MartinDorr

Curious on why you'd need this if you own an HD (unless you want to use the DT w/o the HD)? Enjoy reading your posts ;-)

I make sure my signal level peaks between models do not exceed -12dBFS for anything clean.

Recommend to use digital outputs for metering (you avoid the calibration issues and the unknown of when the analog signal indicates peaks or clipping in the HD's digital domain). I ocasionally use a free demo version of a stand-alone audio metering software on the MAC. There must be something similar for the PC. I have not found a simple clipping indicator software package. Also came to the conclusion that clipping is not that important to look for because you can usually hear it (even before it comes close to really clip). My rules are that no internal HD signal path must exceed -12dBFS peak if you want to stay away from compression / soft clipping. Somewhere between -6dBFS and -3dBFS peaks I always find distortion produced by any HD model I ever checked closely (all preamps and a few EQs, compressors, and boost effects). That said, there is nothing wrong if you like the effect a model produces when it gets close to clipping. And, for optimal signal strength and SNR keep the peaks just below your self-imposed limit.

Confirming radatats. If you did not change the DT default programs you get Spring reverb added to the signal sent from the HD. You can change the default reverb type for each of the DT program slots via MIDI (selected by type for each path; only path A is usable for L6 Link signals from an HD).

I am in the same corner as radatats. If I only use the DT's power amp section (either by going into the DT's effect return or by turning the preamp in the HD off and bypassing the DT preamp) I feel there is little sound difference from changing the DT master volume between 50% and 100%. I am not saying there is none. It's just far less than what I expected to hear. I did a quick and dirty experiment a while back and sent a test tone into the DT power amp section and then measured the difference between peak and RMS levels with the idea that the difference between peak and RMS levels would be an indicator of how the power amp adds 'distortion/compression' or other tube amplifier artifacts. If I remember right I saw the difference shrink as I went from 50% to 75% (good: the tubes are doing something to the tone), but then the difference got a big bigger as I went higher on the master volume. My conclusion was that I get the most out of the power amp tube tone effect at around 3 o'clock DT25 master volume. Have not changed it since. I use CHAN VOL to keep my peak modelling signal in the HD at a healthy strong level just below -12dBFS peak and HD Master volume to adjust to room/venue. Decided against an attenuator after reading on the forum that they negatively mess with post amp effects like reverb, phasing, etc. Martin

Unrelated, but possible ... your tubes may show signs of aging or failing.

Reverb is emulating what a room does to the signal coming out of your speaker. Modelled reverb amplified by a guitar amp and coming out of a guitar speaker system is not 'really' what a room does and the high-end frequency response is lacking when compared to the real thing (or what a Pod sends to its outputs in Studio direct mode). It's a compromise as you noticed and for some reverb models it works better than for others. This is my current personal view, and it may be wrong or only half true. Others may have more or better info or insight. Martin

Can't comment on how the DT50 behaves, but on the DT25 you can tap into some hidden 'features' using a dual amp tone where path A selects the DT power amp and is muted in mixer while path B has the effects and amp model. See my attached PDF for details on the DT25. It may be useful for the DT50 as well, but I suspect the power amp section behaves differently at least for some amp configurations. It's important to realize that the preamp selection in the HD has impact on DT power amp behavior even if Type/Class/Tube configuration seem to be the same (on the surface). DT25 Power Amp Parameters.pdf

Have not tried, but I believe there is another option if you limit yourself to one or a few DT amp configurations you run together with the accoustic amp: You should be able to place the A/B switch into the DT effects loop as A looping back and output B to the accoustic amp. The limitation comes into play because the DT power amp configuration can vary up to 19dB volume wise and if you'd balance by adjusting HD signal level your accoustic amp won't be able to match whatever the DT does, i.e., you can only pick 1 or maybe very few DT configurations that match volume with the accoustic amp. The beauty of this setup would be simplicity. Be careful with levels and start low. Not sure anyone tried this. Combined with a MIDI controlled AB switch you may be able to drive all of this with the HD500 and single push of a button. HD500 | | [L6 Link] v DT[preamp skipped, Verb & Master working] | | [effect loop out] v A/B Switch -[b or A+B]-> Accoustic Amp | | [A or A+B to effect loop in] v DT Power amp section

