Channel Volume Vs Master Volume
Posted 03 December 2013 - 11:14 PM
Does the situation change with the pod hd500 via line6 link? And with the new master on the pod with the update?
Posted 04 December 2013 - 08:25 AM
Posted 04 December 2013 - 08:46 AM
Otherwise, whats the point to using an attenuator if you can just turn it down and preserve the driven tube sound?
Posted 04 December 2013 - 10:17 PM
Stumblin is correct, one point to clarify is that the preamp on the DT is a model (instead of a traditional tube preamp) and you will still need to "balance" the tone between the two channels. I personally run the "clean" channel volume at 95-100%, that way I can balance it against a high gain tone that may only be 60% (but equal volume to the clean tone).
When you add a POD HD via L6 Link the POD becomes the "preamp" as well as the effects, so all of your tone balancing will need to happen there. The nice part about that is you can still walk over to the amp anp move dials and it "talks" to the POD, once you have a sound you like you can hit save on the POD HD for later use.
Posted 05 December 2013 - 12:18 AM
Posted 05 December 2013 - 05:04 AM
Let me get this straight... turning down the Channel Volume (and the master on the pod) attenuates the signal between the preamp and the poweramp?
And the Master on the amp attenuates the poweramp?
So, as long as I have no poweramp distortion, turning the channel volume down and the master up, or turning the channel up and the master down will have no difference at all (apart from the noise floor?)? ie, lots of amplification of a small signal, or little amplification of a hot signal should produce the same output as long as the poweramp does not distort?
If that's correct, then what factors drive the poweramp into distortion?
Posted 05 December 2013 - 06:28 AM
The short answer is the master volume determines power amp distortion
The pre-amp is a digital model - so the channel gain determines how distorted the tone going into the power amp sounds. The channel volume simply increases the volume of that tone rather than increasing the distortion.
At lower master volume settings, the power amp tubes don't distort the tone more - they simply make the pre-amp tone louder. At higher master volume settings, the tubes start to add distortion. If the level of the channel volume is set high, the tubes will start to distort at the lower master volume setting, so it's generally a case of playing around with the gain, channel volume and master volume to find what sounds best to you.
I tend to set the master high, around 75%, the gain around 40% and the channel volume around 50% when playing live (mic'd through the pa - I'm using pedals in front of the amp now, instead of the PODHD). For home use I just turn down the channel volume to about 30% then adjust the master to get the volume I want.
Hope that helps
Posted 05 December 2013 - 06:52 AM
"At higher master volume settings, the tubes start to add distortion."
But I don't think this is strictly true, is it?
If I turn the master up to the point where I start to hear power amp distortion, and then reduce the channel volume, the power amp is not receiving the same level of signal that it was. So it'll not distort either, right? I'd need to turn it up even more to get power amp distortion again? Which would be at the same overall volume level again?
If I understand right (which i probably don't, since I started this thread), you meant to say "at higher _volume levels_, the tubes start to add distortion"..
Is that more correct? Which is why the attenuator is desired...to keep the power amp distortion but attenuate the volume afterwards.
If I'm on the right track, then the way to get power amp distortion at the lowest volume level possible is to dime the channel volume to give the hottest signal into the power amp, which then will distort at a lower volume level than if I fed it a cooler signal..?
If I'm wrong somewhere here I'd be very grateful for a correction! I think I'm still leaning towards there not being a difference.. I wish I had an attenuator so I could really crank it and see..
Posted 05 December 2013 - 07:03 AM
Simply put, the master volume is the volume control for the power section, and the channel volume is the volume control for the preamp section. I don't think you should try to over-think it too much. It probably is possible to set the master high enough where you get some actual power amp distortion, but I've not ever had my DT-25 loud enough to get to that point. I think these power sections are designed so they have quite a bit of headroom. Even in in triode mode, I don't know that I've really gotten true power amp distortion. I can tell that it's more compressed in that mode with the master volume higher, though.
Posted 05 December 2013 - 07:42 AM
Maybe its time for an iso cab or attenuator
Posted 05 December 2013 - 08:25 AM
So there is no exact setting/threshold for the Master that will begin power amp distortion.
