Rloewenherz

Thats a good point too! If exclusively playing at home, a pair of studio monitors might be more suited. besides lower end KRKs i can also recommend the Swissonic ASM Series. They are a Thomann brand and have excellent performance for the price, but I do't know if you could get them outside of Europe. I have a pair of ASM7 that i am very happy with, though i am using them now exclusively for my media center (together with a small Fostex sub).

Hey metallixro, I have a Helix Floor and an Alto TS210 and i am very happy with it. You can definitely get some decent sounds, even at low volume, though you might have to spend a little time tweaking. The good thing about the Helix is that you can compensate for the low volume, by adding EQs, compressors and other effects after your amp-cab-mic simulation and set them up how you like them. Two things to keep in mind: 1) The Helix always models a mic'ed up Speaker, which will be different from the "Amp in the room" sound you most likely are used to. You can still compensate for that with some tweaks and in your case it might even be to your liking (thinking some proximity effect with a nice fat ribbon mic for extra low end) 2) Though the Helix is fairly easy to use (as far as tools of this complexity go), do expect to spend some time learning to use the unit before you are able to tweak the sounds how you really like them. Hope this helps! PS: The Alto TS210 can have some low end coupling to the ground if you put it on the floor like a monitor, best use some acoustic foam underneath or put it onto a stand of some sorts.

oh boy, better get my trusty old tinfoil hat out again!

I don't personally need this, but it is a reasonable suggestion! You should submit this to L6 Ideascale (provided there is not already a similar suggestion on there), as feature suggestions don't get much visibility on the forum.

Im running my Helix though a single Alto TS 210 (quite popular speaker on here) at home. It sounds great and for the money it hard to find a better FRFR solution (maybe now the Headrush FRFR or the TS312?). At practice straigh through the PA, maybe use the Alto as monitor. Always happy with my sound that way. The ony thing to note was that the Alto coupled to my wooden floor a lot, so i put some acoustic foam under it which helped a lot. have not tried the helix over any guitar amp yet. The FRFR setup just sounds so good i can't even be bothered : )

The impulse idea is definitely the way to go. Oh and just to rule out the highly unlikely: How far away was the speaker from you when you noticed? You get 50 ms Delay about every 17 meters due to the speed of sound in air :D

Hey marcofurtado, Your idea about studio monitors is a pretty good one. If you dont intend to play live, but only at home, your best bet would be studio monitors and/or headphones. You get (stereo!) high quality sound for similar money as a single good PA speaker or floor monitor. You can also use them for your computer or home theater as well (The Helix is a great audio interface for your computer). Additionally, studio monitors usually sound the same over a wide volume range, while bigger speakers sometimes do sound very different at different volume levels. If you ever do change your mind about a band and do want to play live somewhere, you can plug your Helix straight into the PA (FOH). If you want your own monitor you can get it when you need it. About different brands: The Helix will sound good with any decent speaker. There are so many tweaking options that you can adapt to different situations very flexibly. I am actually thinking about getting studio monitors myself (currently using an Alto TS210 active speaker) and am looking at the JBL LSR 305. Maybe others can weigh in their experience with different studio monitors.

For (regular Class A or AB) tube amps there is a definitive answer: If you have to mismatch, go for a lower load impedance. Reasons as in my earlier post in this thread. Solid state amps are not so simple, their tolerances vary widely depending on components and topology used. If i had to lean one way, i would agree with the statement that a higher load impedance would be preferable here. Though i would not mismatch my own power amps unless i knew exactly what topology and components were used. The reasoning would be that many semiconductor devices used in audio amplifier are indeed less resistant to overcurrents than vacuum tubes and will most likely be used in topologies without output transformers (significantly reducing the potential for over-voltages) or with multilevel/adaptive supply-voltages (which should add some safety margin for over-voltages). PS: sorry for double post, messed up quotes.

