zolko60

2TS jacks to TRS socket adapter.

21 hours ago, feffa86 said:

I was assured by people more knowledgable than me that that was sub-optimal.

Yes there will be people who claim that you can't directly connect an SPDIF output to an AES input.
But most modern gear will accept SPDIF and AES interchangebly. Don't dismiss it until you have tried it.

When I download IRs back from Helix they are 32 bit and truncated to 2048 samples. This is why I assume they are stored and used as 32 bit.
I do not propose to change anything about 128 limit unless some future firmware update will change it. Please consider the manual is outdated. It needs some lifting.

Page 29 "Helix can load and store up to 128 IRs at a time. 48kHz, 16-bit, mono, .WAV type IRs of up to 2,048 samples are natively supported. But the Helix app allows you to import IR .WAV files of different sample rate, bit depth, length and stereo format, and the app will convert these attributes automatically before sending to the Helix hardware."
Correction:
"Helix can load and store up to 128 IRs at a time. 48kHz, 32-bit, mono, .WAV type IRs of up to 2,048 samples are natively supported. But the Helix app allows you to import IR .WAV files of different sample rate, bit depth, length and stereo format, and the app will convert these attributes automatically before sending to the Helix hardware."

And yes: Customer Service confirmed The Volume Knob is digital attenuator before the chosen DA converter.

I had no luck to buy that free pack from their store (no link sent) but maybe it will work for somebody.
https://amtelectronics.com/new/product/amt-truecab-ir-ma-1960a/

I got interested because of IR lenght discussion. I have always thought it is DSP power limitation. That chart shows it is not the case.

I think the answer is 2 cells below to what I quoted:
"Note some items are restricted by the Helix software which only allows a certain qty per path. Eg AMPs, CAB's, Irs etc.
As such if an amp+cab has a value of 6 then you can use other effects for the remaining 14 DSP."
Some kind of limitation the software developer only knows why. Two amps/cabs/1024 IRs or one 2048 IR per DSP path.

Usually 180Hz at HPF indicates 3dB roll off at that frequency since it is first order filter (3dB per octave). Nothing drastical.
Speaking of the best setting of HPF regardless of what is filtered is pointless. IRs are also filters and can have HPF/LPF included.

Do you guys use Helix DSP Values?
"Helix allows 16 inputs per path so the values I have assigned are based on a DSP being one 16th. So If an effect has a value of 2 then you potentailly can have 8 of them in one path."
says the author of that sheet. It works for me in case of amps and FXs but...
2048 IR loader has 2.6 value and can be loaded only once per path.
What is wrong?

17 hours ago, HonestOpinion said:

In many ways this whole discussion reminds me of the difference between listening to an .mp3 versus a .wav file.

Yes. There is nice online test if that difference is important for you..
http://abx.digitalfeed.net/?fbclid=IwAR29my8UYktEJtujTwCWQP-MrNmWQW4dzvnSXJPqZ0YUN2bU64bM2w_BIiM#numTrials/10/sample/2
You can also make a test of how you percieve IR lenght difference but Helix hardwere is useless for such a test because it uses only low lenght FIR filters. Happily you can always use Helix Native and some free IR loader.
Rock & roll electric guitars are indeed different animals. 48kHz sampling rate and 32 bit floating point math is such a waste of that precious DSP power of two old 450Mhz Sharc procesors. 48/32 It is too Hi-Fi for the purpose. 32kHz, 16 bit would be just enough. ;)

 

1 hour ago, phil_m said:

I got the +16dBu rating from some other gear that uses the same A/D converters that the Helix uses

You assume all gear based on the same converter chip has exact rating. I don't think so. Even Hx return inputs have two switchable full scale values.

1 hour ago, phil_m said:

Guitar In is probably a little higher than that because Line 6 has some proprietary circuitry that increases the dynamic range of that input from 114dB to 123dB.

No. Guitar input is exactly the same as Hx return inputs set to instrument level in terms of dynamic range and noise  performance. According to my RMAA measurements S/N ratio for any output/input loop is 110dB A weighted. If return inputs had 114dB and guitar input 123dB that measurements would indicate some difference and would be audible.

