Welcome to the AudioShark Forums.
Results 1 to 11 of 11
  1. #1
    Junior Member
    Join Date
    Apr 2021
    Location
    Los Angeles
    Posts
    9

    X150.8 front meter dancing around…

    When I was speaking to a Pass technician, he mentioned in passing that when the meter starts dancing, the amp is close to running out of power.

    I find that at an average of 84 db SPL with peaks at 92-95 db, my meter is already dancing with movements of 2 to 4 mm.

    Do you think I need to upgrade my amp for more power? On some songs, I think I hear a little distortion (You Got Me by The Roots), but am not sure. It could be the recording.

    Speaker is a Zu Omen Def MkII. Its a pretty load, flattish at 8 ohms, 96 db -ish (103 db published). Streaming to an Allnic preamp which has really improved my bass response vs a BAT previously.

    Would appreciate feedback.

  2. #2
    Senior Member
    Join Date
    Nov 2013
    Location
    SE Pa
    Posts
    2,027

    Re: X150.8 front meter dancing around…

    I wouldn't call 2mm 'dancing around', more like a slow waltz .....
    Cheers ! …. Dave

  3. #3
    Junior Member
    Join Date
    Apr 2021
    Location
    Los Angeles
    Posts
    9

    Re: X150.8 front meter dancing around…

    Quote Originally Posted by Mikado463 View Post
    I wouldn't call 2mm 'dancing around', more like a slow waltz .....
    My history with the amp is the meter doesnt move at all.

  4. #4
    Banned
    Join Date
    Dec 2019
    Location
    USA
    Posts
    786

    Re: X150.8 front meter dancing around…

    From what I understand the needle is stationary when the amplifier is operating in class A mode. When the needle moves, it indicates class AB operation. I think the 150 leaves Class A at 15 watts. This said, I would call Kent at Pass to be sure ...

  5. #5
    Senior Member
    Join Date
    Nov 2013
    Location
    St. Louis, MO, USA
    Posts
    3,041

    Re: X150.8 front meter dancing around…

    Even leaving Class A wih the Zu you have to be much louder than 84dB unless your listening room is an auditorium. With that being said some Zu are 16 ohms and if that's your case it will limit the power output to less than stated power.

    I had some Zu Soul Super Fly and drove them with Conrad Johnson 100 watt monoblocks and they never stressed. A X150.8 into 96dB speakers should be enough to cause deafening SPL's.

    Welcome to AS
    Aurender ACS10 w/Audioquest Diamond USB, Esoteric N05xd
    Mark Levinson #526, 534 & JBL 4367's
    Clearaudio Performance DC w/Maestro cart
    Clarus Concerto & their Crimson cables

    HT: Marantz AV8003, Linn 5125, JBL SAM3ha, Revel s30,
    SVS PC13 Ultra
    Transparent, Analysis Plus & Tributaries. PS Audio filtering
    Sony XBR-75X940D & BDP
    Parasound P6, MBL 8006b, Artisan speakers/subwoofer

  6. #6
    Junior Member
    Join Date
    Apr 2021
    Location
    Los Angeles
    Posts
    9

    Re: X150.8 front meter dancing around…

    Quote Originally Posted by Mr Peabody View Post
    Even leaving Class A wih the Zu you have to be much louder than 84dB unless your listening room is an auditorium. With that being said some Zu are 16 ohms and if that's your case it will limit the power output to less than stated power.

    I had some Zu Soul Super Fly and drove them with Conrad Johnson 100 watt monoblocks and they never stressed. A X150.8 into 96dB speakers should be enough to cause deafening SPL's.

    Welcome to AS
    The Zu Omen Defs are actually 8 ohms.

    I completely understand what youre saying, however its not the case here. The amp meter starts to move, which I am assuming at this point, thats its leaving Class A, just when Im at my desired listening level. Its not super loud at all, but the bass is pretty serious.

  7. #7
    Junior Member
    Join Date
    Apr 2021
    Location
    Los Angeles
    Posts
    9

    Re: X150.8 front meter dancing around…

    I just got off the phone with a tech at Pass Labs and he confirmed that the meter dancing around means “Ive left Class A” and am in the A/B section.

    The meter would be signaling Im running out of juice if it were pegging the right side.

    That makes sense, though I stressed this amp with a Magnepan 1.7i and never saw it peg to the right.

  8. #8
    Senior Member
    Join Date
    Mar 2014
    Location
    Atlanta, GA
    Posts
    844

    Re: X150.8 front meter dancing around…

    I really like the people at ZU & their products.

    However, IME, all of the ZUs were somewhat less efficient than their specs claimed, when compared to other competitive lines/products and their specs...

