RNDI vs. USB Interface

[Frank Tuesday]

I really don't agree with much of what you said in either post.

Sorry you don't agree with facts.

 

[rumblinbass]

Sorry you don't agree with facts.

Ok.

The Scarlett instrument input is by definition a DI. DI stands for Direct Injection, which just means connecting your instrument into the rest of the signal path, without using a speaker and mic. If you aren't using a mic, you are using DI.

DI is not the same as a DI Box. One is a method, the other is a physical object. A DI Box is a tool you can (but do not have to) use to DI an instrument. It is useful tool because it provides functions such as impedence matching, balancing, ground lifting, signal splitting, buffering, tonal modification, etc. But if you don''t require any of those functions, it is redundant and unnecessary.

So, your definition of a DI sounds like a pretty generic definition for an input. This is a fact?
So, a Mic Pre input is a DI, or a Line input, or an Insturment input, or an Aux input, or...?

DI stands for either Direct Inject or Direct Interface. For me, when someone refers to a "DI", I take it to mean "DI box". Maybe not for you. Fine.

I do not accept your definition as fact.

Also, for what it's worth - to me, an input with high input impedance and gain optimized for an instrument is an "Instrument Input".

You're confusing things. RNDI needs phantom power, but that is not why it "needs" to be plugged into a mic pre. It "needs" to be plugged into a mic pre because it outputs a balanced signal whose impedance, amplitude benefit from a mic preamp because the input on the pre has specifically been designed to accept these input signals.


There are ways to provide phantom power to the RNDI without using a mic pre.

DI's (or I guess for you, DI Boxes) were developed years ago to interface or inject a guitar or bass directly into the Mic Pre Input of a sound board. Many are passive, but those that are active need a power source...again because they typically connected to a Mic Pre, they use Phantom Power...like a microphone. Some use batteries, some don't have that option. The RNDI does not. That is a fact.

I'm not confused though you seem to be a little confused as to why an RNDI "needs" to be plugged into a Mic Pre.
A transformer balanced output can drive both a balanced or unbalanced input. That is one benefit of using a transformer. That is a fact.
A balanced Mic Pre input does not need a balanced source (however it is probably a bad idea to apply Phantom Power to an unbalanced source). That is a fact.

My use of the word "needs" may be a little strong but why would you use anything else?
The RNDI was designed for that application. A Mic Pre has both power supply and gain.
The RNDI needs Phantom Power. That is a fact. I guess you don't need gain...I do.

Maybe there is a box out there somewhere that provides Phantom Power without a Mic Pre.
That seems silly to me because I need gain.

What other ways other than phantom power to supply power to the RNDI are there?

 

[Frank Tuesday]

So, your definition of a DI sounds like a pretty generic definition for an input. This is a fact?
So, a Mic Pre input is a DI, or a Line input, or an Insturment input, or an Aux input, or...?

DI stands for either Direct Inject or Direct Interface. For me, when someone refers to a "DI", I take it to mean "DI box". Maybe not for you. Fine.

I do not accept your definition as fact.

Also, for what it's worth - to me, an input with high input impedance and gain optimized for an instrument is an "Instrument Input".

This is literally the definition of Direct Inject (DI). Recording an instrument while bypassing a speaker and microphone. Most of the time, when people talk about DI, they are using a Direct Box, but not always. From your definition, it sounds like the RNDI is just an Instrument Input with some extra features. Otherwise known as a Direct Box.

DI's (or I guess for you, DI Boxes) were developed years ago to interface or inject a guitar or bass directly into the Mic Pre Input of a sound board.

Many are passive, but those that are active need a power source...again because they typically connected to a Mic Pre, they use Phantom Power...like a microphone. Some use batteries, some don't have that option. The RNDI does not. That is a fact.

I'm not confused though you seem to be a little confused as to why an RNDI "needs" to be plugged into a Mic Pre.
A transformer balanced output can drive both a balanced or unbalanced input. That is one benefit of using a transformer. That is a fact. A balanced Mic Pre input does not need a balanced source (however it is probably a bad idea to apply Phantom Power to an unbalanced source). That is a fact.

My use of the word "needs" may be a little strong but why would you use anything else?
The RNDI was designed for that application. A Mic Pre has both power supply and gain.
The RNDI needs Phantom Power. That is a fact. I guess you don't need gain...I do.

Maybe there is a box out there somewhere that provides Phantom Power without a Mic Pre.
That seems silly to me because I need gain.

What other ways other than phantom power to supply power to the RNDI are there?

Phantom Power Supplies | Sweetwater

Which is why, out of all of the functions that a Mic Preamp serves when used with a Direct Box, it is baffling that you chose the one that is the easiest to replace without loss of sonic quality. I have old mic pres that don't have phantom power. And I could still use the RNDI with them. I have old mic pres that only supply 8v of phantom power. And I could still use the RNDI with them. Because I have other ways of providing phantom power to the RNDI. I can even plug the output of the RNDI into my bass amp or turntable preamp by using a phantom power supply. Clearly, not all of those are good ideas, but none require a mic preamp.

