relay (not directly, of course, but through a relay driver or a transistor) to switch something or an LED to light up, etc.

Then the bottom right button on the UMPC Front Panel can be used to toggle that GPIO3 output (H5) on or off. Otherwise that button is the GROUP button and is customizable in the UMPC configuration menu.

You also kindly shipped me two of your 4 channel stacked jack boards - I cant find the stacked jacks that fit the board - can you give me spec/part number.

I am assuming L1 thru' L8 are the same inductor for EMI/RFI suppression as on the input of the Lucidity. the 3 capacitors for each output are obviously the same for each of the 4 channels. Am I correct in assuming I can use 470pf COGs across the two inductors and then 220pf from each line to ground? IN other words can you tell me the value of C1, C3 and C2 please.

Below is a HALF of the output board schematic (identical to the other half):

Yes, the L1-L8 are the same as L1 and L2 on Lucidity. C1/C2, C4/C5, and so on, correspond to C4/C5 filtering on Lucidity (I use 220pF there). And C3/C6/C9/C12 are the common mode filtering caps, same as C6 on the preamp.

The jacks are dual stacked Neutrik NSJ12HF-1. Let me know if you can't find it in your region, I might be able to get you some from the US. =)

Thanks!

 

[delphi]

Thanx promixe for the reply - that clears up all my "loose end" questions. I'm now having fun getting a case and front panel etc fabricated locally here in Manila.

I have tested one of the boards so far - and extremely happy with it - my usual pres are either the Yamaha 02r96 head amps or Neve and API DIY clones - and the THAT is a really handy different animal - going to be very good on acoustic material where I seek transparency. That said I had one of the best female singers in the Philippines visit my studio yesterday on  a social visit and she did a rendition of "someone like you" using the THAT and a Rode NTK (specifically to let me audition the preamp) and she was "stoked"with the sound. (and she is VERY choosy). Also sounded awesome using a stock Avantone CK7.

Great pre!

If you can source the neutrik stacked jack for me I would be very grateful as unsurprisingly can't find these in Manila and neither could I find them in Thailand when I was there two weeks ago.

Drop me a PM if you can help.

Thank you

Brian

 

[promixe]

I have tested one of the boards so far - and extremely happy with it - my usual pres are either the Yamaha 02r96 head amps or Neve and API DIY clones - and the THAT is a really handy different animal - going to be very good on acoustic material where I seek transparency. That said I had one of the best female singers in the Philippines visit my studio yesterday on  a social visit and she did a rendition of "someone like you" using the THAT and a Rode NTK (specifically to let me audition the preamp) and she was "stoked"with the sound. (and she is VERY choosy). Also sounded awesome using a stock Avantone CK7.

Great pre!

Thanks for the groovy review! =) I do agree that Lucidity sounds ridiculously musical on nearly all acoustic sources. In this particular case I find that the transparency of the sound we're talking about, while very precise and hardly-colored, has an abundance of life and musicality to it. Strange, almost paradoxical, when one tries to talk about it. =)

PS: This singer, her name is not Dian, is it? =)

PPS: I've PM'ed you about the NSJ12HF-1 jacks. =)

Happy 2013 to everyone! =)

 

[delphi]

Agree with your comment about paradoxical. Other transparent pres such as the IMPACTs in my TC Konnekkt 48s are exactly as advertized  - what goes in ostensibly is what comes out, whilst the THAT does sound different but still ultra clean (and very very quiet).



The singer was not Dian . Cant reveal identity I am afraid.

I have misplaced 2 of the SN74LV125A's and cant source DIP version locally (only SOIC) so will drop you a PM.

Cheers

 

[promixe]

Hi All,

Sorry I've been out of the loop with a flu, on the upward slope now, hopefully. =) Brian, I'll sort out stuff on my end and will send you a PM. One thing I checked is that the dual stacked jacks with FULL threaded nose are out of stock at Mouser until 1st week of Feb.

And I do happen to have just two output boards left. =)

SN74LV125A - I'll order a few extra along with the jacks. =)

 

[delphi]

Brilliant - thanks for the offer of assistance re stacked neutriks - and I will definitely buy your two remaining output boards - really useful critters when trying to fit 8 channels in a 1RU and avoiding using DB25 D style connectors (hate the metal work).

Also thanks for the SN74LV125A procurement. Will communicate via PM from now on for this issue.

Had a guy round earlier that runs a little boutique studio and he was real interested in the Lucidity after hearing one of my Lucidity boards record a little acoustic guitar ditty he is working on. He was asking if there could be a digital readout for each channel showing the current gain setting per channel - personally I think that's needless eye candy - but told him I would pass on his comment to you.

Needless to say he also asked about metering. He does a lot of choir and string quartets so wants a workhorse with as many channels as can be jammed into a 1U. He has been using a Burr Brown modded Presonus M80 with Jensen trannies which is needing a major service due to noisy pots etc - and looking for something new and more transparent. He was looking at a Focusrite ISA828 but the price locally made his eyes water and he said they have a color of their own which is great for some material but not for quartets and choral/choir.



