2. amps-preamps
  3. 185222-161121

Budget preamp with quality volume control

Dear Audiogoners,

I used to be a firm believer that the signal path should be as short as possible and, as such, I have been using the two-channel system without a dedicated preamp. For a long period of time, I have relied on the digital attenuator in DAC for volume control, knowing the digital attenuator would compress the dynamic range of the sound. Therefore, I switch the volume control on DAC to the fixed mode, bypass the digital attenuation and use the unity gain knob in the back of the power amp for volume control. Depending on the music recording level, however, sometimes I need to turn the unity gain control way down to get proper sound level. This is particularly painful when I use the full-balance connection because of the double voltage gain.

In short, I am looking for a budgetary preamp with quality volume control that either has relay switch stepped control or precise potentiometer for left-right channel match to curb the issue. I try to summarize important (to me) performance catgories as best I can for various good sounding preamp I know (with or without headphone amp/dac) as shown below. It is found the Schiit Magnius happens to have the highest performance ratio. However, I am pretty sure that I likely miss other good performers due to my limited knowledge and would like to solicit for your inputs. Your kind assistance is appreciated.

 

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Showing 4 responses by mitch2

mitch2
3,694 posts
 

I agree that many have appreciated Placette products over the years so when I was comparing high end volume controls, I inquired to them back in January.

FYI - unfortunately, below is the message I received back:

Please make a note.
Placette Audio has closed.
Regard
Debra

I strongly suggest looking at the Hattor and/or Khozmo line.

mitch2
3,694 posts
 

@chopandchange 

if I am only using the ONE digital source - would I really need a pre-amp at all?

That has been a question asked by many over the years.  Having enough voltage is one piece of the puzzle but impedance compatibility to drive the cables and power amplifier is another piece that is not addressed by simply putting an attenuator in the signal chain.   In short, many have found that preamps having a high'ish impedance input and low'ish impedance output to the power amplifiers seem to do a better job of preserving tonal qualities, dynamics, and drive, compared to using an attenuator alone.  A unity gain buffer following the attenuator can do the job fine in cases like yours where there is enough voltage coming out of the source.   

mitch2
3,694 posts
 

Every passive attenuator company says the same thing, Goldpoint, the LDR folks (i.e., Lightspeed and Tortuga), manufacturers that put attenuators in their DACs like Metrum and Sonnet, and more.  Some say it louder than others.  Hattor/Khozmo offer both options, as well as op-amp or tube active stages to follow their passives, if desired.  I have tried more than a few passives, and currently own 5 different passive units, Goldpoint, Khozmo, Hattor, Endler (attenuators that mount to your amplifiers), and an icOn 4PRO autoformer.  I have also owned the Metrum Adagio DAC, with a lossless volume control.

The ONLY one of those passive solutions that IME preserves the tone and drive to the same level of an active preamp (or active buffer), regardless of how short the ICs are, is the icOn 4PRO AVC preamp, which uses Slagle autoformers.  The autoformers (a type of transformer) have the ability to decrease the output impedance while performing attenuation.  I really like the sound of the 4PRO but I also have a custom, higher quality, Khozmo dual mono passive unit that I use in front of a SMc Audio solid state unity gain buffer, which results in a quite low impedance signal going to my amplifiers.  I like the sound of the Khozmo/SMc buffer combination a little bit better than the icOn 4PRO.  The buffer does not provide gain (above unity), but with the buffer in the path following one of the  passives, I hear improvements in bass, dynamics, tone, and drive, over using any of the passives (except for the icOn) without the buffer.  The icOn 4PRO does not suffer the losses described above that I hear from the other passives.

All that said, only you can decide what type of sound you like, and what you hear in your own room with the equipment you have.  There are many here who like having a passive attenuator, and are happy with the sound.  In the end, any of us here can describe what has worked for us but "try it for yourself" is the only answer that really means anything.

mitch2
3,694 posts
 

Music First Audio was an early adopter of the transformer volume control, or TVC.  I believe they use S&B transformers.  Transformers use two coils around a core and offer isolation while autotransformers, or autoformers, use only one coil and do not isolate but do apparently have a few advantages when used as volume controls.

Autoformers allow for the same voltage/current transformations that typical transformers are used for and have increased power handling capability, flatter frequency response, lower insertion loss and lower distortion than conventional transformers of similar size and cost.

I do like the Apple remote functionality with the icOn 4PRO.  I also like the large display that is so easy to see across the room.  Functionally, it offers everything I want in a preamp, including an HT pass-through.  I have not tried Music First or any of the other transformer VCs, so cannot make a comparison between autoformers and transformers in my system.

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