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Super Redhead "pop" noise on shut down?

Discussion in 'Amps and Cabs [BG]' started by Bass-only, Jan 12, 2004.

  1. Bass-only

    Bass-only Supporting Member

    Oct 9, 2001
    Greetings all!

    I just picked up a used (but in new condition) SWR Super Redhead combo.

    The combo sounds wonderful, but I noticed that there's a pretty good "pop" when you shut the amp down. The longer it's on, the louder the "pop."

    I guess it's what they call a "transient pop"?

    My concern is blowing a speaker or horn with the "pop." I can shut off the internal speaker on the front panel (which is nice), but if I hook up an extension cab, I'd still get the pop through there.

    Is this a normal thing with this amp, or sound like a similiar problem someone else has had?

    Any comments, suggestions would be appreciated!


  2. JMX

    JMX Vorsprung durch Technik

    Sep 4, 2000
    Cologne, Germany
    It's a typical SWR "feature".
  3. Bass-only

    Bass-only Supporting Member

    Oct 9, 2001

    So the "pop" is nothing I should be concerned about in reference to hurting a speaker or horn?
  4. JMX

    JMX Vorsprung durch Technik

    Sep 4, 2000
    Cologne, Germany
    At least I haven't heard anything here in that regard.
  5. chris4001asat


    Dec 16, 2002
    Toledo, Ohio
    Warehouse Manager : Reverend Guitars
    I have the same problem with my Redhead.
  6. Gsxtasy99


    Jul 10, 2003
    Boston, MA
    My redhead did the same thing. I found it was much louder on the internal SWR cab than it was on the extention cab. When i would turn the amp off, the poping was loud enough to clip the pre amp and the power amp. That coupled with the fact the my B string made the cab sound like it was dying, was enough to make me sell it.

    I sold it to a keyboardist, apparantly it makes one heck of a keyboard amp.
  7. xcental34x


    Feb 28, 2003
    Memphrica, TN
    Turn the speaker switch off, then the power switch.

    SWR Redhead. *drool*
  8. Bass-only

    Bass-only Supporting Member

    Oct 9, 2001
    At this point, it's not bad enough for me to want to sell it, I just wanted to make sure it wasn't a unique situation.

    I did notice that too, that the "pop" is not as loud in an extension cab!

    I don't see using it with an extension bottom all that often (in a wedding band that puts the bass throught the mains) so shutting off the internal speaker on shot down isn't that big of deal.

    I had a Trace Elliot amp with a similiar "pop" problem when you brought it out of standby. There was a "fix" for that problem. I wonder if the same "fix" can be done here???
  9. Im a sock

    Im a sock

    Dec 23, 2002
    Central MA
    I think they say something in the manual about that pop not harming your speakers, but just to make sure you should shut the speaker off first.
  10. pedroferreira


    Feb 10, 2003
    In SWR FAQ page http://www.swrsound.com/products/faq.html#amps


    "Q: When I turn my SWR amplifier's power switch to the "ON" position,I hear a "pop" sound through my speakers.
    A: This may be the #1 concern among SWR owners. Unfortunately, there is no effective way to resolve this issue without taking measures that would be detrimental to both the tone quality and reliability for which SWR amplifiers are known. Although many users consider the "pop" or transient heard at power-up to be disconcerting, it is normal and will not damage your loudspeakers. Elimination of the power-on transient would require additional circuitry and the inclusion of a component known as a "relay". Relays are known to degrade signal quality and are prone to failure. When a relay failure occurs, which is not unusual, it can cause the amplifier to completely lose output, requiring significant downtime for repair, not to mention a potentially embarrassing situation during live performance. It is for these reasons that SWR chose not to incorporate this type of component into our amplifier designs. If after taking this into account you still wish to avoid hearing the power-on transient, the following actions may be taken:

    A) For amplifiers that feature a speaker on/off switch - set the speaker switch to the "OFF" position, power on the amplifier, then set the speaker switch to the "ON" position.

    B) For modular amplifiers that do not feature a speaker on/off switch, you may connect your speaker cable to the amplifier's speaker outputs afterpower up if you choose, however it is important to make sure that you are not playing through the unit and that there is no signal present when you make the connection.

    Q: When I turn my SWR amplifier's power switch to the "OFF" position, the LED's on the front panel light up and flicker. Is there something wrong with my amplifier?
    A: No. It is normal for the front panel LED's to illuminate and flicker momentarily during power down. This occurs as a result of the amplifier's power supply discharging and does not indicate any type of internal problem or malfunction."

    The speaker on/off switch only affects the internal cab. That's why you hear the "pop" sound on the extension cab.


    "I found it was much louder on the internal SWR cab than it was on the extention cab. "

    If you are using an 8 ohm extension cab, this is getting half the power of the internal (which is an 4 Ohm cab).

    Best Regards
  11. Bull dung.

    Practically all higher quality amps with a lot more power and better reliability have a time delayed relay on the output.

    They're saving money in the wrong places if you ask me.

    Cheap junk.

    My $0,02 (actually Eur 0,02. That's worth more)
  12. pedroferreira


    Feb 10, 2003

    ahahah :D

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