Bartolini MK-1 upgrade - > TL062 original OpAmps replaced by a set of 3 shiny OPA2196

 This modification is a significative  enhancement that will transform any MK-1 (and I would say any other preamp stuff based on TL06x  )  into a sort of  high-end low noise professional preamp unit.  

If You want to change the tonal performances of this specific preamp... please have a look at my previous posts on the argument !

A BIG WARNING:

 This modification requires good skills on managing and soldering SMD  components and of course will KILL  your pream If You do not know what You are doing....

So if You want to apply this mod  and You are not skilled enough.... ask to a friend with proper skills in a way  to perform the operation in a  safe mode !!!!!

SO LET'S START !!!!!!

I cannot totally understand the reason why in 2021 there are  still around preamp instruments and stompboxes units based on a  Operational Amplifier designed  in 1978.......

:-(
........... come on this is not a vintage tube stuff....  it's a raw opamp!  

TL06x is a 40 YEARS OLD device used now only for saving money ... and battery power...

Nowadays ...it's a kind of traditional stuff  like Santa Claus ... offering low power  consumption and a traditional FET high impedance input stage....   

but it' s limited.... also presenting  for instance a relevant NOISE to deal with...

For the benefit of the readers basically a TL06x is a depotentiated version of a TL07x  that would perform better.... but cannot be used into a battery powered device because of the related high power consumption....

To make a long story short ............

a lot of water is passed  under the bridges since 1978 and SOME very valid alternatives DO NOW EXIST on the market !!!!!!!!

My initial choice was to use a superstar chip like the LT1352 but this costs a fortune ....so i checked for something else with a highest  possible trade-off .....

I found a winner....!!!!!!!!!

And the winner is  ......STILL a Texas Instruments device ...... 

OPA2196 , 

in my case an OP2196 IDR  ,  SOIC-8 format   :-)

So I ordered 3 of them from China at  less that 2 Euro per unit .. a a price that is of course 4 time the one for a TL062 .... but .... come on ..very reasonable for  such high expected improvements...

I recommend You to read the datasheet of this Operational Amplifier  but ... to sum up:

• OPA2196 is RAIL TO RAIL (can run from 0 to batt level) while the TL062 is not 

• OPA2196 has 3 time less noise than TL 062 !!!!!

• OPA2196 standby power consuption is 20% LESS than TL062 !!!!!  

• OPA2196 slew rate is 50% BETTER than a TL062 !!!!

• OPA2166 gain bandwidth is MORE THAN double than the one of a TL062 !!!

• OPA2196 voltage offset is 0.1 mvolt  while TL062 has a  6mvolt offset !!!!

• OPA2196 voltage drift is 0.1microvolt per C° against 10 microvolt per C° of a TL062....!!!!

• An OPA2196 WILL STILL work with a batt down to 4.5 V  while a TL062 will die  at 6V...
• 
  

.... should I continue ? ?  

 :-)

  NO ... LET'S get DEFINITELY  rid of the TL062 stuff..

So  the first step is to extract the preamp from your instrument, in my case my beloved CORT A4  and put in position for removing replacing the 3 TL062 used in the circuit:

Here is the preamp  unit BEFORE the operation:

I will not use an hot air gun because I do not want to generate too much mess and heat that can change the values of the capacitors around the ICs. 
I just put extra soldering tin lead  on the IC 8 pins  for easing the removal :

The three  original TL062 ICs removed.... say Goodbye..!!!!!

:-)

An after some clean up let's solder the 3 new OP2196   ..... with a LOT of CARE and PATIENCE:

Let's put the preamp  back into my Cort A4 controls cavity

:-)

And let's check the power consumption:

WHOAAAA    is this a power consumption   ????????

Kindof 1 milliamp ....   !!!!! 

More than 500 HOURS available with a 9V Battery !!!!!

:-)

Someone worried about the final result on the SOUND...   ????

NO do not be worried .... about the SOUND...

 just BE HAPPY !!!!!!

Sound is SUPER.....

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KKPRINCE
:-)