Adventures in Fractal's Dual Rectifiers

[dk_ace]

@MirrorProfiles I've never owned one of the Mesa 4x12's. They were unobtainium here for a long time! Would still love to grab an OS 4x12 some day for the full Recto experience.

I used to gig my Recto with a Marshall 1960A with G12T75's and Ragdoll's Back to Zero album was the same amp through a Marshall 1960BV with the stock Marshall branded V30's.

You owe it to yourself to play one with their oversized 4x12. This thread had be scanning Craigslist last night hoping to find a deal on a recto….

D

 

[FractalAudio]

Okay, so here's what I found. Our OG Dual Rectifier has a 10A MV taper. The model uses 20A which is the same taper as the Recto2 models (https://store.mesaboogie.com/products/pot-593792-270s-1m-594-shaft-20-taper.html). I don't remember if I did this so that the models would be consistent or if it's simply a mistake.

So for a given MV setting on the real amp you will want to set the MV lower on the model. I'm undecided as to whether I'll change the model as that will mess up presets.

Other than that the model is in very good agreement with the amp.

 

[State of Epicicity]

I think the answer is to buy twenty Rectifier heads, one for each variation, model each one, then hold strongman competitions at FAS HQ involving lifting them in awkward ways. You win if you chain them all together and can drag them 100 yards through a muddy field.

I mean, the 5150 presence knob requires resetting presets too.

 

[texhex]

What other product/company can you directly interact with the lead developer/owner like this? Incredible!

If you weren't a FAS fanboy by now... you should be.

Doesn't hurt that this forum exists either... just sayin'.

 

[MirrorProfiles]

A load box. If that were a cab my cats would be permanently traumatized.

I was wondering if it’s possible to test with a cab rather than a load box….. I don’t mind scaring a few cats and squirrels

 

[FractalAudio]

I was wondering if it’s possible to test with a cab rather than a load box….. I don’t mind scaring a few cats and squirrels

No reason you can't use a real cab. Be sure to pick an impedance curve that's close to the cab. The Red channel has no negative feedback so the response is highly dependent upon the impedance curve.

 

[MTB1973]

Great discussion. Can we have more adventures?

 

[Elf]

What other product/company can you directly interact with the lead developer/owner like this? Incredible!

If you weren't a FAS fanboy by now... you should be.

Doesn't hurt that this forum exists either... just sayin'.

I don’t even own a FAS product but I’m a fan of @FractalAudio very cool to get his first hand opinions and expertise!

B.J. owner and main developer of Metric Halo comes to mind as someone that interacts directly to people over the web.

 

[Orvillain]

No reason you can't use a real cab. Be sure to pick an impedance curve that's close to the cab. The Red channel has no negative feedback so the response is highly dependent upon the impedance curve.

Does that apply to all modes of the red channel??? Raw/Vintage/Modern ??

 

[Orvillain]

Great discussion. Can we have more adventures?

 

[MTB1973]

Uber?

 

[holoholo]

Uber?

Me on helix?

 

[FractalAudio]

Does that apply to all modes of the red channel??? Raw/Vintage/Modern ??

No. Modern has no negative feedback. Vintage has quite a bit. We don't have a model of the Raw mode. I'm not even sure what that does.

If you go to the Power Amp page you can see the NFB.

The OG Dual Rec had no NFB in the Red channel. Why the Multi-Watt calls this "modern" is a mystery. Seems backwards.

 

[Orvillain]

Me looking at NeuralDSP advertising.

 

[Orvillain]

Why the Multi-Watt calls this "modern" is a mystery

Should be called Bizkit Mode tbh.

 

[FractalAudio]

Here's our OG Dual Rec into a real cabinet compared with the model into the appropriate SIC:

Green is the amp, blue is the Axe-Fx.

On the amp the MV is around 9 o'clock (as loud as I dared to go and not get divorced). I had to set the model to 1.2 to get the same response. Above that and the power amp starts clipping and the highs get reduced. This is to be expected given the different taper between the amp and the model.

 

[Orvillain]

Here's our OG Dual Rec into a real cabinet compared with the model into the appropriate SIC:

View attachment 15395

Green is the amp, blue is the Axe-Fx.

On the amp the MV is around 9 o'clock (as loud as I dared to go and not get divorced). I had to set the model to 1.2 to get the same response. Above that and the power amp starts clipping and the highs get reduced. This is to be expected given the different taper between the amp and the model.

Yeah more or less I was seeing a similar thing here. On the model you need to really stay below 2.5 for most of the usable sounds on a recto.

 

[FractalAudio]

Question, are the HF/LF Reso values in the Speaker tab multipliers from the nominal (flat) impedance?
ie. 16ohm nominal, LF Reso=7 so 16*7 = 112 ohm at the resonance peak?

Reason I'm asking is my gigantic DIY 1x12 has a quite narrow resonance peak at about 96Hz, it sounds massive with my tube amp and I want to replicate that.

View attachment 15371

The values are actually logarithmic.

If you send me the curve I can give you the appropriate values to enter. It won't be exact because there is information in the SICs that is hidden from the user. The data should be Z (mag and phase) from as close to DC as possible to at least 20K.

 

[James Freeman]

@FractalAudio
.mdat (REW)

https://drive.google.com/file/d/1CIXnHKG8nak7QItTsvOy8KSMvc1GytvG/

 

[DrewJD82]

Yeah more or less I was seeing a similar thing here. On the model you need to really stay below 2.5 for most of the usable sounds on a recto.

I’ve been saying this for about 2 years!!!!!