THAT vs TI

[calaverasgrande]

We still live in a physical world so mic preamps will remain in use for some time. Of course the first company that combines a microphone with A/D convertor, with no signal integrity compromises will dominate, but that is still a wet dream.

You mean like the Neumann Solution-D or KM-D? Neumann had that 10 years ago. Didn't seem to really take hold.

​

 

[dyamakuchi]

judicious use of dithering.

This guy knows. There are a _lot_ of particulars. Floating point mathematics is another. Or +/-6.02dB increments.

But yeah, That Corp all the way. They _invented_ compression. ...not that there's anything wrong with TI...

 

[JohnRoberts]

This guy knows. There are a _lot_ of particulars. Floating point mathematics is another. Or +/-6.02dB increments.

But yeah, That Corp all the way. They _invented_ compression. ...not that there's anything wrong with TI...

It's not too much of a stretch to credit David Blackmer (the d&b in dbx) with inventing the modern VCA (but not compression).

THAT corp perfected the analog IC VCA or as perfect as it is likely to ever get in a shrinking market.

TI may end up being the last man standing to buy up what's left of the US semiconductor market.

JR

 

[ricardo]

- and it is also far more important to me personally how these ICs behave in normal operating conditions rather than in a situation that so rarely happens and which is the result of an audio engineer’s mistake. By that I mean overload and clipping, not single-ended mode of operation. In these situations, the only thing that matters is that the IC survives such misuse.

If that's the only thing important to you, there are far simpler solutions than even the THAT/TI/AD chips with excellent performance.

Why don't you find Waynes stuff and replicate his results. You don't need fancy test gear to see the PRACTICAL caveats.

If you haven't noticed any difference in your projects ... then it doesn't matter does it ?

 

[moamps]

....You don't need fancy test gear to see the PRACTICAL caveats....

Which are?

 

[rackmonkey]

Ricardo, is it Wayne Kirkwood’s tests/writeups on output stage designs using the 1646 and 134 parts you keep alluding to? If so, all that stuff now lives on his forum:

Balanced Outputs - Pro Audio Design Forum

(he deleted all his posts from here). I think i know the more detailed results you might be referring to. The links to that stuff may be buried in the post linked above. I didn’t poke around enough to confirm though.

 

[Mike Havok]

There's a page somewhere which shows the artifacts from various Sample Rate Converters. Some very big names result in crud which my DBLT panel can pick out on 16b paths.

SRC Comparisons ?

 

[paolomunarini]

Hi everyone.
First post on the board here, so please forgive me if this is the wrong place. Posts here are recent and the topic seems to be matching pretty well.

I'm planning on a MS matrix in the style of Wayne Kirkwood's (https://www.ka-electronics.com/images/jpg/M-S_Simple.jpg) with both encoding and decoding. I'm going for the simple one (not the elaborated new version).

I faced the same question that ruffrecords posted in the first place:

Both THAT and TI make line drivers and receivers with apparently identical specs. Is there anything to choose between them?

Cheers

Ian

And my point has been enforced by elskardio:

For what it's worth...
I have compared the INA137 vs That 1246 in the same circuit and I couldn't measure (or ear) any differences.
The TI part is easier to find and usually at a better price too.

I'd like to use INA2134 for diff inputs (because of the nice 2-in-a-package form) and 2x DRV135 for balanced outs (I looked for the same 2-in-a-package thing but no luck there...). Bonus thing here, I'd like to take the miniaturization route (SOIC package teases me a lot).

Since I'd like to go full TI/BB here, I'd also like to swap the THAT1240s in the encoding/decoding part of the matrix.

From my wandering on the interwebs and from my own knowledge (experiments done on an analog console and in my DAW) I can approach MS "codec" in three ways:

1. 0db cut during encoding and 6db cut during decoding
2. 6db cut during encoding and 0db cut during decoding
3. 3db cut during encoding and 3db boost during decoding

Thoughts on the three respective approaches:

1. I have to have headroom in the inserts in order to accept a +6db gain on the encoded inputs (could be nice if I want to gainstage a comp or something)
2. No headroom issues and no boost necessary (most likely this will be my approach, since I'm planning on EQ-type inserts)
3. I hate to attenuate and boost without any necessity so I dislike this one

Mathematically this applies to both channels equally, but everyone is talking about mono build-up (and also my reasoning is pulling me towards thinking that the sides will be lower in volume). Am I overthinking it?

