Rode NTG3 mic, symptom of growing noise floor.

[Bob Hart]

The Rode mic is a great instrument and this post is in no way a criticism of its design or quality. As with all good things in heavy use over time, wear and tear will have its way eventually.

In this instance the mic and pole went for a sliding tumble off a sound cart and the end of the mic tube struck a hard tiled floor. It worked okay but went dead on the next take.

The soundie got out its twin brother but also mentioned that it was not the best of the pair and that both had over the last four months had been developing an increasing noise floor which he was now routinely having to clean in post. He was awaiting a Sennheiser 416. On its arrival his plan was to send both mics back to Rode for a fix.

Given that any warranties were likely voided due to visible crush damage to the tip of the tube, we opened the body up to meter the obvious culprits like soldered wires falling off XLR pins etc.. We determined that there was an intermittent connection somewhere.

It eventually came down to a small threaded ring fastener which retains the capsule in the tube. There is likely a special service tool like a miniature Rolyn lens spanner to loosen or tighten this fastener. In the field, two prongs of the multimeter and some twisting sufficed.

The fastener had loosened enough for the capsule to move in its clearance fit in the tube and a resistive joint to build between the capsule and the tube body. Once tightened to security, the problem went away.

The other mic was then opened and the same issue found and fixed. Notable was that most of the tiny screws had worked loose in the second mic. As I mentioned, these mics have been worked hard and endured a lot of movement.

The precise machining of all the metal parts is a delight for a backyard machinist to look at and the PCB work, not a single bad hairy soldered joint anywhere in sight, all good work.

The recommended course of things is to send such a precise instrument to professional repair when things are not right. However, if you get caught out in the boonies with this issue, it is re-assuring to know it is likely field-repairable so long as you have miniature Philips and Flathead screwdrivers and good fine dextoral skills.

Take care to remove and fit the screws in the mike tube on a clean floor or in bottom of a large tray with high sides on a worktable. Those little screws can run like the wind when they are dropped.

If you are constantly in field away from accessible product support and operating the mic in rough conditions, banging about in offroad vehicles etc., it might be prudent to periodically make sure all the little screws are secure inside the body, plus those which attach the acoustic tube which has to be removed to get at the ones inside. The old ethos of "if it aint broke, don't fix it" probably is just as valid though.

The capsule itself is fed by a single white wire which attaches by a long screw through a central nylon pillar insulator. The three small screws which hold this tube section to the main tube body must be unfastened and the section slipped forward and off a shoulder. Take care. There is a small short wire which might be broken if violently offended. This wire must be disconnected before you can safely get at the threaded capsule retainer ring to tighten it.

There is an adjustable coil, transformer, inductance or whatever at front-end of the circuit board. The screwdriver slot in the adjust slug is tempting to mess with. Do NOT mess with it. This is a precision adjustment which likely requires specialised test instruments to reset correctly. Leave it ALONE.

When re-assembling the front section containing the assembled capsule to the rear body, take care to look for two tiny matchmarks. Take care also that the tag on the end of the white wire has not become bent by your endeavours and shorting out on the inside of the tube body.


FOOTNOTE: When re-installing parts like tube with screws which are on radial centres, an ideal practice is to fit each screw in its turn, screw it down to contact but not to final tightness, then after all screws are in place, tighten them all to security. If you tighten the first screw to security, you may find one or more of the other screws are difficult to offer up and fit.

As is usual with my home remedy statements, I am not a qualified industry practitioner, therefore my comments should be regarded with caution and tested for truth by separate investigation. The above comments are not endorsed by the manufacturer or vendors of the product. Therefore any attempt to adjust or repair the product by owners or operators is done at their own risk.

In the meantime, all the best in your use of a fine product. I confess to a certain bias. I am Australian as is the manufacturer of the product.

[Allan Black]

Bob,

thanks for this report, as you'd be aware 'visible crush damage' to the tip of any mic, can cause other short and long term problems, which are not immediately visible.

If the soundie registered both his NTG-3s on line with Rode at the time of purchase, then their standard 10yr warranty applies to each one.

If so they'd still be under warranty today.

So with all due respect to him, the first one, then the second or both together, should have been sent into Rode for warranty repair four months ago when he first noticed their 'increasing noise floor'.

Because he noticed BOTH his NTG-3s displaying this same problem, can you ask him, is he using his mics in any but the 'usual' conditions? Is he connecting the mics before turning on their 48volts? .. and off again before disconnecting? .. are his mic cables in good condition and wired Ok? .. and is he placing his babies safely in their aluminium storage tubes after use? You might think of other similar questions to ask him.