1 hour ago, phil_m said:

I believe the main reason Line 6 doesn't publish this sort of data is simply because they believe (rightfully so, imo) that the vast majority of users 1) don't care and 2) don't really understand what it means. Also, it seems that the main use of such information is for people arguing about the superiority of one platform over another.

I believe these two sentences contradict each other :D
I can show you  published specifications for far less valuable gear than Helix. If someone does not read, care or understand so his arguments are ether non existent or stupid. I have never seen an argument that +24dBu interface is better than +12dBu. All info I need is if I connect non clipping Helix via analog to another AD converter can iduce clipping and if return input is worse than guitar input when I want to connect another guitar.  These are the basics. I do not care if THD value is 0,00034 or 0,00152%
I personally think that the manufacturer that publishes specs is superior to one that doesn't. I still can understand the point Helix is sold as guitar modeler and guitarist are dumb "to the eleven" type of men. :D

Please don't be confused. Every AD and DA conversion takes place between dBFS scale and voltage. Voltage can be presented as V units or logaritmic dBu, dBV units with known reference.
Therefore for full scale digital signal (0dBFS) of given converter there is full scale dBu value.
+4dBu is profesional standard for line level signals. It requires some headroom. 14dB headroom is good practice. proposed by BBC (some british radio not Big Black ;) so lots of converters are +18dBu full scale.
Some manufacurers include that data in technical specification of their products. In case of Line6 you have to measure if interested.
There are calculators for V, dBu, dBV conversion: http://www.sengpielaudio.com/calculator-db-volt.htm

Try to make RCA to XLR adaptor with RCA tip connected to XLR hot and XLR cold not connected. It can work just fine.

20 hours ago, felixflemons said:

HX Stomp can load and store up to 128 IRs at a time. 48kHz, 16-bit, mono

BTW. The manual is incorrect. IRs saved from Helix to file are encoded as 32-bit floating point wav files.

46 minutes ago, rd2rk said:

 

That would indicate that they ARE NOT actually "Made for Helix" ,

Welcome to the real world. If there were not Helix folder they would probably have to answer a question "Can I use them with Helix?" ten times a day. ;)

41 minutes ago, MLSoundLab said:

I'm more of a problem solver so I'd rather dive in and play around with the tools available like trying to find a reverb setting that simulates a longer IR tail.

This is not the "reverb tail" problem only. Each FIR sample is a coeficient - FFT point. Complex, hi resolution EQs also require large number of FFT points regardles there have no reverb tail. 
There is something wrong with hardware DSP chips not to be able to keep up to CPUs performance. 
I think for live use 2k loader is just enough. If you are recording and want to take advantage of high resolution FIRs you can use software IR loader and truncate IRs to your taste.

3 hours ago, zolko60 said:

Maybe MixIR2 is just different because it creates and normalizes stereo IR on the fly? This is the only reason I can imagine for such awkward controls not responding in real time.

OK. It seems to be the case. I loaded the whole bunch of 500ms IRs. Reaper CPU load plugin indicator was 0.7% with one 20ms IR and stayed at 0.7% with multiple and longer IRs.
MixIR is just one 8s stereo FIR convolution plugin with engine to mix component FIR files. Smart! 

Sentence "HX Edit lets you import IR .WAV files of different sample rate, bit depth, length and stereo format, and the app will convert these attributes automatically before sending to HX Stomp" states that whatever IR you upload will be OK and will not affect your tone.

6 minutes ago, rd2rk said:

Only.... when an IR company has "L6/Helix" length IRs, what, EXACTLY, does that mean? 1024/18.5ms? 2048/50ms?

It means you buy something "meant for Helix". While Hx does it's truncation to 2048 it does not matter if it is 26, 200 or 600ms
500ms does not also mean much. You can have 200ms of usable tail and the rest is just the noise floor. 

