Lundahl Sound VC2361 6-Channel Volume Control Review

[Davide]

The microcontroller is to connect and disconnect the relays either by using the rotary encoder or the remote.

Sorry I expressed myself badly I think.
I meant, what would be the advantage in using this product over the DAC's digital volume control, where the relative dynamic range is sufficiently high?

 

[Sokel]

Sorry I expressed myself badly I think.
I meant, what would be the advantage in using this product over the DAC's digital volume control, where the relative dynamic range is sufficiently high?

SNR as you correctly said.
I would add an added safety measure (if done right,and this one looks like it is) against a digital glitch which can expose the full volume of a dac as we have (rarely) seen.

It's all about the gain structure and compromises we make at the end of the day.

 

[Davide]

SNR as you correctly said.
I would add an added safety measure (if done right,and this one looks like it is) against a digital glitch which can expose the full volume of a dac as we have (rarely) seen.

It's all about the gain structure and compromises we make at the end of the day.

Ok but, in practical terms, the best SNR is not necessary if the DAC has enough dynamic range.
That's why I don't understand the need for this product...
With $30 of resistors I built 6 passive balanced attenuators so that the volume of the DAC at 100% reached my desired maximum SPL (95dB). With about 115dB of dynamic range of my Motu I am sure that even when I attenuate digitally until I have 50 dBSPL the noise/distortion are still at about -70dB, therefore almost inaudible.
Of course ... I had to study and work for it. But there are also ready-to-use attenuators for sale, and 6 of them don't cost as much as this product.
Sure, they don't provide the ability to use a remote control like this product, but implementing it aside, you hardly get to 1K.
It is not my criticism, it is just to understand if the target of the product is the usual wealthy audiophile or I am missing something...
I would very much like to use such a product in my system, which happens to have 6 channels, but that money to adjust the volume without gaining further performance doesn't make sense to me.

 

[Deleted member 68267]

Audiophonics has a preamp that looks like a good alternative to this one:

AUDIOPHONICS AP310-PREAMP Balanced Preamplifier MUSES72320

Audiophonics is proud to present the AP310-PREAMP, a pure analogue balanced preamplifier. Combining comfortable power with a MUSES72320 volume control and full connectivity, it is a sure bet for anyone wishing for a quality audio system.

www.audiophonics.fr

 

[Davide]

Audiophonics has a preamp that looks like a good alternative to this one:

AUDIOPHONICS AP310-PREAMP Balanced Preamplifier MUSES72320

Audiophonics is proud to present the AP310-PREAMP, a pure analogue balanced preamplifier. Combining comfortable power with a MUSES72320 volume control and full connectivity, it is a sure bet for anyone wishing for a quality audio system.

www.audiophonics.fr

But that's only 2 channels compared to 6 of this one.

 

[Deleted member 68267]

Well, it has 2 outputs and 5 inputs. It also transforms from SE to balanced and the other way round.
And the price is 350€.

 

[AudioJester]

Well, it has 2 outputs and 5 inputs. It also transforms from SE to balanced and the other way round.
And the price is 350€.

The use case is so different. No one looking for a 2 channel preamp is going to be looking at the Lundahl 6 channel preamp, and no one lookung for a multichannel pre will look at the Audiophonics.
Its a very basic point of difference?

 

[georgehifi]

Far better off using these (and cheaper), with far less (TVC) transformer based colouration/distortions.

DACT audio attenuators

Cheers George

 

[theREALdotnet]

Far better off using these (and cheaper), with far less (TVC) transformer based colouration/distortions.

I’m not so sure about that. These DACT attenuators are stupidly expensive, a balanced stereo (!) one costs AU$700, and you’d need three of them in a six channel setup. Then you’d still have to make sure somehow that they’re all set to the same volume.

TVCs are similarly expensive, but I didn’t find frequency response to be an issue (I measured it). They have the advantage that rather then worsening source and load impedance for amp and source, they improve both. In situations where the amp input impedance is already on the low side or the source has a highish output impedance this might make a difference.

 

[georgehifi]

I belive it would all come down to which one would be "truer" to the sound of the source without "flavoring" it's sound, (least colouring it) and that I would think is a resistor without any inductance or capacitance unlike a TVC.

Cheers George

 

[theREALdotnet]

I belive it would all come down to which one would be "truer" to the sound of the source without "flavoring" it's sound, (least colouring it)

Yes, and in practice neither resistive ladders nor TVCs do.

and that I would think is a resistor without any inductance or capacitance unlike a TVC.

Ideal transformers, like ideal resistors, have no reactance. In reality, both have a little. In the 20-20k frequency range, they don’t matter.

 

[dualazmak]

Interesting pro-oriented device and discussion... Let me join, please.

I would like to emphasize (again!) about the pros and merits of relative gain (i.e. tone) control over multiple SP drivers not only in digital domain but also in analog domain using pre-amplifiers or integrated-amplifiers (in my setup). I recently wrote as follows in my post #56 on a remote thread;

Yes, as for safe and flexible tone controls (or I can say "relative gain controls among the multiple SP drivers"), my stance (policy) at least, is that we are encouraged to utilize the "best combination" of "DSP configuration in digital domain" and "analog domain tone controls using HiFi-grade preamplifiers and/or integrated amplifiers".

