Tell Me About Reactive Loads...

MatrixClaw

Silver Supporting Member
Messages
126
Hey guys,

So, I've been trying to downsize to a smaller rig lately and settling on the perfect cab setup for my two amps has made me keep going back and forth on what I want and if I'd just be limiting myself if I go too small. I had looked into the Captor X before so I could record silently if I wanted to, but also use it as an attenuator through my cab, which would probably be how it'd get used most of the time... however, I started researching more on how this technology could be used and I'm curious if I could use it to replace the my cabs entirely but still play through them live without hooking up to a recording interface.

I already have a Line 6 PowerCab Plus for my FM3 that I really like... I'd like to keep two of my tube amps (a Mesa TA-15 and Mark IV), but have more control over their volume when I can't play loud. Both amps sound great, but need some good volume to really get the goods and that's not always something I can do. Can I use a Captor X or Suhr Reactive Load as a loadbox, crank up the amp and then output directly to the PowerCab and use it as my "cab"? This sounds like a pretty interesting setup and one that would be a LOT more flexible, as I wouldn't even have to worry about what cab and speakers I get, as I'd have thousands of IRs at my disposal with every speaker imaginable. I also gain the recording features when I need them, which is cool as well.

The only thing I'm kinda scared of is damaging an amp with one. I've heard some horror stories of people using these and blowing transformers, though not many specifically with these two units.

How are you guys using yours and would you recommend them in my situation if I mostly want it for playing at home through the PC+ and not necessarily as a recording tool? Is the Suhr Reactive Load the same tech as the Reactive Load IR? I don't technically need the IR loader since I have a PC+ that can do it, but it has several other features the basic model doesn't, which leads me to believe it may sound different as well?

Thanks!
 

blackba

Gold Supporting Member
Messages
11,324
I also own a Mesa mark Iva and ta15. Both IMO actually work great at low volumes with the ta15 being the easiest to control. I do agree that they sound better cranked, but I have been pleased with them at home volumes.

Anyway there are a few ways to use the reactive loads and I list this in order of preference. Note I am leaving out the headphone or recording options.

1. amp ->reactive load -> SS or tube power amp -> guitar speaker cab
2. Amp -> reactive load -> Ir loader, which can be your pc -> pa or line6 power cab

In the case of the second option you can use the Suhr rlir since it has a built in ir loader, but you need speaker simulation, sounds like you want to use your pc. I will say I always prefer the first option. Also I wanted to note that you can run effects after your reactive load, but you may need a line to amp attenuator like the diy.re l2a if you need to line Level down to instrument level.
 

Echoplexi

Gold Supporting Member
Messages
10,096
I love the Suhr RLIR, and use it most often as @blackba described option 1. I usually have things like delay/reverb after the load going into the power amp. Also have had success with it recording with the built in IRs, but prefer a real cab if possible
 

HeavyCream

Silver Supporting Member
Messages
3,763
OP, I’m an advocate for reactive load re-amping as well. I use a reactive load (Two Notes Captor) and a separate power amp (Valveking 50w via FX Loop Return) to tame my JTM45 and other amps. I run some FX like verb/delay post amp and use a couple different speakers/cab. I get astounding tones from this rig (imo). Highly recommend.

In your case, yes, you can use your powered cab for reamping. If you’ll be playing through full range speakers you’ll want IR’s, which is what you said anyway. That will give you tons of cab options for DI or low volume playing. It sounds like you plan to keep a couple of your favorite cabs around too. You need a couple for live playing but I like using real guitar speakers with my reamping rig. I don’t have to play so quiet that speakers are useless and I like speakers that give up the goods early. If you want to reamp with real guitar speakers, you’ll need to use a power amp after the reactive load.

Reactive loads are safe because they ‘react’ the way a speaker does so your amp doesn’t see impedance mismatches. Running your amp(s) harder can, however, shorten power tube life or possibly even reveal an existing weak spot in an amp. I’ve been diming my amps nearly every day all year (‘20) without any issues.
 

Ejay

Member
Messages
5,552
putting an IR in your chain changes your sound from a cab..to a miced cabIn the context of a live band thats a major compromise to my ears.
In the context of recording im fine with it.