Seems like the best place for the B9 is the HD500 effects loop placed early (if not first) in the effects chain. I could see a light compression and signal level adjustment before it to get optimal tracking and sustain. If not mixed with guitar sound you probably want to treat it effect- and amp-wise like an accoustic guitar. ... and that leads into how you want to connect your accoustic amp used together or individually with the DT25. I am afraid I have no experience on that topic. Will be interresting to see what others have tried and experienced. Martin

All the preamps and a few effects I checked compress if the input signal peaks are significantly above -12dBFS. For cleans, make sure the guitar input signal level itself stays low enough. Just lowering the output level of the first effect or amp is NOT the same as lowering the real input signal level. Stay away from input 2 Same unless you know it will not push your input signal above -12dBFS (e.g., use USB and DAW or other SW to check). Disable your compressor and signal boost effects initially to build the clean base tone. Once you are happy with that turn them on one by one and adjust effect output level so that the overall tone volume does not change w/o or with the effect. If your guitar has a relatively low input level, try adding a clean boots to bring it up just under the -12dBFS peak guidance to get a feel of how loud you can go while staying clean. Once that is established you can replace the clean boost with a compressor/boost effect setting that matches the output level achieved with the clean boost. Martin

To explore I'd recommend you split PATH A and B right away at the input. Set input 1 to Variax, input 2 to same (this experimentation tone will only use input 2 to drive the DT, input 1 is used to tune only). Mute mixer path A, move path B to center, 0dB. Select 1st power amp setting by selecting a preamp for Path A (it will only select the power amp config in DT because path A is muted in mixer) At this point path B is empty, i.e., the tone setup so far passes your guitar signal w/o any processings to the DT power amp and the DT power amp configuration is selected by the amp configuration in path A. This allows you now to Select any DT power amp configuration independent from whether you use an amp or not in path B Play around with model setting (compression, EQ, ...) in path B without impacting the selected power amp configuration in path A. If you end up with something you like and it uses an amp or preamp model in path B this tone setup is usually overkill and you can combine path A and B amp settings. That step should not be hard. The idea of starting like this is that your power amp control in path A is independent from the models you pick in path B and thus it makes the trial and error phase a bit more controllable. You will quickly detect that the poweramp configuration you choose can change levels up to 19dB. That's a 4x volume difference besides different tone. To correct for that in your experiments use the mixer at the very end of your effects chain and adjust gain down. I posted a PDF a little earlier that gives guidance on volume differences for the different DT power amp configurations so you can get in the right ball park w/o too much trial and error. Let us know how it goes, Martin DT25 Power Amp Parameters.pdf PS: Making accoustics sound good with a DT is a pretty tough problem and there are a few recipes floating around, but all are a compromise from my point of view because the DT just does not have the speakers and amp to replicate full range tone of acoustics.

Watch out for high input signal levels. If you can, use USB to check your guitar input peak level with a DAW or some other measurement equipment with an empty tone (no amp, no effects, mixer 0dB, pan to what you need later). My recommendation is not exceed -12dBFS peak. My JTV69 at Spunk 4 comes in about 9 dB low for single note lines, while the Lester 1 is pretty much right below the mark for single notes. So if I play chords with the latter I need to turn the volume on the guitar down quite a bit if I want to stay within my self-imposed peak guideline. I found that all preamps and every effect I measured will start to compress / soft clip or even distort if peaks significantly exceed -12dBFS. So if you want clean, stay away from those high peaks. Hurhanico's advice should keep you in save territory, but better measure if you use some hot pickups or played around with the Variax guitar model settings. Use amp models to taste and start with 0-5% DRIVE and Channel VOL as needed to maintain an unchanged healthy output level. If VOL does not get you back to original amp input signal level (due to low DRIVE), use a clean boost (Studio EQ or MID Focus with tone neutral setting) or adjust output level of your next effect to get back to just below a -12dBFS level. Most amps (even no amp with a little compression and EQ) will get you a decent clean if your levels are kept in check. Good luck, Martin

