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LDR1 - User Review - First Impressions
End user commentary on the LDR1 Passive Preamp
August 10, 2013
7:40 pm
Morten Sissener
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March 19, 2012
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Gerry E. said

Hi Morten:

Thanks for the reply.  I want to revisit another topic that I briefly mentioned a while ago: adding an "upgraded" power supply.  I know in the manual it says that the stock PS is pretty good for a wall-wart.  I would also guess that it's more than good enough.  However, is it even possible that a good linear/regulated power supply could improve performance?

The power supplies I'm looking at are not expensive, they are in the $20 - $40 range.  That will get you a brand new 12vDC 2 or 3 amp supply.  Also in that price range are used, heavier duty commercial supplies.  Some of those while advertised as 12v, actually output 13.6 or 13.8v.  Would that voltage harm the LDR1?  Any other thoughts about after market power supplies?  Thanks!

Gerry    
 

I've gone around the track several times on whether an upgraded power supply would make a difference with the LDRx preamps. The 12 VDC wallwart supply, being a switching supply, does introduce high frequency noise however it's far above the audio range. Usually 100khz or higher. Unlike active preamps and amps the power supply in the LDRx preamps is not directly interacting with the audio signal, but could conceivably influence it indirectly. But in order for any power supply noise to be seen by the audio signal side of the LDRs it would have to get through a low pass filter on the LED side. So given the high frequency and low pass filtering you could argue that a better power supply won't buy you any noticeable improvement in audio quality as far as your ears are concerned. But of course I could be wrong :) . In all honestly I've not run A/B tests to determine if there's a discernible difference. 

Nevertheless I am thinking of introducing an upgraded linear 12VDC supply both as an original option and as a future upgrade. But it's currently on the back burner of our development priorities but that could change. 

I don't think 13,14 or even 15 volts would be a problem. At some point it could become an issue with the 12 VDC trigger out which is just a pass-through of the nominal 12 VDC power but that's a compatibility question with external gear. Internally the unit steps down the 12 VDC to 5 VDC via a regulator. Although the regulator could handle upwards of 30 VDC heating would likely become a problem. Since the current draw on the LDRx units is very low, the 5 VDC regulator runs without a heat sink. 

Pricing on linear power supplies is all over the map. I find them priced  in the $50-75 range but haven't looked exhaustively. The problem (price) is most have way more power capacity than is needed by the LDRx which is typically around only 200 ma. And even rarer is to find a true "wallwart" linear power supply. Probably because it would be overkill for most consumer electronics not to mention more expensive. 

I'd be interested to hear your impressions if you do try one. Don't forget to make sure the inner barrel of the DC plug is +12 and not the other way around. Reversed polarity power would be a quick way to brick an LDRx. !! 

August 10, 2013
5:24 pm
Gerry E.
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October 27, 2012
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Morten said

Congrats on your upgrade and glad to hear you kept your LDR1. In most instances an LDR based passive preamp will outperform most any preamp and match even the best of breed active preamp. This is especially true if you're driving tube amps that have inherently high input impedance such that impedance mismatch is a non-issue. Rock on! 

Hi Morten:

Thanks for the reply.  I want to revisit another topic that I briefly mentioned a while ago: adding an "upgraded" power supply.  I know in the manual it says that the stock PS is pretty good for a wall-wart.  I would also guess that it's more than good enough.  However, is it even possible that a good linear/regulated power supply could improve performance?

The power supplies I'm looking at are not expensive, they are in the $20 - $40 range.  That will get you a brand new 12vDC 2 or 3 amp supply.  Also in that price range are used, heavier duty commercial supplies.  Some of those while advertised as 12v, actually output 13.6 or 13.8v.  Would that voltage harm the LDR1?  Any other thoughts about after market power supplies?  Thanks!

Gerry        

          

 

July 7, 2013
10:36 am
Morten Sissener
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March 19, 2012
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Gerry E. said
Hi: Here's another update.  I decided that if I couldn't get a silver face-plate from Tortuga Audio to match my Marantz SA-7S1 CD/SACD player then I would replace the player with a black one:   Of course I'm just joking.  However, I did replace the SA-7S1 with a black-finish Marantz SA-11S3.  I wasn't looking to sell the SA-7S1 but when someone advertised that they were looking for one, I thought it would be a good opportunity to sell. Before purchasing the SA-11S3, I gave strong consideration to the new SOtM sDP-1000 DAC/Preamp (see the 6Moons review).  I really liked the fact that the sDP-1000 has both an analog input and analog volume control.  I could run a less expensive player into the sDP-1000 two ways: into the analog input for SACD playback and into one of the digital inputs for CD playback. Of course this would mean no longer needing the LDR-1.  In the end, two factors convinced me not to go that route.  First, I wanted the best SACD playback I could afford and a lesser player probably wouldn't offer that.  Second, I really didn't want to replace my LDR-1 with the (presumably) solid-state preamp section built into the sDP-1000.  Even though the preamp runs off batteries (read the review). In the end, I'm very happy with my decision.  The SA-11S3 sounds even better than the SA-7S1 and of course matches the LDR-1. Gerry P.S. Now if only the LDR-1 had a volume display, it would be perfect!  Smile

