Hi, sorry for the delayed response. The only firmware update conducted was for the firmware of the USB input; however, that was performed in the first week after the DAC1 USB released. If you want to check that your firmware is current, you can e-mail me your serial number of your DAC1 USB at 'michio (at) benchmarkmedia.com'.
All DAC1 USB units manufactured after 11/21/2007 have current firmware.
There is no charge for firmware upgrades on units that are under warranty (other than shipping). All Benchmark products sold in the USA are covered by a 5-year warranty. After the warranty period, the cost for an ugrade is $50. The DAC1 USB has two separate sets of firmware; system firmware, and USB subsystem firmware. The system firmware is entirely separate from the USB subsystem firmware. The USB subsystem can be field upgraded, but the system firmware cannot be field upgraded. On 11/21/2007 we changed the system firmware (not the USB firmware) to change the time constants in the USB muting circuit. This change extended the time interval that must pass before the USB input mutes when no audio is present. This is only an issue in applications where the DAC1 USB is being used to play digitally generated click tracks (metronome beat tracks) in a recording studio, and only when played through the USB input. It does not change the performance or operation when playing music. Most users do not need to upgrade.
Please note that the USB subsystem firmware has never been changed. And, it is highly unlikely that the USB subsystem will ever need changing. Benchmark's native USB system uses standard USB Audio system calls and does not need to be modified as new operating systems are introduced. New Windows, Mac, Linux, and tablet operating systems have been introduced, but the Benchmark native USB system works with these new technologies. This is one of the primary advantages of a driverless USB Audio interface. If it ever becomes necessary to upgrade the USB subsystem, this can be done in the field.
If your unit was manufactured prior to 11/21/2007, and you are using digitally-generated click tracks in a recording environment, you may want to have your unit upgraded. Call us to arrange for an RMA. If you are not using click tracks, there is absolutely no need to upgrade.
Thank you so much for the detailed response. I am really impressed with Benchmark's support quality.
I also have a set-up question.
I use Sennheiser HD600 headphone and Foobar2000 w/ Lenovo W500 laptop.
I have followed the Benchmarl wiki to set up the Foobar2000.
I was,however, a bit surprised that adding the DAC1/USB has little impact on the sound quality of HD600 (compared to W500 headphone jack).
Is there any special setting on DAC1/USB for HD600?
Should I change the jumper to raise the gain?
A little background on my expectation:
I have been dissatified with the sound of HD600 for its somewhat muted presentation of music, especially for CD quality recordings. I was hoping to bring more liveliness to music with Benchmark's headphone amp.
The Benchmark HPA2(TM) headphone amplifier has 3 gain ranges in the DAC1 HDR and DAC1 PRE models. The DAC1 USB has 2 gain ranges, while the basic DAC1 had one gain range. The jumpers allow selection of 0 dB, 10 dB, or 20 dB attenuation.
We added gain-range jumpers to the newer DAC1 models so that a wide variety of headphone could be used without a loss of dynamic range.
The analog volume control on the DAC1 converters delivers the entire dynamic range of the D/A converter over a wide range of gain settings. The full performance is delivered at any volume control setting above 12 o'clock (50% rotation).
The headphone gain jumpers should be used to adjust the gain of the HPA2(TM) headphone amplifier to achieve a comfortable listening level with the volume control in the upper half of its rotation.
I suggest using the 10 dB or 20 dB attenuation settings with all of the Sennheiser HD580, HD600, and HD650 headphones. The jumper settings are described in detail in the manual. The "A" setting enables 20 dB attenuation. The "B" setting enables 10 dB attenuation. For 0 dB attenuation, the jumpers should be rotated 90 degrees for storage on either pair of pins. Please note that there are separate jumpers for the right and left channels.
I use 20 dB attenuation when listening to Sennheiser HD650, HD580, or HD600 headphones. Some listeners may prefer the 10 dB setting if they find the 20 dB setting is not loud enough.
The Sennhieser HD600 headphones have a rather subdued presentation when compared to the HD580 or HD650. The HD580 and HD650 have a very similar sound, but the HD600 is distinctly different. I am not a big fan of the HD600. The frequency response of the HD580 and HD650 are very similar to each other, but the HD600 is definitely different.
All three headphones are spectacular when driven from the Benchmark HPA2(TM) headphone amplifier, but I enjoy the HD580 and HD650 much more than the HD600.
There are some differences between the discontinued HD580 and the newer HD650. The most noticeable difference is that the HD650 is 6 dB louder. The HD650 produces 103 dB at 1 Vrms while the HD580 and HD600 produce 97 dB at 1 Vrms. I have the impression that the HD650 is somewhat cleaner than the HD580, but both are very good.
