A-2X problem

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    • #2148
      Massimo Stefanizzi
      Participant

        Congratulations Chris! You are doing a great job, I really appreciate the videos and the interview with Roger.

      • #2144
        ChrisSoundLab
        Participant

          Hi Daniele,
          I was just at Sound Lab … really rare and interesting timing, but he has a pair of same speakers in from a customer to give them a ‘face-lift and fix up’ – but they sound great just as they are …. not sure if you have seen them without the grill cover …and to note the high frequency … you may want to have them position so highs are on the outside to give wide sound stage (opposite as this photo shows… up to you to experiment. Hope all goes well!
          (I’m not so important, but you might like to see Roger who is the inventor, designer, brains behind all of Sound Lab.)

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        • #2141
          mayloc
          Participant

            Hi Chris I can’t see your contact, can you resend it to me? Thanks Daniele

            • #2142
              ChrisSoundLab
              Participant

                That’s interesting, I suppose I am not able to add a web address in the forum … please see photo or try googling
                Sound Lab Electrostats Japan

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            • #2138
              mayloc
              Participant

                Hi Chris, today I tried to adjust the bias and the settings were both completely counterclockwise. With your suggestion I turned clockwise until I heard light crackling and turned up the music volume. Now the music can be heard, not loud but I had to raise the bias until almost the end of the ride. Are there any problems with the panel if the bias is set that high? Thanks Daniele

                • #2140
                  ChrisSoundLab
                  Participant

                    Let me know if there is anything else I can help you with.
                    If you are new to this site and Sound Lab, you may wish to see my new website and contact me thru that contact:


                    Please note that I can offer service to you anywhere in the world.
                    All the best,
                    Chris

                  • #2139
                    ChrisSoundLab
                    Participant

                      Hi Daniele, there is no problem with bias being set at any position, the bias is intended to be best at higher levels and better performance more to the right clockwise as long as there is no crackling sound which interferes with the music.

                  • #2135
                    mayloc
                    Participant

                      Hi Chris, yes I checked the fuses first but I didn’t know how to adjust the bias. Let’s hope it’s just the bias that needs adjusting. I’ll try tomorrow. Thanks Chris, your advice is invaluable. Daniele

                    • #2131
                      mayloc
                      Participant

                        Hi Chris I tried to disconnect the 220v voltage from a panel but I can’t hear anything so I don’t know if I have 10000v but there is something. for the power supply voltage I think it is right on the back it has the typical European VDE connector. Do you know anyone who may have a wiring diagram? Thanks Daniele

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                        • #2133
                          ChrisSoundLab
                          Participant

                            Sorry to ask simple question – but you have confirmed fuse is OK?

                            And have you used the bias adjust control?

                            Counterclockwise bias is very weak and volume would be low, turning clockwise will increase bias and sensitivity to membrane and should be a crackling sound – proper position is to be just before crackling sound begins. (no damage to membrane with crackle)

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                        • #2127
                          mayloc
                          Participant

                            Thanks Chris for the information, let’s see if I can quickly build a 1:100 probe for my fluke meter. Another test is to disconnect the 220v from a panel to see the difference. both panels sound very low but the same… it is difficult for there to be the same defect in two panels. What do you think ? thanks Daniele

                            • #2128
                              ChrisSoundLab
                              Participant

                                I’d say its rare to have exactly same defect in both panels which is why I suspected no power to charging the panel – if that’s true then yes, disconnecting the power to the backplate and if nothing changes (same very low output) will likely confirm that. Assuming of course that the panels were originally built for 220v?

                            • #2125
                              mayloc
                              Participant

                                here’s a photo of the back

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                              • #2123
                                mayloc
                                Participant

                                  Hi cris thanks for the quick reply
                                  and for your interest, they are not the ones in the photo, mine have light fabric, of the A-2x I only know that they have the upper part the same as the dynastats and the bass part as a panel, do you think the polarization voltage is missing?
                                  How many volts should the bias be? Thanks Daniele

                                  • #2124
                                    ChrisSoundLab
                                    Participant

                                      Hi Daniele,
                                      It would seem so, yes … but I cannot really speculate.
                                      I was checking a little on google, I found this model to be from around 1985. The backplates were much different back then – really everything was different and still in development stages. The regulated bias voltage in back plates now are variable and I have been told many times and I continuously forget. But the old models the voltage potential was much lower because materials and insulation could not survive higher voltages. I know the panels now at peak music power will generate up to 30,000 volts. The older maximum was more like 10,000 I think. Keep in mind the backplates now only draw 2 watts to charge the panel… but I am not at all qualified to comment more and I am afraid I am not sure how I might help you, but someone else on this forum might help.

                                  • #2121
                                    ChrisSoundLab
                                    Participant

                                      I was trying to find the A-2X – my goodness, this goes back a very very long time … I would have to ask Roger (if you are new to the site you should note Roger is the founder and owner of Sound Lab) – but I guess these go way back to the 1980’s…. someone else out there might now more than me on this. (I will see Roger next week though)
                                      I found the photos of A-2X on line…. I don’t suppose these are the actual speakers you are referring to?

                                      Chris

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                                    • #2117
                                      ChrisSoundLab
                                      Participant

                                        First comment I can quickly make is that if the sound is very weak, it is quite possible that there is no power going into the panels.
                                        If amps are powered up and connected to the speakers, there will be still some very low volume sound even if the speakers have not been plugged in.

                                        Chris

                                      • #2116
                                        mayloc
                                        Participant

                                          Hi everyone, I’m new to the forum and I’m asking for advice on the A-2X I bought recently to overhaul the structure and change the canvas. Finally I was able to connect them to a 200w amplifier but the sound can be heard on both but very weak. Can anyone give me some advice? sorry for the English, I’m using the translator. Hi Daniele

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