Community: Message List

Re: DT 2.0!

support@line6.com — Thu, 08 Nov 2012 16:45:55 GMT

Hi Zap,

Perhaps they can implement something similar to what the audio routing through USB does in the POD HD 500 for example. Anyway, I am not a Line 6 developer, so it is just a guess. But a more feasible guess is that I think MIDI control of new amp parameters through L6 Link would be available in the future, as it is already possible.

I am thinking of buying a second DT 25 amp, but due to the more options (mainly the boost) available for the DT 50, I do not know what I should buy. Could you please (or maybe another forum member) explain what the feedback capacitor type and phase inverter B+ do in the tone? I am not familiarized with those concepts, and I am wondering if they are already implemented inside the DT 25 amp, but are not configurable. I know the DT 25 does not have the inverter tube, but with this new software release I would like to come back to the old days when you have an amp an several stomp boxes in fron of you!!! But with the difference that you actually have not an amp, but an amp factory!!!! sweet!!!!

Best Regards,

Daf

Re: HD500 FX Loop ... level drop or not?

support@line6.com — Tue, 06 Nov 2012 19:58:22 GMT

MartinDorr escribió:

The simplest explanation I could come up with was that
The Input 2 setting of Same causes a -4dB change in the HD internal signal level sent out of the effects loop
The Input 2 setting of None (Variax, Mic, Aux not connected) case a change of -10dB for the above (at least when you come in via Guitar as Input 1).
The Mixer adds +5.7dB even when set at 0dB (at least for the no Amp use case).
The effects loop in or out of the path causes a level change of 0.15dB (I found the same effect with the Studio EQ)
This seems to be the simplest explanation, but that does not make it necessarily right.

I have no time to check anything for a while but thought of doing a little experiment using a Studio EQ in front of the Mixer with gain +4 or +10dB to make up for the suspected drop on the input. If the 0dB Mixer setting really causes +6dB gain on the mixer (or if the input did not get lowered and the Studio EQ gain will exceed 0dB) we should see clipping on the output (or more than 0dB output). Now if the Studio EQ caused the clipping we should see the output to come down -6dB if we pull the mixer down -6dB. On the other hand if the mixer caused the clipping (because it really added 6dB gain on the 0 setting) we should see the output not come down (or not below 0) if we pull the mixer down -6dB because the Studio EQ will drive 0dB to the mixer.

I can't do Karl's experiment setup due to lack of equipment. But I can come in with a Variax on the digital input and check output via USB. From the past I already know that for a specific guitar model I will have -10.7dB out with a pre Mixer Studio EQ and a post Mixer Studio EQ, no amp and mixer set at 0dB. Hope that works out and we can determine whether the 0dB mixer setting is really something else ... or we have more puzzles .

The test you proposed is very interesting. Mainly, due to the fact that the output level through USB is not affected by the master volume knob, as opposed to the 1/4" outputs. That is why it should not be very important the "number" measured at the 1/4" output in Karl's experiments (as it should be affected by the master volume position). But what I have found to be very interesting in Karl and Jimsreynolds experiments is the "tendency".

In fact, I have a question: the stomp level is an instrument level (i. e. -10 dB) and line level is +4 dB for the FX loop send? If so, it will explain the FX loop behaviour we have found here.

Best Regards,

Daf

Re: HD500 FX Loop ... level drop or not?

support@line6.com — Tue, 06 Nov 2012 16:55:07 GMT

meambobbo escribió:

my tests show the FX Loop created a 40 sample or ~42 ms latency in whatever channel it was placed in.

it's important to note that two audio signals can be out-of-sync, whereas two specific frequencies can be out-of-phase. When two identical, or near identical, signals are out-of-sync, some frequencies will be in phase, while most will be out-of-phase, to varying degrees.

and I have also noticed there is a difference in the way the loop works when before an amp model vs. behind one. I find it adds much more noise in "pre" than "post" regardless of the levels fed into it.

Hi MeamBobbo, thank you very much for your clarification. As you have pointed out, the proper term in this case should be "sycn" rather than "phase", as we have a group of waves rather than a single one. In fact, what you have described is the explanation of the "comb filtering" effect. Anyway, what I said should still apply, because when input 2 is set to "same", you have exactly the same group of waves going for the two inputs in the performed experiment.

I have to say that I am not an audio engineer and I am not familiarized with the "sample rate" concept for example (but I would like to!!! ), everything that I said is based on physics, so I might be missing something. I would expect always some degree of latency unless we have unlimited power processing capabilities. Of course, my words are not God's words, and I could be wrong!!!!

Best Regards,

Daf

Re: HD500 FX Loop ... level drop or not?

support@line6.com — Tue, 06 Nov 2012 04:47:28 GMT

MartinDorr escribió:

- The difference of 6dB between Guitar/Same and Guitar/Variax seems to indicate 2 summing operations, i.e., adding the input signal 4 times. A single summing of 2 signals with the same level should only get you 3dB.

