fazer

Klark Teknik KT-2A Optical Compressor
« on: February 24, 2019, 12:10:28 PM »
Has anybody tried the Klark Teknik KT-2A Optical Compressor?   $399.00  is so cheap.     What is the opto element used?  I thought the cad opto;s were ban in EU.

Reason I ask is a new voice talent contacted me about the quality of their VO demos.  I said she needs a compressor going into the interface from the Mic preamp.  (Focusrite preamp).

 I use my LA 3A for Vocals and VO's with a Neuman 249.  I recommended an LA3A  and see they are no longer made and UA LA2As are $3500.00 and TB4s are going for as high as 1000.   

 I like the old  Urie 710s but don't see those much and 3As are going for 2500 on REVERB.   Are LA4A's any good.  I've never tried one.    Whats a new VO talent to do. 

Suggestions


scott2000



scott2000

Re: Klark Teknik KT-2A Optical Compressor
« Reply #3 on: February 28, 2019, 08:24:48 AM »
Cool vid....

I'm not convinced the levels were set right???? If they were. the diy LA2A was nicer  imo......

in kingkorg's example, I liked different characteristics of both........ weird.....
« Last Edit: February 28, 2019, 08:29:27 AM by scott2000 »

Rob Flinn

Re: Klark Teknik KT-2A Optical Compressor
« Reply #4 on: February 28, 2019, 09:51:10 AM »
Cool vid....

I'm not convinced the levels were set right???? If they were. the diy LA2A was nicer  imo......

in kingkorg's example, I liked different characteristics of both........ weird.....

Agree that the vids comparison has some flaws.  The DIY one has Sowter transformers too , which are known for being clean sounding.
regards Rob

living sounds

Re: Klark Teknik KT-2A Optical Compressor
« Reply #5 on: February 28, 2019, 10:42:09 AM »
I've got a few of the Klark Teknik tube EQs and compressors. Once you change the tubes in the signal path to something better (I used Tung Sol) they improve quite a bit (dirt and constricted dynamics go away). You need the right screwdrivers (Torx-T10 and T9) to open these units, BTW.

I don't believe there to be anything wrong with the audio transformers. An area of improvement would be the power supply filtering, I would prefer less residual hum. The switching supply will probably not live as long as a good linear one.

At the price these are being sold here, even with the tube upgrade, I couldn't DIY them and they are really good.
« Last Edit: February 28, 2019, 10:47:37 AM by living sounds »

fazer

Re: Klark Teknik KT-2A Optical Compressor
« Reply #6 on: February 28, 2019, 11:10:32 PM »
I've got a few of the Klark Teknik tube EQs and compressors. Once you change the tubes in the signal path to something better (I used Tung Sol) they improve quite a bit (dirt and constricted dynamics go away). You need the right screwdrivers (Torx-T10 and T9) to open these units, BTW.

I don't believe there to be anything wrong with the audio transformers. An area of improvement would be the power supply filtering, I would prefer less residual hum. The switching supply will probably not live as long as a good linear one.

At the price these are being sold here, even with the tube upgrade, I couldn't DIY them and they are really good.

I’ve got to try a pair of these.  Are the tube types the same as in a LA2A.  I see a el84 that’s different but 12bh7 12ax7 are normal.
« Last Edit: March 01, 2019, 07:53:22 AM by fazer »

living sounds

Re: Klark Teknik KT-2A Optical Compressor
« Reply #7 on: March 01, 2019, 11:03:19 AM »
KT-2A:

There's one 12AX7 in the signal path, the other one is just for the sidechain. You can find out which one to replace by temporarily removing it (while the unit is turned off, obviously).

The other tube in the sidechain is the 12BH7A.

Rob Flinn

Re: Klark Teknik KT-2A Optical Compressor
« Reply #8 on: March 01, 2019, 01:33:59 PM »
KT-2A:

There's one 12AX7 in the signal path, the other one is just for the sidechain. You can find out which one to replace by temporarily removing it (while the unit is turned off, obviously).

The other tube in the sidechain is the 12BH7A.

It seems more sensible that the BH7 would in the audio path & in the sidechan the EL84 replaces the 6AQ5, since they are roughly the same sort of valve.  But since I don't have one I'm probably wrong about this.
regards Rob

Kingston

Re: Klark Teknik KT-2A Optical Compressor
« Reply #9 on: March 02, 2019, 04:28:47 PM »
KT-2A:

There's one 12AX7 in the signal path, the other one is just for the sidechain. You can find out which one to replace by temporarily removing it (while the unit is turned off, obviously).