Congrats on your upgrade and glad to hear you kept your LDR1. In most instances an LDR based passive preamp will outperform most any preamp and match even the best of breed active preamp. This is especially true if you're driving tube amps that have inherently high input impedance such that impedance mismatch is a non-issue. Rock on! 

July 6, 2013
4:31 pm
Gerry E.
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Forum Posts: 9
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October 27, 2012
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Hi:

Here's another update.  I decided that if I couldn't get a silver faceplate for my LDR-1, to match my Marantz SA-7S1 CD/SACD player, then I would replace the player with a black one:

 

Of course I'm just joking.  However, I did replace the SA-7S1 with a black-finish Marantz SA-11S3.  I wasn't looking to sell the SA-7S1 but when someone advertised that they were looking to buy one, I thought it would be a good opportunity to sell mine.

Before purchasing the SA-11S3, I gave strong consideration to the new SOtM sDP-1000 DAC/Preamp (see the 6Moons review).  I really liked the fact that the sDP-1000 has both an analog input and analog volume control.  I could run a less expensive digital player into the sDP-1000 two ways: via RCA interconnects into the analog input for SACD playback and via a digital cable into one of the digital inputs for CD playback.

Of course this would mean I would no longer need my LDR-1.  In the end, two factors convinced me not to go that route.  First, I wanted the best SACD playback I could afford and a lesser player probably wouldn't offer that.  Second, I really didn't want to replace my LDR-1 with the (presumably) solid-state preamp section built into the sDP-1000 (even though it runs off batteries - read the review).

In the end, I'm very happy with my decision.  The SA-11S3 sounds even better than the SA-7S1 and obviously is a much better cosmetic match to the LDR-1.

Gerry

P.S. Now if only the LDR-1 had a volume level display, it would be perfect! Hint, hint. Smile

March 6, 2013
7:10 am
Gerry E.
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October 27, 2012
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Hi:

I can’t believe it’s been another two and half months since my last post to this thread.  Time seems to speed up as you get older.  Apologies to Einstein but that’s MY theory of relativity.

I just want to write that my LDR1 continues to perform flawlessly and sound great (and I still haven’t used the Encoder knob).  I did a listening test the other day and the LDR1 allowed me to clearly hear the differences between a well recorded CD and an SACD of the same title.  In other words, the LDR1 didn’t mask the difference. 

I also wanted to mention with additional listening, I detected a slight channel imbalance in my system.  This is not a function of the LDR1, my system always seems to favor the right channel ever so slightly.  It’s most likely related to my listening room.  With a little fine tuning using the LDR1 channel balance function, the channels are now perfectly balanced – something I’m particularly sensitive too.  Keep that in mind if you are considering the purchase of any volume control device that lacks some kind of balance control.                 

In-in-all, if my LDR1 had a volume level display, it would be virtually perfect.  The good news is that future generations will have that display.  Speaking of which, with its bamboo side panels and good sized display isn’t the new LDR3B shaping up nicely?

Gerry                

January 8, 2013
12:40 pm
Morten Sissener
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March 19, 2012
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Gerry,
Your first impressions appear to be very consistent with an independent review by HiFiPig.com. Here are a few quotes below from that review. The full review can be found here.
Morten
 

There is just a sense of absolutely everything having been stripped free of fuzz and imprecision. Instrumental placement isn’t approximate or inferred. Instead, instruments are precisely located at a fixed and exact distance from the others with the space between performers and the characteristics of the recording environment jaw-droppingly obvious.

 … the LDR6 produces a sound completely free of colouration, with a soundstage that was just consistently deeper and better resolved than with any other passive pre-amp I have ever used.

…suitably matched, sonically, the LDR6 is an absolute gem. Jaw-droppingly transparent, with faultless microprocessor control, this pre-amp provides a level of transparency usually the domain of hair shirt enthusiasts, with the convenience of remote control.

