Does remote control degrade the sound of tube preamps?

@emergingsoul

Different use cases. I use a VAC Master preamp in a system with one source (phono stage) that is 2ch only. There’s no need for remote input switching here. Ideally, I don’t want to pay for all those extra inputs. And I absolutely hate the HT Bypass, which I’ve engaged by accident a couple times now (it’s next to and looks like the power knob with no LED indicator) to my MASSIVE displeasure, until I figured out what was wrong. Remote has Mute & Volume Up / Down, which is all I need and want, other than a "Mono" function which this preamp doesn’t have.

It’s hard enough to serve the already narrow market for a $30K preamp, then have to subdivide it further between the pure 2ch guys and family entertainment guys. VAC made what they thought was the best compromise to serve both sets of customers, without sacrificing ultimate 2ch performance.

I can suggest that the ARC Reference preamps are excellent, and provide a full-function remote.

ARC reference preamps are totally inappropriate for home theater use since they are on most of the time during the day and they have so many damn tubes. You’ll be chasing tubes every 12 months if not more.

Yeah I saw the Home theater bypass button looking really obnoxious on the front panel of vac preamp and then they don’t have a remote that’s fully functional how stupid is this?

i have just spent three years researching, designing and prototyping remote control intended for volume production.  My thesis was that it could nto only be a VERy attractive feature, but superior sonically.

The real answer is "it entirely depends on how". 

Leet's take the simplest method- a stepper motor, connected to the existing volume knob's shaft.  This will have zero impact - it mimics your hand.  So that one is 'sounds the same.

Next let's look at the traditional digital solution (e.g.: what's in your phone, mac, pc, etc). This does binary multiplication on the digital stream. Since there is truncation within the allotted 16 (or whatever) bits and no additional resolution int he DAC, this always degrades the sound. In fact at low levels the resolution falls to about 11 bits.  On the other hand the channels track perfectly and there is no additional noise,, aside from the quantization noise (which i note to keep the trolls at bay).

Next we can use a "digital potentiometer" .This is a terrible name, since they are analog and generally dual-resistor pair arrays.  Which is very good. But there are technical problems i wont delve into since they are very complex. I made tow sound really good (better than an ALPS or Nobel POT) but only at huge complexity.

Finally you can use a small embedded computer/contorller, lots of relays or analog switches, and pairs of  resistors. This is the old Mil-spec method and basically the best there is.  Old version used stepped knobs and cost the moon, both in parts and labor. They were also very clunky in many ways. But with a computer, it an be really elegant.  That is what i settled on. It makes old fashioned high end POTS sound veiled and shows thier awful tracking.  Beware there is no going back, take a deep hit and I've got oyu :-)

So the differences are very much n the details adn about 0.01% here will even understand them.  i admit i didn't fully realize what i was getting into with the potentiometer chips - such promise, and such issues.

The best solutions however are not cheap in either engineering or parts,

G

Yes there are MANY ways to employ both manual and remote volume control.  One of the most interesting is the EMIA approach of using an auto-former with many discrete taps that are relay switched.  I believe there are other transformer-based volume controllers, some even utilizing remote switching.  This probably represents the most complex way of doing volume control.

I also like the approach of having only one fixed resistor in the signal path, with volume determined by relay switched set of resistors shunting part of the signal to ground.  

+2 Mapman, couldn't have said it better! At my age, 80, I wouldn't consider a preamp without a remote control. My ears are the limiting factor now, a remote is the least of my worries!!!