Gain Structure help, Mcintosh D100 to Primalune tube amp

Thanks George,

using the variable out is almost a must as this is the only way to control the volume remotely with the D100 remote (looks like the schiit unit does not have remote volume control capability.)

Thanks George,

the interesting thing is that all of the Mcintosh preamps have the same output V range 8v unbalanced and 16v balanced.  And some of their amps have low input sensitivity (I think the tube 275 is at 1.8V.)  Theoretically you wouldn't need to do anything gain wise to plug one of their preamps into their amps, wonder how that works.

Thanks so much George,

this is interesting, I'll test tonight.  I'm almost certain though that the remote's VC and the knob act the same, just by judging at the percentage of volume shown.

I'll check it out and thanks again. 

Another info that I found, but I am not following;

The more astute of you may be thinking as you read that, ‘hang on, this sounds more than a little like a Cambridge Audio DacMagic Plus and the last time I checked, that was a good deal less than three grand.’ This much is true. The functionality of the D100 is replicated on a number of devices that cost quite a bit less than the McIntosh does but the bald feature list doesn’t completely describe what the D100 can do. The first is that unlike most other digital preamps, the D100 has a preamp circuit that is completely separate from the digital board.

McIntosh D100 Design
The reasons for doing this are fairly compelling. If you are acting directly on the digital signal of a DAC you have two options about how to adjust volume. The first is bit reduction which physically reduces the size of the signal the DAC handles. As the name suggests, physically clipping the amount of data in the signal isn’t a great way to maintain quality so this is not ideal and certainly not for McIntosh. The second way is to use DSP to adjust the volume level in the digital domain without actually losing any information. This is much more effective at retaining the overall quality of the recording but it does tend to make adjustment a little slow and unwieldy.

By fitting a conventional preamp to the D100 - albeit one on a rotary encoder rather than a classic volume ‘pot’, the D100 feels like a normal preamp. If you rapidly twist the volume control on the D100, the volume climbs or descends at a ‘proper’ speed rather than coming to terms with the world around it and slowly ‘ramping.’ Furthermore, with an encoder in place, the D100 has a full remote control that means it is possible to use it at rather more than arm’s length although the remote itself is certainly in the running for the ‘most buttons that have no actual bearing on the operation of the product’ award.

The other benefit of implementing a preamp this way is that it also doesn’t have to be part of the signal path. As well as the variable outputs, there are fixed level ones too that ensure that the D100 can be used as a completely normal DAC into one of McIntosh’s preamps and integrated amps (of which there are many). The preamp isn’t deactivated in this instance, it is completely absent from the circuit.

Hi George,

I spoke with Ron at Mcintosh, and he said they are using an analog volume control and there is no bit stripping or any advantage to try to attenuate the output of the unit.  Essentially my range is up to 50-55% (hard to tell with the Primaluna amp if it is clipping at that point or what, but it is plenty loud) which I can live with.  Unit/system does sound amazing even at low levels (20% or whatever) just wanted to make sure I am not leaving anything on the table.

any thoughts?

Looks like they both perform the same function.  If I set the volume with the knob at 30%, then use the remote to reduce it to 20%, then go back at the knob the volume is at 20%.

unless I misunderstood, it seems to me both knob and remote do the same thing with the volume.