THAT4301 compressor

[wolfgang]

Thats very nice!

Do you mind sharing the layout and schematic? I am interested in building some.
So balanced input/output and bypass are offboard??

kind regards,
Wolfgang

 

[flaheu]

Super nice !

I imagine 8 of those in a 2he rack  8)

 

[ungifted]

Yes, balanced in/out and bypass are offboard (any similar project - Igor's or something like, and I'm going to make addons, in/out and bypass too).

The previous version is correct, v1.5 has some minor changes. I'll post full info this evening.

I have some bundles for sale: PCB plus THAT4301 for $18 plus shipping (about $9). And perhaps I'll make a kit. Please, pm me if  interested.
Thank you!

 

[RuudNL]

Here is an application with the THAT 4301.
http://www.groupdiy.com/index.php?action=dlattach;topic=44829.0;attach=7930
Maybe a good idea to see if you can use any features from this design?

 

[ungifted]

Thank you for linking to THAT4301 schema. Variable attack and release around single TL072  is interesting...

 

[emrr]

I bet this is 4301 based, and it'd be hard to DIY for less.  Anyone seen deeper info? 

http://www.bhphotovideo.com/c/product/493332-REG/Klark_Teknik_SQ1D_Square_ONE_Dynamics_8_Channel.html

 

[ungifted]

Need pics or schema. Maybe it's build on CA3080?

 

[JohnRoberts]

I bet this is 4301 based, and it'd be hard to DIY for less.  Anyone seen deeper info? 

http://www.bhphotovideo.com/c/product/493332-REG/Klark_Teknik_SQ1D_Square_ONE_Dynamics_8_Channel.html

If it's modern build KT is owned by Behringer (IIRC) so they could afford to build using THAT engines inside.

JR

PS: I recall back in the '80s trying to sell my tape NR kits against assembled DBX (made in Japan) for less money. Not a good time in the kit business.

 

[emrr]

Memory tells me (possibly wrong) that KT line has been out there 5-6 years at least, I remember it's debut, then forgot about it. 

 

[JohnRoberts]

Memory tells me (possibly wrong) that KT line has been out there 5-6 years at least, I remember it's debut, then forgot about it.

OK, I looked it up.. KT started in 1974... They used to be well regarded for their EQ.

more recently Behringer bought both Midas and KT from Bosch in 2009. So they can now build it inexpensively.

JR

 

[ruairioflaherty]

I bet this is 4301 based, and it'd be hard to DIY for less.  Anyone seen deeper info? 

http://www.bhphotovideo.com/c/product/493332-REG/Klark_Teknik_SQ1D_Square_ONE_Dynamics_8_Channel.html

I've never used the dynamics but have extensive experience with the Square One Graphic EQ and active splitter.  Both sound pretty awful and prone to faults. Based on that experience I would be very hesitant to recommend the dynamics.

 

[emrr]

good to know. It looks like it got good mentions from some established equipment reviewers. 

 

[ungifted]

v1.5 docs attached

 

[ruairioflaherty]

good to know. It looks like it got good mentions from some established equipment reviewers.

Well I'll spare you my opinions on equipment reviews suffice to say that many of the worst pieces of gear I've ever used and heard got glowing reviews in the trade press.  As I said though I haven't heard the dynamics, it could be great.

 

[emrr]

Every review needs from a pinch to a truckload for seasoning. 

 

[ungifted]

Hi guys, sorry for statement about 2u housing. PCB has 82mm in width, it won't fit 2u vertically. Dimention attached.
Will be fixed in the next version.
Anyway we can fit at least 6 channels (or more?) horizontally mounting one above the other.

 

[Nescafe]

Hi ungifted,
did You find any document to implement feed backward and feed forward mode using 4301?
Nice work.......

 

[ungifted]

Thank you!

As the design is based on DN115, 4301 demo etc we used feedforward schema.
Some notes about feedbackward design are here (on page 28):
http://thatcorp.com/datashts/Analog_Secrets_Your_Mother_Never_Told_You.pdf
If I understood you correctly...

 

[Nescafe]

Hi ungifted,
Thank You for the document, I just read it, and it's fun  and if You implement that diagram in Your 4301 schematic, where You will put the nodes to switch between FF and FB mode......? I guess like in the pic but not really sure......and any other parts value need to change because of FB mode?

 

[ungifted]

I think FB is slightly different. Please take a look at DN01A, it describes both approaches:

http://www.thatcorp.com/datashts/dn01A.pdf

Why do you want to use FB schema? THAT docs says that FB has some ratio limitations:
"However, the feedback configuration has the disadvantage
that not all compression ratios are possible.
The high level of feedback required to reach high compression
ratios makes feedback processors more likely
to exhibit instabilities if high compression ratios are allowed."

FB design (and BTW side-chain) based on THAT4301 are in DN03, DN131
http://www.thatcorp.com/datashts/dn03.pdf
http://www.thatcorp.com/datashts/dn131.pdf

and perhaps we have to look THAT2180 docs...