Re amping with SS powersections is ok(ish) at low volumes, but tube powersections defenitly have an edge on higher volumes.

but...you got fm3 and powercab...if that sounds good to you...your amps into that speaker are gonna sound the same as their Fm3 models....which raises the question what the added value is of attanuated amps into the powercab compared to fm3 into powercab...I think that’s zero.

plugging your fm3 into the return of one of your tubeamps however....thats a sound upgrade!!..and that will sound a good as anything at low volume! Try it!...switch cabsims off...and dial the global eq first to compensate for the speaker thats in your cab.
 

piper19

Member
Messages
22
I've been looking into similar solutions as the OP mentions. I wonder if the Captor X can provide these things:
-home playing through phones or active speaker
-home playing on guitar cab through attenuation at highest setting
-rehearsal going direct to PA
-gigs with guitar cab through attenuation on lowest setting and providing PA with a direct signal.
 

baron55

Member
Messages
366
I've been looking into similar solutions as the OP mentions. I wonder if the Captor X can provide these things:
-home playing through phones or active speaker
-home playing on guitar cab through attenuation at highest setting
-rehearsal going direct to PA
-gigs with guitar cab through attenuation on lowest setting and providing PA with a direct signal.
All of the above and then some.
 

teemuk

Member
Messages
3,180
Reactive loads are safe because they ‘react’ the way a speaker does so your amp doesn’t see impedance mismatches.
Not true. With reactive load impedance varies with frequency and presents both inductive and capacitive characteristics. It's much more difficult load for an amp than a purely resistive load. However, as safe as any generic speaker load regardless.

Reactive loads are employed, not because of "safety" but, because the varying impedance characteristics affects frequency response (assuming low damping factor) and therefore emphasize signal unlike a purely resistive load.
 

Gasp100

Silver Supporting Member
Messages
22,226
I've been looking into similar solutions as the OP mentions. I wonder if the Captor X can provide these things:
-home playing through phones or active speaker
-home playing on guitar cab through attenuation at highest setting
-rehearsal going direct to PA
-gigs with guitar cab through attenuation on lowest setting and providing PA with a direct signal.
Yes to all of the above. The Captor X is pretty nice!
To the OP, sounds like all you need is the Suhr RL (not IR). As you described, amp loaded down and line out to powercab + and apply your favorite speaker modeling from the PC+.
And if you want to record or use headphone you can of course to amp loaded down -> FM3 for IR's AND post FX as well!
Adding the Suhr RL to your gear list you would really be able to use everything in varying configurations and get the most out of your amps.
 

HeavyCream

Silver Supporting Member
Messages
3,763
Not true. With reactive load impedance varies with frequency and presents both inductive and capacitive characteristics. It's much more difficult load for an amp than a purely resistive load. However, as safe as any generic speaker load regardless.

Reactive loads are employed, not because of "safety" but, because the varying impedance characteristics affects frequency response (assuming low damping factor) and therefore emphasize signal unlike a purely resistive load.
So, a purely resistive load is safer than a reactive load (speaker or RL box)?

FWIW, I didn’t choose a reactive load box for safety reasons but it was my understanding that an amp would rather see a reactive load than a no frills resistive load. Impedance being a ‘moving target’. No?
 
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Messages
1,004
I recently bought a Boss tube amp expander. It replaced my THD Hotplate I had for over a decade. I was floored how good it sounded as an 'attenuator'. I'm still fooling around with direct in as I think all the cab models they have sound awful.
 

teemuk

Member
Messages
3,180
So, a purely resistive load is safer than a reactive load....
Impedance matched, yes. Much less stress for amp to drive fixed, non-varying resistance than a widely varying impedance (e.g. resonant frequency presents huge mismatch) with capacitive and inductive components that cause phase shifts of current and voltage and flyback.
...But amps have level frequency response to resistive loads, which can sound dull.
 
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HeavyCream

Silver Supporting Member
Messages
3,763
Impedance matched, yes. Much less stress for amp to drive fixed, non-varying resistance than a widely varying impedance (e.g. resonant frequency presents huge mismatch) with capacitive and inductive components that cause phase shifts of current and voltage and flyback.
...But amps have level frequency response to resistive loads, which can sound dull.
I see. Thank you :)
 

kruts

Member
Messages
392
From what I've read, the reactive loads that have a "U" shape curve are the ones that pose the most risk of flyback voltages and damage to the amp's transformer.

The Suhr Reactive Load does not have a "U" shape curve, per-@Husky comments about his design.

I use a Suhr Reactive Load to load my amp, add reverb and delay (to the line level signal), and then re-amp using a tube power amp.

It is a glorious setup, and I can't say enough good things about the Suhr Reactive Load. Thank you John Suhr!!!
 




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