Thoughts on total number of steps and dB range per step in preamp volume controls.

[spiritofmusic]

I'm currently running a Nat Audio Utopia preamp which uses a resistor-based volume control of 53 steps.

In my system and room, I listen to vinyl at steps 15-18, occas as high as 25. CD at 10-12 occas as high as 15-18.

I'm possibly looking at the Emia Autoformer or Elmaformer passive preamps. The Elmaformer has 47 steps at 1.5dB each, which may not be far off my Nat adjustability. The Remote Autoformer has over 50 steps at 1dB each.

But the Manual Autoformer I'm most interested in runs to only 23 steps at 2.5dB per step. I'm a little concerned that this looks a little truncated as a range, and 2.5dB per step may be too coarse.

Even w the 50+ steps of my Nat, there are many CDs where step 9 is too quiet, and 10 is JUST too loud.

Am I looking for trouble considering a preamp w half the number of steps of my current unit?

 

[KeithR]

well, you have an active preamp w/ gain so its not going to work quite the same way. you have efficient speakers, so its just a matter of seeing what your input voltage is on the NAT amps. can't imagine there is an issue.

my Music First TVC has 2db attenuation steps and it doesn't really bother me...that said, i believe the steps in the early attenuation stages are much smaller.

btw, why don't you try an MF since they are local?

 

[Mike Lavigne]

my dart preamp uses analog optical couplers to attenuate volume. it has 1db steps and can be adjusted by hand with the knob or with the remote in .5 increments. i've not yet had a situation where i could not get exactly the gain i wanted.

the volume goes + or - in 100 steps either way (plus the .5 steps in between). there is a repeatable digital readout in .5 increments. each input can be set with an offset, although i don't do that.

mostly the volume stays in a range from -25db to +5 db.....-10db being most common.

 

[microstrip]

Many preamplifiers having a limited number of steps have different attenuation between steps in their range - just counting steps is not enough.

If you have sources with different output amplitude a small number os steps can be a problem. I find that I need not more than 1 dB steps - ARC and cj have typically between .5 and .7 dB between the steps. For comparisons a .5 dB difference is enough to bias a listening session.

 

[spiritofmusic]

My reticence is based on the Koda K10 preamp I demoed once. It's active, but I really cannot remember it's total number of steps or the dB of each step. However, I could rarely find the "right" setting, both for lp and cd. Indeed this would have been a deal breaker had I been able to afford it.

I'm just intrigued that Emia autoformers come in three versions, the most affordable one at $2.5k, Manual Autoformer, sporting what I suspect could be (for me) problematic 23 steps/2.5dB per step volume, the Remote Autoformer sporting 53 steps/1dB, and the Elmaformer sporting 47 steps/1.5dB.

Surely if the most limited adjustments on the Manual weren't an issue, the Remote and Elma wouldn't open up their ranges?

 

[spiritofmusic]

well, you have an active preamp w/ gain so its not going to work quite the same way. you have efficient speakers, so its just a matter of seeing what your input voltage is on the NAT amps. can't imagine there is an issue.

my Music First TVC has 2db attenuation steps and it doesn't really bother me...that said, i believe the steps in the early attenuation stages are much smaller.

btw, why don't you try an MF since they are local?

Keith, the jury is out on Music First. And their TOTL model together w the Bespoke passive, is 2-4x the cost of the Emias.

 

[spiritofmusic]

my dart preamp uses analog optical couplers to attenuate volume. it has 1db steps and can be adjusted by hand with the knob or with the remote in .5 increments. i've not yet had a situation where i could not get exactly the gain i wanted.

the volume goes + or - in 100 steps either way (plus the .5 steps in between). there is a repeatable digital readout in .5 increments. each input can be set with an offset, although i don't do that.

mostly the volume stays in a range from -25db to +5 db.....-10db being most common.

Mike, you're making my point for me. The Dart vol range into 3 figures, and each step adjustable to under 1dB, as small as 0.5 if you like.

Would you settle for the Dart if it only ran 23 steps at 2.5dB each?

