[EliasGwinn]

Quote:

Originally Posted by Xxtest83 /img/forum/go_quote.gif I have a Lehmann BCL Pro (with XLR inputs) connected to the XLR outputs from my DAC1 HDR, but since i plan to buy active speakers soon (probably K+H o300), the XLR outputs have to get free. Do you think it might be possible to hear a difference when i feed the Lehmann amp through a Cinch-XLR cable from the Cinch-output compared to the XLR-XLR connection?

I tried to look-up the specs on the Lehmann BCL Pro headphone amplifier, but I couldn't find any. Can you provide a link?

Thanks,
-Elias

 

[EliasGwinn]

Quote:

Originally Posted by Xxtest83 /img/forum/go_quote.gif Would it hurt the amp (or even the DAC1) if i connected it from RCA to XLR? The amp has not a balanced out but a single ended. My guess is that this version has XLR inputs just because it is more common in studios (pro version). What about a XLR Splitter? It is galvanic splitted between in- and outputs, whatever that means.

It will not hurt the DAC1 to use the RCA's to drive the BCL while simultaneously using the XLR's to drive the K+H's. Also, it will not hurt the DAC1 to use XLR splitters. However, if the input impedance of the BCL is too low, it may cause distortion w/ XLR splitters.

Do you know the input impedance of the BCL pro?

Thanks,
Elias

 

[EliasGwinn]

Quote:

Originally Posted by Roseval /img/forum/go_quote.gif <<The amp has not a balanced out >>?? If you mean DAC 1 RCA out to amp XLR in, this in general works good. As it is a DAC 1 you might use the volume control starting at zero for safety.

Both sentences are true.

Thanks,
Elias

 

[Xxtest83]

Thanks for your answer Elias.

The specs of the Lehmann Audio Black Cube Linear Pro are:

input impedance: 47 k Ohm
maximum gain: switchable 0 + 10 + 18 + 20 dB
frequency response: 10 - 35.000 Hz
S/N ratio: > 95 dB at gain 0 dB
output power: 300 Ohm/200 mW, 60 Ohm/400 mW
output impedance: 5 Ohm
power consumption: ca. 10 W
connections: 2x XLR symmetric
channel seperation: > 70dB/10kHz

Lehmannaudio :: HighEnd vom Toningenieur :: Pro-Audio

My main concern is if a difference to the worse in audioquality is audible when i change to RCA->XLR connection. I guess i will have to buy some cables and try it out.

Regards,
Stefan

 

[EliasGwinn]

Quote:

Originally Posted by Xxtest83 /img/forum/go_quote.gif My main concern is if a difference to the worse in audioquality is audible when i change to RCA->XLR connection. I guess i will have to buy some cables and try it out. Regards, Stefan

Stefan,

You will have no problem driving both of these from the XLR output using splitters. But if you want to try the RCA solution, you should use a cable that has pin 3 of the XLR tied to the shield of the RCA (like this one).

Let me know how it works out.

All the best,
Elias

 

[Xxtest83]

-deleted-

 

[Xxtest83]

I found out that my HDR Version has an irregularity in left-right channel balance with its volume pot. The middle of the stage gets shifted in the left area when the pot is at 9 to 11 o'clock, and slight to the right at around 3 o'clock.

The problem does not occur when i avoid the volume pot by setting the XLR-out to calibrated. It is a problem with the volume pot, and since this is the main part which got worked on in the HDR Version, i wanted to ask if this might be a standard problem of this verion, or if i just got a defective unit.

 

[EliasGwinn]

Quote:

Originally Posted by Xxtest83 /img/forum/go_quote.gif I found out that my HDR Version has an irregularity in left-right channel balance with its volume pot. The middle of the stage gets shifted in the left area when the pot is at 9 to 11 o'clock, and slight to the right at around 3 o'clock. The problem does not occur when i avoid the volume pot by setting the XLR-out to calibrated. It is a problem with the volume pot, and since this is the main part which got worked on in the HDR Version, i wanted to ask if this might be a standard problem of this verion, or if i just got a defective unit.

The new volume pot in the DAC1 HDR is better then the pot in the other DAC1 products. However, subtle channel differences will always occur when using a stereo pot.

