Reactive Loadboxes in 2023

[Eazy-ESP]

He ain’t wrong in the least homie. I realize this was already squashed, but the speaker impedence is a huge, huge thing here. He’s not saying they sound “bad”, they just aren’t accurate. And they ARENT. PERIOD. Just because some of yiu don’t hear it or feel it doesn’t mean the rest of us don’t, especially those of us with great sounding rooms. Just because Steve Stevens used it, great. Do you have his FOH or his pro audio equipment? I don’t think so. The problems we Mortals have may not be issues someone like Steve Stevens has considering the arsenal of resources players like that have.


They aren’t accurate. The driftwood and st rock is the only ones even close, and even then, the way they react with an amps poweramp compared to a cab is STILL off.

Ease up a little homeboy. He likes what he likes. I don’t see how Steve Stevens having better quality FOH or pro audio equipment changes the load characteristics. Also, you’ve been enamoured with the AXE-FX recently. Not what I hear as realistic sounding.

 

[Shask]

It’s most easily understood by looking at the frequency plot of a speaker. Below is the plot of a greenback cab and v30 cab from the tgp thread linked earlier. These are 8 ohm cabs, see the ‘ohms’ on the right hand side of the scale.

View attachment 239105

When you measure an 8 ohm speaker with a multimeter you read a dc resistance of about 7.5 ohms since that is measured at 0hz (DC). However the actual resistance varies quite dramatically at different frequencies. The big low peak around 100hz is the resonant frequency of the speaker cone (cab internal volume also influences what frequency it is at). The rising impedence from about 1000hz up is due to the inductance of the voice coil. Each speaker and enclosure will result in a slightly different curve (where the low peak is, how tall and wide, how much the high frequency increase, etc) but every speaker will have that same general shape. Compare to the plot of the various settings of TAE, which doesn’t represent a real speaker load.

Many older load boxes modeled the high frequency impedence only with no low peak. This is because getting the low resonant peak right is expensive, and requires a pretty specialised capacitor (big, bipolar, very low esr) and inductor (big, high current capacity, as close to zero dcr as possible, no saturation). Easier now as those parts have gotten easier to make and cheaper.

But regarding sound, does it matter? Some people still use hotplates and they sound good to them, and they are much further off. Answer is, it depends.

With my recto in modern mode, there is no negative feedback in the power amp (power amp is ‘undamped’), so the output of the amp follows the impedence curve (which is why recto’s in modern mode have huge bass and treble response). Any change to the load has a large effect on the sound. When I built my DIY load I put a switch on it that shorts the reactive element and turns it into a resistive load. I flip that switch and the recto goes from sounding very punchy and big, to sounding like a practice amp in a cardboard box.

However with my jet city jca50, which has much more power amp negative feedback, there is almost no difference I hear flipping between reactive and resistive. Though if I run the presence high, it’s more noticeable (since turning up presence and depth decreases power amp damping in the high and low frequencies, respectively).

A bit of negative feedback, which linearises the amp output and makes it more stable and less sensitive to the load, and differences between loads become less noticeable.

Thank you for reading my blog

I have the Fractal LB-2. I think it does a good job, but it does have a little less bass, and more highs/presence then running straight in. That is probbaly because it mimics Greenbacks though, and I generally like oversized and V30s.

This is funny, because I said this earlier in the thread, and then your pictures shows exactly that.

 

[vultures]

I used the Suhr RLIR for a bit. It worked fine for recording direct amp out stuff as long as you weren't cranked too loud. I found there to be a high end squeal when I cranked the amp loud. Not amp feedback, like a synthetic note. It made re-amping pretty difficult and capturing with a Quad Cortex quite difficult. Tried using everything on the same power conditioner, everything on different power conditioners, moving the amp and the RLIR to opposite ends of the room, still happened. Although I was using IIC+'s with the Masters at 3, which is unbearably loud when plugged into a cabinet. Anyone run into an issue like that on other loadboxes?

 

[Arch Stanton]

I used the Suhr RLIR for a bit. It worked fine for recording direct amp out stuff as long as you weren't cranked too loud. I found there to be a high end squeal when I cranked the amp loud. Not amp feedback, like a synthetic note. It made re-amping pretty difficult and capturing with a Quad Cortex quite difficult. Tried using everything on the same power conditioner, everything on different power conditioners, moving the amp and the RLIR to opposite ends of the room, still happened. Although I was using IIC+'s with the Masters at 3, which is unbearably loud when plugged into a cabinet. Anyone run into an issue like that on other loadboxes?

It's the capacitors causing that.

Undersized.

You want a cap that has outstanding high frequency characteristics, low dielectric absorption factor, high current capacity, and handles fast high current pulses.

