Clipping wireless.

[FrankD77]

I bought a lekato wireless 5.8ghz after reading great reviews. It did solve a small issue I had sometimes with interference.

When i switched to the synergy i found it very hard to get a clean signal, constant clipping on the neck and bridge humbuckers.

Volume back helps so i just blamed that
After installing the engl power amp i heard it on all settings. To my surprise when i switched to the cable it was crystal clear. No clipping.

It seems to only happen with high output pickups. Seeing i can't change the level i mailed lekato for help.

Anyone else this problem ?

 

[TalismanRich]

I have the Joyo version ( got it after your comments ) and have had no issues. I've used it with Lollar P90s, Tele single coils and SD Seth Lovers and haven't had any issues with any clipping. It seems a better match when I run direct into my Tascam interface, but also running into my Princeton Reverb and Strymon Iridium.

I just spent a couple hours the other night recording my H-530 with P90s direct through the JW06, and then hooked up the Tele to my pedal board with the Strymon.
Also, my bass playing buddy got one and used it at our last jam. He's playing a Guild JS2 bass with humbuckers. Sounded fine.

Is it possible that the output of the Lekato is significantly higher than guitar by itself and is overloading the input? I don't know that I've actually checked it that way. I just plugged and played. And yeah, it's possible that a high output pickup might overload the wireless. If you turn down the volume on the guitar does it stop popping?

 

[Papanate]

I bought a lekato wireless 5.8ghz after reading great reviews. It did solve a small issue I had sometimes with interference.

Anyone else this problem ?

The Lekato 5.8gHz are known to have this issue - the solution is to go with something else. The max input is limited to about 1.4 Vp-p, 507mV RMS/−3.7 dBu before it starts clipping BTW.

 

[rob aylestone]

All good radio systems have adjustment for input level - after all, it varies so much between pickups and pickup types. With a cable you cater for this by the input level control - on a radio system, that has a preset level, going over sounds nasty - turning down the guitar level sort of sorts that distortion, but of course throws away lots of signal, meaning at best, the quiet playing gets into the noisy area, and available dynamic range is reduced. Happens with mics too - many of these do not have attenuation either - somebody speaking 6" from the mic, vs somebody screaming lips on basket windshield. -10 or even -20dB reduction (as you see on all big brand systems) is essential. The cheaper wireless system are lacking this and the results are nasty distortion or noise!

 

[FrankD77]

Indeed.
With single coils and an older softer humbucker no problems. As soon as I use the jems it's terrible on bridge and neck. Also a Chapman 7 string clips like crazy but that one has blackout pups

The weird thing is that i bought it to solve a problem which it did and at that time i did not notice it. When i started using the jem7v it went wrong.

 

[ecc83]

1.4V p-p is crazily low! Whoever designed that device knows FA about guitars. Most battery gadgets these days use at least a 5V supply giving a p-p output of about 4V or some 1.5V rms. Yer common or garden guitar pedal running at 9V gives about twice that and we rarely see clipping problems with those?
The only immediate solution I can see is to turn the guitar down. Now I know players don't like doing that because it can cause "tone suck" or HF loss on a long cable but that wireless device will surely be on a very short cable? Or, as suggested, buy a better mousetrap!

Dave.

 

[FrankD77]

Turning down volume has a rather big impact on the sound. I'm back on the cable now and will see what I do. Probably only use the wireless when we have interference although I think we fixed that in the mean time or sell it.

 

[TalismanRich]

1.4V p-p is crazily low! Whoever designed that device knows FA about guitars. Most battery gadgets these days use at least a 5V supply giving a p-p output of about 4V or some 1.5V rms. Yer common or garden guitar pedal running at 9V gives about twice that and we rarely see clipping problems with those?
The only immediate solution I can see is to turn the guitar down. Now I know players don't like doing that because it can cause "tone suck" or HF loss on a long cable but that wireless device will surely be on a very short cable? Or, as suggested, buy a better mousetrap!

Dave.

For most lower output pickups like a Seth Lover, SD59 or other PAF style, P-90 or Strat / Tele single coil, 1.4v is more than reasonable. Most normal passive pickups will be under 250mV peak output for a full on chord.