Let's suppose that I'm going for the second choice (cut in encoding, no cut in decoding), would the INA2137 best suited for this thanks to its selectable +6dB/-6dB gain?

Sorry for the long post but this arises from a month or more of time spent thinking on the issue.

Paolo

 

[abbey road d enfer]

Hi everyone.
From my wandering on the interwebs and from my own knowledge (experiments done on an analog console and in my DAW) I can approach MS "codec" in three ways:

1. 0db cut during encoding and 6db cut during decoding
2. 6db cut during encoding and 0db cut during decoding
3. 3db cut during encoding and 3db boost during decoding

The actual answer depends very much on the characteristics of the sources and receivers. Particularly if interfacing with converters, their actual calibration (dBu vs. dBfs) is a dominant factor.

 

[paolomunarini]

The actual answer depends very much on the characteristics of the sources and receivers. Particularly if interfacing with converters, their actual calibration (dBu vs. dBfs) is a dominant factor.

I will use the MS encoder-decoder as a part of a piece of gear. Let's say as input/output switchable stage for an EQ/comp.
No particular other device will be connected, since it's gonna be "hidden" inside the EQ circuitry.

The insert point could even be single ended send/return since it's already inside the circuit.

 

[abbey road d enfer]

I will use the MS encoder-decoder as a part of a piece of gear. Let's say as input/output switchable stage for an EQ/comp.
No particular other device will be connected, since it's gonna be "hidden" inside the EQ circuitry.

The insert point could even be single ended send/return since it's already inside the circuit.

Then it is essential to base your decision on the actual level diagram of this piece of gear.

 

[Newmarket]

"Since I'd like to go full TI/BB here"

Why ?

 

[paolomunarini]

"Since I'd like to go full TI/BB here"

Why ?

Because of price difference and availability.

 

[FIX]

It's not too much of a stretch to credit David Blackmer (the d&b in dbx) with inventing the modern VCA (but not compression).

THAT corp perfected the analog IC VCA or as perfect as it is likely to ever get in a shrinking market.

TI may end up being the last man standing to buy up what's left of the US semiconductor market.

JR

Interesting thing about David, when he was a contractor for API, they wanted to use a gain stage for automation. David wanted it for compression and expansion, API already had a FET compressor and had no interest in another one. I remember a drawing and prototype of a 3U compressor with 2 side chains, compression and expansion (discrete VCA drawn) and an RMS detector (discrete drawn). The schematic was all hand drawn and the prototype had one meter. At some point, David had enough, patented the VCA (if he had ever enforced it, he would have been a rich man) which was a class B VCA, meaning that you had to bias it so the transistors overlapped enough to lower the distortion, and temperature drift was distortion (a lot of it). He then left and formed DBX, which rumors say it was DAVID BLACKMERE's EXPANDER. That drawing and prototype became the DBX 160, the first feed forward compressor. Everyone loved it, then hated it, then loved it...


Side note: One of the reasons America left consoles on all the time and rack gear on all the time was because if you shut it off, you had to recalibrate the VCAs, 2 trims per channel, and of course the Eventide Harmonizer that would drift in pitch as it warmed up.

 

[JohnRoberts]

I will defer to Paul about API history... he was there.

JR

PS: Back in the 80s I wrote a magazine column addressing the question of leaving gear powered up. As I recall the lightbulb on my desk lamp burned out when I turned it on to write that column.

 

[Bo Deadly]

PS: Back in the 80s I wrote a magazine column addressing the question of leaving gear powered up. As I recall the lightbulb on my desk lamp burned out when I turned it on to write that column.

It seems you did everything "back in the 80s" JR.

Back in the 80s a tail light on my toy Hess truck went out. I opened it up and found a wire broken off. I taped it back on and that fixed it. It was rad.

 

[JohnRoberts]

I can talk about the 80s because the statute of limitations has expired.

JR

 

[Michael Tibes]

I can talk about the 80s because the statute of limitations has expired.

JR

This just gave me a big laugh )

 

[FIX]

And they didn't have cell phone pix...

 

[ruffrecords]

It is amazing how things have changed during my working life. Back in the 80s the main method of communicating with customers was via Telex (and later Fax). I had a Commodore 64 at home at the time and managed to get a telephone interface add on for it. I seriously impressed a prospective customer when I sent him a Telex at 1am on a Saturday morning from home. He was convinced I had to be in the office at that time to send it.

Cheers

Ian