I only am being pedantic because you have the opportunity to educate people on the importance of impedance matching, level matching, gain staging, balanced vs unbalanced signals, etc. But you chose phantom power? It's a disservice to people who are trying to learn.

Even Rupert Neve Designs calls the instrument input on their 517 a DI. Functionally, it does the same thing as the instrument input on the Scarlett: feed the instrument input into the mic preamp.

 

[DirkP]

I own the RNDI and like it as a high quality DI. But I think it is a bit overrated as a sound creating tool, DIs are used to change the signal to mic-level to allow longer cable routes without adding noise and not to manipulate the sound. The transformer might have a bit of an influence on the sound, but not much. For 300,- it is a bit overpriced. I would rather buy a preamp and even more so a good clone of an 1176 or LA2A comp if it is about shaping your sound.

 

[rumblinbass]

This is literally the definition of Direct Inject (DI). Recording an instrument while bypassing a speaker and microphone. Most of the time, when people talk about DI, they are using a Direct Box, but not always. From your definition, it sounds like the RNDI is just an Instrument Input with some extra features. Otherwise known as a Direct Box.




Phantom Power Supplies | Sweetwater

Which is why, out of all of the functions that a Mic Preamp serves when used with a Direct Box, it is baffling that you chose the one that is the easiest to replace without loss of sonic quality. I have old mic pres that don't have phantom power. And I could still use the RNDI with them. I have old mic pres that only supply 8v of phantom power. And I could still use the RNDI with them. Because I have other ways of providing phantom power to the RNDI. I can even plug the output of the RNDI into my bass amp or turntable preamp by using a phantom power supply. Clearly, not all of those are good ideas, but none require a mic preamp.

I only am being pedantic because you have the opportunity to educate people on the importance of impedance matching, level matching, gain staging, balanced vs unbalanced signals, etc. But you chose phantom power? It's a disservice to people who are trying to learn.

Even Rupert Neve Designs calls the instrument input on their 517 a DI. Functionally, it does the same thing as the instrument input on the Scarlett: feed the instrument input into the mic preamp.

Well; for educational purposed then, here is the definition of a DI Box or unit provided by a quick google search -

"A DI unit (direct input or direct inject) is an electronic device typically used in recording studios and in sound reinforcement systems to connect a high-output impedance, line level, unbalanced output signal to a low-impedance, microphone level, balanced input, usually via an XLR connector and XLR cable"

The RNDI follows this definition.

RNDI does not have gain so no, it does not follow "my definition" of an Instrument Input.

Phantom Power is a pretty standard feature on all current Mic Pres. Considering that the RNDI has only been around for what...6 or 7 years...maybe 8...would be designed to work with current, modern Mic Pres.
I'm glad you have Mic Pre's without Phantom Power. They didn't always come with Phantom, so you would need a box like that which you linked. Like I said...Phantom power is a standard feature with most modern Mic Pre's.

I'm sure there are many ways to power an RNDI. However, the RNDI was designed to work with the modern and widely accepted Phantom Power scheme. For educational purposes I would not muddy the waters with, as you said, those that are not all good ideas.

It is baffling that I chose the one (Mic Pre?) that is the easiest to replace without loss of sonic quality? Really?
There are plenty of Mic Pre's that have plenty of color. Some are chosen for their color. Some are chosen for their cleanliness. Since you mentioned Rupert Neve Designs, the Mic Pre in the 5035 and 5025 were designed to offer color and a different flavor as opposed to other RND Mic Pres.

The Instrument Input on a 517 is INST. Not DI. For educational purposes I'm glad I cleared that up.
Like the INST input on the Scarlett Interface it has a high input impedance and gain. Which is consistent with what I consider an instrument input.

 

[Frank Tuesday]

Yes, you posted a definition for a "DI Unit". I've never claimed the RNDI isn't a direct box, so I don't know what your point there is.


And the Rupert Never Designs website disagrees with you. They explicitly call the 517 a "500 Series Mic Pre / DI / Comp". But what would they know?

517 Mic Pre / DI / Compressor (500 Series) — Rupert Neve Designs

 

[rumblinbass]

That is the definition that comes up when searching Direct Inject.

I have been in the audio industry in several roles for more than 25 years. I have never heard anybody ever refer to DI as a method.
This entire thread has been about the RNDI not a method.

You referred to the instrument input on the 517 - not the product description.
The instrument input jack is literally labelled INSTR - not DI.

 

[Frank Tuesday]

That is the definition that comes up when searching Direct Inject.
You want to call inputs "direct injects"?
You do you. Not terminology I'm familiar with.