Hi Martin. This is not necessarily true, as it depends on the "coherency" of the signals. Well, that is true only if you have two incoherent signals. But if you have two coherent signals (the same frequency), then you should consider also a "phase" term , which should be the case when you have input 2 as "same". And if there is no "delay" between those two signals (known as "constructive interference"), then the sum would bring a 6 db increase, due to the "phase" term. This increase has been proved before by another forum member (maybe MeamBobbo or Hurghanico?). Anyway, I think Meambobbo believes that the phase is other than 0°.

Another thing to consider. Summing two acoustic signals could be different than summing two electric signals. If you sum two signals based on its amplitudes, then you would have around a 6 dB increase, but if you sum two signals based on its power quantities, you would have around a 3 dB increase. What does the POD do?

Best Regards,

Daf

Re: HD500 FX Loop ... level drop or not?

support@line6.com — Tue, 06 Nov 2012 05:23:15 GMT

Karl_Houseknecht escribió:

But my results show that there's a 2 dB boost at the FX Send jack if the Loop is after the mixer and the mixer is at 0dB. Are we saying that the mixer somehow adds 6dB of of boost even when it's at 0? That doesn't really make any sense.

I'm not sure what we've found here, bug or whatever else, but it isn't very consistent, is it?

This is something I would expect due to the way the experiment has been carried out. Anyway theory is one thing and practice could be another one.

I am not sure about what you have found here (I mean, if it is a bug or not). Today I suspect that the 4 dB decrease at the FX loop send jack is intentional, as the FX loop send level is additionally affected by the level switch (line Vs stomp). I guess your tests were done at stomp level maybe?

There is something very funny to me: In spite of the fact that there is a level difference at the FX loop send jack by placing the FX loop effect before or after the mixer (which can be explained according to the concepts of "monosizing a stereo signal" and "summing two signals"), the POD HD device seems to be smart enough to know that, so that you always got the same signal level at the 1/4" output jack, no matter if the FX loop effect was placed before or after the mixer!!!

Best Regards,

Daf

Re: HD500 FX Loop ... level drop or not?

support@line6.com — Fri, 02 Nov 2012 04:38:58 GMT

Karl_Houseknecht escribió:

Well, that depends on the configuration. Note that the one that gets you closest actually has a 2dB BOOST at the effects send. Not a drop.

No Karl, from your results you would always have a 4 db drop in the signal at the FX send jack (i. e. you should have a 6 db boost, not 2 db as the signal is supposed to be doubled by the mixer). The interesting thing is that the FX send level is at 0 db. Would you believe it is due to a physical impedance mismatch at the jack? Have we discovered a bug?

Best Regards,

Daf

Re: HD500 FX Loop ... level drop or not?

support@line6.com — Thu, 01 Nov 2012 18:43:48 GMT

Very interesting Karl, thank you and Jim for the time and effort at doing these tests. So, it seems that the sound drop is located at the FX loop send jack by 4 db, even if the send level is at 0 db?

Re: Question: what does the processing in a Pod HD 500 / DT-50 combination?

support@line6.com — Thu, 01 Nov 2012 16:35:32 GMT

greghall escribió:

dscheidt wrote:

With the new firmware for the DT-50, is the amp modelling offloaded to the amp? That would be SUPER cool, then the HD could just be used for effects.

Actually, I think you can do this with the new firmware, provided you use a no amp patch, or you switch off the amp model in the HD patch. The drawback is that all effects are then in the 'pre' position (except perhaps reverb, which you can now set on the DT). Very super cool :-)

Or, you can use the 4CM and control the amp through MIDI commands from the HD 500 (requires additional midi connections). It sounds really cool!!!

Re: HD500 FX Loop ... level drop or not?

support@line6.com — Thu, 01 Nov 2012 15:24:45 GMT

Yes Karl, but in Jimsreynolds' test, there is a patch cable placed between FX send and FX Left (only) return, so that the output is the 1/4" left out.

It is quite interesting your results in comparisson to Jim's ones, as one can conclude that the sound drop only takes place when the signal is returning again to the POD.

Another interesting thing to me: According to Jim's results (post #3) at first set of test, and I guess that Jim has the FX loop placed before the path split (which is not clear), one should expect a sound drop in all cases, when comparing FX loop on Vs FX loop off, but it is not the case. It only applies when Pan A and Pan B are at center position.

Best Regards,

Daf

Re: si tengo mi pod hd 500 conectado a la corriente y se va la corriente, corro el riesgo de que se da;e? ya que no tiene conmutador de encendido y apagado

support@line6.com — Thu, 25 Oct 2012 22:07:47 GMT

Que tal, bienvenido al foro!!!

No soy experto electrónico, pero te diria que, como sucede con los aparatos electrónicos de hoy, pueden presentarse problemas cuando hay variaciones de voltaje. Ademas, puede que no se dañe inmediatamente el equipo, pero seguro se acorta su tiempo de vida util. De todas formas, supongo que estos equipos deben tener algun fusible que proteja la motherboard y los procesadores de las subidas de voltaje.

Procura utilizar buenos estabilizadores de voltaje, algunos tienen la capacidad de compensar los bajones de energia (hasta 85 V) y suprimir los picos. Es lo mejor.

Saludos,

Daf