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Title: Is it possible for an active bass to damage a wireless pack?
Post by: Jon Brunskill on January 07, 2019, 09:39:50 pm
At New Years, I pulled out my Sennheiser G2 wireless system out for a bassist.

He plugged in, and there was no sound, unless he was playing as hard as he possibly could. When the sound did come through it would let through a short, sharp nasty sounding note, and then gate it off really hard.

I've finally had a change to look at it, and it's doing the same thing to me. It works just fine with a mic, but with a guitar, keyboard, it does this awful gated thing.

Has anyone else come across this problem? Is it possible that the bassists' active bass could have put a voltage down the cable into the input section of the transmitter and shorted something out?

Thanks
Title: Re: Is it possible for an active bass to damage a wireless pack?
Post by: Bradford "BJ" James on January 07, 2019, 09:56:03 pm
Probably a bad cable. Simple stuff first.
Title: Re: Is it possible for an active bass to damage a wireless pack?
Post by: Scott Hofmann on January 07, 2019, 10:19:04 pm
Have you tried to adjust the input sensitivity via the transmitter menu? Could be the bass is overloading the transmitter.
Title: Re: Is it possible for an active bass to damage a wireless pack?
Post by: Jon Brunskill on January 07, 2019, 10:20:41 pm
Probably a bad cable. Simple stuff first.

Cable tests good! First thing I tried.
Title: Re: Is it possible for an active bass to damage a wireless pack?
Post by: Scott Helmke on January 07, 2019, 10:39:25 pm
It's possible that there was damage.  The guitar signal for those Evo systems goes through the ring contact, while the mic goes through the tip of the 1/8" plug. Might have been damaged previously, though.

Maybe the jack itself is damaged, rather than the input circuitry.  That's not an especially difficult repair.
Title: Re: Is it possible for an active bass to damage a wireless pack?
Post by: Mal Brown on January 08, 2019, 01:30:53 am
Unlikely...  I play active basses from 9 v to 18v.. or passive P Basses.  Never clipped a wireless
Title: Re: Is it possible for an active bass to damage a wireless pack?
Post by: Keith Broughton on January 08, 2019, 06:49:46 am
There are 2 ways to wire these cables.
Check to see if there is (appx)5 volts from tip to ring of the cable when plugged into the pack and pack turned on.
If there is, it's wired incorrectly.
If not...I'm stumped. I have used G2 for this application before and not had this type of problem.
Title: Re: Is it possible for an active bass to damage a wireless pack?
Post by: Jon Brunskill on January 09, 2019, 09:56:26 pm
It's wired 100% correctly and tests good. I made another cable, using the ground and the tip, or mic input into the wireless, and that works. So it's my best guess that some part of the 'line input' circuitry is dead. I do suspect that bass, as I used the system the day before with my own band, and it worked perfectly.
Title: Re: Is it possible for an active bass to damage a wireless pack?
Post by: Keith Broughton on January 11, 2019, 06:05:42 am
If it works on the mic input, then great!
With an active pickup, I would have figure the mic in would get overloaded.
Title: Re: Is it possible for an active bass to damage a wireless pack?
Post by: Tim McCulloch on January 11, 2019, 12:50:47 pm
Unlikely...  I play active basses from 9 v to 18v.. or passive P Basses.  Never clipped a wireless

Nine volts at the bass guitar output?  That's more than most console outputs deliver with an "average" signal.

Tell me those are the batteries...
Title: Re: Is it possible for an active bass to damage a wireless pack?
Post by: Stephen Kirby on January 11, 2019, 03:54:36 pm
Nine volts at the bass guitar output?  That's more than most console outputs deliver with an "average" signal.

Tell me those are the batteries...
Yes, that's just the supply to the internal pre-amp.  Actual output is more like a volt.
Title: Re: Is it possible for an active bass to damage a wireless pack?
Post by: Geri O'Neil on January 17, 2019, 10:23:06 pm
At New Years, I pulled out my Sennheiser G2 wireless system out for a bassist.

He plugged in, and there was no sound, unless he was playing as hard as he possibly could. When the sound did come through it would let through a short, sharp nasty sounding note, and then gate it off really hard.