K, you can forget 2/3rds of what I wrote. The 6dB boost when moving L/R to center stands. Enjoy your L2, I am thinking about getting 2 of them in the future and track what you guys figure out Martin

If you go just into 1 amp (with path A and B out) and then with both paths into the mixer, you'll get a 6dB boost compared to leaving the mixer at [<100/100>]. You always get left/right signals out of the mixer, idependent of your mixer settings. But if you never use a stereo effect before the mixer you'll always have the same signals on left/right mixer out. I never had a need to boost the amp output (or A/B effect chains) with the mixer. Channel Volume always did the trick to adjust the output level to optimal strength for low DRIVE settings. Personally I use the mixer almost exclusively at the very end of my effects chain and to lower the output signal to level DT tones that use different DT amp configurations (there is a 19dB difference between softest and loudest). I think the 'oomph' is really just a 6dB rise in output level and does not change tone unless you are already close to maximum signal strength and cause some clipping by increasing output by up to 6dB (depending on how much you move the sliders to center). If you have a computer and a DAW or other SW displaying input signal strength via USB (or other measuring device), it is pretty educational to see what levels you get after each model. My persoanl guideline is to keel peak levels always below but close to -12dBFS for optimal signal strength and lowest noise transfer. My first step in every tone is to adjust my first effect so that the output level follows that rule of thumb. Also interresting to start with an empty tone (amp disabled) and just add a tone neutral boost (e.g., Studio EQ) to get the signal strength up and listen to your pure guitar sound. If you want to do this with the DT as an amp I recommend a tone where you use Path A to select the DT power amp configuration but then mute Path A in the mixer and use path B to carry the gain staged guitar signal to the DT. In this setup there is no preamp model because the DT thinks it gets the preamp modelling from the HD but the preamp model is muted in the HD mixer. I found that listening to your guitar like that is very educational and lets you pick a guitar sound that is as close as possible to the final tone target your aming for. Good luck, Martin

I found that my guitar tones (especially clean ones) get fuller if I set the initial effect to produce a solid output signal with a peak level not exceeding -12dBFS. For example, using my JTV-69 this means that I need to raise the level by 9dB for a Spank 4 and not at all for for Lester 1 playing single not lines. Listening to pure guitar sounds (no effects & no amp) is very educational and good advice to get a feeling on whether the selected amp will actually get in the way or help to get where you want to be sound-wise. Martin

I don't have the GSP1101, but it does have a stereo effects loop. Seems to me you have at least 2 basic choices: Put the GSP1101 in the POD effects loop use the POD effects loop out (mono) to get into the GSP1101 input and the GSP1101 effects loop send or output into the POD effects loop return, or use the POD effects loop out (stereo) to get into the GSP1101 effects loop return and the GSP1101 output into the PODD effects loop return Put the POD in the GSP1101 effects loopsame drill as above, just switch the names Level matching may be a problem. Both units offer adjustments, but you probably need to try all options to find what works best for you. Sorry, can't be more specific as I am not familiar with potential GSP1101 limitations. Good luck

I have a DT25 and are very happy with what it does, but accoustic guitar tones are likely worse than the ones you got from your current setup. I am still experimenting with making accoustic guitars sound good (and there are a few posts on how others approached this topic), but I do not expect to get really close to ideal as there is no high-frequency speaker in the DT. At this time I am afraid it is a trade-off between real tubes (no real good accoustics) or tube modelling and good accoustics. I looked at the L2/3's before and if I'd have to buy again I'd go with L2m+t instead of the DT25 for best cost/volume/sound/fexibility compromise. Slightly flatter than the L3s, one mixer is enough, plenty loud enough, stereo ear candy, and HD tube modelling. Enjoy the ride, Martin

