Best Volume Control

dan31

Well-Known Member
Jul 22, 2010
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Sure. Plenty of fine preamps using ALPS BV pot. Of course there are stepped attn preamps that are equal or better. As the cost goes up you see more of the hand matched volume components.
 

flm09

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May 1, 2020
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Sure. Plenty of fine preamps using ALPS BV pot. Of course there are stepped attn preamps that are equal or better. As the cost goes up you see more of the hand matched volume components.

So stepped attenuator are always superior?
 

analogsa

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Apr 15, 2017
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So stepped attenuator are always superior?

It depends on the attenuator. A silver alloy Shallco in a shunt or ladder configuration using the best sounding resistors just about slaughters any mechanical or electronic pot.

Very few commercial devices use attenuators of such quality. Remote operation is difficult and expensive, the cost of resistors can quickly mount once you realise 40 or even more steps are essential. Even getting the desired resistor values is far from trivial in really high quality resistors.

And this is the reason some manufacturers choose a $2 electronic pot, carve a case around it out of a solid alu block and plaster a "Reference" designation in front :cool:
 

flm09

Well-Known Member
May 1, 2020
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It depends on the attenuator. A silver alloy Shallco in a shunt or ladder configuration using the best sounding resistors just about slaughters any mechanical or electronic pot.

Very few commercial devices use attenuators of such quality. Remote operation is difficult and expensive, the cost of resistors can quickly mount once you realise 40 or even more steps are essential. Even getting the desired resistor values is far from trivial in really high quality resistors.

And this is the reason some manufacturers choose a $2 electronic pot, carve a case around it out of a solid alu block and plaster a "Reference" designation in front :cool:

Yeah true but you think in a blind test people can tell the difference between Shallco and Alps Blue velvet since tube preamps have lot of distortions anyways?
 

DaveC

Industry Expert
Nov 16, 2014
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Yeah true but you think in a blind test people can tell the difference between Shallco and Alps Blue velvet since tube preamps have lot of distortions anyways?

Many tube preamps have very little distortion and there is a night and day difference between an Alps pot and a good stepped attenuator, to the point I think an Alps pot would result in significant degradation of a top end system. In a top end system the volume controls are one of the most important considerations as there are large differences between options. FWIW, I'll be going with silver autoformer based VCs for my next project.
 

microstrip

VIP/Donor
May 30, 2010
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Hey guys,

Can a Alps Blue Velvet compete with stepped attenuators regarding sonics?

As always it depends on the external conditions. The only thing you are stating clearly is the Alps Blue Velvet, a nice sounding name for a good quality conductive plastic potentiometer. I have listened to many pieces of equipment sounding great with this component, the main drawback was a lack of accurate balance at low levels.
 

kernelbob

Well-Known Member
Oct 23, 2011
102
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A key issue with volume controls and switches is that the signal has to jump across the contacts or wiper of the control. This includes poteniometers, stepped attenuators, and switches. The impact becomes progressively higher as the attenuation increases. Of course, implementations and parts quality vary, but the only way for the signal to avoid having to make that "leap" is to use soldered connections.

I use a Totuga controller that implements hard soldered light dependent resistors (LDRs) to perform attenuation as well as other functions that would otherwise require switches such as selecting between inputs, choosing between various input impedances, and even toggling absolute phase (which varies from one recording to the next). My Tortuga LDRxB does all this using LDRs with all functions available using a standard Apple remote.

The Tortuga has full bodied bass with great extension to the lowest frequencies. Dynamics, soundstage width & depth, instrumental timbre and coherence are all there. I've seen it better five figure preamps & controllers. Worth taking a look at www.tortugaaudio.com.
 

flm09

Well-Known Member
May 1, 2020
161
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A key issue with volume controls and switches is that the signal has to jump across the contacts or wiper of the control. This includes poteniometers, stepped attenuators, and switches. The impact becomes progressively higher as the attenuation increases. Of course, implementations and parts quality vary, but the only way for the signal to avoid having to make that "leap" is to use soldered connections.

I use a Totuga controller that implements hard soldered light dependent resistors (LDRs) to perform attenuation as well as other functions that would otherwise require switches such as selecting between inputs, choosing between various input impedances, and even toggling absolute phase (which varies from one recording to the next). My Tortuga LDRxB does all this using LDRs with all functions available using a standard Apple remote.

The Tortuga has full bodied bass with great extension to the lowest frequencies. Dynamics, soundstage width & depth, instrumental timbre and coherence are all there. I've seen it better five figure preamps & controllers. Worth taking a look at www.tortugaaudio.com.