I'm asking this because I'm pretty sure in saying that Rode hasn't seen this problem before now, most definately not with 2 NTG-3s from the same user over the same period .. and they'll want to inspect them here at their Silverwater HQ. More to come on this.

Cheers.

PS: to everyone reading this, DON'T DO THIS AT HOME .. or anywhere, puleeeze don't disassemble any Rode mic. yourself, just ain't worth it baby.

[Bob Hart]

Allan.


10 year warranty. That has to be a pretty convincing affirmation of confidence by a manufacturer in a product.


On reflection, I have probably committed a bit of a sin here. My post was more of an anecdoter I guess.

There may be somebody caught with a damaged mic, an impossible distance away from product support on a project which may fall over because of it.

There will always be those with more money than brains or those with little or no money and urgent need to get someting fixed who will open their mics up anyway for whatever reason. My hope was to at least give those mics some chance of survival.

Sure, people should plan some equipment redundency into their expeditions but travelling light and/or nonsensically low budgets can have their way with such things and people take chances.

The pressure that was on last night was driven by the location not being available again and the production would have been aborted or entirely reshot. Not good for a 30 minute indie short within a day or two of wrapping. So the soundie had to come up with the goods or seriously lose some street cred which is not hard in a small indie production community like Perth.

The soundie - Yes. A sensible course would have been to submit the mics for repair long ago. I was sort of confounded when he disclosed he had soldiered on for so long given his care for quality recording, especially given there is a 10 year warranty unless he has done something which would have voided it. I think he said something about a long warranty on the capsule.

Finance has a bit to do with it I guess. Just enough work to tease a person a little but not enough beyond keeping the rent paid and food in belly. Money to pay for the shipping and repairs and replacement rental during away time getting put off for another day.

As for how he connects them and switches phantom power on, I did not observe. He seems to take due care. Except for the fall damage, I did not observe any other skin and hair had been knocked off them and there was no sign of any dust or water entry.

I only got involved when things went "crack" on the floor. His cables are good. He has two black capped tubes which the mikes go inside of when not in use. He uses them in a conventional arrangement on a graphite telescoping boom pole and patches them through a Sound Devices 402 mixer.

He also has a radio system they can connect to via the normal XLR plugs. This apparently requires a phase reversal for the mikes to work properly. That is high science beyond my ken.


I certainly endorse what you have said regarding owner-repair.

THE RODE MICROPHONE HAS BEEN DESIGNED AND PUT TOGETHER BY PEOPLE WHO HAVE TAKEN THE TIME AND TROUBLE TO GET IT RIGHT. THEIR WORKMANSHIP SHOULD BE RESPECTED BY CAREFUL HANDLING AND TRANSPORT AND CAREFUL USE OF THE PRODUCTS AND NOT RUINED BY CAREFREE INVESTIGATIONS INTO THE INNARDS. I DO NOT RECOMMEND SELF-REPAIR ATTEMPTS BY OWNERS EXCEPT WHERE DISTANCE FROM PRODUCT SUPPORT AND URGENCY ARE FACTORS.

I hope that statement lets me off the hook.

If Rode would be genuinely interested in inspecting the mics or knowing what happened, I am happy to give them a more detailed report on what I found. I will see if I can convince the owner to part with them for the time it takes. He may be hard to convince now that they are working fine again but may relent once he receives his 416.

As for myself. - Rode directionals, - I wish.

My field mics are all Sony. 2 x ECM-674 which are quieter than the Rodes but sound fine for dialogue, plus secondhand mics, 2 x C74 and 2 x C76. Both the 76s have the noise floor of a strong wind blowing through a nearby hedge. I guess they were good in their time but they look cool at least.

I do have three Rode mics, all NT2a, which I bought in for a symphonic recording session when I probably should have saved the cash or spent it less rashly. However I now have them. I have since used them as hidden supplemental mics for a fixed wide shot along the walk path of two actors who were delivering dialogue enroute through a pineforest. They performed very well in this situation.

[Allan Black]

Thanks Bob. Ha ha .. you were never on the hook mate :)

Can you PM me the name and phone number of your sound guy thanks and we'll follow this up. Thanks and have a great week.

Cheers.

[Bob Hart]

Allan.

Thanks for that. I'll convey this to him and get his details. The Rode mic I have the most to deal with is a NTG1 belonging to Steve Rice and it has been faultless thus far ( 3 years ).

[Bob Hart]

I probably should qualify this comment as my unique use of words versus accepted industry nomenclature may mislead :-

"My field mics are all Sony. 2 x ECM-674 which are quieter than the Rodes but sound fine for dialogue"

My use of the word "quieter" means the Sonys require more gain on the MixPre I use, to present the same output level to the recorder. It does not refer to signal-to-noise performance, which is something I have not researched between the two brands.