    But they could be sooo musically involving...
    DPT4ME - Dynamics, Presence & Tone for Musical Engagement; MBP (3) - stripped down for music only; Shunyata Omega & Sigma USBs; ISO REGEN w/short Curious USB links; Berkeley Alpha USB; Aqua La Scala II Optologic DAC; Schiit Yggdrasil - fully updated; Ayre Codex dac - updated; Pass Labs INT-60 integrated amp; Wyred 4 Sound STP-SE-2 preamp, Quicksilver Mono 120 amps w/Tung-Sol KT150s; Quicksilver Mid Mono amps w/Gold Lion KT77s; Fyne Audio 703s; Symposium Svelte Plus & Ultra Platforms; REL S-812 subwoofers; Duelund DCA12GA speaker cables; AV Room Service EVPs, Stein Music Harmonizers, Duelund DCA16GA & 20GA ICs; Shunyata Denali 6000S/V2; Tripp Lite PCs; Wyred 4 Sound power cords; AudioDharma cable cooker; dedicated custom room; various GIK & ASC room treatments; etc.

    www.getbettersound.com

  9. #9
    Junior Member
    Join Date
    Apr 2021
    Location
    Los Angeles
    Posts
    9

    Re: X150.8 front meter dancing around…

    Quote Originally Posted by Jim Smith View Post
    I really like the people at ZU & their products.

    However, IME, all of the ZUs were somewhat less efficient than their specs claimed, when compared to other competitive lines/products and their specs...

    But they could be sooo musically involving...
    I agree. The only company whose Sensitivity rating I feel I would trust at face value is Devore. Its not really a matter of honesty, just the effort and resources they put into it.

  10. #10
    Senior Member
    Join Date
    Nov 2013
    Location
    St. Louis, MO, USA
    Posts
    3,041

    Re: X150.8 front meter dancing around…

    Still if the Maggies didn't stress the 150.8 the Zu shouldn't even if a bit less than rated efficiency. Zu is driven by SET owners so shouldn't be an issue for your amp

    I wonder if the Omen maybe wired incorrectly and impedance dipping very low.

    I feel there is an issue with a component or connection in your system. What you are experiencing is not normal.
    Aurender ACS10 w/Audioquest Diamond USB, Esoteric N05xd
    Mark Levinson #526, 534 & JBL 4367's
    Clearaudio Performance DC w/Maestro cart
    Clarus Concerto & their Crimson cables

    HT: Marantz AV8003, Linn 5125, JBL SAM3ha, Revel s30,
    SVS PC13 Ultra
    Transparent, Analysis Plus & Tributaries. PS Audio filtering
    Sony XBR-75X940D & BDP
    Parasound P6, MBL 8006b, Artisan speakers/subwoofer

  11. #11
    Junior Member
    Join Date
    Apr 2021
    Location
    Los Angeles
    Posts
    9

    Re: X150.8 front meter dancing around…

    Quote Originally Posted by Mr Peabody View Post
    Still if the Maggies didn't stress the 150.8 the Zu shouldn't even if a bit less than rated efficiency. Zu is driven by SET owners so shouldn't be an issue for your amp

    I wonder if the Omen maybe wired incorrectly and impedance dipping very low.

    I feel there is an issue with a component or connection in your system. What you are experiencing is not normal.
    Sorry if I didnt mention it clearer. The Pass amp meter didnt fully peg to the right with the Maggies, but it was stressing. Popcorn bass for one at medium SPL.

    Zu sound excellent. No problem with them. I am just a little surprised that as you say, they can be driven by 3 watt SET amps, but they shine with the Pass amp. I just didnt understand what the meter is saying. Now I do, but still not completely per my Maggie experience.

AudioShark - The Best High End Audio Discussion forum.

AudioShark forum is a leading forum site for High End Audio Discussion, Stereo System Discussion, Home Theater System Discussion, Best Home Stereo System Discussion, Home Theater Installation Discussion etc.

The AudioShark forum was created for sharing the passion of high-end Audio. We have Audiophiles from all over the world participating and sharing their knowledge. From novice to experts, you will find a friendly environment for discussing about High End Audio, Stereo System, Home Theater System, Home Stereo System, Home Theater Installation, Amplifiers, Speakers, Subwoofers, Integrated System, Acoustic treatments & Digital Room Corrections and many more.

At AudioShark, we also have incorporated an exciting Marketplace where members can peruse terrific buys on used gear, as well as meet dealers and discuss the purchase of new gear.

We are as crazy about this hobby as you are! So come on in and join us! Audioshark.org the Friendliest Audio Forum!

Industry Participation Disclosure : The owner and administrator of Audioshark is the owner of Suncoast Audio LLC in Sarasota Florida. Suncoast Audio has a full brick and mortar presence in Sarasota with several great show rooms with many world class brands. More information can be found at http://www.suncoastaudio.com

Audioshark is a community of like minded individuals. Audioshark welcomes participation from all manufacturers and owners of all brands and products. It is our belief that online forums provide a community of like minded audiophiles and music lovers to encourage the growth of this wonderful hobby.

Sincerely,
The Audioshark.org Team


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •