Please ensure Javascript is enabled for purposes of website accessibility Jump to content


  • Posts

  • Joined

  • Last visited

  • Days Won


Everything posted by jeremyn

  1. It could simply be where your ears are relative to where a mic would normally be placed. If you stick your face up to the speaker grill and listen to it in the near field, it will have much more high frequency content than if you stand a few away and 30 degrees off axis. In the far field, a 12" speaker beams higher frequencies in an increasingly tighter angle as the frequency goes up, especially frequencies past about 1kHz. This is why FRFRs have a crossover to send those frequencies to a speaker with a smaller aperture and/or a horn. It's all about the changing angle of dispersion over the frequency response of the speaker.
  2. Regarding the humbuckers, I'm yet to find a traditional type humbucker targeted for that iconic tonally warm 'character' that is fully balanced. Some are better than others, but all seem to suffer to a degree. The ones that are best at hum-cancelling are pickups that are often considered 'sterile'. For example, EMG active pickups are balanced well. Q-Tuner has a range of pickups that were near perfectly balanced, but they are also very much like a perfect microphone with an extremely wide and accurate frequency response. Also, ZVEX pickups are very well balanced and quiet. Although those seem to be aimed at the single coil market with pickups of varying 'character' that fit into a single coil 'hole'. The ZVEX pickups offer a very high degree of hum cancellation due to the 6 in-a-row matched coils. Of course, ZVEX is all about hum-cancelling, so hum-cancellation would have been a priority in his pickup design. These days humbuckers are about the tone, with hum-cancellation being a nice side effect. That pushes builders to priorities tone over hum-cancelling perfection.
  3. Even when the electrical tests pass it is still possible have incorrect wiring in the walls. The tests and inspectors are supposed to make sure that you have a functional and correctly installed earth system. They should check the power points to make sure active/neutral/earth are correctly wired relative to each other. However, those testers can't always tell if neutral and earth have been reversed depending on how the earth has been connected at the service entry. Also, if the wiring in an inaccessible location includes a bunch of 'patches' that create big earth loops, then bad wiring may go undetected. Old style single pole remote switches (for lights) that only switch the active can also be a problem because the forward and return paths are along completely different cable runs. It's worth trying your noise test with the lights off if you suspect this might be an issue in your home. You can also trying turning off various (or all) appliances to track down the offending circuit - radiated noise picked up by your guitar isn't necessarily anything to do with the circuit that your amp is plugged into. Usually the only side effect of wiring that is badly done - but passes electric continuity tests - is significant EM radiation. It may be unsafe if a double fault occurs somewhere, but usually the really dangerous stuff like open neutral or crossed lines is detected during electrical continuity tests. However, it's worth noting that TheDaveDaveDave had various professional entities come to his home and all declared that there was no fault. Then he himself noticed the actual fault, which in addition to being the cause of all the radiated hum/buzz, turned out to be something that could also be potentially fatal.
  4. Copper shielding in the guitar helps with the electrostatic component of the EM field, but doesn't do anything for the magnetic field component. When there are big earth loops in the venue and high currents running (or worse, switched high currents like dimmers and neon signs), you can end up with a pretty strong field around you. If the wiring and earthing is correct, the current returns down a parallel adjacent cable (i.e. active and neutral wires). When this happens, the fields are in opposite directions and cancel each other out. So correct wiring and earthing significantly reduces EM radiation. If however there is a broken neutral, and the current returns through an alternative earth path, the forward and return currents won't be parallel/adjacent, so there won't be any forward/return field cancellation. This can also happen if the active/neutral/earths are swapped around in a wall socket, or at the board. And as mentioned in an earlier post by TheDaveDaveDave, if the main neutral return wire is not connected, the current returns through the physical earth/ground back to wherever they are connected together (either at the service entry point to your house), or in the case of TheDaveDaveDave's broken service neutral, probably through the ground/neutral connection at his neighbour's house (which is highly dangerous and why the electricity company came out immediately). There can also be issues if the wiring is not a parallel pair (eg. separate cables for neutral, earth and ground, or someone has wired the pairs incorrectly). Many of these wiring faults can actually be hazardous beyond just a lot of extra EM radiation. The other thing that doesn't help is that vintage PAF style hum buckers don't necessarily have balanced coils (even the hot higher wound ones). In fact, when winding a side by side hum bucker coil, there is an 'improvement in tone' by having an intentional imbalance - something that pickup builders almost always exploit when they're aiming for iconic tone over pure hum-cancelling capability. The bigger the im-balance there is, the less external magnetic field gets rejected.
  5. No, that is a problem related to single coil pickups picking up the magnetic field in the environment. Fixes for that include: use positions 2 and 4 on a strat, use humbuckers, use something like the Suhr/Illitch silent backplate, avoid rooms with badly run power or electrically noisy dimmers, stay away from large transformers that radiate a strong field, turn your guitar so it is faces perpendicular to the induced field (minimum noise position), use outboard gear like the EHX Humdebugger that notches the 60Hz signal, use pickups not based on magnetic induction (piezos), roll down the guitar volume when not playing, embrace the hum and learn to like it, etc Ground isolation, power conditioners,and other methods to reduce system noise will have little to no effect on field induced hum in a single coil pickup.This is an age old problem that precipitated the invention of humbuckers.
