Teach me about pot(s)

[muslhead]

Was looking at a splurge buy ... the new violectric v550 which lists for $2800. They have a "pro" version which is $600 more than the std model ... the difference is nothing more than the pro comes with a 256 step relay volume.

Nobody can provide me the answer of whether the additional cost is worth it or not as i have to determine that for myself. But I need some help understanding the advantages / disadvantages of the step relay pro version (reed relay attenuator with 256 steps of 0,4 dB each) vs their standard offering which looks like its the Alps RK 27 motorized volume control).

I am not sure if this matters but a manual volume control is not something i use a lot on an amp as I tend to control hp volume via my software (either roon or jriver).

Please, no lecturing on the lower cost and better performing options as I already have one. I just like the looks and the step backwards in performance will not be audible to my old ears but its looks will bring me additional pleasure. If you want to lecture, do so on the technicals and advantages of different pots.
Thanks

 

[solderdude]

The advantages of relay volume control are:
Easy to remote control.
Can use up-down buttons or rotary/direction encoders.
L-R channel matching is excellent over a wide range.
Easy to create (multiple) volume presets if needed.
Can easily make 4-gang (pure balanced) or even more channels.
Using soft/firmware you can create 'tapers' and update it if one wants to change behavior.

Disadvantages:
Makes sounds (at least normal relays do, reed relays may be very silent.
Limited amount of steps.
Volume control is stepped so not as exact as digital or analog.
At some point relay (contacts) can fail.
Requires software/firmware and drive circuitry.
Takes up considerable board space.
More expensive than cheap pots.

Don't expect better 'sound quality' despite manufacturers and users stating it does.

Steppers:
advantages:
L-R channel matching is excellent over a wide range.
Can easily make 4-gang (pure balanced) or even more channels.
One can easily create a certain 'taper'.

Disadvantages:
Very limited amount of steps.
Volume control is stepped and usually larger steps at lower volume levels so not as exact as digital or analog.
At some point contacts can fail.
Takes up considerable room inside the device when a good amount of steps is needed.
More expensive than cheap pots.

Good mechanical pots (with superb tracking over a wide range) and a good mechanical 'feel' are expensive.
A motor + control is needed for remote control.

Cheap pots often have poor L-R matching in the lower part of the volume range.
Fixed semi-log behavior for attenuation.
Tactile feel can be poor.

 

[JayGilb]

The reed relay attenuator uses a series of reed relay switches connected to fixed resistor values that are opened via magnetic force as the attenuator rotates. The accuracy between L and R channels depends on how closely the fixed resistors are matched in each detent position.

The Alps volume control uses circular strips of resistive material and a metallic wiper which creates an infinite level of volume settings.
Alps are usually high quality pots and I have not noticed a large difference in resistive values between each side.

 

[muslhead]

Thanks to both that have replied.
For $600, if this were your decision, would you upgrade to the pro version (please assume you wanted this amp and the only decision is pro or non-pro)

 

[egellings]

Nope. I'd go with a good potentiometer.

 

[JayGilb]

Nope. I'd go with a good potentiometer.

Especially if you are going to control volume via software.

 

[antcollinet]

I think others have provided the same answer I would - so I'll just add the comment:

It is very pretty. But holy hell it's a lot to pay for some sleek aluminium. . Have you looked at the SPL Phonitor X? An equally ludicrously priced, but even prettier device (in this beholders eyes anyway). Annit has VU meters!!

SPL Phonitor x - Review

Review written by Ian Dunmore (@Torq) Introduction The “SPL Phonitor x” is a premium, feature-rich, headphone amplifier, and pre-amp, billed as having features and performance that lend it equal facility in professional/studio settings as well as in the role of an audiophile headphone system...

www.headphones.com

 

[muslhead]

The phonitor is pretty but look at the reviews. UGH
I ended up getting the Violectric v380 which provided more power and (almost) as pretty (no vu) meters though

 

[antcollinet]

Agh - sorry, Not sure how I managed the thread necromancy there.

 

[jasonhanjk]

All potentiometer will add noise.
Control volume in the digital domain is currently better.
Newer dacs that control both digital and analog gain is the best currently.