Tone loss turning guitar volume down

[Pahako]

I am new to the pod go and have previously used  individual pedals. I use my volume knob a lot in my playing style and frequently play with it turned down some for my main sound, and crank it up if I need more for a solo. All my guitars either have a treble bleed or 50’s wiring so I don’t loose tone when I back off the volume knob. With the pod go I loose all the tone when I back of the volume knob. If I back off on the volume pedal I don’t loose the tone, but for me that is not nearly as efficient as using my volume knob. I am wondering if there is a “workaround “ for this or if that’s just the way it is with these pedals. Other than that it does everything I need it to do. Thanks

[voxman55]

Three suggestions. First, ensure your noise Gate is switched off. Second, place a buffered pedal in front of Pod Go. A buffer will help retain signal strength and the top end. Any Boss pedal will be buffered ... even with the pedal switched off. Third, if you go wireless with a Line 6 G10 Relay the G10 will act the same as a buffered pedal. 

 

[ElecTech]

LINE 6 PodGo Treble Loss @ Guitar Input

The problem with the treble loss at the input jack is that Line 6 connected a 1000pF (.001uF) cap (C124) from tip to ground at the input jack. This combined with your pickup's impedance and the series resistance introduced to the signal when you turn down your guitar volume creates a filter that cuts off the treble at a frequency that drops as the impedance (resistance) is increased. So the more you turn the volume down the more treble is cut off. 
But it's not just the Input jack, the same thing happens on the effects returns, only on those inputs there are TWO .001uF caps to ground, or 2000pF from each return (L/R) to ground. If you want to run a standard volume pedal within the loop, which is something I have always liked doing, the treble drop is even more severe than at the guitar input jack. The part that bothers me is: No other pedal in the Pod or Helix line has this kind of heavy filtering on its inputs. I would love to hear from Line 6 as to why they felt it was necessary to employ brute-force filtering on this model and not on any others. Was it a band-aid to a poor design in order to keep interference from the processor clocks at acceptable levels? Was is an engineering error, where they meant to spec 10pF caps and instead spec'd 1000pF? As a technician and a guitarist who owns a PodGo, I would love to get a real answer to this, as well as to what might happen if I remove these caps from my unit, besides voiding my non-existent warranty.  

The offending treble cut caps are: 

Guitar Input:  C124 (.001uF/1nF/1000pF)
Effects Return 1: [Tip] C121 & C135  (.001uF) 
Effects Return 2: [Ring] C110 & C129 (.001uF)

[wagdog]

On 12/16/2022 at 5:13 PM, ElecTech said:

LINE 6 PodGo Treble Loss @ Guitar Input

The problem with the treble loss at the input jack is that Line 6 connected a 1000pF (.001uF) cap (C124) from tip to ground at the input jack. This combined with your pickup's impedance and the series resistance introduced to the signal when you turn down your guitar volume creates a filter that cuts off the treble at a frequency that drops as the impedance (resistance) is increased. So the more you turn the volume down the more treble is cut off. 
But it's not just the Input jack, the same thing happens on the effects returns, only on those inputs there are TWO .001uF caps to ground, or 2000pF from each return (L/R) to ground. If you want to run a standard volume pedal within the loop, which is something I have always liked doing, the treble drop is even more severe than at the guitar input jack. The part that bothers me is: No other pedal in the Pod or Helix line has this kind of heavy filtering on its inputs. I would love to hear from Line 6 as to why they felt it was necessary to employ brute-force filtering on this model and not on any others. Was it a band-aid to a poor design in order to keep interference from the processor clocks at acceptable levels? Was is an engineering error, where they meant to spec 10pF caps and instead spec'd 1000pF? As a technician and a guitarist who owns a PodGo, I would love to get a real answer to this, as well as to what might happen if I remove these caps from my unit, besides voiding my non-existent warranty.  

The offending treble cut caps are: 

Guitar Input:  C124 (.001uF/1nF/1000pF)
Effects Return 1: [Tip] C121 & C135  (.001uF) 
Effects Return 2: [Ring] C110 & C129 (.001uF)

Fwiw, removing C124 clears up the input jack - it was like taking a wet blanket off the sound. I wasn’t aware of the effects return having the same issue as I don’t use it. I have not noticed anything detrimental occurring from removing that cap. I can’t comment on the effect return.

