[tortugaranger]

The topic of break-in has been a slowly evolving one from my perspective. First because I'm just inherently skeptical until I'm convinced otherwise. And probably also because it's a case of being too close to the trees to see the forest. Commissioning new units each week doesn't provide enough time and then the unit I use for personal use has been around long enough that it's beyond any break-in and it runs on a different system than what we use for commissioning. Simply put, I don't get to experience the process....just the end result.

I've been accumulating  feedback from customers who do go through the experience very deliberately and then take the time to let me know about it. There is now a clear consensus that there is indeed a break-in period with LDR preamps. One very enthusiastic owner advised the process took upwards of 2-3 weeks. Another ran his unit 48-72 hours non-stop into an unpowered amp with music playing that emphasized strong dynamics such as tight bass and sharply percussive music. Others reported noticeable changes after a few days and perhaps 10-15 hours of play time.

Prior to break-in the sound stage may be a bit pinched/tight and highs may be a bit emphasized. After break-in the sound  becomes more relaxed and open. Sound stage widens and it's easier to place instruments within the sound stage.  Clarity, articulation, and lack of coloring - core characteristics of LDRs - are present from the get go and do not appear to change.

In summary, you should expect initial break-in after 10-20 hours of listening and depending on how often you use it figure on 2-3 weeks of regular moderate listening for the process to complete - worst case.

If any of you have similar or different experiences please let us hear from you.

Cheers,
Morten

[kernelbob]

My experience is that every component needs a break-in period-- cables, amps, speakers, DACs, etc.  The length of time may vary from a week or so to several months.  Even with just moving interconnects, it may take an hour for them to return to their performance plateau.  Many rooms at audio shows are very disappointing on Friday, tolerable on Saturday, and may start sounding up to their capabilities Sunday afternoon just before the equipment is shut down and crated for shipping.  Some otherwise excellent rooms are often ruined by one piece of equipment that was hurriedly built and shipped with no break-in.

Regarding the Tortuga preamps, I just received an LDR1B with the upgraded copper wiring.  Fresh out of the box, there was a broad upper midrange glare and less than extended bass.  After a day or so of a track on a CD set on repeat with lots of intense transients, that glare started to clear up and after three days the unit was coming into it's glory.

One other thing I noticed was that on the first day out of the box, at some impedance settings, I was getting some L/R imbalance and some low level hum/buzz.  Again, after a couple of days that all cleared up.

I'd recommend that a new unit be powered on and exercised with transient-rich music for a couple of days before exploring the impedance settings and certainly before making any judgements of the sound quality.  Once the Tortuga preamp settles in, it's an amazing product and a huge bang for the buck component.

[robertopisa]

So according to your reasoning, each time we change impedance value setting, should we break in? This change is similar to changing cables.
-R

My experience is that every component needs a break-in period-- cables, amps, speakers, DACs, etc.  The length of time may vary from a week or so to several months.  Even with just moving interconnects, it may take an hour for them to return to their performance plateau.  Many rooms at audio shows are very disappointing on Friday, tolerable on Saturday, and may start sounding up to their capabilities Sunday afternoon just before the equipment is shut down and crated for shipping.  Some otherwise excellent rooms are often ruined by one piece of equipment that was hurriedly built and shipped with no break-in.

Regarding the Tortuga preamps, I just received an LDR1B with the upgraded copper wiring.  Fresh out of the box, there was a broad upper midrange glare and less than extended bass.  After a day or so of a track on a CD set on repeat with lots of intense transients, that glare started to clear up and after three days the unit was coming into it's glory.

One other thing I noticed was that on the first day out of the box, at some impedance settings, I was getting some L/R imbalance and some low level hum/buzz.  Again, after a couple of days that all cleared up.

I'd recommend that a new unit be powered on and exercised with transient-rich music for a couple of days before exploring the impedance settings and certainly before making any judgements of the sound quality.  Once the Tortuga preamp settles in, it's an amazing product and a huge bang for the buck component.

[tortugaranger]

So according to your reasoning, each time we change impedance value setting, should we break in? This change is similar to changing cables.
-R

I would argue that changing impedance level is not comparable although I can't prove it either way. My reasoning is that changing impedance, while it does change an electrical characteristic of the system, does not in any way involve the disconnection/reconnection of components or otherwise physically alter the audio pathway.

What happens when impedance is changed is that the combined resistance of the 2 LDRs in each channel (the Series and Shunt LDRs) are changed to add up to a new combined value. It's as though you changed from say a 10k pot to a 50k pot except in the case of LDRs it's the exactly the same hardware only it's behaving slightly differently in terms of its electrical behavior. It's literally as if you had a potentiometer (pot) with an impedance adjustment feature - a magical second knob you could turn in addition to the primary volume knob.

A brief tutorial: Volume control is voltage division where Vout = Vin x (Rshunt/(Rseries+Rshunt) and dB (attenuation) = 20 x log(Vout/Vin). Thus when you change from say a 10k to a 50k impedance it's the denominator (Rseries + Rshunt) that is being changed. Now in order to establish the dB attenuation schedule for that new impedance level (denominator) you need to calculate and set up the new Rshunt and Rseries pairs at each dB step (70 of those) that gives you both the new impedance level as well as the targeted dB schedule. In reality, in order to get all the way down to -60 dB you can't maintain the  fixed impedance over the full range and so the impedance actually rises starting around step 20 as you go down to step 1. Beyond around step 20 the impedance remains constant. All of that is handled with software during the auto-calibration process.

In conclusion, I would submit that simply changing the Rseries/Rshunt resistance levels of the existing LDRs does not require additional break-in insofar as these very same LDRs had already gone through break-in and normally operated across a wide range of resistance levels/ratios at the prior impedance level.

[33na3rd]

I experienced the break in phenomena with my LDR3.V2.

It was blissfully short, but it was there!

Thanks again for a great product, Morten!