I used to think the Suhr Reactive Load IR always digitizes [I was wrong]

[Orvillain]

The Suhr RL IR... has built in IR loading. I never use it. I only ever use the unfiltered output.

In such a situation, if you clip the IR side of the loadbox - either the amp being too loud or the DI level of the box being too loud - it still affects the tone of the unfiltered audio output. This necessarily must mean that it digitizes the entire signal, even if you're not applying an IR.

If true... mega suckage.

I was wrong.

 

[James Freeman]

I think it's true.
I was wrong too.

I use my Suhr RL IR as passive load like a cab from the 'SPKR TRU' of the X-Load and take a line level signal from the X-Load, so the entire setup is passive. That also allows me to switch between two load curves by pulling the cable out from the 'spkr thru' output from the X-Load.

 

[James Freeman]

You can also use the Suhr RL IR passively from one speaker output and take a DI signal from the second speaker output jack of your amp into a 25k volume box then into a high impedance input or a buffer (boss pedal for example) then into your recording setup.

 

[GuitarBilly74]

Wrong too

 

[Jarick]

Interesting...glad I have the all analog version!

Did you ever have the non-IR model?

 

[GuitarBilly74]

Interesting...glad I have the all analog version!

Did you ever have the non-IR model?

I did, and honestly, they sound the same. Whatever Suhr did for the conversion, it's well done (as long as you don't clip it, I guess).

 

[Chocol8]

It's definitely true since the Unfiltered Out does not work without power. If it was a true all-analog path (like the non-IR version), it would still work.

Very NOT true. It just means that the unfiltered out has powered components which may be nothing more than a powered analog buffer. That could also be clipped so I don't think anything said in this thread implies that the signal on the unfiltered out is or is not converted to digital.

 

[ZEN Amps]

It’s not true. Any analog design can be pushed into clipping, and there seems to be confusion between analog and passive/active in this thread.

 

[Orvillain]

Did you ever have the non-IR model?

No but I think I'm going to get one. Because I don't entirely trust that the digital circuitry doesn't add perceptible latency, as far as cloning technology goes.

It’s not true. Any analog design can be pushed into clipping.

Then why does the digital side show the clipping LED, but the analog side doesn't?

And if you crank that DI level high enough, it does sound like digital clipping. Not analog. I don't trust that block diagram right now.

 

[EOengineer]

This fear, baseless or not, was part of why I opted for the OG Suhr RL. I’d prefer to keep digital crap out of my load box.

 

[ZEN Amps]

Then why does the digital side show the clipping LED, but the analog side doesn't?

And if you crank that DI level high enough, it does sound like digital clipping. Not analog. I don't trust that block diagram right now.

The distortion you’re hearing is the active output stage being slammed, and yes this can sound similar to digital clipping. The LED position is irrelevant.

John Suhr explicitly answers what you’re unsure about in post 7 here, and frankly the block diagram makes robust technical and practical sense.

If you believe Suhr is being dishonest on both counts then next step is to reverse engineer the unit. You’ll find his claims are indeed true.

https://www.thegearpage.net/board/i...g-a-tube-amp-unfiltered.2498629/post-37648993

 

[Orvillain]

The distortion you’re hearing is the active output stage being slammed, and yes this can sound similar to digital clipping. The LED position is irrelevant.

John Suhr explicitly answers what you’re unsure about in post 7 here, and frankly the block diagram makes robust technical and practical sense.

If you believe Suhr is being dishonest on both counts then next step is to reverse engineer the unit. You’ll find his claims are indeed true.

https://www.thegearpage.net/board/i...g-a-tube-amp-unfiltered.2498629/post-37648993

Okay, thanks for confirming.

The unit sounds bad when you drive it with even a moderately loud amp, regardless. So.... I need a different unit I think. I'm really getting sick of it. I notice that when I do a capture of my amps with my Neve DI Box (and a real cab as the load), they sound great. When I do it with the Suhr, very often they turn up sub optimal.

PS: It's a bit strong to say I was accusing him of being dishonest. I was just saying I don't trust a picture.