The JEM has a high output pickup in it, but I wouldn't really expect it to be much over 1V, maybe it will when hitting full chords hard. Ratings I've seen are in the 400-450mV range. Active pickups might get higher.

Here is a chart for Dimarzio high output pickups. It doesn't say out they generate the output voltage but you can see the numbers. Their PAF styles are in the low 200mv range. Strat pickups are in the 100s.

 

[FrankD77]

it does fit the narrative indeed.
Never knew this. They should give much more info about that.

 

[rob aylestone]

Would it not be better to just fix the interference?

 

[FrankD77]

We already tried everything.
We live on an industrial area. Very quiet (unless i play ) have line isolators that solved some other issues. And power filters. We have the idea it's somewhere in the powergrid also because it's random but always during day time.

It's not often that it happens. Maybe once every week or so and only for a few hours. It's no problem when playing. You can't really hear it but when recording I want it as quiet as possible.

Wireless seemed to have solved it.
For now I'll just probably keep it as a backup.

Its a hobby space so it's more of a "i want to beat this" than "I have to solve it".

 

[ecc83]

For most lower output pickups like a Seth Lover, SD59 or other PAF style, P-90 or Strat / Tele single coil, 1.4v is more than reasonable. Most normal passive pickups will be under 250mV peak output for a full on chord.

The JEM has a high output pickup in it, but I wouldn't really expect it to be much over 1V, maybe it will when hitting full chords hard. Ratings I've seen are in the 400-450mV range. Active pickups might get higher.

Here is a chart for Dimarzio high output pickups. It doesn't say out they generate the output voltage but you can see the numbers. Their PAF styles are in the low 200mv range. Strat pickups are in the 100s.

View attachment 151840

Much obliged for the chart Rich. Assuming those numbers are for rms output, the X2N is bang on the overload point of the OP's kit and several others are close.
It is professional practice to give a 20dB headroom for inputs. Maybe that is asking a lot from a budget device but 10dB is reasonable?

There have been similar cockups before. The first Focusrite 2i2s had pitifully low instrument input headroom. The amp company I worked for had a problem with a 5W amp. That would overload for a very high output guitar if really thrashed. Not input clipping though, further into the pre amp and single resistor value change sorted it.

I am however somewhat suspicious about the chap saying "backing off guitar changes the sound" It shouldn't if the VC is configured properly (and the cable is very short) Could however be "psychological" ? Often guitarists mistake a level drop for an HF loss. Try making up the gain elsewhere in the chain. If indeed the guitar's VC is an odd one, leave at max and use an external aperiodic attenuator.

Dave.

 

[ecc83]

We already tried everything.
We live on an industrial area. Very quiet (unless i play ) have line isolators that solved some other issues. And power filters. We have the idea it's somewhere in the powergrid also because it's random but always during day time.

It's not often that it happens. Maybe once every week or so and only for a few hours. It's no problem when playing. You can't really hear it but when recording I want it as quiet as possible.

Wireless seemed to have solved it.
For now I'll just probably keep it as a backup.

Its a hobby space so it's more of a "i want to beat this" than "I have to solve it".

I have had a fair bit of experience of fixing RFI problems in audio kit (Google Rugby and Daventry transmitters. I am in Northampton) Yes, you can sometimes fix it with filters on inputs but don't forget speaker wiring! This rarely solves the issue though and you need an experienced tech to fit the filters INSIDE the amplifiers. Equipment in EU has to meet certain regulations regarding RF ingress and egress and it is rare to have a problem these days.

Dave.

 

[FrankD77]

I have had a fair bit of experience of fixing RFI problems in audio kit (Google Rugby and Daventry transmitters. I am in Northampton) Yes, you can sometimes fix it with filters on inputs but don't forget speaker wiring! This rarely solves the issue though and you need an experienced tech to fit the filters INSIDE the amplifiers. Equipment in EU has to meet certain regulations regarding RF ingress and egress and it is rare to have a problem these days.

Dave.

I probably made the issue seem more noticable than it is.

When we started there was always one block on the x32 and a slight wissle on my DI. Solved ground loop with a line isolator.

Added 2 power conditioners and two extra line isolators to the x32 from the rack. Studio is now actually totally silent even on lower gain settings i hardly use a gate anymore.