Your mileage may vary... Your mileage may vary...
At the end of the day 1 mile is 1 mile and 10 miles are 10 miles no matter if something nice happend during 1 mile and nothing during 10 miles ;)
Longer IR just means better resolution just like higher sample rate and bit depth. 1024 and 2048 IR loaders are used in Helix because of very limited DSP power hardware modelers provide.
If you can not hear it you can see what FR plots shows with FIR filters truncation.
One can ask - what maximal IR lenght should be - where natural cab "reverb" ends and room reverb starts. Noone knows. You can make distant miced 4-6s IRs in churches but no present hardware modeller will make use of them.
I can understand Pete Thorn point. While he is the Suhr endorser and Suhr makes 1024 samples IR amp so this is enough. If he was Fractal endorser 8192 would be enough.  ;)
Most of hardware modelers users have no chance to hear the difference so your mileage is just your mileage. :D
 

On 5/11/2019 at 7:28 PM, Verne-Bunsen said:

Hi Zolko,

 

I'll try to provide what help I can.

(...)
I hope some of this helps!

A little... ;)
 I still can not figure out eg: 
- what the sliders under the block icon do. 0% leaves the dry signal only. 1-100% I can hear no difference. Does this control make sense only with blocks mixing?
- what mix parameter in IR block do. If I have IR1 set at 50% and IR2 set at 50% , how it differs from 100/100%?
- Why can't I hear any volume difference only block "balance" when I mix blocks?

Maybe MixIR2 is just different because it creates and normalizes stereo IR on the fly? This is the only reason I can imagine for such awkward controls not responding in real time.

To mix IRs no special software but DAW is needed.
For a normal DAW work free NadIR is just perfect.
BTW: I have just made a test Pete Thorn proposed using MixIR2 handy truncation on the fly and I noticed what I am loosing using 20,40ms (1024,2048) loaders instead of 200,500ms 
 

5 hours ago, phil_m said:

The max input level is like +16dBu.

I don't think so. According to my measurements Hx instrument level is 11dBu full scale and line level 19dBu FS.
It would be nice somebody can confirm it. I have no true RMS voltometer.

My friend says this is the tactile switch that fits Helix and other Line6 products: https://www.digikey.pl/products/en?keywords=CKN9098-ND

I can confirm that Helix acts just opposite to my other USB powered interfaces.
It seems to "ground" or "shield" my guitar enviroment via USB cable so the computer/laptop power supply interference is silenced. Playing with Hellix LT USB connected and disconnected with a the computer or laptop near by is the different experience. What i write about is the headphone listening, connecting monitors causes plenty of different nature issues.

That's great MixIR2 works for you. I found it too be too complicated for me. What is parallel, what serial,  what controls do was not inuitive enough and produced unpredictable results.  Either I have bad habits or I am dumb. This is why I dropped it several years ago and started to use simpler IR loaders.
I tried to read the manual but there are whole sections I can not understand.  Maybe you can help me: Where can I find any information about saving IR mix to IR?
https://www.redwirez.com/mixIR2UsersGuide.pdf

"Part of the reason we gave you so many options is because we wanted you to feel like you’re sitting in the control room with an assistant in the live room moving the mic around the cabinet. If you’ve ever mic’ed up a real speaker cabinet, you will likely be perfectly comfortable with the number of choices we offer. But, if you usually leave that stuff up to the sound guy, then you may be feeling a bit overwhelmed."
Oh really? Each "sound guy" I know (live or studio) is able to mic guitar cab with one or two mics with great results - same rule for "IR micing". More than two mics  induces so much comb filtering and other phase/eq phenomenons so anybody claims he knows what he is doing is some kind of sound shaman for me. ;)

On 4/29/2019 at 10:48 PM, rd2rk said:

You definitely DO NOT want to connect either of the outputs on the back of the Torpedo to the Helix. That would cause all of the magic smoke to escape from your Helix, reducing it to a very expensive door stop! The connectors on the BACK of the Torpedo are for Speakers ONLY! SEE MANUAL!

(...)

REPEAT: 

The connectors on the BACK of the Torpedo are for Speakers ONLY!

 

To clarify you definetly can't cause any magic smoke to escape from your Helix because Hx Input impedance is too high to draw current. All you can do is to damage your tube power amp. -20dB attenuated speaker output can work just fine as additional line output.