Whats the RTL (latency) on a Bias head?



  • My Kemper has ca 3.5 ms latency, and I know Axe FXs has less, below 2ms or so.

    What latency does a Bias head have?

    Here's a text I'm very cautious about:
    "The BIAS Head is a massive 600-watt Class D power amplifier that ensures every nuance of your performance is heard on any size of stage, all at zero latency."

    ZERO LATENCY? I don't even think that is possible with digital amps.
    Every digital has AD/DA conversion and THAT TAKES TIME!

    They cant say "zero latency" if isn't LITERALLY ZERO latency. Even 0.1ms latency is latency.
    If they had 0.1ms latency Positive Grid would be the fastest digital amp in the world.
    But I wanna know FACTS about this, not sales pitch about "zero latency".

    ---AND PLEASE................---
    And please dont come with the been-there-heard-that cliche "if you stand X feet from speaker thats X seconds" answer. It pops up in every thread about latency in digital hardware amps asking for the actual RTL of the unit instead of answering the actual question...



  • So I'll say right away I have no idea of the numerical value regarding the latency. I do however own the bias head and have used it as my main amp for a little while now and haven't ever experienced any delay between me hitting the strings and getting something from the amp. I know that doesn't fully answer your question, but I can safely say the bias head has little enough latency for it not to matter



  • @liam I'm sure the Bias hardware is perfectly good on it's own. :)
    But that's basically true for every digital amp ever.

    What I'm concerned about is when it's starts to add up:

    Wireless guitar system latency
    Digital amp latency
    Digital mixer desk latency
    In ear monitoring latency

    Basically all these things add some latency on their own that can stack up in the end.

    Even if I'm a happy Kemper owner, the 3.5ms latency is something I'm sort of concerned about if adding all the other gadgets into the mix.
    My buddy has a Ax8 which is supposed to have lower, maybe below 2ms!



  • @cederick-forsberg i use a Bias Head, a wireless G10 unit, use a focusrite scarlett 18i20 as a mixer, and out to our floor monitors. There's no in-ear monitors, but at least with all that setup i cannot detect any latency whatsoever. I'm sure that if i were running it through my DAW for some additional effects i might detect a slight amount (more from the plugins/processing than the interface or anything else in the chain), but as it stands the Head's latency does indeed seem to be imperceptible.



  • @ash-wolford Ok, cool....
    But that still doesn't really answer my question...

    Just wondering. What kind of music do you play?



  • the majority of my usage is in my cover band. we play a variety of stuff, from classic rock to 90s alternative to modern metal. i have a few different presets configured on my Bias Head and Bias Distortion pedal, and switch them during performance using a heavily modified FCB1010. I use the Head's built-in reverb, and otherwise go pretty light on my signal chain, with a wah and volume pedal and that's about it.



  • @cederick-forsberg I play in a hardcore/metalcore band. I use an Audio-Technica System10 Stompbox wireless along with the Bias Head and I have no perceivable latency. Similar to the others that have commented, I don't have the exact figures, I can just tell you what I play/feel. You could always buy a head, try it out, and return it to your retailer if you don't like it. Or you can open a Support ticket at the main Positive Grid site and try to get an answer through their actual Support staff. I don't think any end-users here are going to have the technical answer you are looking for, as it doesn't appear to be published information.



  • it would be fairly trivial to test out, and i may bring my Head home with me next time i'm over at the band room just to run a test and see exactly how much latency there is. should be as simple as sending a signal out from an interface and back in using a simple jumper cable, recording the latency, then doing the same thing with the Head in the chain and comparing the values.



  • welp, it's like 12 days late, but while I was doing an RTL test of my Scarlett 18i20 I went ahead and did some tests with the BIAS Head added into the chain. I ran ten tests of [O -> I] and then ten tests of [O -> Head -> I] using the Acoustic Sim amp setting, and then ten more tests using a Triple Rectifier style setting.
    I chose 64smp for the buffer value for this test, but did a few smaller tests with other values just for added certainty and had consistent results -- not that it should matter, but y'know.

    0_1523827664964_b1a77162-564f-4b17-b7c2-95c2c84d3cb8-image.png
    0_1523828411372_20175bfe-bc21-4adc-b02c-e3fd0a793b7d-image.png
    The average 64smp latency WITHOUT the Head was 8.015ms
    The average WITH the Head (clean amp setting) was 10.986ms
    The average WITH the Head (dirty amp setting) was 11.481ms

    Based on the above, the Head adds a latency of roughly between 2.971ms and 3.466ms depending on the amp chain. It is possible that individual module settings may affect this (IR loader is of particular interest to me atm), and I may do some more testing to determine the extent of which, and maybe even determine the latency of individual modules.

    In conclusion, you are absolutely correct in that claiming "ZERO LATENCY" is somewhat disingenuous at best (and blatantly false advertising at worst if we want to be pedantic). Realistically speaking though, that 3.5ms of the BIAS Head and your Kemper, and the ~2ms of the Ax8 are all effectively zero latency, especially when compared against each other.
    You have to push what, 30ms or higher before your brain can even really detect any audio latency at all? Chances are that 1.5ms (or even the full 3.5ms) is not going to make any real difference in practice, unless your other gear (and yeah, as you said yourself, distance from speaker; that'll likely net you an additional ~3-4ms) is adding so much latency as to be on the edge of problematic already.

    Basically, if you're having to micromanage your latency that much, it'd almost definitely be better all-around to just go with a physical amp and save the whole 3.5ms than to shave off the completely inconsequential ~1.5ms difference with the Ax8, unless you're also actively taking steps to reduce the latency of every other component in your chain as well.



  • You're correct. Though, regardless of distance, every amp has *some latency. Even analog gear. I mean, if we're talking literally "zero-latency". No. Zero is not possible. I've never tried the head - just the software; but I'd think the actual head would be a bit "faster"(?) Idk. Sorry if that's a cliché, I just deduced that.
    I can't "hear" or "feel" any latency w/BA2 on a 2011 iMac 12G ram in LPX. Cheers.

    My thoughts are: if you're thinking of getting one, I wouldn't let that detail, or, "oversight" in performance description deter you. (just make sure the return policy is good, lol)



  • @ash-wolford ^Exactly. This^. 3.5ms IS virtually zero latency. I can't even hear it until (depending on how squashed signal is) 40-50ms; though I can feel it around 20-30. Never seen PG's ad campaign, but I agree (and for all those who wouldn't automatically deduce this) they should have at least put an asterisk explaining all of this. Blatant false advertising is a bit of a stretch - I mean, knowing there's no such thing as the demands of the "on the fence" customer above; I'd never once think that PG would actually mean literally zero latency. that's like a freezer that makes ice at absolute zero (i think, lol. Not sure)..
    If it were indeed zero latency; then I'm sure there'd be an asterisk, lol. Cheers. Shred on(!)