K&K Audio / Lundahl Transformers Welcome! Need support, you got it. Or share youe ideas and experiences. |
|
In Reply to: RAKK DAC Passive output Volume posted by UK Ray on October 2, 2013 at 10:48:07:
There's a potential problem with your plan. If you build a stepped resistor I/V control and connect it directly to the DAC outputs, you will hear a substantial "pop" sound as the resistors are switched to control the volume. However, if you connect low value I/V resistors across the DAC outputs and then follwo those with a "U type" shunt attenuator, there are no "pop" noises, presumably because the value of the volume control resistance seen by the DAC outputs (>10K) is very high compared to the I/V resistors that load the outputs.
You are suggesting something different than the first situation described above in that you have a transformer interposed between the switchable I/V resistors and the DAC outputs. I have no personal experience with this set-up, only with the one using a shunt potentiometer, which obviously results in no abrupt changes in load on the DAC outputs as the volume is varied. The practical problem with the potentiometer application is that the value of the I/V resistor should not exceed about 5K with LL1674s set to 1+1:8 as they are on the Passive Output Stage board. 5K log pots are not plentiful...
I will take my trusty passive output equipped Mk II RAKK dac and try what you propose and see what sounds other than music occur. I'll let you know in a day to two.
Kevin Carter
K&K Audio
www.kandkaudio.com
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- RE: RAKK DAC Passive output Volume - KevinC 12:06:49 10/03/13 (3)
- RE: RAKK DAC Passive output Volume - UK Ray 13:21:30 10/03/13 (2)
- RE: RAKK DAC Passive output Volume - KevinC 13:37:04 10/03/13 (1)
- RE: RAKK DAC Passive output Volume - UK Ray 23:30:29 10/03/13 (0)