Bass weak

[juihung]

Hi,

  I find the bass from my Mainline to be weak.  The mids and highs seem to be ok.  Is there something that I can do?  Re-biasing?  Or perhaps this is the signature sound of Mainline?

  Thank you for any insights.

With regards,
JH

[juihung]

Oh, I forgot to mention that I am using a Senn HD800s.

[Tubejack]

High or low impedance setting? 

Balanced or SE?

Original or newer version of the HD800? 

Any mods to either the headphones or the Mainline?

[Alonzo]

What music type do you mostly listen to?  What are you comparing the Mainline to (headphone and amp)?  The Mainline will not be a HipHop or Bassheads first selection, the Mainline has clean, quick bass response but is limited to the headphones used.  A set of closed back phones will improve the bass you hear and feel.

[Doc B.]

Also, what is your source's output impedance?

[Natural Sound]

I'm with Doc B. Your source components may hold the key.

[juihung]

Hi all,

  I am using single-ended, high impedance.  Original version of Mainline, built by myself in 2018.  No mods to the Mainline or HD800s.

  My music is a variation of classical, instrumentals and vocals.  I am not a bass-head. 

  My source is from a SoTM SMS200 UltraNeo, USB output to a Mystique V3 DAC and RCA to Mainline.  I usually play flac or wav files.

  When I listen to the music, I find the sound stage, clarity, textures and resolution to be amazing.  I felt that with a slightly stronger bass, the mids may be richer, hence bring some soul to the music.  I read lots of good reviews on Mainline, with a good bass paired with HD800.  So I was wondering if I did something wrong with my Mainline build, and what I can do if there's something to fix.

  Please don't get me wrong.  I really like the Mainline.  I tried other amps before, and I keep coming back to Mainline.

  Perhaps you are right that the source is the issue, which I will look into.

With regards,
JH

[Natural Sound]

Well your source gear seems worthy enough. Ive noticed that digital music is a mixed bag. For example some of my 16bit CD rips sound better than the 24bit versions Ive purchased over the years. I guess there a lot of variables.

One other thought. If any of your components have been sitting for a while they just might need a little time to break in again. Ive noticed this phenomenon with some items I had in storage for a while. I'm guessing it has to do with the film capacitors.

You may want to verify that all of the voltages still check out. Other than that I'm not sure what else to recommend.

[juihung]

Hi Natural Sound,

  Thank you.  I will give that a go.  If everything checks out, then the issue may be with the headphones.

[jjvornov]

Make sure you're getting a good seal on the headphones. I had a pair of MrSpeakers Aeons that had anemic bass when I first got them until one day I took my glasses off and they suddenly sounded exactly right.

[Doc B.]

If you have the HD800 and not the HD800S look into the mods that are out there. I found the old Anax mod helped tame some of the brightness of the HD800 that can make them sound lean. The are newer mods that are reputed to be better -

https://www.head-fi.org/threads/senn-hd800-ultimate-s-mod.879024/

[juihung]

Hi,

  Thanks for the suggestions thus far.

  Just some updates. I ran through the resistance and voltage tests.  They all came out ok.

  The biasing stage was a surprise.  The reading at terminal 20 was lower by 10v, and terminal 30 was higher by 5v.  I could have sworn that they were at 145v when I finished the build 2 years ago.  I readjusted them.

  Threw some music.  Yeah, I thought it sounded better now.  More analog, less pitchy.  So the bass comes out a little bit stronger now.  I am not sure how the biasing works.  Perhaps someone can educate me? 

With regards,
JH