It’s possibly the most transparent pre-amp I’ve yet used.  

December 23, 2012
12:43 pm
Gerry E.
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October 27, 2012
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Hi:

It’s been more than three weeks since my last post and I can confirm everything I wrote previously with one exception (see below).  My system is sounding ultra-smooth, rich and liquid with an exceptionally wide soundstage.  Much of the credit for that goes to my high quality single-ended triode amps and vintage ALNICO magnet speakers.  However, if the LDR1 was inhibiting those performance attributes in any way I would hear it and it doesn’t.

I still haven’t used the Encoder knob.  With the excellent remote control, I’m just not motivated to do so.  The one exception to what I wrote previously is the volume level when turning the unit on.  It appears that it will start up at step 15 if the previous volume level was 15 or higher at turn off.  If the level was less than 15 at turn off, it will start at that previous level but with a minimum start up level of 5.  Once again, this is all good by me – it will never start up at too high a level and it will always start up with at least a little volume (step 5).

I don’t recommend anyone doing this but when I performed the volume tests above, I did so with my amplifiers still ON.  I assume all or most audiophiles know that you turn your amp(s) off before turning your preamp off and vice-versa on start-up – to avoid on/off transient noises.  This first time I turned the LDR1 off with the amps still on was by accident.  Nothing bad happened so I continued to do so including turning the LDR1 on with the amps already on.  All of this is another example of noise-free and glitch-free operation of the LDR1.

Gerry                                       

November 29, 2012
9:49 pm
Gerry E.
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October 27, 2012
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I forgot to mention that the LDR1 operated flawlessly.  However, there was one operational item that differed from what is written in the owner's manual.  On Page 7, under the section titled Controlling Volume - "When the unit is turned on, the volume level will ramp up to the same level it was at when it was last turned off... "

Whenever I turn the unit on, the volume starts at Step 15 (I counted).  I tested this numerous times and no matter what level it's at when I turn it off, it always restarts at 15.  I actually prefer this then returning to the previous level.  I would rather err on the side of caution when it comes to volume. BTW, for reference, my general listening level has been between 24 and 28.

Gerry    

          

November 28, 2012
1:48 pm
Gerry E.
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Forum Posts: 9
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October 27, 2012
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Hi:

I’ve had my LDR1 for a week so it’s time to write my initial impressions.  Let me state up front that the LDR1 is the most pure, neutral, transparent, noise-free and grain-free component I have ever heard.  Because of this, it sounds even better than my prior LDR-based preamp – the DIY Paradise Eva 2.  Images are sharper and there’s nothing but empty space between them.  The Eva is excellent in all of the above attributes so this is high praise.

Here are some other things I like about the LDR1:

1.  The feature I like the most is the finer volume steps – approx. 1dB per step.  This allows me to raise the volume without making it too loud (not so with Eva's 3dB steps).

2.  I haven’t had to use it because the channels are perfectly balanced but it’s nice to know that balance control is available.

3.  The full size remote is nicer and easier to use than the Eva’s micro remote.

4. After having my subwoofer connected via speaker level inputs for many years, it's a nice change using the 2nd set of output jacks to connect the sub via line level.  I don’t know if it sounds any better but surprisingly I had to turn the subwoofer level control way down with the line level connection.

Here are some things I don’t like about the LDR1:

1.  The blue “Death Star” indicator LED is bright!  I’m only half serious but I wish it weren’t quite as bright.  OTOH, since it’s the only indication of various operation modes it's important to be able to see the indicator LED.

2.  I still miss having some kind of volume level indicator.  This was previously mentioned and Morten said that it may be a future upgrade.  You get used to not having one but it’s still a nice-to-have.

3.  The LDR1 is WAY bigger than the Eva and a lot more conspicuous (this may be a positive attribute for some people).  It’s attractive and well-made but unfortunately in my situation it doesn’t match my other equipment (see the photos below).  An optional silver face-plate would be nice.  I may have a maple wood case made for mine to match my other equipment.  Hey Morten, do you know a good wood worker?  Smile       

4.  I don’t see the need for the Encoder knob.  It’s much easier to use the remote for all functions.  Matter of fact, I haven’t even used the Encoder knob, not once (I suppose I should to verify that it’s working correctly).  I would rather the LDR1 come with a back-up remote and eliminate the Encoder knob – perhaps at reduced cost. 

Nitpicks aside, and that’s mostly what they are, the LDR1 is a terrific passive preamp.  As far as I can hear, the input signal passes through virtually unchanged, except the volume level of course.

Gerry

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