Tortuga Preamps

https://www.tortugaaudio.com/

Are these still being made and what is the link to purchase?
Are these offered with real balanced connections.?

Yes send a PM or there are many other ways just Google, or if you have the diy skills build one for yourself, as I've given all the instructions here.  
https://www.diyaudio.com/forums/analog-line-level/80194-lightspeed-attenuator-passive-preamp.html

And no I don't believe in xlr, unless your in a studio with with lots of noise problems, extra long runs of interconnects.
My customers use these if they need, XLR to RCA adapters, Neutirk being fair value for money, some are much less expensive 
 https://i.ebayimg.com/images/g/wrMAAOSwDk5UBLdo/s-l300.jpg

Cheers George 

I try desperately to stay out of the subjective vs. measured debate...it gets so old and tired.

I try to keep it simple. Do you like what you hear? Yes? Stay with it.

Don’t like what you hear? Try something else.

Is that so hard?

I know people read all these things about what’s good and what’s not and what are they to believe? Please, tell me what to believe!!!!

The neurochrome report screams one thing and one thing only in my view. It does a very good job at making the point that measurement (beyond a certain threshold point) is simply not relevant or informative.

One would think that neurochrome’s measurements would indicate that the Tortuga model that was measured would sound awful. It does not!

Moreover, we are several iterations beyond the model measured by neurochrome and it only gets better.

Trust your ears.

Cheers,
Morten

Regarding "active forced matching" mentioned above, the way it's described in this thread is NOT how Tortuga Audio implements this feature. During normal operation of the passive LDR preamp there's zero active matching going on. That measurement circuitry is disconnected and inactive when you're using the preamp. What we call LDR calibration or "auto calibration" only takes place when the preamp is essentially offline. Inputs and outputs are disconnected and the preamp operates in isolation during the calibration process that typically takes around 10 minutes for all 4 LDRs. This process is manually initiated by the user. I think it's fair to say that this calibration process is 90% all about the software behind it and only 10% about the hardware configuration. It took a boatload of software development work to sort this feature out and get this working smoothly. As a result, if/when an LDR goes bad, goes far enough out of spec limits, or simply shifts its performance curve, it's a simple matter of unplugging the bad LDR, popping in a new one, running a calibration cycle and Bob's your uncle ;)  I do agree that it would have been far easier for us to use pre-matched LDRs which we did do in the beginning. Easier for us but not so much the customer  if/when an LDR goes south. ;)