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Old 9th May 2014, 11:35 PM   #1231
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Quote:
Originally Posted by lehmanhill View Post
I have heard Bob and others say that they like Uriah's Lighter Note attenuator. It may have been in reference to other amps. Have you heard an LDR attenuator with a My_Ref amp? If so, I would like to hear your opinion.
Hi Jac,

I've had an LDR attenuator (one of the first version of Uriah's ones) and it sounded really clean, pretty transparent.

But it had some drawbacks (none of them directly related to sound but I found them annoying):
  • you can't have complete attenuation, you'll have some output even at minumum
  • at least in my case, LDR have been fragile, I've fried mines (and the attached DCB1) with static from hands.
Quote:
Originally Posted by lehmanhill View Post
I have been thinking about in input chain and trying to keep it simple rather than convenient. I was thinking that an LDR approach might be the fewest components in the signal chain and it seems to me that the My_Ref amp rewards clean and clear signals.
A LDR attenuator is no different than a plain pot in this regard.

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Originally Posted by lehmanhill View Post
From my reading online, it may be that an LDR attenuator would be simpler and cleaner than even the best potentiometer. Any thoughts?
Maybe but the difference from the smd attenuator I often suggest was not that big.

I don't have a direct comparison experience but the TKD pot I'm using now seem pretty similar to the LDR attenuator from what I can recall.
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Old 10th May 2014, 12:31 AM   #1232
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Thanks Dario.

The LDR is interesting technology, but you have pointed out some things I didn't know before. Nice to hear the comparison with the TKD too.

Bob was nice enough to lend me a Lighter Note in response to my question. In the near future, I hope to have a personal audition of several attenuator/preamps. I hope to compare a plain pot (an old and rather plain Alps, not a TKD), the digital volume control on the Squeezebox, the Lighter Note, and my Relaixed2 preamp (stepped attenuator switched by relay, plus buffer). At the moment, I'm listening to the Relaixed2 and it sounds good, but I am curious how the sound of the others will compare.

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Old 10th May 2014, 08:03 AM   #1233
AndrewT is offline AndrewT  Scotland
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Quote:
Originally Posted by ClaveFremen View Post
............ it had some drawbacks ..................
you can't have complete attenuation, ..................
Who listens at complete attenuation?

Using series connected series LDR elements and parallel connected Shunt LDR elements combined with ultra low operating current gets beyond -80dB ref full volume.
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Last edited by AndrewT; 10th May 2014 at 08:05 AM.
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Old 10th May 2014, 11:04 AM   #1234
bcmbob is offline bcmbob  United States
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Quote:
Originally Posted by ClaveFremen View Post
.......
I've had an LDR attenuator (one of the first version of Uriah's ones) and it sounded really clean, pretty transparent.

But it had some drawbacks (none of them directly related to sound but I found them annoying):
I loaded him up with both the basic Lightspeed and the LN. The only slight annoyance I've experienced is a small horizontal shift on big movements of the volume pot. Both versions have a balance pot to compensate but it's not needed that often. While checking out the LN before shipping, I did notice a tiny lag in the balance function. Not a problem but interesting, something that became apparent only at that extreme near field position.

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Originally Posted by AndrewT View Post
Who listens at complete attenuation?

Using series connected series LDR elements and parallel connected Shunt LDR elements combined with ultra low operating current gets beyond -80dB ref full volume.
This is kind of an old story/debate I have with myself, but as someone who currently uses PC/digital as a source 95% of the time, I have a direct link between the DAC and the power amp. There is a very small compromise using the PC drivers for volume control but it's acceptable for non critical listening. (plus it allows complete system function control from my phone ). The volume is always up a little and signals when the rather long PC boot sequence is finished.

One of my major spring projects is to resurrect the vinyl playback system which will require putting a discrete device back in the chain. I suspect it will be the JC-2 Pre with the LN as it's volume controller. That worked out quite well in the integrated build from a couple years ago.
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Old 10th May 2014, 12:14 PM   #1235
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Quote:
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Who listens at complete attenuation?

Using series connected series LDR elements and parallel connected Shunt LDR elements combined with ultra low operating current gets beyond -80dB ref full volume.
I was curious about Dario's comment as well. As an experiment, I set the Relaixed2 at a good listening level, then reduced to the lowest level I could hear from my listening position. Since the Relaixed2 has discrete, known volume steps of nominally 0.95 dB per step, I was surprised that I could still hear the music at about 44 dB below listening level or 59 dB below ref full volume. Of course, the full 80 dB that you described would be inaudible, but I appreciated that two steps down on the Relaixed was full mute. I agree with you that I will never listen at such low levels, but I also understand that a fully muted option might be nice to take a phone call or converse with someone else in the room. I could see where an LDR with a switched full mute option might be an interesting idea.

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Old 10th May 2014, 12:21 PM   #1236
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Quote:
Originally Posted by AndrewT View Post
Who listens at complete attenuation?

Using series connected series LDR elements and parallel connected Shunt LDR elements combined with ultra low operating current gets beyond -80dB ref full volume.
Hi Andrew,

Obviously no one... but the one I've owned didn't attenuate so much, the audio was clearly audible.

Quote:
Originally Posted by lehmanhill View Post
I agree with you that I will never listen at such low levels, but I also understand that a fully muted option might be nice to take a phone call or converse with someone else in the room.
Exactly
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Old 10th May 2014, 01:33 PM   #1237
AndrewT is offline AndrewT  Scotland
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For range of volume adjustment of "listen-able audio" the LDR in it's various options is perfectly adequate.

If one requires a mute then add a mute switch. Many remotes have a mute function that could be used to pull in a muting relay if the preamp is too far away from the listening seat.
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Old 10th May 2014, 01:50 PM   #1238
bcmbob is offline bcmbob  United States
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The only solution is turn the da*m phone off (or switch to silent mode), shut the silly world out and just enjoy the music.

If it's important they will call back or send you an email
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Last edited by bcmbob; 10th May 2014 at 01:58 PM.
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Old 12th May 2014, 04:10 PM   #1239
ElEsido is offline ElEsido  Switzerland
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Originally Posted by bcmbob View Post
One of my major spring projects is to resurrect the vinyl playback system which will require putting a discrete device back in the chain. I suspect it will be the JC-2 Pre with the LN as it's volume controller. That worked out quite well in the integrated build from a couple years ago.
OT: Bob , did you look into the various arduino-controlled attenuators that allow re-calibration of the LDRs and volume level / resistance control by software?
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Old 12th May 2014, 06:09 PM   #1240
bcmbob is offline bcmbob  United States
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No, I wasn't aware of those but I just took a quick look. I'll do some reading. Thanks.
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