I really like the LDR! Can you make a simple pre DHT 300b preamp with LDR volume control?
 

kernelbob

Well-Known Member
Oct 23, 2011
102
103
948
Hi flm09,

Tortuga has various controllers. active preamps, tube or solid state buffers , and standalone LDR volume control packages that can be implemented in other units such as your DHT 300B preamp. One more thing, I'm running my LDRxB from a 12V battery. Tortuga offers a battery power supply or you can easily make your own-- I use an Optima marine battery and a trickle charger which is way overkill, but still cost effective. Morten Sissener of Tortuga is great to work with.

Best,
Robert
 

flm09

Well-Known Member
May 1, 2020
161
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Hi flm09,

Tortuga has various controllers. active preamps, tube or solid state buffers , and standalone LDR volume control packages that can be implemented in other units such as your DHT 300B preamp. One more thing, I'm running my LDRxB from a 12V battery. Tortuga offers a battery power supply or you can easily make your own-- I use an Optima marine battery and a trickle charger which is way overkill, but still cost effective. Morten Sissener of Tortuga is great to work with.

Best,
Robert

Hey Robert,

Unfortunately I am not a hobby builder looking for a finished product using 300b!
 

kernelbob

Well-Known Member
Oct 23, 2011
102
103
948
I still recommend that you try a Tortuga (Morten offers a 30 day trial). I think you'll be surprised and that the price is a bargain. I'm using the LDRxB in a system with a Lampizator Pacific DAC as input. The Tortuga drives a biamped pair of Von Schweikert VR100XS speakers. A pair of Lampizator Pacific 211 monoblock amps drive the mid/treble and a pair of Spectron Musician III Mk2 amps as monoblocks drive the bass.

Robert
 

flm09

Well-Known Member
May 1, 2020
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I still recommend that you try a Tortuga (Morten offers a 30 day trial). I think you'll be surprised and that the price is a bargain. I'm using the LDRxB in a system with a Lampizator Pacific DAC as input. The Tortuga drives a biamped pair of Von Schweikert VR100XS speakers. A pair of Lampizator Pacific 211 monoblock amps drive the mid/treble and a pair of Spectron Musician III Mk2 amps as monoblocks drive the bass.

Robert

Ok i will check it out thanks!
 

analogsa

Well-Known Member
Apr 15, 2017
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Yeah true but you think in a blind test people can tell the difference between Shallco and Alps Blue velvet since tube preamps have lot of distortions anyways?

Not sure what distortions you have in mind, but if it's about harmonic distortions I can assure you it is not a lot. 0.02% thd is easily achievable even without nfb. And even if that is a lot, why should it matter? I cannot imagine anyone in this hobby not hearing obvious differences like that.

Ironically, the very well regarded LDR attenuators are distortion champions, at high levels easily eclipsing tube harmonic distortion.
 

flm09

Well-Known Member
May 1, 2020
161
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Not sure what distortions you have in mind, but if it's about harmonic distortions I can assure you it is not a lot. 0.02% thd is easily achievable even without nfb. And even if that is a lot, why should it matter? I cannot imagine anyone in this hobby not hearing obvious differences like that.

Ironically, the very well regarded LDR attenuators are distortion champions, at high levels easily eclipsing tube harmonic distortion.

Oh I didn't know that! So sticking with Alps blue velvet is good enough?
 

DaveC

Industry Expert
Nov 16, 2014
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Not sure what distortions you have in mind, but if it's about harmonic distortions I can assure you it is not a lot. 0.02% thd is easily achievable even without nfb. And even if that is a lot, why should it matter? I cannot imagine anyone in this hobby not hearing obvious differences like that.

Ironically, the very well regarded LDR attenuators are distortion champions, at high levels easily eclipsing tube harmonic distortion.


I use an LDR in my 6SN7/12SN7 buffer preamp. They have tradeoffs like anything, the power supply is audible, source switching still requires switching contacts. I plan on switching it out with silver autoformers, but remote control may be an issue. Bent audio had an autoformer pre with remote, the TAP-X I think, not sure it's possible to get the remote parts still. It's tough to give up remote VC! :)
 

DaveC

Industry Expert
Nov 16, 2014
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Oh I didn't know that! So sticking with Alps blue velvet is good enough?

It's fine for the price, a high quality stepped attenuator is much more expensive. IMO it's worth the cost, but the choice depends on budget and expectations.
 
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flm09

Well-Known Member
May 1, 2020
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It's fine for the price, a high quality stepped attenuator is much more expensive. IMO it's worth the cost, but the choice depends on budget and expectations.

Ok thanks Dave! I'm looking into a Bee pre but not sure i want to put together. They have stepped attenuators.
 

MikeHorns

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Jul 6, 2014
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I like step attenuators and I use them on my system(mono/mono). I've tried the Chinese hand solder ones from eBay and Gold Point matching 1/8 watt Vishay resistor ones, and the Gold Point was a lot better sounding. Then I tried the Gold Point V47, 47 step discrete matching chip resistor attenuators, and I like that even better. On my system, the chip resistor attenuators sounded cleaner, more open, with lot more detail than the Vishay resistor.
 
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