who makes the best volume pots / stepped attenuators?

Hi,

I guess it depends upon the definitions and comparion standards.

I amused myself recently with designing a relay actuated resistor based attenuator (commercial pressures). It is not easy to get good performance from that and that is with only maximally seven resistors daisychained and them SMD Tantalum ones at that.

But then again, based on the sonic evidence I think the cirrus logic and bb/ti digital pots are complete garbage, which has not stopped gear including them being highly reviewed.

So buy what suits, preferably after auditioning.... :MILD:
Ciao T

 

What about the chip based attenuators?

VFV - V for Vendetta, your tagline was a clue

 

Hi,

The ones I have tried ranged from "completely revolting" to "pretty awful". The biggest possible upgrade on the Shanling SP-80 Amplifier is jumper it's solid state preamp board with Burr Browns best chip attenuator, the biggest upgrade for the Shanling SACD Player is to bypass the same chip volume control (not just a jumper on the new models, just a jumper on the old ones).

Ahh, I was not tracking on the abbreviation. I was thinking "what volume control abbreviates to "VFV"....

The film majorly kicked booty and hade nice musical themes, such as 1812 twice, with major explosions. My wife loved it too (rare, if one of us really likes a film the other usually hates it - recent exceptions where V and Howls Moving Castle).

Ciao T

 

Yet the mags rave about them. Interesting.

Was it faithful to the book? In spirit at least.

 

Hi,

Never read the manga or novel, so no idea. Indications are, it is not very faithful, but still good in it's own right....

Here another of my fav. lines:

Voilà! In view, a humble vaudevillian veteran, cast vicariously as both victim and villain by the vicissitudes of fate. This visage, no mere veneer of vanity, is a vestige of the vox populi, now vacant, vanished. However, this valorous visitation of a bygone vexation stands vivified, and has vowed to vanquish these venal and virulent vermin vanguarding vice and vouchsafing the violently vicious and voracious violation of volition. The only verdict is vengeance; a vendetta held as a votive, not in vain, for the value and veracity of such shall one day vindicate the vigilant and the virtuous. Verily, this vichyssoise of verbiage veers most verbose vis-à-vis an introduction, so let me simply add that it's my very good honor to meet you and you may call me V.

Ciao T

 

Hi,

Why not make your own?

It is a standard shunt attenuator with a standard switch and Tantalum resistors. You can even read the values off the photo, halve them and you have a 50k one.

One thing to beware of though is that with shunt attenuators the maximum output impedance is around four times as high as with a conventional ladder or dual step type.

This means you progressively loose bandwidth and gain extra interactions with the amplification stage driven (to wit, in valves - grid current which in never zero and capacitance, in J-Fets mainly dynamic capacitance modulation and where bipolar devices are used high, signalmodulated base current).

This needs careful planning to work out best. When replacing a standard pot with a shunt attenuator it is best to go for one of one quarter value, but that in turn may cause problems for the source, which may not "like" to see as low an impedance as that.

My experience has been that shunt attenuators are best kept at very low resitance levels (I tended to use no more 470R series resistance) and buffered on the input with a very high quality buffer.

The old discontinued AD BUF03 was a good choice, a pair of complementary J-Fets in a John Curl type are okay, a 5687 or 6N30 connected correctly as white cathode follower with 0V output DC shift and symmetric supply worked great as well.

THAT SAID, the best volume controls I have found where all transformers, I suspect becuase they simply eliminate all the issues of the non-ideal behaviour of the input device following the volume control interacting with a significant impedance.

Ciao T

 

Colin Chapman

Sorry, I meant John, not Colin of Lotus fame

 

Recently bumped into this:http://www.shallco.com/frameset.html

Used in the Lyra preamps.

Expensive but yummy.