You are right there. a higher load impedance will result in less current flow for a given load voltage. This is however precisely what causes the higher voltage swing, as an output stage behaves somewhat like a current source, so it "tries to push the current into the load by applying more voltage". I can try to explain it better, but it will get quite long again. First a little preface: i am tallking about classic vacuum-tube amplifiers in Class A or AB Operation. Most of it translates to similarly operated solid state amplifiers.But many modern solid-state power amps are so called Class-D amplifiers and do not contain an Output transformers but only a low-pass filter. Also, pure Class-B amplifiers (rare in guitar applications) are not as susceptible to transformer overvoltages. The load impedance will be reflected (say "translated") by the output transformer. For a common vacuum-tube power-stage the say 8 Ohm load impedance gets reflected to a few thousand Ohms (depending on the winding ratio of the OT) at the power tubes. This reflected load impedance is what the output tube see and it defines the slope of the so called load line. A higher impedance means bigger voltage change for a given change in current and vice versa. Since we are dealing with a reactive load, you can have a dc bias current without any significant voltage drop over the transformer. So your output stage is sitting at the full supply voltage already when its idle. If you now put a signal into it, the voltage at the primary side will swing around this operating point. So with a higher load impedance the voltage will swing to much higher levels during the negative half swing of the input signal. For anyone interested in learning about design of vacuum tube amplifiers i can highly recommend the website of the brilliant merlin blencowe : http://www.valvewizard.co.uk/index.html You can find a bit more in depth explanation on this subject on the "Single Ended" page. Though if you are new to vacuum tubes maybe check out the triode and Pentode section first. BTW: OPs power-amp is actually a Class H one, which is basically a Class B amplifier with variable levels of supply voltage.

Sorry to jump back to the earlier discussion about impedance mismatches, but i feel i should add my .2 on this. First, i would highly recommend not to use the water/pump analogy on amplifiers, since the reality is much more complex. It is only a good tool for passive circuits. I will focus on the example of vacuum tube amplifiers since they are still very common in guitar related applications, but pretty much all of it translates to solid-state amps as well. Most power amps (pretty much all tube and many if not most transistor based ones) have an output transformer. A mismatched load impedance will not only affect the current through the power stage components, but also the voltage across the Transformer primary widnings. Especially in the case of a vacuum tube amplifier, this is a much more immediate concern than the current draw. The thermal time constants of the tubes, transformer and all the passive components are very high. So even if you operate them in overcurrent for quite some time they wont get damaged that easily. An output tube will actually start glowing red (redplating) for some time before it dies. To cook an output transformer you really need to push it. You will usually smell something is off before the insulation melts. The over-voltage faults are not so forgiving however. The a higher load impedance (than matched) will increase the voltage swing across the transformer primary significantly. (In an idealized case of an ideal pentode, transformer and infinite impedance the votlage swing would become infinite for any non zero gate signal. And yes, the voltage can exceed the supply voltage because of the inductive behaviour of the transformer) Over-voltage on the transformer will cause arcing between the infividual windings that will damage the insulation, resulting in shorted paths in the windings which if bad enough will ruin your output transformer. It can also cause arcing between output tube grids in case of a vacuum tube amplifier. I usually worry about the output transformer first, since it is the most expensive component in the power stage. That said, semiconductor devices like MOSFETs or BJTs are usually more susceptible to over-current than vacuum tubes (due to shorter thermal time constants and low maximum junction temperature), therfore it is more critical to match the impedance in a solid state amplifier, than it is in a vacuum tube one. Besides the danger of faults, a mismatched impedance will also alter the sound characteristics of your amplifier. For example, it can cause earlier and asymmetric clipping. Sorry if this got long and technical, the tldr is this: Match your load impedance! -> If you cant: Vacuum tube amplifier: use a lower load impedance (within reason!) and be careful with the volme settings, monitor the output tubes for redplating and keep your nose sharp for the smell of something cooking. (its usually safe though) Solid state amplifier: only use mismatched impedance if you like living on the edge! Hope this is helpful to someone. :D Cheers, Rolf PS: typed this in a bit of a rush at work, may edit some mistakes later. :rolleyes:

I only got my Helix recently and i love it already! Using it with an Alto TS210 and it sounds superb. The Litigator Model is my favourite currently and i've been tweaking a preset based on it for a week now. All my other gear is sitting in the corner gathering dust now, the only exception being my self buit amps which i do fire up every now and then for some extra raw sound. :D