Community: Message List - Looking for details on how Pre-Amp modeling parameters map to real Amp controls

Re: Looking for details on how Pre-Amp modeling parameters map to real Amp controls

support@line6.com — Wed, 19 Sep 2012 02:21:38 GMT

Hi all,

I feel a little cheeky posting here for the reasons

1. My abilities and knowledge probably place me in the bottom 0.05% of the worlds guitar owning popluation, and

2. Though I have a HD500 on the way, I have not as yet used any line 6 product.

However, as I have been researching my purchase for some weeks, this issue regarding what the inputs should be set to really is rather perplexing.

I have read many threads on this subject, and just when I think it is concluded, I note more questions or uncertainty on the subject. Of course it would make some sense to test this for myself once my unit arrives, BUT, I am really really really confused why Line 6 have not commented to clarify this issue.

It seems to make some sense that certain settings might essentially 'recombine' a single signal such that any slight variance would result in a slightly out of phase signal (seemingly explaining the reduced clarity or unrequired distortion/phasing that some users seem to report). I am also aware (though I cant recall enough to quote) that the user manual does provide adivice regarding the signal level in these situations.

It seems odd though, that a number of those commenting seem to find a night and day difference in certain situations. If this is the case, surely a more comprehensive, yet understandable explanation of the impact of these options really should be provided. As someone else has mentioned before, how many people are likely to be sufficiently unclear in this regard that they are ignorantly producing sounds that are of a lower quality that the unit is capable of. And I inlcude people who have taken time to read the manual.

I guess I am particulary concerned because I have no real point of reference (I would hope my 80's and 90's budget pedals would be surpassed by a poorly set up HD) so I would be aghast if I found out after some long term ownership, that I had been playing, in effect, a 'crippled' product. This may seem a tad harsh (it is quite possible that I will be impressed with the unit even if I were experiencing this problem) but the whole raison d'etre of this product is its sonic capabilities. As such, whilst it may be a 'set up' issue, I am in some disbelief that the 'out of the box' set up, does not take this issue into account.!?!?!

Re: Looking for details on how Pre-Amp modeling parameters map to real Amp controls

support@line6.com — Tue, 18 Sep 2012 14:43:15 GMT

to be honest, i've never analyzed it like that. I'm actually a bit confused about that issue still to this day. Sometimes when I do a test to try to determine why I prefer Input 2: Variax, I can't hear any difference. But for some patches it's clearly different. I A/B'ed at least a dozen patches and always preferred the Input 2: Variax one over same.

To my ear, it's not simply a levels issue. There is a phasing to the sound that makes it slightly fake sounding - that's my issue.

Now, it might be that the levels are what creates the issue. IE - when I run a Distortion effect early in my chain with 0% Drive, the tone is different due to the levels - with Input 2: Same I'm getting a slight distortion whereas with Input 2: Variax I'm not.

I'll make this a priority to research, as it still confuses me to this day.

Re: Looking for details on how Pre-Amp modeling parameters map to real Amp controls

support@line6.com — Mon, 17 Sep 2012 22:17:12 GMT

Thanks for the advice, will check whether this tool or something similar runs on OS-X.

Do you think my 3dB guess on how much difference there is between an Input 2 setting of 'Same' versus selecting another source with nothing connected is about right or do you have a different experience (you must have played with this for quite some time to get to the bottom of it and change your mind on what 'Same' does)?

By the way, really appreciate your guide, it's a treasure troove. Too bad Line 6 is so skimpy about informortion on how it actually works or what they exactly modelled. I'd prefer the possibly nasty truth and work with it rather than guessing.

Martin

Re: Looking for details on how Pre-Amp modeling parameters map to real Amp controls

support@line6.com — Mon, 17 Sep 2012 16:05:12 GMT

hey Martin,

I wish I could be more helpful, but my advice is to download Voxengo Span, which is a frequency analyzer. You can set it to smooth the frequencies a lot and tweak lots of other options, so it shows you a nice smooth, flat line when you run white noise through it. I download a white noise clip, set it to repeat on my iphone and run that into the Aux jack of the Pod, then mess with stuff in HD Edit and see how it affects the frequency response.

Span is a VST plugin, but you can run it basically as a standalone software using the VSThost program, which a google search will quickly find for you.

Re: Looking for details on how Pre-Amp modeling parameters map to real Amp controls

support@line6.com — Mon, 17 Sep 2012 03:27:26 GMT

I did a little more related checking and tried the Blackface 'Lux Vibrato channel comparing it to the Lux's Normal preamp model. I have to set the Studio EQ's gain up by about 16 dB to match the output volume (also have a Studio EQ in front of the Normal channel with 0 gain) for the Normal model to exclude any effect the EQ causes just by itsellf. This does not quite add up to what I read about how the real Amp works unless the model assumes the guitar is plugged into the second input (which is supposed to add 6 dB gain) and the Vibrato channel adds another 10 dB when comapared to the Normal channel. 10 dB seems rather high. The Line 6 Model gallery just states that the Normal channel has 'less brightness and gain'. Do any (previous) owners or other experienced players can shed some light on this?