I've finally had a change to look at it, and it's doing the same thing to me. It works just fine with a mic, but with a guitar, keyboard, it does this awful gated thing.

Has anyone else come across this problem? Is it possible that the bassists' active bass could have put a voltage down the cable into the input section of the transmitter and shorted something out?

Thanks

No, not likely any damage done by the bass. The Fender American Elite is one of the hottest-output basses out there. Shure, Sennheiser, Line 6, and my favorite and what I use, the Lectrosonic, all handle that bass's output just fine.

I don't understand what you mean with you say it works fine with a mic, but not an instrument. Are you referring to the receiver, or using something like a lapel mic on the beltpack?

In any case, I hope it's a setting or a cable issue. Sennheiser isn't repairing those G2 units. I have a couple of G2 IEM units in the A band (you Frequency Police read that again in case you feel a rush coming on) and I had to replace a pack with one from Ebay.

Good luck. Now allow me to prepare myself for the eventual drop-kicking of this thread into somewhere most appropriate.
Title: Re: Is it possible for an active bass to damage a wireless pack?
Post by: Jon Brunskill on January 20, 2019, 06:00:19 am
Hi Geri,

I'm not talking about a bass with a hot output overdriving the wireless pack, I'm interested in if the active preamp of a bass guitar could possibly send a DC voltage into a wireless pack that could damage the input. Some basses have 2x 9 volts in series for an 18 volt power supply, and that seems to me like it could potentially cause damage.

A lapel mic does still work just fine on the body pack. Sennheiser packs have a mic input AND a line input.

The wiring is like this: for an instrument, the tip and sleeve of a TS jack go to the ring and sleeve of the bodypack TRS input. On my unit this doesn't work.

When you use a lapel mic, it's wired to the tip and sleeve of the TRS. This does work on my unit just fine - however as it's a mic input the gain is high.
Title: Re: Is it possible for an active bass to damage a wireless pack?
Post by: Mike Caldwell on January 20, 2019, 09:35:38 am
Hi Geri,

I'm not talking about a bass with a hot output overdriving the wireless pack, I'm interested in if the active preamp of a bass guitar could possibly send a DC voltage into a wireless pack that could damage the input. Some basses have 2x 9 volts in series for an 18 volt power supply, and that seems to me like it could potentially cause damage.

A lapel mic does still work just fine on the body pack. Sennheiser packs have a mic input AND a line input.

The wiring is like this: for an instrument, the tip and sleeve of a TS jack go to the ring and sleeve of the bodypack TRS input. On my unit this doesn't work.

When you use a lapel mic, it's wired to the tip and sleeve of the TRS. This does work on my unit just fine - however as it's a mic input the gain is high.


Yes I could see if a guitar pre-amp was passing a high level of DC voltage it could damage an input on a wireless pack.

Take a volt meter and check for DC voltage on the guitar cable.

The guitars I have worked on that use two 9 volt batteries do not have them wired in series but use each battery as a supply for op amps in the pre amp circuit, one battery supplies the + rail and the other supplies the - rail. The + of one battery and the - of the other battery are tied together at a common ground reference point.
Title: Re: Is it possible for an active bass to damage a wireless pack?
Post by: Jon Brunskill on July 20, 2019, 03:32:39 am
A belated update -

The wireless pack had indeed been fried and has a cooked electrolytic capacitor. The repair guy said he'd never seen this issue before. I didn't get it fixed in the end as even if the SMD cap was replaced, there might be further issues and I didn't want to pay for a whole board on an older G2 wireless. It's working just fine on the mic input, so the saxophone player in my band is using it along with an ATM350, and I've treated myself to a new G4 series wireless for my guitar.
Title: Re: Is it possible for an active bass to damage a wireless pack?
Post by: Geri O'Neil on July 20, 2019, 09:47:23 am
Nine volts at the bass guitar output?  That's more than most console outputs deliver with an "average" signal.

Tell me those are the batteries...

9 or 18 volts is nothing more than the power requirements of the instruments’ preamp to power it up. Usually in the form of either 1 or 2 9-volt batteries. Most basses will supply between mic level and line level (“instrument” level, I guess) output signals.

I kinda gave up on following this post because I couldn’t understand exactly what the symptoms were. No matter, the OP has solved his issue to his satisfaction. That’s what matters.