Reactive load, but 'better'

[rootz]

Not to sound arrogant with that title, but you know, I'm Dutch lol.
I'd been thinking about a new load lately and a hard time choosing one. Suhr: great load, but resonance peak at 120Hz, so not a simulated open back cab. Captor X: great software, but no reactive load, so unrealistic amp response. Ox: closed system, expensive, but also very good.
But hey, I like DIY, so why not build a 'better' Aiken load. Switchable presence and low end resonance peak (open back, closed back). Modelled after a single G12 65 in a closed and open cab.
No frills. No reamping, no speaker sim. Got a C.A.B. M+ for that. Works like a charm and takes any amp I throw at it.

[dorrisant]

Very nice!

[rccolgan]

woooooowwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww

[Bombacaototal]

Cool project!!

[gktamps]

Truly excellent work!
Any chance you would share your BOM and schematic?
Cheers,
Greg

[rootz]

Thanks for the kind words, or in Ryans case long word lol.
I do not have a BOM of this project, but based on the schematic and layout that is easy to figure out.
See the added LTspice screenshot for the main differences between the Suhr reactive load (non-IR version) and what I turned it in to. I ditched the line transformer of the Suhr load. Costs a lot and I don't see the benefit with the CAB M right next to the load. Short cables, so not much noise picked up.
Now, can you say late night practice without Boss Waza or Ox budget? Love this thing.

[Guy77]

Thanks for the kind words, or in Ryans case long word lol.
I do not have a BOM of this project, but based on the schematic and layout that is easy to figure out.
See the added LTspice screenshot for the main differences between the Suhr reactive load (non-IR version) and what I turned it in to. I ditched the line transformer of the Suhr load. Costs a lot and I don't see the benefit with the CAB M right next to the load. Short cables, so not much noise picked up.
Now, can you say late night practice without Boss Waza or Ox budget? Love this thing.

You said the magic words that peaked my interest! Open back cab and G1265 speaker. That is all I have been selling lately, so I am interested in trying this out.
Just need to clone myself first so I can have the time needed to build them LOLOLOLO
Great work as always Bas!

Guy

[rootz]

Not so sure if the electrical characteristics differ much between say a G12M of G12 65, Guy. The general principle is: get rising impedance with high end and get one (or two) impedance peaks in the low end. Two for a ported cab, one for closed or open back. I use a piece of software called REW to measure the characteristics of a build in speaker. Big fun with a EVM12L: resonance peak at 45 or so Hz in an open back cab. Rising impedance with frequency seems a bit flatter than with a G12 65. Might be one of the (more minor) reasons the speaker sounds a bit flatter/balanced/hifi with just about any guitar amp?
Anyway Guy, the design is in archive.zip. I did that for you, but I can't make extra spare time for you bro lol.

[Reeltarded]

Fantastic and NOT inexpensive! I am replacing Palmers with something a little more connective but without reactance. In main boxes 400w 16R with input, Jensen TRS/XLR, thru and external module for rheostat for thru added after I get happy response.

That thing you made is a monster!

[bepone]

interesting, i would need one too, i have never checked this , is this attenuator also or just load for the amp?

[Stephen1966]

Hey Bas,

Just want to say thank you! I heard one YouTube contributor call the Ox a "gamechanger". YouTuber born yesterday. But yours is a significant contribution here. Okay, it doesn't do everything the Ox does but - my opinion - it occupies an empty niche in the market. Something middle of the range. A lot of guitarists don't know one end of a screwdriver from the other. So, apart from the ampheads who live here, have you thought about taking this to market? You should. Not everyone can afford a $5k amp but if you can find an affordable price point, for all those metalheads who don't want to see a court injunction from their neighbours, I think you are onto a winner.

[rootz]

Hi Stephen, I'm not taking anything to the market soon. Which is why I shared the schematic and board layout, so folks can make their own PCB's. Too bad for the people who'd probably hold the screwdriver the wrong way around lol.

To answer your question Bepone: this is not an attenuator, but it could easily be. There are certain options. My preferred option would probably be to couple the load with a power buffer and use the line out to a DAW. I do not like the attenuation function of e.g. the Captor X.

Anyway, in an ideal world this load would be coupled with a stereo IR loader, or something like the digital/software side of the Captor X, which I do like.

Reeltarded, I highly recommend going reactive. But yeah, not inexpensive. I already had some parts, but making such a load will set you back around 200 bucks.