306,085 members
190,433 posts
  • New
    Newcomer - Level 1

    I have an NX6000 that came with a Euro style 220-240v cord. Do I need to change the power supply to run 120v 60hz in the US?

    0 13
    • JoeA
      Dale_M Please note this is not a possible option as there are different power variants of the amp available depending on the terriototy it is sold in (Japan/Europe/USA) they cannot be converted.
      • Mar 9
  • New
    Newcomer - Level 1



    I'm looking for a distributor for the Lucia and E series amplifiers in the UK. Can Music Tribe assist? 

    I need: 


    Lucia 120/1-70

    Lucia 240/1-70

    Lucia 120/2 






    1 36
  • New
    Newcomer - Level 1

    Need to know how the NX300 performs when the inputs are turn on at 3 oclock position how to hook 2 woofers and the best way to use the crossover  LF. HF.  Full Range. Also the Mode switch for the woofers Thank you in advance.

    0 10
  • New
    Newcomer - Level 1


    I recently acquired these vintage speakers from my grandparents. They are 18 inch Tannoys made sometime in the 60s I believe. Does anyone have any advice on which amp to get for these? I am hoping to order it online and For Decent quality on a budget.
    I cant move them to show the back because they are extremely heavy so I hope these photos give you a good enough idea.
    Thanks again!
    0 55
  • New
    Newcomer - Level 1


    I just purchased a nx4-6000 amp. After hooking a stage monitor to it, it went into Protect Mode on all four channels. I unhooked all cables and followed the instructions to reset it, but it still won't do anything. The breaker in the back doesn't seem to have tripped or at least it won't reset. Any ideas.


    0 438
    • SpideyMan19622
      Nigel67 Hi SpideyMan19622. I am sorry to hear that your brand new NX4-6000 has failed straight away. It looks as though you have tried everything possible to get the unit out of the Protect Mode and it hasn't worked. If the unit is still under 30 days from purchase, you can go back to the shop that sold you the amplifier and request a DOA replacement. If older than that, still go back to the shop and they will get the amplifier repaired.
      • Jan 11
    • SpideyMan19622
      RacerX I have the same problem, NX4-6000 locked in protect mode and need some help please. I tried to purchase the schematic for the NX4-6000 and support just sent out a basic reply about finding a repair location in my area. I asked them the following question: If you can not send a schematic, can you please tell me the part type and number of the following amp board devices?
      R319 Nothing, crickets... maybe one of you might be able to help me. I bought these amps due to them supposedly having built in protection... they have protection, from starting a fire, but definitely not protecting the amplifier! Thank you!
      • Jan 29
      • My NX46000 Power Amp is stuck in Protect Mode
        RacerX Still no help? Pathetic.
        • Feb 19
    • SpideyMan19622

      Just had one of our amplifiers do the same thing.

      • May 16
    • SpideyMan19622

      Had same issue twice with same amp. They repaired it. Worked for awhile. Then took it home and stored it. Pulled it out for a show and it broke in same way. I repair electronics. I’m going to get this figured out. Needed a reason to get another O-Scope

      • Nov 9
  • New
    Newcomer - Level 1

    Error light blinking 

    please help 

    View Video
    0 22
    • kbherrig
      Paul_Vannatto Page 5 of the manual explains the error light purpose. Check the input signals as well as the wordclock to make sure they are correct.
      • Jan 20
  • New
    Newcomer - Level 1

    My PMP500 seems to have developed a problem. When pwered up the unit comes on for a few seconds and then cuts out. It seems the internal fan is not coming on. I assume it may be more than replacing the fan but have no idea as I'm not an electrician.

    0 20
    • Stevemaccal62
      WilliamR Hello, this sounds like a hardware issue that may need service. Please click on the Support link above and create a Tech support ticket and someone will contact you directly as soon as possible.
      • Jan 12
  • New
    Newcomer - Level 2

    I bought a spare input board for my 14000 amp direct from their parts dept. However I never used it because it was not the board that was giving trouble at the time. The amp started to give trouble again so I decided to put in the board. It never worked so they replaced it. The replaced one never work also so I ordered another through one of their repair agent. It never worked also. They advised me to ship the amp to one of their repair shops, saying it maybe another issue with it. The repairers told them that the input board is not compatible with the older model amps and it is for the newer models. They refused to take back the two boards and closed my case leaving me with two useless boards. Spending $4000 US for a amp and having these problems does not worth it. Better to buy chinese knockoffs because they help you with parts that can repair their amp.