Well, I am glad you kept your humor through this. I have my 'dream' now for 2 years and I just start to more easily find the source of my problems, but not necessarily always a solution. Nothing is perfect. It is what it is ... and we make the best of it. Enjoy (even if that means you might get rid of something), Martin

I think what radatats referred to was that running your DT in standby LVM mode and listening to the DI output could be very close to running a full amp models on the HD and listening to that via headphones on the HD (skipping the DT altogether). Clearly I (and possibly radatats) don't know, but you would be running exactly the same models, just in a different box. I admit there is fair amount of guessing in this assessment, because, as you stated, the HD goes into 'combo amp' mode when you connect to a DT and then the DT's LVM DI signal generation is another unknown. But I'd still think it would be worth trying to either hand configure the HD to 'studio out' or disconnect it from the DT if you doing your tone experiments. Having said that I believe any LVM of full amp model tone tuning experiments would generally not carry over well to DT full amp use modes because L6's full amp models are quite a different beast than the voicing, class, tube configuration approach in the DT power amp stage (as demonstrated by their totally different effect on the produced output volume).

Got 1 round of LVM DI measurements and confirming your experience and Line 6 information. Any set of tones using different amp configs that are balanced with speaker or DI in full amp mode comes out with widely different volume levels on the LVM DI output. Voicing I, A/B is even 3dB louder than my the full power level. One was about same and the rest was way quieter (up to 21dB for Class-30TB). I guess the best you could do is build your own set of LVM tones that are balanced ... and you may need 2, one for LVM speaker and one for LVM DI, as you apparently found out. Consider going with a power amp attenuator if you want 'quiet' while using DI and full models. Seems anyway why the DT exists (the LVM mode is really a different set of power amps L6 had in its pocket from the HD models and did not have to develop much to expand their potential customer base). Martin PS: Use this data at your own risk. Have not checked tones to track model selection or repeated measurements.

Just finished a round of measurements using full power mode DI through a mixer into my iPhone and found that all my balanced amp configurations deviated no more +/- 0.6dB from my target level I used for balancing via DT25 speaker. I am tempted to say that it is probably less as my speaker measurements where far less solid in terms of repeat measurements, i.e., a few could be easily off by 1/2 dB. Most of us have a hard time hearing that volume difference anyway unless the tone has exactly the same frequency spectrum. I consider doing an adjustment correction using DI measurements and then check how far off the speaker measurements are. If I'd guess I would say less than +/- 0.6dB. Not sure I can get to the LVM measurements so I thought I better let you know what I have found so far. Martin PS: As a side note, with my Mackie 1202 mixer's mic input sensitivity at 100% and unity gain on the channel strip, my mixer thought the DI level was surprisingly low and high on high frequency noise. A bit dated technology, but still considered above average at its time.

Was your question to Line 6 support requesting this infor for LVM or regular power amp mode or both? If this is a problem only for LVM mode and you use DI out strictly for home practice with head phones (amp in stand by) you may get away with just setting up matched tones for that purpose. If you actually want full power mode and matched DI out (assuming this mode at least works) but you want to do realistic but quiet tone experiments at home, you could get a fairly cheap power amp attenuator or load box to quiet the speaker for home use and bypass this device when you can use the speaker. If you get a good box (like a Rivera Rockcrusher) you can also use it to push the tube amp while maintaining sane sound levels and don't miss out on the sound quality unless you are into lots of effects. Hope you get something out of your invested time. I use my DT25 almost exclusively at bedroom levels, but always in full power mode. I do understand the experiment predicament: nobody wants to hear them (besides the one who does them). Martin

I don't think that works although I never tried. Once you disable an amp in Path A, the HD/DT control SW switches you over to Channel B on the DT and thus you may loose HD voicing/class/tube controls over the DT Channel settings,and subsequently you may only get what you dialed in by hand for Channel B on the DT. Having said that I remember seeing a recent thread on the forum explaining how to use the HD to send MIDI to the DT and if this works you could possibly configure the HD to select channel B settings via MIDI. But I don't remeber the details and may not recall crucial details. Martin

This is good data to know. Thanks, Martin