The other tube in the sidechain is the 12BH7A.

Or you could just look at the LA2A schematic and follow the signal path with a multi meter. 12BH7 is the output stage driving the output transformer.


living sounds

Re: Klark Teknik KT-2A Optical Compressor
« Reply #10 on: March 02, 2019, 07:08:58 PM »
Or you could just look at the LA2A schematic and follow the signal path with a multi meter. 12BH7 is the output stage driving the output transformer.

I don't think the KT-2A is an exact copy of the circuit. But removing a tube and seeing what happened is fast and worked for me. ;-)

abbey road d enfer

Re: Klark Teknik KT-2A Optical Compressor
« Reply #11 on: March 03, 2019, 04:16:21 AM »
Whats a new VO talent to do. 
I would suggest checking Golden Age Project
https://www.goldenageproject.com/outboards-2/
I haven't myself tried their comps, but I know their preamps and EQ's and can vouch they are very close to the originals. Various surveys seem to indicate it's the case for their compressors.
Who's right or wrong is irrelevant. What matters is what's right or wrong.
Star ground is for electricians.

jensenmann

Re: Klark Teknik KT-2A Optical Compressor
« Reply #12 on: March 03, 2019, 07:56:36 AM »
I have a KT2A here right now. My DIY LA2A smokes it. The Klark loses lowend and doesn´t do the nice creamy lowmid color that my DIY version does (original UTC trannies + Urei T4B). Besides the difference in tone the compression behaviour is very close. Maybe the Klark is a good starting point for further improvements as it´s dirt cheap.

The LA4 is a nice compressor. I really like them. It´s very slow though. My pair has different opamps which makes them a bit cleaner. The original LA4 is no slouch either, though.
Jens
Quote from: PRR
The tubes of course don't care what frequency they distort

peterc

Re: Klark Teknik KT-2A Optical Compressor
« Reply #13 on: March 03, 2019, 01:05:31 PM »
I love LA4s. When I started out in studios (1987), my engineering guru said to me 'they just work'.

And so they do. Big fat squelchy compression. Lovely!

Peter
If opportunity doesn't knock, build a door.

rockinrob86

Re: Klark Teknik KT-2A Optical Compressor
« Reply #14 on: March 03, 2019, 03:58:34 PM »
I have a KT2A here right now. My DIY LA2A smokes it. The Klark loses lowend and doesn´t do the nice creamy lowmid color that my DIY version does (original UTC trannies + Urei T4B). Besides the difference in tone the compression behaviour is very close. Maybe the Klark is a good starting point for further improvements as it´s dirt cheap.

The LA4 is a nice compressor. I really like them. It´s very slow though. My pair has different opamps which makes them a bit cleaner. The original LA4 is no slouch either, though.

Stock KT2a? 

Even with the differences you are saying, the DIY La2a is at least $700 in parts, so roughly double the KT2a.

jensenmann

Re: Klark Teknik KT-2A Optical Compressor
« Reply #15 on: March 03, 2019, 05:33:51 PM »
Yes, it´s stock.
I don´t care about the difference in price. It´s all about tone for me.
Jens
Quote from: PRR
The tubes of course don't care what frequency they distort

living sounds

Re: Klark Teknik KT-2A Optical Compressor
« Reply #16 on: March 03, 2019, 05:45:56 PM »
Yes, it´s stock.
I don´t care about the difference in price. It´s all about tone for me.

Try a tube upgrade, it found it to make a huge difference in all the KT units.

ruffrecords

Re: Klark Teknik KT-2A Optical Compressor
« Reply #17 on: March 04, 2019, 04:28:28 AM »
I notice the T4B cell shown in the video of the DIY version has a CE mark on it. How does the supplier manage that considering it contains cadmium sulphide?

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

gyraf

Re: Klark Teknik KT-2A Optical Compressor
« Reply #18 on: March 04, 2019, 05:15:30 AM »
 ;D Good question...

..maybe they're NOS, from before 2013? (not that this would make them legal today anyway)

Jakob E.
..note to self: don't let Harman run your company..

abbey road d enfer

Re: Klark Teknik KT-2A Optical Compressor
« Reply #19 on: March 04, 2019, 05:23:09 AM »
I notice the T4B cell shown in the video of the DIY version has a CE mark on it. How does the supplier manage that considering it contains cadmium sulphide?

Cheers

Ian
It's a long time I haven't been concerned with regulations, but isn't the presence of CdS an RoHS issue? Maybe CE is not concerned about it...
Who's right or wrong is irrelevant. What matters is what's right or wrong.
Star ground is for electricians.


 

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