The Sennheiser headphones have much lower distortion than most of the other headphones we have tested. They are also so comfortable to wear that it is easy to forget that you have them on.
For the above reasons, Benchmark recommends the Sennheiser HD650.
Hi, sorry for the delayed
Hi, sorry for the delayed response. The only firmware update conducted was for the firmware of the USB input; however, that was performed in the first week after the DAC1 USB released. If you want to check that your firmware is current, you can e-mail me your serial number of your DAC1 USB at 'michio (at) benchmarkmedia.com'.
Thanks,
Michio
DAC1 USB Firmware Upgrade
All DAC1 USB units manufactured after 11/21/2007 have current firmware.
There is no charge for firmware upgrades on units that are under warranty (other than shipping). All Benchmark products sold in the USA are covered by a 5-year warranty. After the warranty period, the cost for an ugrade is $50. The DAC1 USB has two separate sets of firmware; system firmware, and USB subsystem firmware. The system firmware is entirely separate from the USB subsystem firmware. The USB subsystem can be field upgraded, but the system firmware cannot be field upgraded. On 11/21/2007 we changed the system firmware (not the USB firmware) to change the time constants in the USB muting circuit. This change extended the time interval that must pass before the USB input mutes when no audio is present. This is only an issue in applications where the DAC1 USB is being used to play digitally generated click tracks (metronome beat tracks) in a recording studio, and only when played through the USB input. It does not change the performance or operation when playing music. Most users do not need to upgrade.
Please note that the USB subsystem firmware has never been changed. And, it is highly unlikely that the USB subsystem will ever need changing. Benchmark's native USB system uses standard USB Audio system calls and does not need to be modified as new operating systems are introduced. New Windows, Mac, Linux, and tablet operating systems have been introduced, but the Benchmark native USB system works with these new technologies. This is one of the primary advantages of a driverless USB Audio interface. If it ever becomes necessary to upgrade the USB subsystem, this can be done in the field.
If your unit was manufactured prior to 11/21/2007, and you are using digitally-generated click tracks in a recording environment, you may want to have your unit upgraded. Call us to arrange for an RMA. If you are not using click tracks, there is absolutely no need to upgrade.
Thank you and a set-up question
Setting the Headphone Jumpers
The Benchmark HPA2(TM) headphone amplifier has 3 gain ranges in the DAC1 HDR and DAC1 PRE models. The DAC1 USB has 2 gain ranges, while the basic DAC1 had one gain range. The jumpers allow selection of 0 dB, 10 dB, or 20 dB attenuation.
We added gain-range jumpers to the newer DAC1 models so that a wide variety of headphone could be used without a loss of dynamic range.
The analog volume control on the DAC1 converters delivers the entire dynamic range of the D/A converter over a wide range of gain settings. The full performance is delivered at any volume control setting above 12 o'clock (50% rotation).
The headphone gain jumpers should be used to adjust the gain of the HPA2(TM) headphone amplifier to achieve a comfortable listening level with the volume control in the upper half of its rotation.
I suggest using the 10 dB or 20 dB attenuation settings with all of the Sennheiser HD580, HD600, and HD650 headphones. The jumper settings are described in detail in the manual. The "A" setting enables 20 dB attenuation. The "B" setting enables 10 dB attenuation. For 0 dB attenuation, the jumpers should be rotated 90 degrees for storage on either pair of pins. Please note that there are separate jumpers for the right and left channels.
I use 20 dB attenuation when listening to Sennheiser HD650, HD580, or HD600 headphones. Some listeners may prefer the 10 dB setting if they find the 20 dB setting is not loud enough.
Sennheiser HD650, HD600, and HD580 Headphone Comparison
The Sennhieser HD600 headphones have a rather subdued presentation when compared to the HD580 or HD650. The HD580 and HD650 have a very similar sound, but the HD600 is distinctly different. I am not a big fan of the HD600. The frequency response of the HD580 and HD650 are very similar to each other, but the HD600 is definitely different.
All three headphones are spectacular when driven from the Benchmark HPA2(TM) headphone amplifier, but I enjoy the HD580 and HD650 much more than the HD600.
There are some differences between the discontinued HD580 and the newer HD650. The most noticeable difference is that the HD650 is 6 dB louder. The HD650 produces 103 dB at 1 Vrms while the HD580 and HD600 produce 97 dB at 1 Vrms. I have the impression that the HD650 is somewhat cleaner than the HD580, but both are very good.
The Sennheiser headphones have much lower distortion than most of the other headphones we have tested. They are also so comfortable to wear that it is easy to forget that you have them on.
For the above reasons, Benchmark recommends the Sennheiser HD650.