Low Output from DAC1 HDR?
Low Output from DAC1 HDR?
Submitted by ramossp on Tue, 2011-02-22 19:05Hi,
I used to own an original DAC1 and recently switched to a DAC1 HDR to allow for it to function as a preamp in my system. I've noticed however, that through a wide variety of amps the output from the HDR seems very low. Additionally I've found that the output of the headphone amp seems similarly restricted (I have to turn the volume all the way up with my AKG 501s to acheive listenable volumes with many sources, both digital and analog - something I don't recall having to do with my original DAC1).
Was the calibration of the HDR version updated in any way in relation to the alps volume pot, to allow for a more "ideal" range? The list of amps I've used the HDR with that I found the volume output insufficient without adjusting the attenuators is as follows:
Nuforce Ref9 160W/Ch 20db Gain
Ayre V-3 100W/Ch 32db Gain
Ayre V-5xe 150W/Ch 26db Gain
CiAudio D200 200W/Ch 26db Gain
My speakers are not reasonably insensitive at 89db/w/m, nor is my room overly large (though ceilings are high at 20'). Any idea why I find with sources like DVDs, DVR, and my turntable, the output at the -20db attenuator is insufficient? It would seem the gear listed above is more or less in line with what is standard for consumer level audio, for which the -20db attenuator is designed.
I can switch to 10db (or even 0db) but shouldn't I be able to get sufficient volume with the stock setting?
Also what's with the weird output impedence spike on the 10db attenuation (425Ohms)? Will it adversely affect the sound with that level of impedence, should 0db prove too loud?
Finally does this sound like the normal experience for HDR users? I purchased the pre new from an authorized retailer, should I have it checked out for any issues with the output?
Apologies for the long-winded inquiry. Thanks for your assistance.
Regards,
Sebastian
Low Output from DAC1 HDR?
Hello Sebastian,
What you are experiencing is not abnormal. Let me explain. Early versions of the original DAC1 were shipped with the attenuator jumpers in the '0dB' setting, meaning no attenuation. This turned out to be very 'hot' for consumer gear and could overload the inputs of preamps/integrated amps when used in the 'calibrated' setting. In the 'variable' setting, the high output from the DAC would give only a small range of use of the volume control. So, we began shipping DAC1 and all subsequent DAC1 series models with the jumpers in the 20dB setting. However, it seems this might be a little low for your amps. If turning the volume up all the way on the HDR still doesn't get you to a clean volume level, move the jumpers up to the 10dB setting. This will give a maximum output of about 5.5 Vrms which should drive any of your amps to full output. Even in the 20dB setting, the output reaches 1.73Vrms which will drive many amps to full output. The impedance changes with jumper settings will have no audible effect. All of your amps have very high input impedance.
Concerning the headphone output, the HDR has output gain jumper settings so as to give you nice range of use of the volume pot depending on the efficiency of the headphones. These jumper settings are an added feature set along with the XLR jumper settings, that were added to the HDR, DAC1Pre, and DAC1USB. The factory jumper setting for the headphone output is at 10dB of attenuation. This can be raised or lowered 10dB depending on the headphone efficiency.
All of the above is discussed in much more detail in the HDR manual. There are also pictures showing the proper jumper settings for both the headphone and XLR outputs. If you have any additional questions you may post them here, or call us at 800-262-4675.
Best regards,
Rory Rall, Sales Mgr.