A little off topic, but does anybody know how much gain difference there is between setting Input 2 Source to Same versus Aux, or Mic. I can't set it to Variax as my guitar is a Variax. I read before in some other threads that setting it to Same should add about 6 dB. Seems this does not make sense considering that the summing of 2 same channels may get you 3 dB (double the power) but not 6 dB. Anybody out there having done some real measurements or other comparisons?

... and in regard to dB measurement or digital clipping detection: Is there a good way to visualize this with a stand-alone SW tool?

Regards,

Martin

Re: Looking for details on how Pre-Amp modeling parameters map to real Amp controls

support@line6.com — Thu, 10 May 2012 22:27:10 GMT

You can address the +6 db boost by choosing input 2 option as "same". Thus, the signal is increased around that value. However, you would have that increment for the effects located at pre-position too.

Best Regards,

Daf

Alternatively leave the inputs as they are and place a studio EQ immediately before the Amp with the gain boosted by 6dB.

Re: Looking for details on how Pre-Amp modeling parameters map to real Amp controls

support@line6.com — Thu, 10 May 2012 17:04:29 GMT

Thanks for the replies. Would be nice if someone from Line 6 could confirm that PRESENCE should be set to 0% on HD500 if the amp knob control does not exist on the real amp and one tries to emulate real amp behavior

Hi Martin, I am afraid that no one from line 6 is going to answer this thread, as it is not marked as a question (although technical support service has changed a time ago, it seems that they keep answering these threads). You can make a call directly to Line 6 in order to ask for this kind of information (which does not mean that you would get it for sure)

Appreciate the nice reference to the Pod XT manual, which may apply to HD500 as well (I did read though that the HD series was developed by a new Line 6 team)).

Actually, It may and may not apply. There is no information about it anywhere.

Nevertheless, it would be helpful if Line 6 would offer a couple more details and guidelines on how model controls match/emulate the real amp controls. The existing one-pagers do not explain much.

Yeah, I agree with you, specially if you are accustomed to use the real amps.

For example, they could suggest ways of how to best address the +6 db boost (i.e., a compression effect setting) and the bright switch (a range of presence settings or an EQ effect) for the Fender Twin reverb / Blackface Dbl.

You can address the +6 db boost by choosing input 2 option as "same". Thus, the signal is increased around that value. However, you would have that increment for the effects located at pre-position too.

Best Regards,

Daf

Re: Looking for details on how Pre-Amp modeling parameters map to real Amp controls

support@line6.com — Thu, 10 May 2012 15:07:26 GMT

Thanks for the replies. Would be nice if someone from Line 6 could confirm that PRESENCE should be set to 0% on HD500 if the amp knob control does not exist on the real amp and one tries to emulate real amp behavior (Appreciate the nice reference to the Pod XT manual, which may apply to HD500 as well (I did read though that the HD series was developed by a new Line 6 team)).

I understand that one cannot expect precise matching of model and real amp controls. ... and that would not even make sense as different (aged and used) amps could be quite different anyway. Nevertheless, it would be helpful if Line 6 would offer a couple more details and guidelines on how model controls match/emulate the real amp controls. The existing one-pagers do not explain much. For example, they could suggest ways of how to best address the +6 db boost (i.e., a compression effect setting) and the bright switch (a range of presence settings or an EQ effect) for the Fender Twin reverb / Blackface Dbl. I am sure there are many other details on the other amps that are modeled.

Clearly this is a bigger issue for players who do not have access to vintage gear and have not used or at least heard it for hours in live settings. If you already know what tone you are exactly looking for this may not be easy, but at least there is less doubting of what it should be. In my opinion, using recordings as only guide can be quite miss-leading unless you are into direct guitar recording anyway.

Re: Looking for details on how Pre-Amp modeling parameters map to real Amp controls

support@line6.com — Wed, 09 May 2012 02:17:28 GMT

In regard to the example you gave (fender twin reverb 65 amp), I do not think that you can have the modeled amp (pod hd 500 + dt 25) working the same way like the real amp does. Do not get me wrong, because in spite of that, you can emulate the same sound (at least, according to my ears).

For example, in the real amp, If the group of tone controls is turned fully counter-clockwise, there will be no sound coming from that channel. The real amp has in both channels a trebble booster switch (bright switch) which is intended to replace the presence control of the earlier versions, and it boosts the high frequency range by a fixed amount, and that amount depens on the volume level. I guess also that the volume in the real amp is a global control, affecting both the gain and the output level. And there are two inputs per channel, input 1 provides a +6 db boost (and a different input impedance value), which is very nice to get a nice dirty blues sound.

Anyway, as I said before, I have been able to get the same sound with my POD HD 500. I have not probe it yet pairing with my new DT 25 combo, but I am quite sure that it will work as nice as alone.

Best Regards,

Daf

Re: Looking for details on how Pre-Amp modeling parameters map to real Amp controls

support@line6.com — Tue, 08 May 2012 22:34:24 GMT

you can find some description (not 100% complete) in the manual of the old POD XT ..

some models are inspired by the same amps..

if presence control does not exist on the real amp should be set to 0% to reflect the real thing..

bass mid and treble if don't exist on the real amp should be set to 50% to reflect, the real thing..

but sometimes you may want more flexibility, and then also use the additional controls to better shape your sound..

on google you can easily find pictures of real amps and see what controls are actually present on each amp..