Was: "Just bought an ATG-1 floorboard"

Started by DLC86, November 21, 2017, 03:05:53 AM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

admin

#50
Quote from: DLC86 on January 19, 2018, 06:50:37 AM
I finally managed to install the luthier kit  in my strat and I'm blown away, no audible latency, perfect pitch shifting and pretty good models. Definitely money well spent.

Anyway I have an issue: when palm muting or strumming hard causing some fret buzz I hear a pretty nasty high frequency noise, it's also present with atg off but it seems the atg boosts it quite a bit, and it's annoying mostly on the low E string.
I tried to play a bit with saddles distance settings and that changes the tone of that noise but couldn't find a setting that make it tolerable.

I think the cause is the comb filtering correction the ATG makes to flatten the response of the hex pickup (based on its position), probably fret buzz and palm muting introduce frequencies that shouldn't be captured by the pickup in that particular position revealing the eq correction.

Any way to solve this problem? I'm actually thinking about installing my graphtech ghost saddles in place of the hex pickup since, I assume, the piezo setting in the atg doesn't have the correction eq.
I know piezos can exhibit other problems but maybe they're more negligible than this one, I already tried some palm muting on them with unprocessed sound and it doesn't seem so bad.

PS: eventually how could I adapt the piezo output level and impedance to enter the ATG?

I assume you currently use a mag hex PU

The Hex PU input sensitivity per string adjustment (STRING GAIN) which is crucial to adjust for your playing technique - The  internal ATG kit has that adjustment using the Luthier Kit setup app.
Lower the string gain until the distortion anomalies go away

DLC86

I have the mag hex pickup atm (the one included in the kit), I tried pretty much every setting on that page and the only setting affecting the noise is the string offset.
Btw I have set strings gain pretty low to match the output of my strat pickups.

GuitarBuilder

Quote from: DLC86 on January 19, 2018, 06:50:37 AM
I finally managed to install the luthier kit  in my strat and I'm blown away, no audible latency, perfect pitch shifting and pretty good models. Definitely money well spent.

Anyway I have an issue: when palm muting or strumming hard causing some fret buzz I hear a pretty nasty high frequency noise, it's also present with atg off but it seems the atg boosts it quite a bit, and it's annoying especially on the low E string.
I tried to play a bit with saddles distance settings and that changes the tone of that noise but couldn't find a setting that make it tolerable.

I think the cause is the comb filtering correction the ATG makes to flatten the response of the hex pickup (based on its position), probably fret buzz and palm muting introduce frequencies that shouldn't be captured by the pickup in that particular position revealing the eq correction.

Any way to solve this problem? I'm actually thinking about installing my graphtech ghost saddles in place of the hex pickup since, I assume, the piezo setting in the atg doesn't have the correction eq.
I know piezos can exhibit other problems but maybe they're more negligible than this one, I already tried some palm muting on them with unprocessed sound and it doesn't seem so bad.

PS: eventually how could I adapt the piezo output level and impedance to enter the ATG?

It seems like the simple solution is to adjust your neck and saddles to eliminate the fret buzz!  ;D
"There's no-one left alive, it must be a draw"  Peter Gabriel 1973

admin

Quote from: DLC86 on January 19, 2018, 07:20:23 AM
I have the mag hex pickup atm (the one included in the kit), I tried pretty much every setting on that page and the only setting affecting the noise is the string offset.
Btw I have set strings gain pretty low to match the output of my strat pickups.

There is more to the equation - if you play very aggressively - you will achieve an odd distorted tone with any of the VGuitar systems ( Roland/Boss/ Line-6/ Antares) if the string sensitivity is not set for your playing style  - try lowering the string sensitivity further  -

and of course have a Luthier check if your Guitar's  frets need a leveling / polishing

DLC86

Quote from: GuitarBuilder on January 19, 2018, 07:41:12 AM
It seems like the simple solution is to adjust your neck and saddles to eliminate the fret buzz!  ;D
Yeah, probably raising the action a bit would work too, I have it set pretty low. Anyway my main concern is that it happens on palm mutes too.

Quote from: admsustainiac on January 19, 2018, 08:05:56 AM
There is more to the equation - if you play very aggressively - you will achieve an odd distorted tone with any of the VGuitar systems ( Roland/Boss/ Line-6/ Antares) if the string sensitivity is not set for your playing style  - try lowering the string sensitivity further  -
and of course have a Luthier check if your Guitar's  frets need a leveling / polishing
I already have it set to minimum for all strings except the two Es (cuz I have a compound radius neck and these two strings are a bit more distant from the pickup).
I'm also pretty sure it's not a distortion sound nor exclusively related to fret buzz, with palm mutes I can also hear it when picking gently.
I'll post a sample as I go back home.

DLC86

#55
I found a discussion on the ATG forum about the same issue (i think) but it died without a solution. Anyway someone posted a sample (here) where this noise can be heard very clearly. Listen to the first two notes, then go to 0:56 and it's even more evident.
This metallic clicky sound make me think of a very narrow band being emphasized by the ATG comb filter correction.

