Q: My speaker lights up with a bright white or orange glow when it starts up. This goes on for a couple of minutes and then it gets better. Is my cell bad?

A: Your electrode and cell need cleaning. Bright glow effects are often the result of deposits and tip cratering. Follow the instructions for cell cleaning and look at the end of the electrode. You will probably see that it is cratered. If it is, carefully sand out the crater and smooth the end of the electrode. You may still see some effects (we call them fireworks) but they won't be as bad and will clear up more quickly. Electrodes with more operating time on them tend to need maintenance more frequently. If this happens too often you might very well need a new electrode.

Q: When I run my system I can see the plasma flicker sometimes. The sound seems to be good but I'm wondering if this is normal.

A: On startup some flicker is normal. Until the cell heats up and stabilizes plasma instability and singing are common. After warmup though you should never see the plasma flicker. You are overdriving the speaker so much that the plasma is becoming extinguished with the louder parts of the program material. Either you don't have the proper high pass filter blocking out the low frequency program material or you are simply trying to play it too loud. Either way you risk serious damage to the modulation transformer and feedthrough capacitor if you continue to operate this way. The absolute maximum voltage the speaker can stand without going over 100% modulation is 2.16 volts RMS and this is well into the high distortion region of operation.

Q: How do I know when the electrode needs to be replaced?

A: Replacement of the electrode is somewhat subjective. They continue to operate for some time past their prime but at reduced efficiency and eventually they get to be more trouble to keep stable. Towards the end of life they require more frequent maintenance and plasma ignition becomes more difficult and unstable. When an old electrode becomes more trouble than you want to deal with, replace it. A good quick rule is that when about two thirds of the tip has burned away it's time to replace the electrode.

Q: Why don't you guarantee the lifetime of your electrodes like DuKane did?

A: DuKane guaranteed 1200 hours on a new electrode. DuKane had a very difficult time with the Ionovac because it was a product so far ahead of it's time and it had the disadvantage of requiring a lot of maintenance. Guaranteeing the cell and providing cheap replacements was a way of promoting sales. Even so the Ionovac was a sales failure and was quickly dropped from production. Now that those cells are no longer supplied by DuKane the guarantee is essentially only an interesting artifact of history.

We don't guarantee a service lifetime because it depends on the environment the speaker is operated in and the condition of the speaker electronics, all of which is well over forty years old at this time. Besides all the guarantees in the world aren't going to make a product better or worse, it only serves to provide advertising hype for the consumer.

I have run thousands of hours of life tests on samples and on our new stock electrodes. It is common for them to last for 2000 hours and more. Under normal conditions you should expect several years of service assuming a couple of hours of operation per day. We don't want anyone using our electrodes to be wary that they may be inferior. If you are hesitant about the quality you are welcome to try and find an old DuKane kit and pay the going price.

Q: Do you have or are you going to sell quartz cells?

A: Yes Ionovac.com has Cell Kits available for sale.

Q: Do you sell Ionovac speakers.

A: No. We only sell unique repair parts and offer free information and advice on maintenance.

Q: Do you repair work on Ionovac speakers?

A: Yes. See the repair section of the ionovac.com web page.

Q: How do I know if a speaker needs a new electrolytic capacitor?

A: All of the Ionovac speakers are well over 40 years old by now. I would suggest that you replace all of the electrolytic capacitors if they haven’t already been replaced recently. The signs of a bad electrolytic can be as subtle as poor performance or as final as blowing fuses or preventing plasma ignition. One way to easily tell is to sub in a good capacitor and see if anything changes. It’s best to use test equipment and measure the DC and AC voltage changes while you do this but I realize that not all owners are familiar with or own electronic test equipment.

Q: My speaker isn’t working. What’s wrong with it?

A: This is a lot like asking; “My car won’t start, why not?” It could be a lot of things from bad capacitors, bad tube, open interlock switch, loose plate clip or a long list of problems.

Q: I think the modulation transformer in my speaker is bad. Do you have replacement transformers for sale?

A: We only offer parts that are not available anywhere else. We would like to help but we just cannot stock everything you would need for repair. Transformers are available from electronics distributors. Although the average guy would have a hard time finding one we don’t sell them. We will give you information on where you might get one.

Q: I just bought an Ionovac speaker. The seller didn’t know if it works or not. What should I do to check it out?