 

[VESmedic]

Ease up a little homeboy. He likes what he likes. I don’t see how Steve Stevens having better quality FOH or pro audio equipment changes the load characteristics. Also, you’ve been enamoured with the AXE-FX recently. Not what I hear as realistic sounding.

My point is, the things that may hamper us with limited resources may not hamper someone who can get nothing but green M&M’s in the green room, you know what I mean? It doesn’t change the load characteristics of course, but that may become completely irrelevant with how awesome everything else in his signal chain is, that’s all I’m saying.

 

[tallcoolone]

My point is, the things that may hamper us with limited resources may not hamper someone who can get nothing but green M&M’s in the green room, you know what I mean? It doesn’t change the load characteristics of course, but that may become completely irrelevant with how awesome everything else in his signal chain is, that’s all I’m saying.

I’m sorry this makes no sense to me—guy is just a guitar player plugging a guitar into a board, into an amp, into the TAE then into a cab. I assume he’s using mics to feed his signal to FOH but he could also be running direct using IRs. Just like the rest of us guitar players do. What’s he got in his chain that I won’t have in mine this Saturday night?

 

[Eazy-ESP]

I’m sorry this makes no sense to me—guy is just a guitar player plugging a guitar into a board, into an amp, into the TAE then into a cab. I assume he’s using mics to feed his signal to FOH but he could also be running direct using IRs. Just like the rest of us guitar players do. What’s he got in his chain that I won’t have in mine this Saturday night?

Probably some hair spray residue.

 

[VESmedic]

I’m sorry this makes no sense to me—guy is just a guitar player plugging a guitar into a board, into an amp, into the TAE then into a cab. I assume he’s using mics to feed his signal to FOH but he could also be running direct using IRs. Just like the rest of us guitar players do. What’s he got in his chain that I won’t have in mine this Saturday night?

Oh I don’t know, someone who knows what they are actually doing? A 200,000 Midas board? Actuallly good preamps? A monitor tech just for his in ears that (again), knows what he’s doing? A line array system that’s actually tuned to the room? Side splash/fills? Do you have all of that down at the local watering hole on Saturday night?


I take it back, your arrogance is much worse than I thought. I didn’t realize professional guitar players and bands didn’t have anything that local bands don’t at the local dive bar on Saturday night, my bad.

 

[tallcoolone]

Oh I don’t know, someone who knows what they are actually doing? A 200,000 Midas board? Actuallly good preamps? A monitor tech just for his in ears that (again), knows what he’s doing? A line array system that’s actually tuned to the room? Side splash/fills? Do you have all of that down at the local watering hole on Saturday night?

None of which have anything to do with his guitar feed which is what we are talking about.

I take it back, your arrogance is much worse than I thought.

Oh my, I hope I’ll be able to make it through the day

Maybe you should block me so I stop making you so upset. You came barreling into this thread throwing out accusations and making a general ass of yourself all on your own, deflect all you want. As I’ve said to you 3 times now, I don’t care what you think man

 

[VESmedic]

None of which have anything to do with his guitar feed which is what we are talking about.


Oh my, I hope I’ll be able to make it through the day

Maybe you should block me so I stop making you so upset. You came barreling into this thread throwing out accusations and making a general ass of yourself all on your own, deflect all you want. As I’ve said to you 3 times now, I don’t care what you think man

I KNOW you don’t care what I think, because you look like an arrogant moron. I may look like an ass, but Atleast I’m not blatantly arguing with people on a topic I admit I know nothing about…



And none of which has anything to do with his “guitar feed”? LOL….thank you for continuing to prove my point on your arrogance.



Also, continue to come back into this thread to tell me how much you don’t care what I think, you’re doing a great job of proving that.

 

[Devin]

I feed my guitar Mexican cuisine

 

[Arch Stanton]

I feed my guitar Mexican cuisine

 

[nightlight]

Wow, I sure missed a lot.

Reading more and more about reactive load boxes, I think the best way to record direct with one of these boxes is to hook up to a cabinet, so that the load is defeated and you have an accurate cab to record with.

My only concern is that my attenuating the amp, while still trying to get enough power out of the amp to push a DI the right way, you could damage the tubes or maybe the transformer. I am scared to try it, but will do my best one of these days, maybe tomorrow.

On the subject of people using equipment that they say is dangerous or bad, I treat them the same way as people who say equipment is good and great but don’t use it. By that I mean, it comes across as unreliable and disingenuous.

Also, one thing I have learnt in audio is not to rely too much on what you see, such as curves on a graph, but rather what you hear. I remember I had the same disconnect with the Kemper when I had one, where a tone match curve would indicate it was exactly the same as a source amp, but when I heard it, there was a lot of low end content missing.