  6. Just picked up a Radial Ice Cube line isolator that works perfectly for protecting the Helix from phantom power being applied to its output. The Ice Cube has a male and female XLR connector and an optional ground lift switch. The transformer sounds really transparent too, and most importantly doesn't saturate when driving decent levels through it. Although this isn't a DI, its perfect for interfacing devices XLR to XLR while preventing phantom power from passing through, and helping with ground related problems with excessive noise that exceeds the common mode rejection capability of the input side.
  7. A typical 12" guitar speaker rolls off at around 5 to 6kHz at about 20dB per octave. It has response from about 7kHz to 20kHz that bottoms out about 20 to 30dB below nominal with some unevenness and a very directional response pattern. Roll off in the low frequency side is more gentle at about 10dB per octave and starts to drop off around 70Hz to 100Hz being about 30dB down at 30 to 40Hz. So an IR with equivalent frequency response should have some decent roll off just like a real speaker, and should not need extra filtering if the IR is doing its work properly. If the IR output is not at 100% blend (ie. some raw signal is being mixed in), then it will seem smoother and the high and low frequencies won't be attenuated anywhere near as much as would happen with the IR by itself. This is irrespective of any high/low cut filters. It is possible to apply a filter to the IR to create the desired roll off if the natural speaker capture wasn't enough. However, what has been observed is that the same IR used in a DAW IR convolver is a lot less bright/harsh than the same IR processed in the Helix. Since it is the same amp and signal path, the only things left are either something wrong with the IR processing in the Helix (or the DAW), or there is some raw signal mixed in parallel with the filtered output in the Helix. It should not be necessary to add extra low/hi cut filtering to get the same frequency response in the Helix as happens in a DAW. The convolution algorithms should either be the same or mathematically equivalent. Anything else is either user error (possibly because of counterintuitive/hidden default behaviour), or a bug in the Helix. There's more than enough frequency resolution in a 1024 or 2048 point IR to map the high frequency response of a guitar speaker to the point where a signal convolved with the same IR should be indistinguishable between the Helix and a DAW. If there's a difference, the source of the problem should be determined. Bandaid solutions like adding low/hi cut filters should not be necessary to get an IR response to match between the Helix and a DAW.
  8. Thanks amsdenj, that might go a long way to explaining why some of the distorted amps can sound overly 'fizzy' without the high cut filter in place. And the problem with the high cut filter is that it doesn't roll off steeply enough to kill the high end properly without starting it so low that it starts to kill the cut and sparkle of the amp. Convolution shouldn't be something that has 'flavours'. Obviously, if an IR is too long then it needs to be truncated which will change its tone and characteristics. But, absent truncation, the only differences should be incredibly subtle rounding errors during the FIR or FFT/IFFT processing. Even if the overlap add/save methods are used, the FFT based convolution should be mathematically equivalent to just using a really long direct convolution with an FIR kernel. There are no window functions here, so no subjective trade offs or choices that may impact tone. Internally accumulated rounding errors in the FFT/IFFT may cause an increase in the noise floor if the processor is relying on 32 bit floats with a 24 bit mantissa. But, if they are using 32bit integer arithmetic with a block floating point exponent, then the noise will be insignificant. If the output of the IR convolution isn't completely serial (ie. mix level isn't really 100% IR and a little bit of raw signal is leaking through) then this would impact the expected frequency response of the IR in a way that would make any attenuation (at any frequency) seem far less dramatic than it should be. ie. at a 50% mix, an IR that cut a given frequency band by 90dB would appear to only cut it by 6dB as the original signal is mixed back in at 6dB down after being cut out. When using cabinet IRs, make sure the blend is set to 100% to avoid this problem. If there is still a problem, then maybe there is a bug that is causing some raw signal to bleed 'around' the IR.
  9. The Ebtech line level shifter worked well for me when I was trying to use a digital reverb processor with a super hot amp effects loop (the amp needed up to 70V Pk-Pk back into the return loop to get full volume). It has 12dB of gain to go from -10dBV (which is about -8dBu) to +4dBu. The only issue is that if you use it on both the input and output you end up isolating the ground connection to the device in the middle. This can be a good thing if both pieces of gear are grounded and you are experiencing some hum. But if one piece of gear is being powered with a 2 prong switch mode supply, semi isolating it from ground with the Ebtech will cause it to hum like crazy. In your application, it looks like you only need to drop the level of the Loop1 Send from line to instrument so it doesn't overdrive your amp input. The Ebtech is perfect for this and you only need to use one of its channels.
  10. It's because if you press them both at the same time it toggles between preset change and bank change modes. It would annoying if it flicked the patch or bank up/down whenever you tried to change modes due to the incredible difficulty of hitting the buttons at exactly the same instant. It's much easier to gate out that sort of glitch if the button doesn't act until the release. The other option is to put in a much bigger 'debounce' delay before a press takes effect. But, that is annoying in a different way.
