KRK Rokit 8 Gen 2 Upgrade

[rudyneuman]

Hey Bobby. I had one of my G2s blow up on me recently, and I'm definitely interested in going down the route of doing these board upgrades. Would you say that your mixes have improved because of the component upgrades? I'm curious of the results of the effort before I just say to heck with it and throw down on some HS8s or something.

 

[rudyneuman]

Got it working no more annoying random sounds and pops. New TDA7296 has more clarity than the old obsolete TDA2052. Revealing more details in the mid range. I have a few more boards left if anyone has a pair of these old speakers and they need a re-vamp.

Also, what would you need from me if I needed those boards? I just need to get it fixed so I can get back to mixing.

 

[Bobby Baird]

I haven't had time to do any mixing as I am working all the time. I just believe they sound better now. These first version boards have some through holes that are really tight for component leads. The footprints are the 1N5392 Diodes & the CN4 connector header, as well I ended up jumpering the R102, R103, R115, & R116 trimmers. For this reason I would just give the boards away. I have corrected these errors in Rev1.1 although I have no need to produce more boards.

 

[Bobby Baird]

I went ahead and ordered 5 sets of Rev. 1.1 boards with footprint corrections.

 

[Bobby Baird]

New Boards Rev.1.1

 

[jeffmills]

Hey Bobby!

Amazing job on the KRK Rokit 8 Gen 2 breakdown and repairs. The schematics were invaluable. Any chance I could buy your latest board for these guys? I have been trying to repair these speakers but the PCB was so very badly damaged by corrosion and a previous repair by others that it is not looking hopeful. I love the idea of the upgrades you mentioned as well. Please let me know if this is possible. Thank you in advance.

Also quick question, if one of the Rokit 8's has sound coming from both the tweeter and woofer, but it seems like there is very little if any bass, is it safe to assume that I should just replace all the caps or is there other components which could be the cause?

Cheers brother!

 

[DalipChand]

Modified power supply.
I will replace the cheap obsolete 647, 667 transistor buffered zener shunt approach to a regulated power supply using LM317, & LM337 regulators. As well as, trimmers for fine tuning voltages. Attached is the original schematic vs. my modification Rev.1.1. This will hopefully provide stable power to the preamp thus feeding cleaner signal to the amp.

Hello Bobby, I'm totally new here. Can you or anyone you know can upgrade my KRK Rocket 8. Either exchange the boards for a fee or replace my caps and everything that's needed.
Please point me in the right directions. I have 3 of these speakers.

 

[DalipChand]

Modified power supply.
I will replace the cheap obsolete 647, 667 transistor buffered zener shunt approach to a regulated power supply using LM317, & LM337 regulators. As well as, trimmers for fine tuning voltages. Attached is the original schematic vs. my modification Rev.1.1. This will hopefully provide stable power to the preamp thus feeding cleaner signal to the amp.

 

[DalipChand]

Hi mate,
Do a favour to yourself, open one of your monitors and do a BOM (bill of materials) that you need for the repair/upgrade just to be 100% sure.

Take note of the uF and volts of every capacitor, buy those thar are rated 105C, they work longer than 85C for obvious reasons (inside the monitor gets hot!)

On the power section try to use as much as possible good film capacitors like panasonics, specially replacing the old mylar green caps on those the sound depends and ceramics are excellent for PSU filtering but a bit harsh for audio.

I wouldn't mess with the opamps, they are just fine in that circuit and faster opamps without adding extra decoupling capacitors might bring some unwanted high frequency oscillations.

If you can replace all the high watt resistor by metal film that would be great, as termal noise is something to be avoided.

Take care of measuring diameter and pitch of electrolytic capacitors (here size matters!) and buy from reputable sellers like Mouser, Farnell, TME, Digikey, RS, etc, depending in your location.

I have an old pair of KRK Rokit V1 from 2007 about 18.000hs of use and the power supply caps were very bad (original caps are very cheap chinese and most of them were out odf specs).
After removing the whole black glue I replaced all the electrolytics by Panasonics and Nichicon, and the 100nF by Panasonic and Wima. Also some resistors. Now they work as they should, after more than 15 years of using them in my job every day I am so used to their sound that I really was missing it.

Bytheway, Neumann KH120 have the same power IC, I saw a pic of the inside, just the version for 60volts and they have a regulated PSU (I believe) ofcourse drivers maybe better and other plus like dacs and room correction circuit, but KRK are like standard sound on home recording studios, I love mine.

Good luck!

Hello, I'm totally new here. Can you or anyone you know can upgrade my KRK Rokit 8. Either exchange the boards for a fee or replace my caps and everything that's needed.
Please point me in the right directions. I have 3 of these speakers.

 

[Bobby Baird]

Hello Bobby, I'm totally new here. Can you or anyone you know can upgrade my KRK Rocket 8. Either exchange the boards for a fee or replace my caps and everything that's needed.
Please point me in the right directions. I have 3 of these speakers.

You would need to find someone local to do your repair. You could try posting here to find someone. https://groupdiy.com/forums/jobs-available.12/