 

It would be nice if L6 was more transparent on the issue. I will say that removing C124 was like taking a wet blanket off the POD Go. I’m using it for the effects only into a squeaky clean fender quad reverb and it sounds great now.

[ElecTech]

wagdog - You're welcome. ;) 

 

[wagdog]

On 12/22/2022 at 11:55 AM, ElecTech said:

wagdog - You're welcome. ;) 

 

In your opinion, am I correct in assuming that if I don’t use the effect loop that the offending caps will have no effect?

 

 

[ElecTech]

On 12/22/2022 at 11:38 AM, wagdog said:

In your opinion, am I correct in assuming that if I don’t use the effect loop that the offending caps will have no effect?

 

 

Correct - there is no loop issue for "normal" loop users, or those who do not use the loop at all. But the published 1M loop return impedance is only true for DC measurements. For any audio frequency (AC) the input impedance will drop as the freq is increased. At 800Hz the effective input impedance of the effects return is ~100K Ohms. Still high enough for most effects units, but 10 times lower than the published spec.. At 80 Hz the return impedance will be ~500K Ohms. At 2KHz the input impedance will be ~40K Ohms. At 5Khz it will be ~16K Ohms. A 10:1 impedance ratio is considered the minimum for modern connections, so @ 5Khz the output impedance driving the effects return must be 1.6K or less. But at 10KHz this figure is halved again: 8K:800 Ohms. A far cry from the published 1M Ohm spec. 
This is exactly what is happening on the Guitar input also, but the impedance figures are double because the capacitance is half as much. I don't know how the 360K Ohms @ 1KHz figure was measured, but personally I think it is optimistic. My calculations, derived from the values published in the Pod Go schematic, put it @ ~137K Ohms.    
  

[espechemode]

ElecTech, is it advisable to remove those caps from the fx loop? I have this Victory Kraken preamp pedal that I tried using in the loop of the POD Go and it absolutely trashed the tone of the pedal. Compared to running the Kraken direct into my power amp, the fx loop of the POD Go removes tons of high end and dulls the tone. It’s a night and day difference. Would removing the offending caps fix that? L6 already did the input impedance mod on my unit. Thanks for the help 

[arcanjil]

Anyone know if the BOSS JB-2 (BOSS BD-2 and JHS Angry Charlie) pedal is buffered or not?  I'd like to get one to use, but would like to know if it will stop the treble drop.

 

Thanks

[silverhead]

On 11/17/2023 at 12:54 PM, arcanjil said:

Anyone know if the BOSS JB-2 (BOSS BD-2 and JHS Angry Charlie) pedal is buffered or not?  I'd like to get one to use, but would like to know if it will stop the treble drop.

 

Thanks

Why not just get your POD Go fixed? Open a support ticket. It will be repaired at no cost under lifetime warranty for this issue.

[hevimental]

Yesterday I had a similar problem twice during band rehearsal. After turning the guitar down with the potentiometer and turning it up again, there was no sound at the output. He had to re-insert the cable that went to the mixer to get the sound back. This problem did not occur on the previous software.
 

[voxman55]

On 11/17/2023 at 6:58 PM, hevimental said:

Yesterday I had a similar problem twice during band rehearsal. After turning the guitar down with the potentiometer and turning it up again, there was no sound at the output. He had to re-insert the cable that went to the mixer to get the sound back. This problem did not occur on the previous software.
 

When upgrading firmware, did you reset back to factory as recommended by Line 6?  (backing up patches first, of course, to re-import).  This is essential to get rid of any code 'remnants' from previous firmware versions that can cause odd behaviours (think of it as a 'clean install' when upgrading a PC's operating system)

[arcanjil]

Got my RMA from LIne6 to return my PG for fixin'.

 

Gotta say, the response from Line6 was quick and friendly.  I hope the turn around is quick, too.  I miss things when they are away, LOL.

[trainguy]

I was told there would be no math...