  11. iOS and MacOS aren't based on Linux. They both use microkernels based on Mach instead of the monolithic Linux kernel. iOS takes it a step further and removes unnecessary backwards compatibility to simplify the OS and avoid security problems. iOS is currently targeted to run on Arm processors that are not at all binary compatible with Intel's, and the Helix uses an Analog devices SHARC series DSP for its grunt work, which is even further away from being compatible with existing VST/AU plugins.
  12. It just a single 12" Celestion 70/80 speaker with a relative neutral amp, so not so much FRFR, as the Celestion 70/80 isn't super flat, and rolls off at around 5kHz. But, if you're micing the cabinet, this is much better than trying to mic a real FRFR active speaker that uses multiple speakers to get a flat response and even dispersion across the whole audio frequency band.
  13. As Peter mentioned earlier, this is the same as using a TS to TS cable and only plugging the cable in up to the first notch (click) on the expression pedal end (and all the way in at the Helix). ie. The Tip only goes in far enough to touch the ring contact, and the sleeve still contacts the sleeve. If you push the TS to TS cable all the way in, the R and S get shorted together by the long sleeve on the TS connector since both R and S contacts in the pedal will touch the sleeve.
  14. It is possible that there is ground noise on the SPDIF line that would otherwise be audible as a buzz or hum if the connection was analog. This is why TOSLINK (optical) exists. It is possible to transformer isolate an SPDIF line, but I've never tried as I've always used SPDIF/TOSLINK adapters when I did a lot of work with digital audio and ADAT.
  15. Helix 1/4" send/receive are unbalanced and therefore won't be affected by the ground lift switch. You may need an inline dual channel DI box or 'hum eliminitator' like one of the Ebtech boxes to isolate the grounds.
  16. A passive DI is ideal. Then you don't have to worry if there is phantom power or not. The output impedance of the Helix is low enough to easily drive the transformers in a passive DI. Something like the Radial ProDI is perfect for this, as it has good linear headroom and shielding. The Radial Stagebug SB-2 passive DI is a cheaper option with similar performance.
  17. With tone like that, you can rock back and forth all you want!
  18. I'm hearing quite a bit of overdrive on the guitar tones in that clip. Definitely not clean. They also sound like they are running really loud and compressing as the whole amp saturates. Try a Fender Deluxe Reverb running hot with a high volume level.
  19. Way better tone than what you'd expect from an amp called 'Fatality'! I've always just skipped over it assuming it was only good for 'teh brootulz'.
  20. Sadly no. For my dual source Tom Anderson Crowdster+2, I use two separate transmitters mounted to my strap and a splitter cable with two tails, one longer than the other.
  21. The main audible differences between 2048 and 1024 sample sizes is the effective frequency resolution (which is quite noticeable in the lower frequency band) and the detail you get by not cutting off a reverb tail with an IR that is too short for the chamber being modelled. But, depending on the IR and what it is modelling, the two lengths may sound nearly identical. Think of it kind of like a 10 band EQ vs a 5 band EQ. If the 5 band is already EQing all the right frequencies in just the right way for your situation, then adding more bands isn't going to improve anything. However, if the 5 band is just missing a few spots that happen to be between bands, then the 10 band will give you just enough extra control to make things better. When using acoustic guitar body IRs, the tail is noticeable up to about 8192 samples, with 4096 being about optimal when taking diminishing returns into consideration. Once you start dropping samples lower than that, the acoustic body IRs sound less realistic, where at 2048 and 1024 they're still ok, but less detailed. Same applies to cabinets. Maybe it won't even matter when used live due to other instruments / reverb masking the subtleties. Some speaker cabinets are not very resonant and therefore there isn't much audible difference between long and short IRs. While other more resonant cabinets can really benefit from both the extra low frequency resolution of 2048 sample IRs and the extra detail in the longer tail.
  22. First, as previously mentioned, make sure phantom power is off for both channels, as that may cause all sorts of unpredictable behaviour with the Helix outputs. Then, swap the channel cables and if the levels don't change, the problem is at the board.
  23. It sounded like Sigma IR on the Crowdster was a couple of dB quieter, but the sound was full bodied and most importantly still had a strong mid range. I agree that with the Crowdster the Sigma was best, with raw a close second (but with obvious piezo bridge characteristics). It shows how good the Crowdster is when it comes to a great plugged in acoustic tone. Thanks Peter.
  24. In their Youtube demo with the electric, I preferred the raw electric cleans over the IR version. But, with the piezo equipped acoustic guitar, the improvement was phenomenal. I can't wait to hear PeterHamm's demo.
  25. I wonder if these have been tailored for 'dry' thin body electrics to give them more of a full bodied sound? The Aura wasn't too bad, but Fishman intentionally left out their 'image casting' images from their gallery, which meant the only option was to mix and match 'full size' images that weren't meant for piezo bridge electrics. After trying numerous images, I kind of got close, but the Crowdster always sounded better (or at least just as good) with the Aura's image blend at zero percent. It'd sound great for a few weeks, then I'd turn the blend down from 30% to 0% and go, "wow, that's better". Setting it above 30% never worked live as it sounded too plinky and got lost in the mix. What kind of blend percentage did you end up running with these 3-Sigma IRs?
  • Create New...