Cheers

 

[subbass]

Hello and thank you for this promising project!
Just for the sake of interest: did you take in account with your layout that with this modern chip it is (as the feedback resistor was removed) now possible to optimize noise at *low* amplifications (where normally the preamps are the most worse)? http://thatcorp.com/datashts/De-integrating_Integrated_Circuit_Preamps.pdf
A more practical question: is there any date when the controller board is in stock again (and perhaps even when the tcp/ip and meterbridge perhaps will be available)?
Woudl love to order a few...
Thanks, Martin

edit: as I see the output stage seems to be the one suggested "after Birt"?

 

[promixe]

Hi Martin,

Thank you for your interest in this project. That's a groovy link to THAT's presentation - haven't encountered that one before, will be a good read tonight, thanks for that too. =)

...is there any date when the controller board is in stock again (and perhaps even when the tcp/ip and meterbridge perhaps will be available)?

I do have 5 Front Panel PCBs in stock at the moment, as well as 4 MIDI Remote PCBs. I've also designed a new PSU for the system, which is more compact, has trimmers for the dual rails and a few more cool things, I have 10 of those in stock, but I haven't even had time to test it, let alone publishing pictures and info about it. =)

I'm currently in the process of the TCP/IP firmware development for the OSCAR project. In fact, gonna get back to it as soon as I'm done answering here. =) I'm not gonna say much right now, but in overall it seems that it's going the direction that is way beyond of its initial scope that I originally envisioned. =) But one step at a time is what I'm gonna do, so I'm intending to release a beta version of OSCAR hardware/software this summer. It will allow to remotely control up to 32 channels of Lucidity (or 32 channels of one other super-cool remote preamp I'm designing right now) within a single app (win/osx/linux desktop versions come first).

As far as the meter bridge, I'm designing a solution right now that will integrate the Front Panel facilities with built-in networkable metering. This will come as the next generation of UMPC blocks, I'll elaborate when time comes for me to show something. =)

edit: as I see the output stage seems to be the one suggested "after Birt"?

Yep, I used Birt if configured as balanced output (as described Here), but I'm not sure whether or not the unbalanced circuit is credited to his name as well. So, at least 50% of the output is Birt. =)

Thanks!

 

[plinker]

Hello,

What is the purpose of the Quad Buffer?

I've looked at the THAT notes (and schematics) for the ICs your using, and they don't mention a quad buffer.

Thanks,
Jim

 

[promixe]

Hi Jim,

It's on page 15, figure 11 - http://www.thatcorp.com/datashts/THAT_5171_Datasheet.pdf
And on page 14 in "Flexibility in SPI Address Setting with a Tri-State Buffer" explains the reasoning behind the buffer. Quite honestly, I never understood why 74LV125A + OE-inverter were chosen for the buffer, as opposed to just using 74LV126A, which is the same except polarity of OE (Output Enable) pin. Using 74LV126A would spare an extra reset pin on the uC, but at the expense of not being able to separately control the output of the buffer (which my firmware is taking advantage of by delaying buffer's output by a few 10s of mS upon reset of the 5171, which gets out of reset a bit earlier than the buffer, if that makes any sense).

In short, you wouldn't need that buffer if you didn't address multiple 5171s on the _same_ SPI bus. I have around 50 Lucidity channel boards that don't have the buffer (early protos) but are fully usable when having a separate controller per channel. =)

I've also been searching for a 3.3V part (I wish TPIC6 series were) to integrate discrete transistor relay drivers with tri-state buffers and save more space by hooking it up directly to bare relays, but haven't been able to find a suitable DIP package. Any ideas?

What is the purpose of the Quad Buffer?

I've looked at the THAT notes (and schematics) for the ICs your using, and they don't mention a quad buffer.

 

[brandondrury]

anyone wants to chime in as to what would be the reason for this design to remain unpopular? =)

Finally a question I'm qualified to answer. 

The short versions is they (you know, "they") have taught us that "clean" preamps are for classical music and are "clinical", "boring", "unmusical", etc and that the real money is in Neve, API, Trident, etc.  I had about $15,000 in high end preamps that fit this bill.  Ironically, the Martech MSS-10 is considered a "Ferrari" at Mercenary Audio and is definitely doing the clean thing.

I picked up a certain clean chip based preamp for $51 on Ebay and the whole game changed for me.  I'd rather have this than API, Vintech, Wunder, etc.  It was what I've wanted for some time.

When guys hear a straight wire-type preamp for the first time, they usually add a positive adjective + "detail", "top end" etc that comes with the faster slew rates and such.  In other words, they are generally surprised that a straight wire preamp is so good.

So ultimately, to see a billion straight wire preamps you'd need to change the general consensus.  I have no problem with people liking their Neve and API.  (I certainly don't dislike those tools.)  However, I'd imagine most of the populous is basing their views on dirty preamps on internet discussion more than listening experience.  I know I did. 

Brandon

 

[ngineer]

Does anyone know if this series of boards is still available?

 

[Upacesky]

Try to contact him via facebook, he always answered, at least to me.

 

[AudioHammer]

What are the jumpers CHA (A, B, C, D) on the UMPC MIDI Remote and what should the default settings be? 

Thanks!

 

[AudioHammer]

Bump on last question...

Alex at Innersonix asked that post questions on this forum instead of direct emails or facebook...so I did.

no response...  Anyone have any info on the umpc midi remote jumper settings?

Thanks!

 

[therald2000]

I finally am building a pair of these preamps, a power supply, and the front panel. I am looking for the ribbon connectors and wiring header sources. Do you have any part numbers?