Fully differential eq circuits?

[pucho812]

Are there any eq’s out there that are a fully differential circuit?

Is it too costly to do?

 

[Gold]

ADT V700 series. They are very expensive. https://www.adt-audio.com/Audio_Modules/Audio_Modules_V700.html

 

[pucho812]

ADT V700 series. They are very expensive. https://www.adt-audio.com/Audio_Modules/Audio_Modules_V700.html

Well one of the things that caught my attention in the aspen pitman interview was how he talked about fully differential circuits and  how it improved audio and why.  was wondering why more companies didn't do that.

 

[Gold]

I’ve never heard any of those modules. I’ve never known or heard of anyone using them. A search at the purple place brings up basically nothing.  I’ve heard of people using the Toolmod series.

That said they are very interesting.  There are some features that aren’t available anywhere else. The designer obviously put a lot of thought into them. Maybe if the modules were in 19” rack units they would be more popular. Spending $50K on a 5RU module system isn’t how most would allocate funds.

 

[Ricardus]

I just noticed they do a large format recording console, too. These guys are maniacs.

 

[pucho812]

I’ve never heard any of those modules. I’ve never known or heard of anyone using them. A search at the purple place brings up basically nothing.  I’ve heard of people using the Toolmod series.

That said they are very interesting.  There are some features that aren’t available anywhere else. The designer obviously put a lot of thought into them. Maybe if the modules were in 19” rack units they would be more popular. Spending $50K on a 5RU module system isn’t how most would allocate funds.

I am purely focused on the idea of fully differential. Not interested in buying them. But wanted to see who is doing it 

 

[emrr]

RCA did it in some obscure passive filter sets in the 1930’s.  Balanced H types. 

Maybe interesting is the idea of driving an EQ differentially rather than single ended. 

 

[pucho812]

RCA did it in some obscure passive filter sets in the 1930’s.  Balanced H types. 

Maybe interesting is the idea of driving an EQ differentially rather than single ended.

That too. Imagine a channel strip that is pre and eq and fully differential drop top to bottom vs just at the I/O

 

[shabtek]

What benefit justifies the additional complexity of parts matching ?

Differential drive  with tuned shunts would not need matching .

What order filter is that?
Cascaded and ganged stages will be needed for steeper boost cut.

 

[abbey road d enfer]

Are there any eq’s out there that are a fully differential circuit?

Is it too costly to do?

Passive EQ's support differential implementation. It's more costly, since the series components have to be duplicated, but not the shunt elements. It can make sense, if it saves input/output xfmrs.
Active filters do not lend themselves easily to differential implementation. There are some examples in telecoms and instrumentation, probably resulting from transformation of passive filters into active ones.
I believe Aspen Pittman was referring to certain aspects of circuit implementation that benefit from differential path, such as distortion cancellation, noise rejection; there are good examples of differential circuitry in A/D and D/A converters, but I don't think there is one definite example of differential EQ's that make sense.
However,

 

[jensenmann]

I’ve never heard any of those modules. I’ve never known or heard of anyone using them. A search at the purple place brings up basically nothing.  I’ve heard of people using the Toolmod series.

That said they are very interesting.  There are some features that aren’t available anywhere else. The designer obviously put a lot of thought into them. Maybe if the modules were in 19” rack units they would be more popular. Spending $50K on a 5RU module system isn’t how most would allocate funds.

I know several mastering engineers using  ADT V700 gear. Each of them is full of praises.
In my dayjob I use one of their 5MT consoles and racks full of their Toolmod gear. I can highly recommend all of their gear. There´s not one single piece amongst which is less than stellar.

 

[Gold]

I know several mastering engineers using  ADT V700 gear. Each of them is full of praises.

It seems ADT mostly serves the German language market. It’s rare to see it in the US.  There is not much gear  I have any desire    to check out. The V700 series is an exception.