Benchmark DAC1 now available with USB
Jan 15, 2008 at 11:07 PM Post #1,216 of 3,058

mcbiff

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I just bought a DAC1 (non-USB) from a fellow member here at head-fi. It will be used between my laptop and my speaker system which consists of a Densen B110 amplifier and a pair of Monitor Audio RS6 speakers. Now, I have read most of this thread, and the issue has been touched upon to some extent, but I feel I need to ask once and for all:

Should I set the output to variable or calibrated if connecting the DAC1 to my Densen using RCA (i.e. unbalanced) cables?

If I did miss an answer to this specific question I do apologize, and if someone could point me in the right direction I'd be grateful. Otherwise I hope one of the Benchmark representatives has the time to give me a straight answer.

My understanding from what I've gathered here is that I won't damage anything as long as I make sure to turn down the volume of my amplifier when switching the DAC1 to calibrated. I just feel (perhaps incorrectly) that if I don't need the pre-amp functionality of the DAC1 I should cut that part out of the equation so to speak.

Thanks
 
Jan 16, 2008 at 1:27 AM Post #1,217 of 3,058

infinitesymphony

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Quote:

Originally Posted by mcbiff /img/forum/go_quote.gif
Should I set the output to variable or calibrated if connecting the DAC1 to my Densen using RCA (i.e. unbalanced) cables?

My understanding from what I've gathered here is that I won't damage anything as long as I make sure to turn down the volume of my amplifier when switching the DAC1 to calibrated. I just feel (perhaps incorrectly) that if I don't need the pre-amp functionality of the DAC1 I should cut that part out of the equation so to speak.



As you have hinted, the real reason for variable output is to use the DAC1 as a preamplifier to feed a power amplifier (either in active monitors or a standalone amp). Calibrated mode essentially turns the DAC1 into a normal source, with an output no higher than that which you'd see from a typical CD player or DAC.

The only situation where you'd use variable output to feed a preamplifier (like the one in your Densen integrated amplifier) is if the preamp can't handle the output level of the DAC1. This would result in distortion due to overload. However, most amps are designed with a fair amount of headroom to prevent overloading the inputs.

So, calibrated.
biggrin.gif
 
Jan 16, 2008 at 6:59 AM Post #1,218 of 3,058

happybob

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Quote:

Originally Posted by EliasGwinn /img/forum/go_quote.gif
Ah, the remote control.
rolleyes.gif
I know, I know... the DAC1 needs a remote.
redface.gif


We have not yet found an independent volume controller of high enough quality to suit the DAC1 product line. Many preamps use a digitally controlled volume control IC, which has significant issues with regards to audio quality. We don't want to go that route because we feel it would compromise all the things the DAC1 PRE was created for...ultra-low distortion playback controller.

I really want to say, however, that your suggestions and other feedback are very much appreciated. We will take all of this into account during future product development.

Thanks,
Elias



what about as a compromise have a remote that can at least allow source switching? would that also impact the audio quality?
 
Jan 16, 2008 at 9:19 AM Post #1,219 of 3,058

mcbiff

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Quote:

Originally Posted by infinitesymphony /img/forum/go_quote.gif
As you have hinted, the real reason for variable output is to use the DAC1 as a preamplifier to feed a power amplifier (either in active monitors or a standalone amp). Calibrated mode essentially turns the DAC1 into a normal source, with an output no higher than that which you'd see from a typical CD player or DAC.

The only situation where you'd use variable output to feed a preamplifier (like the one in your Densen integrated amplifier) is if the preamp can't handle the output level of the DAC1. This would result in distortion due to overload. However, most amps are designed with a fair amount of headroom to prevent overloading the inputs.

So, calibrated.
biggrin.gif



Awesome. Thanks so much for the help!
 
Jan 16, 2008 at 9:49 AM Post #1,220 of 3,058

poo

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Quote:

Originally Posted by infinitesymphony /img/forum/go_quote.gif
As you have hinted, the real reason for variable output is to use the DAC1 as a preamplifier to feed a power amplifier (either in active monitors or a standalone amp). Calibrated mode essentially turns the DAC1 into a normal source, with an output no higher than that which you'd see from a typical CD player or DAC.