A: If it still has a cell and electrode the usual things are to replace electrolytic capacitors, check the modulation transformer for shorts and clean or replace the electrode. Obvious faults like burned up resistors need to be replaced and the cause found for why they burned up. If you don't want to wait and replace electrolytics first you can apply power to see what happens but if the fuse blows don't try it again until those caps have been replaced. Another common failure is the modulation transformer. They get turn to turn shorts and primary to secondary shorts from overdriving the speaker. A primary to secondary short will put the 120 volt AC line in direct connection to the speaker input terminals. Connecting the input to a grounded amp will pop a fuse like thunder and it won't do the amp any good either. Many used Ionovacs were taken out of service because the cells were used up and replacements were no longer available. You should probably expect to at least replace the cell with a new kit. If the power supply is good and you still have problems replace the 6DQ6 tube.

Q: One of my speakers squeals a little after it’s been running for a while. I thought they only did that when you turned them on?

A: If you have recently installed new electrodes they will occasionally sing after startup. This is normal until a sufficient break in period. If you leave them operating ordinarily it will stop on it’s own in a few minutes. The break in varies but after about 100 hours they should stop.

Q: I have a speaker that blows fuses. Can I put in a bigger fuse?

A: As an old TV repairman friend used to say “The fuse is the second thing to fail”. You either have a shorted electrolytic, a shorted rectifier diode (rare) or a shorted modulation transformer shunting AC current to ground through the amplifier.

Q: My speaker doesn’t light up all the time. Sometimes it will but the plasma seems weak.

A: It could be a spent electrode or a weak tube. A marginal electrolytic capacitor can also do this.

Q: I bought a pair of restored Ionovac speakers. I’d like to add them to my system. How do I hook them up?

A: The Ionovac is used much the same way as any high frequency tweeter. You need to separate out the high frequency program material and apply it to the Ionovac. While the Ionovac cannot respond to low frequency program material below about 1500Hz, because of their higher amplitudes, low frequency signals will seriously overload the speaker and can cause serious damage. Ordinarily separating the low from the high frequency material is done using a speaker crossover network consisting of high efficiency capacitor/inductor band pass filters. DuKane recommended a crossover with a rollover frequency of 3500Hz. That is to say it begins to pass all program material above 3500Hz and rejects anything below that. The specific means to accomplish this depends on your existing speaker system. There are a number of reference books on crossover design, audio web sites and audio retailers that can supply you with information and hardware for this.

Q: Do you have quantity discounts on electrodes?

A: No. The manufacture and sale of electrodes in the quantity that satisfies the need is too small to be able to offer a discount. There is probably no more demand for the number of them that you could hold in your hand. Anything less than the current asking price would not be worth our time and expense to have them specially made. We hope to fill a need and in order to do that we have to charge what will make it allowable.

Q: What if I buy electrodes and they don’t work any better than the old ones. Can I send them back for a refund?

A: If they don’t work any better then you probably have a failure of some component in the speaker or the old electrodes are still serviceable. As with most suppliers of electronic or automotive parts we don’t accept returns on items that have been used unless there is evidence of a defect in material or workmanship. The electrodes are all made of the same material stock and are simple enough to be easily inspected for compliance to standards of workmanship before sale. If you wish to return an unused electrode in original factory condition we will refund the purchase price.

Q: I have an ElectroVoice T-3500 speaker. I heard it’s the same as an Ionovac. Will the Ionovac electrode work?

A: No. The EV T-3500 uses the same basic principle as the Ionovac but the cell is very different and it is not interchangeable.

Q: Can I use Ionovac electrodes in a Fane speaker?

A: Yes. The Fane ionic speaker is essentially a copy of the DuKane Ionovac design. We have supplied DuKane cell kits for Fane speakers and they work just as well.

Q: Why does the Ionovac use quartz cells? Why couldn't the electrode be put into a machined ceramic tube?

A: This is exactly what the design engineers at DuKane wanted to do. They initially tried pure Alumina as a cell material. Ceramic was their first choice because it was much easier to have it molded and fired than to precision grind quartz but unfortunately it didn't work. After a few hours, sputtering from the electrode began to make deposits on the plasma chamber. When that happened it deformed the plasma creating hot spots and causing noise.

Q: I cleaned my Ionovac cells with some scouring powder and they look pretty good now but something happened. When my Ionovacs start up the plasma lights up but it never really settles down. The singing lasts quite a long time. The plasma jumps around and sometimes there is a bright light. What can I do?
A: The cell cannot be safely cleaned except by gentle scraping followed by a mild detergent swab and rinse as described in the Care and Maintenance article and in the cleaning video. Bead blasting, scouring powders, glass etchants and other invasive cleaning methods damage the cell in a way as yet undetermined. The cell will never again support a normal stable plasma. Replace the cell with a new one.

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