We need to note (and to respect for) that analog domain tone controls (relative gain controls among the multiple SP drivers) give no effect nor influence at all on the upstream DSP configuration (XO/EQ/Gain/Phase/Polarity/Group-Delay). I believe that this is a great merit of flexible tone controls in analog domain. We know well, on the other hand, in case if we would like to do the "tone/gain controls" only within DSP configurations, such DSP gain controls always affect more-or-less on "XO" "EQ" "phase" and "delay" of the DSP settings which will leads you to possible endless DSP tuning spirals every time; within DSP configurations, XO EQ Gain Phase and Delay are always not independent with each other, but they are always interdependent/on-interaction.

Just for your possible reference, my DSP-based multichannel multi-SP-driver multi-amplifier active system has flexible and safe analog level on-the-fly relative gain controls (in addition to upstream on-the-fly DSP gain controls) for L&R subwoofers, woofers, midrange-squawkers, tweeters, and super-tweeters, all independently and remotely. My post here shows you a typical example case for such safe and flexible on-the-fly analog-level tone controls. This my post would be also of your interest.

Of course, I know well that I (we) can also perform such relative gain control using DAC8PRO’s 8-channel output gain controllers. I do not like, however, to change the DAC8PRO’s output levels frequently on-the-fly (while listening to music) due to safety and inconvenience concerns; I like to keep DAC8PRO’s analog out gain level always at constant -4 dB which should remain to be usually “untouchable” in my case.

One of the very unique aspects/features of my multichannel audio rig is that I fully utilize four HiFi-grade “integrated amplifiers” plus L&R active subwoofers, each of them have its own gain (volume) controller for safe and flexible relative gain (tone) control in analog domain even on-the-fly i.e. while listening to music.

In this perspective, my posts #438 and #643 on my project thread should also give you better understandings. Furthermore, my posts #317(remote thread), #313(remote thread) would be also of your reference and interest.

 

[dualazmak]

Yes, and in practice neither resistive ladders nor TVCs do.

And, I also assume (or believe) "resistive ladder" type gain/volume controllers always have possible long-time-range "non-uniform burn-in" issue even audible or not.

 

[dualazmak]

Ideal transformers, like ideal resistors, have no reactance. In reality, both have a little. In the 20-20k frequency range, they don’t matter.

Talking about "Ideal transformer" VC, do you mean e.g. like the products from BESPOKE AUDIO Co.?; extraordinary expensive though...
- https://www.thebespokeaudiocompany.com/our-product
- https://www.thebespokeaudiocompany.com/our-process

 

[theREALdotnet]

Talking about "Ideal transformer" VC, do you mean e.g. like the products from BESPOKE AUDIO Co.?

I’ll consider one of those when they make a version in stitched corinthian leather

; extraordinary expensive though...

Indeed, it seems a lot of money and effort is spent on the bling aspect. The one I used to have was made by Promitheus and much more down to earth. The transformers were top notch, though.

 

[georgehifi]

That's a lot of fine wire including L, C and R with what's inside those tranies, to think it will stay totally uncorrupted and stay true to the sources sound.

Cheers George

 

[theREALdotnet]

That's a lot of fine wire including L, C and R with what's inside those tranies, to think it will stay totally uncorrupted and stay true to the sources sound.

There most certainly are L, C and R, like in any physical system. It doesn’t need to be perfect, it just needs to be good enough. The alteration of the signal needs to be inaudible, that’s all. I can assure you, expensive TVCs like the Bespoke and even inexpensive ones like the Promitheus I used to own do not alter the signal in an audible way.

You will also observe that the device tested in this review, a resistive ladder attenuator, shows some HF droop in one of the two tested (out of six total) channels. Perfect? No. Audible? Nope.

 

[georgehifi]

I can assure you, expensive TVCs like the Bespoke and even inexpensive ones like the Promitheus I used to own do not alter the signal in an audible way.

Yeah sure, OK.

Cheers George

 

[Rewind]

No, a different company: https://www.lundahlsoundsystems.com/#optimizer_front_text-4

Yeah, everyone is called lund-something in Sweden. Including me.

 

[Roland301]

Ok but, in practical terms, the best SNR is not necessary if the DAC has enough dynamic range.
That's why I don't understand the need for this product...
With $30 of resistors I built 6 passive balanced attenuators so that the volume of the DAC at 100% reached my desired maximum SPL (95dB). With about 115dB of dynamic range of my Motu I am sure that even when I attenuate digitally until I have 50 dBSPL the noise/distortion are still at about -70dB, therefore almost inaudible.
Of course ... I had to study and work for it. But there are also ready-to-use attenuators for sale, and 6 of them don't cost as much as this product.
Sure, they don't provide the ability to use a remote control like this product, but implementing it aside, you hardly get to 1K.
It is not my criticism, it is just to understand if the target of the product is the usual wealthy audiophile or I am missing something...
I would very much like to use such a product in my system, which happens to have 6 channels, but that money to adjust the volume without gaining further performance doesn't make sense to me.

DACs that don't have a dedicated volume control?

Personally, I just do not trust any digital volume setting that is controlled from an operating system, when dealing with a chain that can get loud enough for serious damage.
I've encountered a lot of situations where I could have gone deaf due to operating system volume resetting to 100% on USB re-connection, or playback software grabbing control of it (looking at you, Tidal).

I run headphones directly from a Purifi 1ET400A, so I can NOT under any circumstance risk the volume control resetting itself while the headphones are on my head

That said, I am not against a (dedicated) digital volume control if it's well implemented and has sufficient SNR. Motu M2/M4 being a good example.