The only situation where you'd use variable output to feed a preamplifier (like the one in your Densen integrated amplifier) is if the preamp can't handle the output level of the DAC1. This would result in distortion due to overload. However, most amps are designed with a fair amount of headroom to prevent overloading the inputs.

So, calibrated.
biggrin.gif



Agreed - has been a much better way to go for me...
 
Jan 17, 2008 at 6:03 PM Post #1,221 of 3,058

Wavelength

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Gang look it has been assumed that Benchmark has some inherent problem with apple iTunes 7.5 that mysteriously occured. They state in their Detail#1 in the latest Stereophille MC page 135 that when using 441 and iTunes 7.5 that a DSP errors to -80dB and truncation occurs that severly limits the quality of sound from any device. They also state that using VLC resolves this issue.

I did the following test: PowerMac G5---->USB--->Benchmark====> Prism dScope III Audio Analyzer

iTunes 7.5 using a 10K test tone showing the tone and the FFT analysis of the waveform:

bmitunesusb.jpg


VLC using the same 10K test tone:

bmvlcusb.jpg


As you can see there is very little difference between these two and there really should not be. As both of them use Core Audio and if they are both running at 44.1 with the correct setting then this should not happen.

The test file is a digitally created 10KHz wav file no compression. That is indicated by the FFT spike at 10KHZ.

Guys let's face it... I don't see the problem they are stating even with their equipment.

NOW if it is because of sample rate adjustment somewhere then ok. But this is the way it has worked on an Apple since day 1. You have to set the correct rate before you enter the iTunes application.

Let's face it really the only problem with iTunes is that Lossless appears to work in 16 bit only files. If you want to use 24 then AIFF, WAV or other file is required.

If I am missing something please advise.

Thanks, back to work have tons of new products to get out. Thanks all for those that stopped by at CES. We had a great deal of fun!
Gordon
 
Jan 23, 2008 at 5:50 PM Post #1,225 of 3,058

clarke68

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Hey Elias,

As others have repeatedly mentioned, this is a great thread! Your presence here is helpful, and says a lot about Benchmark's respect for their customer base.

Question for you about the future: is Benchmark looking into supporting HDMI? High-res players (like the Oppo 980) are coming on the market that support SACD over HDMI, and it would be nice to be able to drive them into something other than a home theater receiver.

Thanks! Hope 'ya had a good time at NAMM.
 
Jan 23, 2008 at 6:08 PM Post #1,226 of 3,058

EliasGwinn

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clarke,

We currently do not have any plans to integrate an HDMI interface in our products. Also, we don't support the SACD format, as it has a lot of unresolved issues relating to audio quality.

Thanks,
Elias
 
Jan 24, 2008 at 4:24 PM Post #1,227 of 3,058

joijwall

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Reading Gordons Post I couldn't avoid raising the eyebrow on "the only problem with iTunes is that Lossless appears to work in 16 bit only files". I use iTunes to rip my cds to Apple Lossless and listen from my hdd. Is this good strategy, or should I avoid Apple Lossless? Thanks! /Joachim
 
Jan 24, 2008 at 4:57 PM Post #1,228 of 3,058

Wavelength

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Elias,

It might be a good idea for you and John to write another Comment for Stereophile to print. The one in the recent Stereophile makes it look like iTunes is broken.

When in fact the only real problem has been there all along. That being it does not change sample rates on the fly.

~~~~~~~~~

Joachim,

The nice thing about lossless is just that it will be original content. You can convert this to other formats without losing information.

One thing we found that on slower machines Apple Lossless does not sound as spacious as AIFF/WAV files do. At CES we showed users that had slower computers to convert their files to AIFF and the space was recovered.

So using Lossless now and changing later will not result in loss or errors of the files you have.

Thanks
Gordon
 
Jan 25, 2008 at 3:52 PM Post #1,230 of 3,058

jdh500

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I'd be interested in the answer to the question on whether the DAC1 pre can be configured with an HT bypass feature on the Analogue input ? If not currently available, is it something that can be considered as an option in any future revision.

JDH.


Quote:

Originally Posted by Terje /img/forum/go_quote.gif
Elias,

One last question from me, or more correctly from another member in the slimdevices forum.

Thanks for the response.

Terje



 

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