Stereo pots are ideal for maintaining dynamic range, low distortion, and linear frequency response. Slight channel inbalances are the trade-off (but definately worth it compared to the loss of dynamic range with digital volume controls, distortion with analog volume IC's, or non-linear response of passive attenuators).

If there are gross errors between the channels, perhaps you have received a defective pot. How bad are the differences?

Thanks,
Elias

 

[Xxtest83]

For me the effect is significant. But since you asked i just tried to quantify the effect by reducing the left or right channel volume at the PC.
When the Volume pot is at 10 o'clock i have to reduce the left channel by 2 percent and at 3 o'clock to increase left channel by 1 percent to get the Stage where it is with other Sources (where it should be). Those 2 Percent sound significant to me, especially because the balance-change happens through a small degree (9 to 11 o'clock).

I wonder if it is only my unit having this problem, or only me having a problem with this effect.

 

[EliasGwinn]

I'll contact you via PM to arrange a solution...

-Elias

 

[little-endian]

Hello Elias,

as I recently noted, the "interior view" of the DAC1 picture gallery have been removed.

One of them was available under:

http://www.benchmarkmedia.com/dac1/p...-rm_inside.jpg

Any special reason for that?

 

[EliasGwinn]

Good question...?? They must have been forgotten when the new website was built.

I've sent an email to our webmaster...we should see them by this afternoon.

ATB,
E

 

[hh83917]

I was just reading about some DAC1 HDR reviews few minutes ago and it mentioned that it uses National Semiconductor LM4562 op-amp. Then I remembered I've saw that National Semiconductor somewhere... and it turns out that the apartment I live in now was right across the National Semiconductor manufacturing plant. I thought that was pretty funny.

It also just happens that my younger goes to Syracuse University, where Benchmark is located. And I just happened to be a DAC1 HDR owner. Small world indeed.

P.S: Been using the DAC1 HDR for few months now and still enjoying it, thanks Benchmark.

 

[denonfan]

I just purchased a Benchmark DAC1 USB. However, I am having major problems with the USB connection. I am running Vista Ultimate, 32bit, computer is a Thinkpad, about 2 years old, music player is foobar2000 v0.9.6.1. I am playing APE files. The Benchmark is plugged into a dedicated USB port on the laptop, no USB hub involved. I have restarted the laptop, plugged the laptop into a differet USB port on the laptop, all to no avail.

Whenever foobar is running by itself, the USB connection works fine. No problems.

However, whenever I am browsing the web using either Firefox or IE, the Benchmark seems to lose the USB connection. Those 2 blue LED lights start flashing, I get some nasty clicks, then no sound. Sometimes the sound comes back, sometimes the sound doesn't. And the problem doesn't go away until I close either the Firefox or the IE, and restart foobar2000 and just let foobar2000 play on its own.

The buffer length in foobar2000 is set to max, 8000ms, output device set to Benchmark 1.0. I even fiddled around with the process priority setting in the Task Manager, setting the foobar2000 process to realtime. No help.

This is most frustrating. Can anyone help? I don't know what else to do. Did I get a defective unit?

Thank you




Update 07/23/09 --

-- Just got off the phone with Elias from Benchmark media. Elias spent a considerable amount of time going over this problem with me. In the end, it looks like the problem is with my laptop, not the Benchmark DAC1. Oh well, I have been thinking about picking up a new laptop for a while now. I guess now I have that extra incentive.

-- Two thumbs up to Elias for outstanding customer service, and to Benchmark Media for manufacturing an outstanding product.

 

[little-endian]

@Elias

Hehe, thanks for investigating. Not that I'd miss them that much, just wanted to prevent wild speculations on another forum about their absence in the first place.

@denonfan

If the connection works before starting any browser, it's quite unlikely you got a defective unit.

Does the browsing actually work flawlessly? Any suspect high CPU usage?

How does it work on a different PC? There are different chipsets and some are unfortunately just too lame ...

Puh, if you got "nasty clicks" over USB, there seems to be an advantage of S/PDIF .. never got one no matter how crappy the connection was (just to settle myself as an owner of the "good old one"

).