2. misc-audio
  3. 195456-110266

Adding Volume control to an older preamp

I need suggestions from the group please-

My current system consists of Harbeth SHL5 speakers, Pass Lab 150.8 amp, Audible Illusions Modulus 3 preamp, Denafrips Pontius II DAC, Wiim Pro streamer and Nordost/Monster cables. I listen to a mix of music but mostly jazz and classical I reallyI enjoy my current system.  

I would like some advice from members of the forum as to how to control the volume from my listening chair as the Audible Illusions preamp does not have a remote volume control.

As a quick fix, I recently purchased a remote for the Wiim Pro to control the volume at the streamer but have read that controlling the volume at that point in the chain is not the best.


I have come up with two possible solutions and would like your feedback is to which is the best or is there a better third choice? Also, WAF is not a problem as my listening room is in the basement .

1) I can purchase a Schiit Saga with a remote and use the passive mode. But, will there be any impedance issues placing the Saga between the preamp and the amp?

2) I can move the preamp next to my listening chair and control the volume manually but will need to purchase longer cables. I would need either 14 foot interconnects between the preamp and amp or 14 for speaker cables. From what I have read, shorter interconnects and longer speaker cables is the way to go.

Both solutions will cost about the same. Any advice would be greatly appreciated. 

Thank you in advance.

2tuby

Showing 5 responses by lanx0003

lanx0003
1,232 posts
 

The Pass Labs 150.8 has plenty of input impedance—50 kΩ for single-ended and 100 kΩ for balanced—so the Saga 2’s tiny 75 Ω output impedance is no problem at all. Even with the Pontus II feeding the Saga 2, you’re still looking at 625 Ω output into a 10 kΩ input, which is fine too. Saga 2 only takes single-ended inputs anyway, you’re all set.

lanx0003
1,232 posts
 

The 10k ohm input imp. is standard on all Schiit preamps.  For headphone amp and preamps, however, the input imp. is designed as 50k ohm.  If you don’t believe me, you could check with Schiit.

Technically speaking, I like the preamp section in the headphone amp/preamp like Asgard but it does not come with remote.

lanx0003
1,232 posts
 

passive mode is "max 4.7K"). With 4.7K ohms you ideally want a source output impedance below 470 ohm

Saga2's output imp. being 4.7kohm does not mean its output imp. is also 4.7kohm.  I believe all Schiit preamps (not headphone amp/preamp) have a standard 10kohm input imp.

lanx0003
1,232 posts
 

Not a good idea to use a longer interconnect and Ethernet cable just for the convenience of volume adjustment. I’d rather take the opportunity to get some exercise — or consider the following:

  1. If you keep the Wiim for streaming: It has a ReplayGain setting that lets you normalize volume across albums or tracks. I recall Qobuz only supports track-level normalization, but it still reduces the need for constant volume adjustments. In the Wiim, ReplayGain is applied as metadata and processed with 32-bit precision before DAC conversion, so there’s no audible harm to fidelity.

  2. If you still decide to move the gear closer: Consider an optical-Ethernet setup, which many end users have found effective.

lanx0003
1,232 posts
 

A standard 10K input impedance for the active preamps seems an odd choice;

I would agree.  Their HP/Preamp series has 50k ohm input but even the higher-end preamp like Kara/Freya stick with 10k.  Why, don’t know, ask bud dry!

My understanding of "true" passives is that input and output impedances are generally the same by definition

A passive device simply means it has no active gain elements such as transistor, op-amp or tube and operates without an external power supply for amplification. This implies nothing about input and output impedances being equal.  You could look at the "SYS" model, i.e., its input and output impedances are 10k and 5k (max) ohm, respectively.

Lastly, the Saga’s gain (ratio) is 1/2 for SE/Balance in Low-Gain active; and 4/8 in High-Gain active. (Amplification = 20 log(gain) is 0 dB when gain = 1)  It is found the Low-Gain active sounds the best, better than the passive mode with slightly more dynamic/openness without hint of constriction.  In addition, Low-gain tends to have lower THD+N than High-gain, as frequently demonstrated in the measurements.

 

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