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A nice new DAC2 from Benchmark showing at RMAF - Page 15

post #211 of 220
The pot is a relatively cheap one, albeit as i understand it bespoke for Benchmark, i believe its based on an Alps blue pot. Whereas these are not complete junk, they nevertheless still have dreadful channel tracking and can easily be a couple of dB out, especially at low volume settings where such problems are clearly audible channel imbalance. Ok since they are passive components, they do sound OK but the channel tracking issues and inevitable track wear and them resulting crackles, is not very appealing. Check out the duty cycle specs for Alps pots and you will be mortified how low they are.

Given the DAC is constantly whirring the pot - for every volume change, every mute and unmute, every power on and off, every source change - then the early demise of the pot is probably going to occur sooner than people expect. I can only assume Benchmark programmed in these seemingly unnecessary pot movements in order to lower the volume and reduce the rather unpleasant clicks and pops. It's a bodged solution all around.

I would have infinitely preferred an led display, digital volume control and a resistive ladder / stepped attenuator for the analogue inputs.
Edited by Chippy99 - 5/15/14 at 8:04am

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post #212 of 220
Quote:
Originally Posted by Chippy99 View Post

Whereas these are not complete junk, they nevertheless still have dreadful channel tracking and can easily be a couple of dB out, especially at low volume settings where such problems are clearly audible channel imbalance. 

 

No measurements of the DAC-1 or DAC-2 that I have seen show any significant channel imbalance. Stereophile measured 0.25 db at high volume on the DAC-2.

 

Quote:
Originally Posted by Chippy99 View Post

...the channel tracking issues and inevitable track wear and them resulting crackles, is not very appealing. Check out the duty cycle specs for Alps pots and you will be mortified how low they are.
Given the DAC is constantly whirring the pot - for every volume change, every mute and unmute, every power on and off, every source change - then the early demise of the pot is probably going to occur sooner than people expect.

 

How long has the DAC-1 been on the market? Must be close to a decade. It is one of the top selling DACs on the market. So where are all the reports of noisy or failing volume controls? It sounds like you don't own one and you don't actually know for certain the make/model of the volume control, but you are claiming faults that no one has actually reported in the real-world (as far as you or I know anyway). Besides that, Benchmark has an excellent warranty and I'm told the in-house repair service is very good.

 

Benchmark touts their measurements because it measures as one of the very best DACs on the market regardless of price. If you don't think measurements reflect the listening experience, I'll respect that, thought I strongly disagree.


Edited by VandyMan - 5/15/14 at 9:40am
post #213 of 220
Quote:
Originally Posted by VandyMan View Post
 

 

No measurements of the DAC-1 or DAC-2 that I have seen show any significant channel imbalance. Stereophile measured 0.25 db at high volume on the DAC-2.

 

Well Stereophile got lucky then. My DAC1-HDR's is something like 3dB out at its worst point - it's by FAR the weakest aspect of the DAC1's otherwise exemplary performance.  The ALPS spec says up to 5dB out at volumes -60dB to -40dB is within spec, and 3dB of error between -40dB to 0dB again is within spec.  Staggerly bad.  Interestingly I don't think Benchmark quote a figure for the DAC1, despite giving you every measurement under the sun.  I can imagine why they miss this one out!

 

Originally Posted by VandyMan View Post
 

How long has the DAC-1 been on the market? Must be close to a decade. It is one of the top selling DACs on the market. So where are all the reports of noisy or failing volume controls? It sounds like you don't own one and you don't actually know for certain the make/model of the volume control, but you are claiming faults that no one has actually reported in the real-world (as far as you or I know anyway). Besides that, Benchmark has an excellent warranty and I'm told the in-house repair service is very good.

 

Benchmark touts their measurements because it measures as one of the very best DACs on the market regardless of price. If you don't think measurements reflect the listening experience, I'll respect that, thought I strongly disagree.

 

 

Your comment about lack of reports of faulty DAC1's is a valid one, so perhaps they are more reliable than I had at first suspected.

 

Now, how do I "sound like I don't actually own one" exactly?  Frankly that's just a plain stupid comment.  And regards your last sentence, I have no  idea what you are talking about.  I don't recall at any point saying that either the DAC1 or the DAC2 don't sound excellent, because they do.

 

If you want me to DEMONSTRATE that I own both DACs, I am prepared to do this:  Tell me what to write on a piece of paper, and I will write it and photograph it on top of both my DACs.  But here's the deal, I am only going to go through this pantomime - and it is a pantomime - if you give me your solemn word that you will apologise clearly and unconditionally for basically calling me a liar.  Over to you.


Edited by Chippy99 - 5/15/14 at 11:25am
post #214 of 220

I read your previous post ("not that appealing") to mean you don't own one, but it is not important and I will certainly take your word. I assumed incorrectly that if you owned a Benchmark DAC for any significant period of time you would not be claiming the volume control becomes noisy without first-hand experience.