 

[asiufy]

2.5dB steps is just too much, IMHO. At Keith's, I can hear a huge difference between each step, enough to make me uncomfortable for long term use.
I've also notice the same with MSB's internal preamp (passive). Going to an active preamp with fine volume control like the Ref10 allows one to adjust for that volume "sweet spot".

 

[Mike Lavigne]

Mike, you're making my point for me. The Dart vol range into 3 figures, and each step adjustable to under 1dB, as small as 0.5 if you like.

Would you settle for the Dart if it only ran 23 steps at 2.5dB each?

i never settle.

 

[spiritofmusic]

Mike, touché.

 

[spiritofmusic]

2.5dB steps is just too much, IMHO. At Keith's, I can hear a huge difference between each step, enough to make me uncomfortable for long term use.
I've also notice the same with MSB's internal preamp (passive). Going to an active preamp with fine volume control like the Ref10 allows one to adjust for that volume "sweet spot".

Alex, this is my suspicion. I think if I go down the Emia passive route, it'll have to be the Elmaformer w 47 steps at 1dB each.

 

[KeithR]

Keith, the jury is out on Music First. And their TOTL model together w the Bespoke passive, is 2-4x the cost of the Emias.

Not out at all - I own one. Phil loves it too on Zu. I believe you can do 1.5db steps for extra $.

I find it interesting you'll spend $30k on cables and tweaks but won't spend $5k on a preamp that that you can audition in your own system that supports your local economy

 

[spiritofmusic]

That's a bit of a loaded statement, Keith. No problem supporting British, my tt, arm, analog psu.s, cables, balanced transformer, spkrs isolation footers, and supertweeters, are all British. And at the rate the £ is veering against the $ and €, soon British is all I'll be able to afford.

I've heard Music First as well as Townshend Allegri passives, and found them wanting dynamically.

And when Emia TOTL is way less expensive than MF TOTL, and Emia comes highly rated, I don't need to justify considering them, esp w my poor MF experience.

 

[KeithR]

2.5dB steps is just too much, IMHO. At Keith's, I can hear a huge difference between each step, enough to make me uncomfortable for long term use.
I've also notice the same with MSB's internal preamp (passive). Going to an active preamp with fine volume control like the Ref10 allows one to adjust for that volume "sweet spot".

Yes, but my MF costs $24k less.

Most volume controls suck, i'll give you that - especially the motorized Alps ones.

 

[spiritofmusic]

Keith, I was also considering the LTA MicroZotl pre/integrated. But had similar warnings about the Alps pot it uses.

 

[KeithR]

I've heard Music First as well as Townshend Allegri passives, and found them wanting dynamically.

Did you have the MF in your system? Because there is no dynamic restriction in my auditions of them with Phil vs numerous preamps. And that includes your own speaker, no less.

 

[KeithR]

I'll also note that in Fremer's review of the Bespoke (which uses an older version of the MF transformer) he specifically states there was no dynamic degradation compared with his active.

 

[spiritofmusic]

Keith, it wasn't w my Zus. And I learnt to take reviewers with a pinch of salt after seeing Martin Colloms give the Townshend Allegri passive one of his highest ratings, and yet in my system it was so schizophrenically poor I could not reconcile Colloms' words.

OTOH, Phil says he's never heard any 211 amp sound near convincing on Zus (indeed went so far as to preclude them from his Druids VI amp roadshow), feels Nat are not overly impressive, and yet my Nat 211s are magical on my Zus.

 

[spiritofmusic]

This preamp change will only happen if I move from Zu to an alternative that demands total silence, the only real failing of my Nats.

 

[Al M.]

2.5dB steps is just too much, IMHO. At Keith's, I can hear a huge difference between each step, enough to make me uncomfortable for long term use.
I've also notice the same with MSB's internal preamp (passive). Going to an active preamp with fine volume control like the Ref10 allows one to adjust for that volume "sweet spot".

Lack of fine adjustability also made me refrain from the stepped volume option for my Octave HP 700 preamp. I have the version with a high-quality pot which I can exquisitely fine tune. Do I miss that way the last iota of sound quality? Perhaps. But being able to listen exactly at the volume I want overrides that small concern. The preamp is a superior component as is.