You can cause that power amp to overdrive at lower Master settings if you send a very hot signal to it or you can have a higher Master setting with no power amp drive if you keep the preamp stage low enough to not cross that threshold. That threshold is a variable depending on the settings of the two parameters...preamp output...and...power amp level.
For home use I would create presets that let modeled power amp distortion come into play (use full models) because the DT amps need to be outputting extreme volume to give up power amp drive.
Posted 05 December 2013 - 10:44 AM
I think the best way to understand this is to understand the purpose of each knob, what it does and how all the pieces fit together to generate the final sound we hear.
Channel Volume - controls amp block signal output within the preamp.
- use the Channel Volume to level outputs between various amp models within your setup. Set your quietest amps full up and balance your high gain amps against that by lowering it.
POD Master - controls preamp signal output to the power amp.
- use the POD Master to vary the signal sent to the Power Amp. It is a modeled signal and cannot be distorted by turning it up. Any distortion in the signal is generated by the blocks within the preamp section and will be sent as is, softer or louder to the Power Amp.
DT Master - controls power amp output.
- use the DT Master to vary the current sent to the Power Amp tubes, hence the strength of the final signal applied to the speakers. As stated earlier, final volume is generated by a combination of preamp signal (modulated audio to be amplified) and power amp current (the "horsepower" that does the amplification). These two have to combine to provide the final signal to drive the speakers.
You can either go low POD Master, high DT master or vice versa. Either way remember, your tone is really being generated in the digitally modeled preamp signal. You are feeding the exact same signal to the power amp at low settings or high settings. What does change is the current being applied to the tubes by the DT master. With the DT turned up, the tubes have the POTENTIAL for higher output based on the applied preamp signal. This is where "headroom" comes from, the ability to handle transients, pick attack, stuff like that when fed with a lower preamp signal. If the DT master is low with a strong POD feed, there is little reserve to feed those transients. Personaly, I prefer the high DT Master, with a varied POD Master and I am very glad they gave us this option.
As for Power Amp distortion, I agree with the previous posters that it is unlikely to occur at levels we would be willing to play at home! That takes both the strong DT current to the tubes and a strong preamp signal working together to "overload" the tubes capabilities to respond cleanly. The final piece we don't seem to mention is speaker cone breakup which is an essential element of high volume guitar sound and only comes with volume and use. Thankfully, some of that is modeled into the signal within the preamp.
This is the best way I have found to understand how these pieces all fit together and how to use it. Please feel free to correct me if I have it wrong somewhere... Have fun with it!
PS - LVM is only used for the DT by itself! It switches the INTERNAL preamp section from Pre models to Full models in anticipation of your lower DT master levels. It really is no use to you with the POD because you have full control of the modeling yourself within your patch and it will not be adjusted by the LVM switch.
Posted 06 June 2014 - 02:00 AM
We were setting up my sound on stage before our show and the sound guy yelled at me for having the master volume on my HD500x higher than my master volume on my DT50. He said i would compress the tubes if I have it set like that. From what i have read on this thread this isn't true? Now im kind of confused and hoping someone can clear it up because It sounds like you guys know what you are talking about. Basically I'm wondering if it will hurt my amp having the master volume on the HD500x higher than the Master volume on the DT50, Thanks!
Posted 06 June 2014 - 04:44 AM
We were setting up my sound on stage before our show and the sound guy yelled at me for having the master volume on my HD500x higher than my master volume on my DT50. He said i would compress the tubes if I have it set like that. From what i have read on this thread this isn't true? Now im kind of confused and hoping someone can clear it up because It sounds like you guys know what you are talking about. Basically I'm wondering if it will hurt my amp having the master volume on the HD500x higher than the Master volume on the DT50, Thanks
Won't hurt anything. Yeah we beat the hell out of this topic a while back and basically they both do the same thing. I don't think it matters either way. If you think about it, before the firmware update, the POD was on full blast all the time and you had to use the DT Master to adjust so I don't think the sound guy really knows what he is talking about...