Sometimes there is a sorf of waving interference. Not heard on clean but only on the mid to high gain signals. I'm a bit of OCD when it comes to sound so wanted it out switching to wireless helped weirdly enough.

But it's not a big deal.

 

[TalismanRich]

I'm thinking that the numbers in the chart are probably RMS numbers, so hitting a peak of 3 or 4 times that on a strike is probably not unheard of . The JEM usually has EVO pickups, so they probably can hit 1.5V or more for a peak.

All of my guitars have lower output pickups. I've never had any pops. In the band I saw last night, the guitarist uses the JW06 system which is the same as the Lekato with the charging block. He used a Les Paul Jr and an Epi FIrebird and was good all night.

Maybe I'll put it after my Notaklon and start to turn up the level to see if I can get mine to crackle. Unfortunately, I don't have a scope to measure the actual voltage swing, which is what would be needed. You should be able to look at both the input level and the output waveforms to see if it's cutting out or just flat topping the signal.

 

[Old Music Guy]

This may not be on point, but I have an XVive 2.4GHz wireless. I have several P90 guitars, one with Seymore Duncan Phat Cats, and a slew of other SD single coils. I've not run into that problem at all. But, a friend gave me a Cry Baby and when I used it with the XVive, directly into my Fender, I got the most horrific "noise" almost like feedback, ~3Khz.
I have no doubt that it has something to do with some RF feedback loop.

 

[TalismanRich]

I was doing a bit more research on outputs and I found info from EMG about their active pickups. They DEFINITELY would clip these wireless transmitters. With outputs of 4.5 volts for a full strum, they would be unusable. Of course that also explains why the metal folks like active pickups vs old school passive pickups. They would slam that front end of an amplifier in a way that a passive pickup never could.

 

[ecc83]

I was doing a bit more research on outputs and I found info from EMG about their active pickups. They DEFINITELY would clip these wireless transmitters. With outputs of 4.5 volts for a full strum, they would be unusable. Of course that also explains why the metal folks like active pickups vs old school passive pickups. They would slam that front end of an amplifier in a way that a passive pickup never could.

View attachment 151851

Indeedy! I see the pickups use a 9V PP3 so that 4.5V is pk-pk or about 1.6V rms (~+5dBv , +8dBu) and such a voltage will start to drive the first Triode stage of an amp into serious distortion, something lesser, passive pups are rarely able to do. That will produce a particular sound, not one often encountered with valve amps. In fact, 4.5V would in principle produce about 270V pk-pk at the anode but since the HT supply is rarely more than 300V, not going to happen and you get a seriously clipped output.

This is why valve guitar amplifiers are capable of an almost infinite variety of tones. For instance, just a different value for the grid stopper on that front end valve can change the sound. 68k is a common value but you can go a factor of ten each way from that if you want to experiment.

Dave.

 

[rob aylestone]

My video studio has loads of RF gear in it - including a repeater, which is on 24/7 and a marine AIS unit which sends data bursts every now and then. The only issue I had was a quiet 'burbling' when the AIS triggered - the repeater was silent to my audio wiring in the studio. In the end I tracked it down to the cables between interface and one keyboard. Swapping the cable made no difference. In the end a twin channel transformer - in a DI style box cured it. I think Dave's on the right track with my own situation - the cable screen (hence why swapping it made no difference) was acting as the 'antenna' and access point for the noise, which then travelled on the system grounds. The transformer broke the physical path and the problem just went. Neat!

 

[ecc83]

I think the worse case of RFI I had to fix was a Simms-Watts guitar amp which used an op amp front end. The dee-lightful 741!

Chap lived in Daventry and the first line of filters, RF choke on input, 220puff cap, did not do a lot. I decided to get heavy with the fekker! Every pin, DC included, had a small RF choke inline and 100pf from pin to 0V. Plus a 1cm piece of copper clad PCB was glued to the top of the chip and caps taken from it to 0V. A screen was fabricated from a bit of baccy tin and soldered over the PCB side of the 741.

Fixed it!

If any of of you remember the "E -E 75R aerial link used for VCRs, this would cause a ground loop in rare cases. Fixed by making a "Braid Breaker" with a bit of double sided copper clad board and some caps. I shall not go into the hell we were caused by the Rubber Duck brigade and their 100W ERP burners!

Dave