kontai69
1000+ Head-Fier
- Joined
- Feb 27, 2005
- Posts
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- 19
INTRODUCTION
I’ve owned the HeadAmp GS-1 headphone amp with the “standard” Alps Blue Velvet volume control (pot) for well over a year now. I am extremely satisfied with it powering my MS-Pros, as well as my K701s. In fact, I would say that the sound of my system is nearly faultless, to my ears. However, I started reading about and researched stepped attenuators and learned of its sonic benefits over standard volume pots (e.g. greater clarity, less noise, better channel balance). Inevitably, the upgrade bug bit me and I (impulsively) bought another GS-1, this time with the DACT stepped attenuator (http://www.dact.com/html/attenuators.html), which is a $175 option. I would like to share my impressions comparing the Alps volume pot with the DACT stepped attenuator with the GS-1. I used only my MS-Pros for the comparison to make things simpler.
ASSOCIATED EQUIPMENT
Headphones: Alessandro MS-Pro
CD transport: Music Hall CD25.2
D/A converter: Ack! dAck! v2.0
I'm hoping not to get too many of the ubiquitous "you need to upgrade your source" comments.
Cables: Kimber Silver Streak IC; power cords: VH Audio Flavor 1 (transport) and Zu Birth (amp); DiMarzio Big Red extension cord; Ack! Industries The Digital Connect digital cable
Can you guess which amp has which volume control?
METHODOLOGY:
I level matched the volume output of both amps to a fraction of a decibel using a Rat Shack SPL meter. I did my A/B/A comparisons by listening to a portion of a song over and over and over again until my ears got conditioned to the sonics of the recording. I would then rapidly move the interconnects, power cable, and headphone cable to the other amp and listen to the track again and note any differences.
I let the new DACT GS-1 burn-in for around 150 hrs before I did the comparison. Just to cover all posiblities, I swapped the removable amp modules between the Alps and DACT GS-1s and redid the comparison to make sure the differences I heard were not due to differences in burn-in time or some unforeseen design changes in the amp circuitry. It turns out my observations were still the same, confirming the differences that I was hearing were strictly due the different volume controls between the two amps.
IMPRESSIONS:
I never used a stepped attenuator before and did not expect the amount of “play” within each step. I (wrongly) assumed that there were crisp and distinct indentations at each step, so it felt quite sloppy at first but I got used to it. On some occasions, I could not find just the right volume (i.e. it was either a little too low or a little too high), as some people have noted. However, with the low and high gain switch, this becomes less of a problem.
OK, the sonic differences…
The most noticeable difference in the sound between the Alps and DACT is the treble. Using Steve Winwood’s Higher Love as the test track, the Alps is brighter, with more “sizzle.” The DACT is slightly duller. The percussion at the very beginning of the song is more crisp and has more “air” with the Alps. On certain other recordings, the “tape noise” is better heard with the Alps, which can be a good or bad thing depending on how you look at it. I would recommend the Alps pot for darker headphones (e.g. Sennheisers) if you had a choice when ordering a particular amp.
To test vocals, I used the Beatles’ Yesterday. With the Alps, Paul’s voice appears to have slightly more graininess and texture. The DACT seems “cleaner” and smoother. With the DACT, the solo acoustic guitar in the right channel has more decay and you can get a better feel for the body of the guitar than with the Alps.
The bass on the DACT is ever so slightly greater but is noticeably more articulate. My test track for bass articulation is The Police’s Tea in the Sahara. With the DACT, each bass note was easier to distinguish. With the Alps, it was slightly more slurred. With U2’s Bullet the Blue Sky, the kick drum sounds a little tighter with the DACT.
The Alps presents a slightly more forward soundstage compared to the DACT.
CONCLUSIONS
To me, it seems the DACT stepped attenuator is more neutral than the Alps volume pot. “Neutrality” is the word that keeps coming to my mind when listening to the DACT GS-1. I spent some time listening to the Grado HP-1 at a recent meet using my Alps GS-1. Based on memory, the DACT GS-1 makes my MS-Pros sound more like the neutral HP-1 than before. I think the Alps is coloring the sound slightly, which can be a good thing with regards to the treble and midrange...it makes for a livelier sound. The thing that bothers me most about the DACT is the slightly duller treble. This drawback is most noticeable when I use my DACT GS-1 as a preamp for my speaker system. I may have to change to a brighter IC between the GS-1 and speaker amp to compensate.
In the end, I am going to keep the DACT GS-1 and sell the Alps GS-1. I think the DACT’s benefits outweigh the slightly duller treble. However, I think after listening to it more and not doing anymore A/B comparisons, my brain will just adapt to the DACT's sound and everything will be "faultless" again as before.