I have been in the audio industry in several roles for more than 25 years. I have never heard anybody ever refer to an input as a DI.

You referred to the instrument input on the 517 - not the product description.
The instrument input jack is literally labelled INSTR - not DI.

The literal input jack is not a DI box, but using the instrument input is using the unit as a DI box, just the same as the Scarlett.

 

[Rich Fiscus]

My question wouldn’t necessarily be about whether I’d prefer the sound with the RNDI, which I almost certainly would, but whether I could get the same or better sound after recording straight to my interface. To my ears, the RNDI sounds like the kind of DI a top notch studio engineer would have built back in the days when things like DI boxes in a good studio were built in house by the resident mad scientist. It seems like something you should be able to recreate inside a DAW for a lot less than the price of the hardware.

 

[Krisfield]

There’s quite a bit of discussion in the gear forums regarding Hi Z vs DI Box. The consensus in the way I interpret the discussions, is use the RNDI Box if you wish to add some colour or character to your signal while recording. Or use the Hi Z input if you want a dry signal to play around with in the DAW. So if you’re after that Rupert NEVE DI signature sound, use that and go into the Low Z input of the user interface. If you’ve got some good plugins, use the Hi Z input. Another thing I’ll add is the Focusrite Scarlett is an entry level user interface and RNDI is a pro level DI. I would be more comfortable pairing the RNDI with something like an UAD Apollo user interface that has very good mic pre’s and AD/DA converter. But then again, I probably wouldn’t need the RNDI if I had an Apollo.

Is anyone using an RNDI to record direct and do you think the quailty is much better than just using the built-in DI on an interface like the Focusrite Scarlett series. Thank you.

 

[rumblinbass]

Even Rupert Neve Designs calls the instrument input on their 517 a DI. Functionally, it does the same thing as the instrument input on the Scarlett: feed the instrument input into the mic preamp.

I mis-read this. My mistake. I apologize.
Yes, you are correct. The 517 DI has an instrument input.
Functionally, the instrument input does not into the Mic Preamp. It is Blended with the Mic Preamp.
I have the Scarlett Solo, which is a little different than the other Scarlett interfaces. The Solo has physically separate input connectors and separate gain control for the Mic Pre and Inst/Line. I cannot speak with any certainty about the signal path.

Our conversation has made me think on the terminology of DI, DI Box, and Direct Box. All 3 of these terms are used interchangeably.

Again, I do apologize.

 

[Frank Tuesday]

I mis-read this. My mistake. I apologize.
Yes, you are correct. The 517 DI has an instrument input.
Functionally, the instrument input does not into the Mic Preamp. It is Blended with the Mic Preamp.
I have the Scarlett Solo, which is a little different than the other Scarlett interfaces. The Solo has physically separate input connectors and separate gain control for the Mic Pre and Inst/Line. I cannot speak with any certainty about the signal path.

Our conversation has made me think on the terminology of DI, DI Box, and Direct Box. All 3 of these terms are used interchangeably.

Again, I do apologize.

I hope I didn't come across as a complete ass.

 

[rumblinbass]

I hope I didn't come across as a complete ass.

Me too.

 

[DirkP]

(...)To my ears, the RNDI sounds like the kind of DI a top notch studio engineer would have built back in the days when things like DI boxes in a good studio were built in house by the resident mad scientist. It seems like something you should be able to recreate inside a DAW for a lot less than the price of the hardware.

You are wrong about mad scientists

Back in the days, the engineers creating for example DI boxes or mixing desks only had one goal: not to manipulate or shape the sound in any way, but to reproduce the sound of what is going in as accurately as possible without adding any noise or distortion. They have used the best technique available at the time. First tubes, later they were happy that these noisy distorting tubes were replaced with a much cleaner and more accurate technology: transformers.

The simple goal of a DI box is to transform instrument level (HZ), that is very sensitive to noise and looses the higher frequencies when a cable is longer than 30 feet, to line or mic level.

A mic- or line-level carrying cable can be as long as a kilometer or nearly a mile without a degredation in quality of the audio signal. This wouldn't be possible with an instrument-level signal.
The most important use case are gigs, where the bass and other signals had to be transfered to the FOH mixing desk far away from the stage.

In studios you didn't want the sensivity of the instrument cables to noise and transform their signals to mic or line level.

DIs were never intended to manipulate or shape the sound of their sources, quite the opposite.

We might - justified or unjustified - praise these ancient technologies now for the way they were working against that goal of the engineers, but these engineers only wanted clean sound without noise. It is the same with "tape-saturation". It really has the effect that is praised now on very good and expensive tape machines (not and never on cheap 4-track cassette recorders btw) - but if you would have worked in a studio in the 70s as an engineer and set the input levels of a tape machine too high, into the red area, it is highly likely that this would have been your last day working there.