    0 13
    • thunderbpsounds
      Dale_M In hindsight it may have been better to have organise a non warranty repair with an official Lab Gruppen approved repair centre, if you still require assistance please go to the Support tab above and select Service so our team can advise you of your options.
      • Jan 12
    • thunderbpsounds

      The amp is at an approved centere in the USA and they are the ones that determine the input boards are not compatible with the older model 14000 amps and the parts department refused to take back the boards. I have two useless boards and a huge bill to repair the amp. That could have been resolved where the amp is used in the Caribbean had they sold me a compatible board in the first instance. If you update the board you suppose to know if it will work on older model amps.

      • Jan 12
  • New
    Lab Gruppen
    Triber Moderator

    E Series

    Learn More:

    Amplifiers with Flexible Output Channels and Energy Star Certification for Installation Applications

    From: $2,399

    #LabGruppen #E204 #E404 #ESeries #PowerAmplifiers

    0 36
  • Gasper
    Contributor - Level 1



    I am new here. I would like to ask some technical question about new Lab Gruppen PDX3000 amp. It seems to be a perfect solution for my JBL4645Cs. First of all I would like to know what is the DAMPING FACTOR (aprox. up to 300Hz)?. For the input on XLRs I would like to connect it directly from the integrated amplifier from speaker terminal (high level to low level); I made some measurements and normally high level does not exceed 0,5V - how much volts can take XLR input on PDX3000?


    Thank you very much in advance.


    Kind regards,


    Gasper Jancigaj

    0 424
    • Gasper

      Hi Gasper,


      The following is a white paper published by Lab.gruppen detailing why we do not use Damping Factor in our specifications.


      Damping factor

      The damping factor is determined by the quotient of the speaker impedance and the output impedanceof the amplifier. To state the damping factor figure of an amplifier is meaningless, as the speakerimpedance’s varies with the frequency and the various types and brands of loudspeakers existing.The figures of the true damping factor are only valid for a specific amplifier/ loudspeakercombination. This fact gives one of the reasons why Lab.gruppen don’t publishes the damping factorfigures.The only figures that are relevant for amplifiers are the output Impedance figures. Most amplifiers onthe market only show low output impedance (or high damping factor) at low frequencies and high(er)at high frequencies. This is due to the improper design of the output network and/or frequencydependent feedback. Lab.gruppen design has the feature to have nearly constant impedance over theaudio frequency band with a value of 0.05 to 0.07 ohms (50-70 mohms) . This causes less coloration.Another feature of the power supply in the fP 2200 - fP 6400 (thanks to the stabilised power supply),is that the output impedance doesn't rise during clip situations. In most conventional amplifiers theimpedance rise 10 or l00 times during clip. That causes uncontrolled movements of the speaker-cone.The conclusion must be that the Lab.gruppen switch mode power supplies sound better or have betterdefinition, especially in the bass region, compared to conventional designs.


      Damping factor influences on active and passive frequency divided loudspeakers

      Another reason not to publish the damping factor is that it’s not relevant to the audio quality of the power amplifier. For example; a professional loudspeaker driver has a DC-resistance between 2 and 5ohms, which is connected in series with the driver in the equivalent circuit diagram of the driver. Inthis case, the damping factor has more to do with the speaker itself than the amplifier, as the speakerdriver is connected directly to the power amplifier just as in an actively divided system (see example below).In a passively divided speaker system the filter network circuit are placed between the power amplifierand the speaker driver. In this case, however, the filter impedance determines the damping factor ofthe speaker driver. The output impedance of the power amplifier can influence the characteristics ofthe filter response, but it’s not sure that a lower impedance (higher damping factor of the poweramplifier) will give a better response. A classical example is the tube amplifier, which has relativelyhigh output impedance and which gives a very good sonic result in most cases.





      I am not entirely sure I understand your question,  "For the input on XLRs I would like to connect it directly from the integrated amplifier from speaker terminal". Could you explain what you wish to do in a bit more detail please?


      The PDX inputs are Line Level, if you are using an appropriate audio source then it will be a line level output also. What are you planning on using to drive the input on the amplifier?

      • April 6, 2020
    • Gasper
      MrPaulDavidThomas I'd like to know how you get on with your JBL 4645C's. Alas the answer you got didn't really help as far as I can see :-(
      • December 7, 2021
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