 

[Chocol8]

This fear, baseless or not, was part of why I opted for the OG Suhr RL. I’d prefer to keep digital crap out of my load box.

If you don't use the IR, I think the only difference is the OG has a higher impedance on the passive output whereas the IR version gives you the powered (analog) buffered output with a significantly lower impedance which has some real world advantages. It doesn't make sense to convert the DI signal to digital and then back to analog if not doing any processing to it.

 

[laxu]

The unit sounds bad when you drive it with even a moderately loud amp, regardless. So.... I need a different unit I think. I'm really getting sick of it. I notice that when I do a capture of my amps with my Neve DI Box (and a real cab as the load), they sound great. When I do it with the Suhr, very often they turn up sub optimal.

Does the problem go away if you connect a cab to the "amp thru", effectively disabling the reactive load?

You could probably test things easily with the line out of the Mesa Mark V since it's tapped from the speaker out.

 

[ZEN Amps]

Okay, thanks for confirming.

The unit sounds bad when you drive it with even a moderately loud amp, regardless. So.... I need a different unit I think. I'm really getting sick of it. I notice that when I do a capture of my amps with my Neve DI Box (and a real cab as the load), they sound great. When I do it with the Suhr, very often they turn up sub optimal.

PS: It's a bit strong to say I was accusing him of being dishonest. I was just saying I don't trust a picture.

Yeah I know man, that’s why I said “if”!

It does indeed sound shit when it clips, but I’m
surprised rolling back the DI level is having negative side effects for you. Sub-optimal how?

 

[EOengineer]

If you don't use the IR, I think the only difference is the OG has a higher impedance on the passive output whereas the IR version gives you the powered (analog) buffered output with a significantly lower impedance which has some real world advantages. It doesn't make sense to convert the DI signal to digital and then back to analog if not doing any processing to it.

Which makes logical sense but at the time it was difficult to get a conclusive answer. Even if they did keep the converters out of the equation I’d always choose to keep my IR loader separate. The loader Suhr uses in that unit is garbage anyway.

 

[ZEN Amps]

If you don't use the IR, I think the only difference is the OG has a higher impedance on the passive output whereas the IR version gives you the powered (analog) buffered output with a significantly lower impedance which has some real world advantages.

Yes this is the case.

On that, I'm not sure the impedance issue associated with the OG is that widely-known or understood. I certainly was unaware when using one for the first time, I just thought it sounded dull.

 

[Orvillain]

Does the problem go away if you connect a cab to the "amp thru", effectively disabling the reactive load?

You could probably test things easily with the line out of the Mesa Mark V since it's tapped from the speaker out.

Yeah it sounds a lot better. The Neve sounds better still.

Yeah I know man, that’s why I said “if”!

It does indeed sound shit when it clips, but I’m
surprised rolling back the DI level is having negative side effects for you. Sub-optimal how?

Can't get the output loud enough without clipping the analog circuitry it would seem. Like I genuinely have issues getting the Stadium into the green zone without having the DI out on the RL above 1 o'clock, and it tends to start to sound a bit driven and crap there.

Yes this is the case.

On that, I'm not sure the impedance issue associated with the OG is that widely-known or understood. I certainly was unaware when using one for the first time, I just thought it sounded dull.

Maybe this is why ... hmmmmmm....

 

[laxu]

Yeah it sounds a lot better. The Neve sounds better still.

What about if you connect the Suhr RL in parallel with your real cab?

E.g use the Mark V 4 ohm outputs -> 8 ohm cab + 8 ohm Suhr RL.

In this scenario the volume should drop by about 3 dB so compensate with amp if needed.

 

[ZEN Amps]

Can't get the output loud enough without clipping the analog circuitry it would seem. Like I genuinely have issues getting the Stadium into the green zone without having the DI out on the RL above 1 o'clock, and it tends to start to sound a bit driven and crap there.

I know very little about the Stadium - can you adjust its input level? Maybe it's just set too low and is attenuating the signal more than is required for the load's output?