DLC86

#56
Today I connected graphtech ghost saddles to the atg and the problem is gone, palm mutes work fine if I place my palm above the saddles, I don't hear any issues with dynamics and even output level is ok, just a couple dB higher than the mag hex pickup.
But most importantly now the models sound way better than before (they just lack some low end compared to my strat output) and this leads me to think there's some issue with my mag hex pickup setup, even though I double checked everything and all seems fine. The only doubt I have is if the pickup is too far from the bridge, it's about 2mm beyond the range suggested on the installation guide, do you think this could be the cause of my problem?

admin

#57
QuoteThe only doubt I have is if the pickup is too far from the bridge, it's about 2mm beyond the range suggested on the installation guide, do you think this could be the cause of my problem?

Yes it could be a problem

you might be experiencing occasional string slap on your Hex PU if mounted too far away from bridge

and the PU distance setting must be entered into the ATG with the actual PU distance for correct DSP Guitar Modeling voicing


DLC86

#58
I already checked and the strings are not touching the pickup, and the fact that the problem goes away with the piezo saddles (with the mag hex pu still mounted on the guitar) kinda proves the noise is introduced by the processing.

Obviously I also measured and set the correct PU distance and even tried to play with several values with no luck, it just changes a bit but never goes away.

I'm more and more convinced it has something to do with the comb filtering applied to compensate for the PU position. Placing the pickup closer to the bridge would shift those peaks toward the upper frequencies and maybe make them almost inaudible.

cags12

I am surprised the piezos sound good with the magnetic Hex version of the DSP. I had to order a modified version that supports piezos. At the end of the day if it sound goods to you, that is what really matters.

I hope you are not a high gain player otherwise you will experience an even worse symptom.

https://www.dropbox.com/s/4kdb2u8zms52tu9/distorted_static_noise.wav?dl=0

https://www.vguitarforums.com/smf/index.php?topic=20455.0

DLC86

#60
Quote from: cags12 on January 22, 2018, 07:35:13 AM
I am surprised the piezos sound good with the magnetic Hex version of the DSP. I had to order a modified version that supports piezos. At the end of the day if it sound goods to you, that is what really matters.

I hope you are not a high gain player otherwise you will experience an even worse symptom.

https://www.dropbox.com/s/4kdb2u8zms52tu9/distorted_static_noise.wav?dl=0

https://www.vguitarforums.com/smf/index.php?topic=20455.0

Luckily I'm not really into high-gain :)
Anyway I am aware that cross-talk could be a problem with piezo and one of the first things I tried was to find some artifacts or pitch warble when notes die: I could not so everything's fine there. Obviously I made sure the saddles were not touching each other and thought about adding something made out of rubber under the screws to reduce it even more, but until now I haven't felt the need.
Which piezo system do you use?

I'd also like to know exactly what's the difference between the piezo and mag version of the atg circuit (except for input level and impedance). I was wondering if that could affect somehow the sound of the models.
For example I noticed they lack quite a bit of low end compared to my strat but it could just be the way they're supposed to sound. Anyway I can make the strat model sound pretty much identical with a low shelf EQ set at 300Hz and 8-9dB boost.

cags12

I use the AT-200 stock piezos and also Graphtech's on a Hipshot bridge. In both cases saddles do not touch. The issue with high gain surprisingly is with cross-talk through your palm. In other words, your hand acts as a bridge for vibrations causing the undesired effect you can hear on the audio clip.

The difference I believe is just impedance and level. The rest is compensated digitally when you set-up the input as piezo or magnetic in ATG Settings Manager.

cags12

Forgot to mention. The issue is only apparent with alt tunnings. The higher the pitch shift the worse the effect. For that reason I have also ordered a magnetic version which I am still yet to install.

DLC86

Quote from: cags12 on January 22, 2018, 08:18:59 AM
I use the AT-200 stock piezos and also Graphtech's on a Hipshot bridge. In both cases saddles do not touch. The issue with high gain surprisingly is with cross-talk through your palm. In other words, your hand acts as a bridge for vibrations causing the undesired effect you can hear on the audio clip.

The difference I believe is just impedance and level. The rest is compensated digitally when you set-up the input as piezo or magnetic in ATG Settings Manager.
Good to know, I didn't test it with palm muting, I'll do it asap.

I suspected it was just digital processing but wanted to be sure, thanks! ;)

Elantric

#64
I can add that if you forget to configure the correct ATG mode for your hex PU type  - things sound very wonky

ATG-1 Manual
https://www.vguitarforums.com/smf/index.php?topic=13067.0


Thomas Nordegg's ATG-1 floor unit was sounding "off" with distortion ,  - he was using a custom Relish guitar with a piezo hex PU, but the ATG-1 was set for magnetic GK PU and the String Gain sensitivities were way off.