I’ve owned the HeadAmp GS-1 headphone amp with the “standard” Alps Blue Velvet volume control (pot) for well over a year now. I am extremely satisfied with it powering my MS-Pros, as well as my K701s. In fact, I would say that the sound of my system is nearly faultless, to my ears. However, I started reading about and researched stepped attenuators and learned of its sonic benefits over standard volume pots (e.g. greater clarity, less noise, better channel balance). Inevitably, the upgrade bug bit me and I (impulsively) bought another GS-1, this time with the DACT stepped attenuator (http://www.dact.com/html/attenuators.html), which is a $175 option. I would like to share my impressions comparing the Alps volume pot with the DACT stepped attenuator with the GS-1. I used only my MS-Pros for the comparison to make things simpler.
ASSOCIATED EQUIPMENT
Headphones: Alessandro MS-Pro
CD transport: Music Hall CD25.2
D/A converter: Ack! dAck! v2.0
I'm hoping not to get too many of the ubiquitous "you need to upgrade your source" comments.
Cables: Kimber Silver Streak IC; power cords: VH Audio Flavor 1 (transport) and Zu Birth (amp); DiMarzio Big Red extension cord; Ack! Industries The Digital Connect digital cable
Can you guess which amp has which volume control?
METHODOLOGY:
I level matched the volume output of both amps to a fraction of a decibel using a Rat Shack SPL meter. I did my A/B/A comparisons by listening to a portion of a song over and over and over again until my ears got conditioned to the sonics of the recording. I would then rapidly move the interconnects, power cable, and headphone cable to the other amp and listen to the track again and note any differences.
I let the new DACT GS-1 burn-in for around 150 hrs before I did the comparison. Just to cover all posiblities, I swapped the removable amp modules between the Alps and DACT GS-1s and redid the comparison to make sure the differences I heard were not due to differences in burn-in time or some unforeseen design changes in the amp circuitry. It turns out my observations were still the same, confirming the differences that I was hearing were strictly due the different volume controls between the two amps.
IMPRESSIONS:
I never used a stepped attenuator before and did not expect the amount of “play” within each step. I (wrongly) assumed that there were crisp and distinct indentations at each step, so it felt quite sloppy at first but I got used to it. On some occasions, I could not find just the right volume (i.e. it was either a little too low or a little too high), as some people have noted. However, with the low and high gain switch, this becomes less of a problem.
OK, the sonic differences…
The most noticeable difference in the sound between the Alps and DACT is the treble. Using Steve Winwood’s Higher Love as the test track, the Alps is brighter, with more “sizzle.” The DACT is slightly duller. The percussion at the very beginning of the song is more crisp and has more “air” with the Alps. On certain other recordings, the “tape noise” is better heard with the Alps, which can be a good or bad thing depending on how you look at it. I would recommend the Alps pot for darker headphones (e.g. Sennheisers) if you had a choice when ordering a particular amp.
To test vocals, I used the Beatles’ Yesterday. With the Alps, Paul’s voice appears to have slightly more graininess and texture. The DACT seems “cleaner” and smoother. With the DACT, the solo acoustic guitar in the right channel has more decay and you can get a better feel for the body of the guitar than with the Alps.
The bass on the DACT is ever so slightly greater but is noticeably more articulate. My test track for bass articulation is The Police’s Tea in the Sahara. With the DACT, each bass note was easier to distinguish. With the Alps, it was slightly more slurred. With U2’s Bullet the Blue Sky, the kick drum sounds a little tighter with the DACT.
The Alps presents a slightly more forward soundstage compared to the DACT.
CONCLUSIONS
To me, it seems the DACT stepped attenuator is more neutral than the Alps volume pot. “Neutrality” is the word that keeps coming to my mind when listening to the DACT GS-1. I spent some time listening to the Grado HP-1 at a recent meet using my Alps GS-1. Based on memory, the DACT GS-1 makes my MS-Pros sound more like the neutral HP-1 than before. I think the Alps is coloring the sound slightly, which can be a good thing with regards to the treble and midrange...it makes for a livelier sound. The thing that bothers me most about the DACT is the slightly duller treble. This drawback is most noticeable when I use my DACT GS-1 as a preamp for my speaker system. I may have to change to a brighter IC between the GS-1 and speaker amp to compensate.
In the end, I am going to keep the DACT GS-1 and sell the Alps GS-1. I think the DACT’s benefits outweigh the slightly duller treble. However, I think after listening to it more and not doing anymore A/B comparisons, my brain will just adapt to the DACT's sound and everything will be "faultless" again as before.