Results 1 to 8 of 8

Thread: Jbl Sa-600 amplifier question

  1. #1
    fredmarantz
    Guest

    Jbl Sa-600 amplifier question

    Hello!

    Is it normal that this amplifier (JBL sa-600) causes driver excursions when I turn it on or off. I have seen this phenomenon on some HK-receivers as well. I don't like it, but it seems that nothing harmful happens. My spearkers are jbl 4333A - should be rugged enough to take it?

    Some good comments are appreciated.

    many regards

    Freddy

  2. #2
    Junior Member
    Join Date
    Jun 2007
    Location
    Sri Lanka
    Posts
    7
    Dear Freddy,
    I am uaing a JBL SA600 for the last 20 years. I am using JBL Lancer 99 speakers. This speaker excrusion is due to non availability of speaker protection. But any good speaker will handle it.

    Regards,
    Ananda.

    Quote Originally Posted by fredmarantz View Post
    Hello!

    Is it normal that this amplifier (JBL sa-600) causes driver excursions when I turn it on or off. I have seen this phenomenon on some HK-receivers as well. I don't like it, but it seems that nothing harmful happens. My spearkers are jbl 4333A - should be rugged enough to take it?

    Some good comments are appreciated.

    many regards

    Freddy

  3. #3
    Senior Member Jan Daugaard's Avatar
    Join Date
    Apr 2003
    Location
    Denmark
    Posts
    236

    How to switch on/off without noise

    I have sent you a PM (you have to log in to see it).

  4. #4
    Moderator hjames's Avatar
    Join Date
    Nov 2005
    Location
    NoVA - DC 'burbs
    Posts
    8,547
    Before it went off for repairs, my old 6260 amp would sometimes thump loudly on power up.

    I found out it helped to turn on the preamp and any sources first.
    I also helped to turn the Amp volume all the way down before powering it up.
    2ch: WiiM Pro; Topping E30 II DAC; Oppo, Acurus RL-11, Acurus A200, JBL Dynamics Project - Offline: L212-TwinStack, VonSchweikert VR-4
    7: TIVO, Oppo BDP103D, B&K, 2pr UREI 809A, TF600, JBL B460

  5. #5
    Senior Member SMKSoundPro's Avatar
    Join Date
    Apr 2005
    Location
    Anchorage, Alaska
    Posts
    1,019
    I always turn of the power amps first!
    Then I wait for the soup can capacitors in the power supply to wane.
    Then I turn off the preamp and all of the processing gear, eq and such, as a group.

    When powering on...Preamps and processing gear first.
    Thek power amps last.

    I am using Yamaha P2200's for my workshop rig with the L200b's and my double 2245 cabinet crossed over at 80hz. It sounds great in my shop!

    Once, I didn't wait long enough for the power amps to recede, and turned off the preamp stuff and BLAMO! The 136 woofer jumped and barked and let me know how unhappy they were with me!

    Just be careful when using "pro" amps!

    Scott.
    One step above: "Two Tin Cans and a String!"
    Longtime Alaskan Low-Fi Guy - E=MC² ±3db

  6. #6
    Senior Member BMWCCA's Avatar
    Join Date
    Feb 2006
    Location
    Virginia
    Posts
    7,742
    Umm, the SA600 in the original post in this thread is an integrated amp. Makes it kind of hard to turn on the pre-amp without the amp.

  7. #7
    Moderator hjames's Avatar
    Join Date
    Nov 2005
    Location
    NoVA - DC 'burbs
    Posts
    8,547
    Quote Originally Posted by BMWCCA View Post
    Umm, the SA600 in the original post in this thread is an integrated amp. Makes it kind of hard to turn on the pre-amp without the amp.

    Are you saying power on (or power-Down) thump is normal with that model?

    Even so, turning the volume all the way down should help.

    Otherwise, I'd think someone needs to have a look at it (power supply filtering and such)!
    2ch: WiiM Pro; Topping E30 II DAC; Oppo, Acurus RL-11, Acurus A200, JBL Dynamics Project - Offline: L212-TwinStack, VonSchweikert VR-4
    7: TIVO, Oppo BDP103D, B&K, 2pr UREI 809A, TF600, JBL B460

  8. #8
    RE: Member when? subwoof's Avatar
    Join Date
    Aug 2003
    Location
    fingerlakes region, NY
    Posts
    1,899

    thumper

    Many early solid state amplifiers had this issue and in reality the only way to prevent this is to construct an external relay bank that disconnects speakers at turn off and connects them WITH a delay upon power up.

    This way an entire system can be remotely controlled or powered up with a single switch.

    With vintage monitor components reaching unreal prices for repair ( and in some cases parts are NLA ) this is good insurance and practice.

    Crown ( and a few others ) used a CMOS switch ( chip ) in between the input opamp and the power section ( IE: the PS200/400 and the consumer versions PL3,4 ) that prevented the preamp section from causing this and it does work well for their designs.

    The older "D" series used a couple of capacitive tricks to do the same BUT with the inevitable degrading of electrolytics with age and the tolerance factor ( +/- 20% ) it wasn't enough protection for critical monitoring use. Stories abound of these crowns whistling and squealing on turn-off and a mod is required to correct this. I have done this mod to hundreds but some amps just refuse to get with the program.

    The JBL/UREI lines used high current mechanical relays for the speaker leads and this gives the additional DC protection if needed in case a major output stage malfunction happens that does NOT blow a fuse ( usually a SINGLE output transistor shorts C-E ).

    poof.

    sub

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. JBL SA600 integrated amplifier
    By fredmarantz in forum Lansing Product General Information
    Replies: 23
    Last Post: 08-19-2017, 10:57 AM
  2. JBL Paragon Sound Reproduction Question
    By Gary Hunt in forum Lansing Product Technical Help
    Replies: 12
    Last Post: 10-18-2009, 06:14 AM
  3. Another JBl recone question.
    By scott fitlin in forum Lansing Product Technical Help
    Replies: 7
    Last Post: 08-15-2006, 09:01 AM
  4. Another amplifier question
    By andywin in forum Lansing Product General Information
    Replies: 0
    Last Post: 01-31-2005, 02:35 PM
  5. my old jbl L96. question pls. read
    By danechristian in forum Lansing Product Technical Help
    Replies: 8
    Last Post: 09-03-2003, 01:09 AM

Posting Permissions

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