After we re-adjusted the ATG-1  - things sounded correct again


Also I know a few here are discussing the Peavey AT-200 , the Antares Internal Kit and the ATG-1 FLoor unit

AFAIK - each have different support for Mag PUs

and using the latest firmware makes a difference too  -older firmware does not support string gain adjustment

Here is the Antares Internal Luthier kit thread with PDF docs on the 1st post
https://www.vguitarforums.com/smf/index.php?topic=13462.0
Read chapter 5 String Gains

cags12

Just to note, the issue I described is present in the AT-200 DSP3 and in the Piezo-based Luthier Kit DSP4. It's a mechanical limitation or piezos/your hand that is worsen by a pitch shifting algorithm limitation when cross-talk is present (as described by Andy Hildebrand in the user manual).

admin

#66
Quote from: cags12 on January 22, 2018, 09:21:18 AM
Just to note, the issue I described is present in the AT-200 DSP3 and in the Piezo-based Luthier Kit DSP4. It's a mechanical limitation or piezos/your hand that is worsen by a pitch shifting algorithm limitation when cross-talk is present (as described by Andy Hildebrand in the user manual).

Agreed - and Ive experienced similar phenomena ( Palm Muting hand on Piezo Hex PU  = crosstalk anomolies on DSP Alt Tuning ) on VG-8, VG-88, VG-99, GR-55, GP-10   

cags12

Quote from: admsustainiac on January 22, 2018, 09:22:52 AM
Agreed - and Ive experienced similar phenomena ( Palm Muting hand on Piezo Hex PU  = crosstalk anomolies on DSP Alt Tuning ) on VG-8, VG-88, VG-99, GR-55, GP-10
Yeah, the Variax is also susceptible as reported on the L6 forum. However, the symptom is different to what ATG does (distortion). You know, totally different pitch shifting algorithms with different characteristics.

DLC86

#68
Last week I finally received a couple batteries for my ATG, 7.4V lithium for drones remote control that fit perfectly in the spring cavity with 2 hard tension springs.

For anyone using alternative batteries like this there's a simple workaround I just tested to make the ATG shut off at the correct voltage for the battery and to make it show the "low battery" signal on the LED: install a resistor in series with the battery.

I used this calculator to find the correct value but in the end I just used what I had at home (2x 8.2 ohm resistors in parallel =4.1 ohm). With these the ATG turns off when the battery reaches 5.7V.
I suggest using a value of at least 4.7 ohm to stay on the safe side and make it turn off at around 6V, this should avoid shortening your battery life.

PS: be sure to use at least 0.5W resistors

cags12

I am not very electronics savvy but are you sure there are no consequences of doing that hack? Perhaps, reduced battery life or heat emission?

DLC86

#70
Quote from: cags12 on February 09, 2018, 12:37:21 PM
I am not very electronics savvy but are you sure there are no consequences of doing that hack? Perhaps, reduced battery life or heat emission?
Yes battery life (intended as the duration of a single charge) will be a bit shortened, the resistor dissipates ~0.25W which means about 35mA at 7,4v. It's a little price to pay but at least you'll be sure you won't damage your battery by discharging it too much.

Heat is not a problem as long as you use a resistor with the proper wattage rating (1/2 watt is the double of what the calculator suggests). I touched it about half an hour after it was turned on and it was just a tad warm.
You can also use higher ratings and it will remain totally cold.

cags12

You should not have over-discharging issue with your battery as long as it has a BMS (protection circuit board). Although it is handy to have the indicator of low battery.

I was thinking myself on using RC control batteries BUT I would use only LI-ION ones for the Remote controllers and not the actual RC devices. Those ones are LIPO unprotected and pose a fire hazard. They use unprotected ones on the RC devices because they rather squeezing until the last drop of electrons out of the battery as long as their RC will not crash in free fall.

I strongly recommend you maybe using other batteries for safety.

cags12


DLC86

Sure if you have a protected battery there's no risk of overdischarging.
I bought this cuz it was the only one I found that fits perfectly in the spring cavity.
The one in your link is made of two 18650 and that would need an additional routing on the body (something I wanted to avoid).

Anyway these LiPo batteries have high discharge ratings so there should really be no chance for fire with a current of just 300mA if you carefully prevent the risk of shorts.

I'll probably install an external protection circuit anyway

DLC86

#74
A couple updates:

1) about the resistor discussed above, for some unknown reasons the ATG led signals low battery with only one of my two (identical) batteries. The only realistical reason I can think of is that the two batteries have a slightly different discharge curve and one drops off too quickly under the cut-off voltage of the ATG.

2) by reading a bit around the net I tracked the lack of low end issue I had with the piezo saddles to the impedance mismatch with atg board inputs.
I thought that a low input impedance would affect the high end (as it usually happens with magnetic pickups) but with piezos it works the opposite way.
The reason is that this phenomenon depends on the impedance curve of the source: a traditional mag pickup has low output impedance for lower frequencies and it gradually increases until it reaches the resonance peak (in the 2-5KHz range, depending on the type of pickup) and then decreases again for higher frequencies.

Piezo pickups instead have higher impedance at lower frequencies, so connecting them to a low impedance input is like having an high-pass filter (first resonance peak is well above 20KHz)

To solve this issue I'm planning to build a little buffer to install between the graphtech saddles and the atg input. I found THIS project that seems perfect for the purpose (obviously I'll need six of them).
I just hope it doesn't introduce too much noise.