 

It is not just Stereophile that found no significant issues with Benchmark DACs in their measurements (and they have reviewed/measured at least three Benchmark DAC models). Take a look at the anti-Stereophile, The Audio Critic. He has measured a few different models and says about the DAC-1 HDR: "All in all, the Benchmark DAC1 HDR is damn close to a perfect piece of equipment. Neither its digital performance nor its analog performance could be meaningfully improve"

 

I'm glad you enjoy your DAC-1 as much as me. I'm not sure I get why you are making such a big deal about the volume control since your own experience, measurements, etc. don't back the idea that it is significantly flawed. Perhaps it is not ideal for the studio as another poster said. It certainly has some usability/ergonomic issues. However, I see nothing to back your claim that it is noisy, becomes noisy with regular use, or suffers from audible channel imbalance. Sure, no moving part will last forever (nor will some of the electronics like the capacitors), but the Benchmark came out more than a decade ago and, as you agreed, I don't see reports of problems on the audiophile forums.

 

My next DAC will probably be the Auralic Vega, but the Benchmarks are a tremendous bargain and a first-rate DAC, in my opinion. And, actually, I think we share that view!


Edited by VandyMan - 5/15/14 at 12:15pm
post #215 of 220

One more... Ken Rockwell measured a channel imbalance of around 1.5 db on the DAC-1 HDR (worst case), if I'm reading correctly. That is more than others measured and could admittedly be audible for trained listeners under ideal conditions, but it is still very low.

 

http://kenrockwell.com/audio/benchmark/dac1-hdr.htm

 

If you are getting significant channel imbalance, have you tried adjusting the calibration? Here are directions Benchmark sent me a few years ago:

 

Directions for calibrating

Submitted by EliasGwinn on Tue, 2011-03-08 14:01.

Directions for calibrating the DAC1 USB:

WARNING: This procedure involves playing a test tone that should not be played through your speakers.

1. Disconnect all analog cables from the DAC1 USB.

2. Download this test tone (1 kHz sine wave @ -20 dBFS):

http://www.benchmarkmedia.com/audio-test-files/1k%204416%20-20.wav

3. Play the test-tone through the USB input of the DAC1 USB.  Make sure all computer/software volumes are set to 100%.

4. Make sure the rear-panel ‘output mode’ switch is set to ‘Calibrated’ (the upper most position)

5. Measure the AC voltage between the center and ring of one of the RCA outputs. 

6. Adjust the corresponding calibration trim-pot until the voltage measures 0.2 VAC.

7. Repeat steps 5 and 6 for the other RCA output.  Your DAC1 USB is now calibrated. 

8. Delete the test-tone from your computer (or at least remove it from your media player library) to avoid accidentally playing through your speakers it in the future

9. After calibrating, if you are connecting the DAC1 USB directly to an amplifier and/or active monitors, be sure to set the rear-panel ‘output mode’ switch in the ‘Variable’ position (the bottom position).


Edited by VandyMan - 5/15/14 at 1:11pm
post #216 of 220

The "pops" occurring when turning on or off the DAC2 is not an issue at all if you follow a simple procedure: Always have your amp (or powered speakers) off when turning on or off the DAC2.  

 

This means that you turn on the DAC2 before you turn on your amp.  And you turn off your DAC2 after you turn off the amp.

 

Many have done this for years with other preamps to avoid the pop -- the DAC2 is not unusual in this regard. 

post #217 of 220

this is the real big reason we use the dac1 in the studio. we use the calibrated fixed output on the xlr's. it is set with a calibrated certified multimeter.

 

stereophile, at high volume. yeah, the problem with these pots is at low volume. the calibrated fixed is clearly closer than the front pot.

 

I am not a fan of ken Rockwell but he might have actually performed a correct test for once.

post #218 of 220

Just wondering... You are running the calibrated output to powered speakers? Do you correct the speakers for channel imbalance?

post #219 of 220

sometimes. the calibrated are l-r. you set them the same with a multimeter. should check sometimes because it can change.

post #220 of 220
Understand about calibrating, and i am sure it would help. But i found with the -20dB pads, most of my listening is above 11 o'clock where the balance is pretty good. Arguably still audible imbalance, but I've tried to ignore it and since i tend to listen sitting slightly off centre anyway, i've found I can forget about it.

I have to say I love my DAC1, despite this minor irritation. There's much to like about the DAC2 as well. It sounds slightly different - arguably better; the front display of bit rate and word length is useful; the digital channel tracking is of course faultless; and finally the HT bypass is useful. I have the DAC2 driving my power amps directly and my HT processor feeding the DAC2's analogue inputs in HT bypass mode.

The only thing that disappointed was these damned clicks, but it's really not a terribly big deal. It's just surprising given the DAC1 is so polished in this regard.

Happy listening!
Edited by Chippy99 - 5/16/14 at 2:09pm
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