Wednesday, September 24, 2014

Brief maintenance of Minikorg 700s

TheI ordered a brand of synthesizer fader/ potentiometer grease.

It was kinda of waste of money. It didn't seem to make the sound better but it seems worse off...softer and weaker portemolo.

Here are the innards of my minikorg 700s.

This is a picture of the offending/vibrating oscillator panel...nope the grease didn't make it better...I was recommended to use electrical spray to clean it sir, I am not going I risk it...not on my only korg left (DV800 is almost gone to Synth heaven)

The birth certificate of the 700s 
It could a case of leaking chemical spray or water? The seal and date of manufacturer and testing are all blurred there is no way I determine the manufacturer late.

Sunday, September 14, 2014

Everything falls to bits

DV800 Kaput!!

14 sept is a bad evening.

I was playing the maxikorg to Kitaro's 'Koi', everything came to bits at the chrous.

The drifty pitched upper deck VCO gave way and stopped sounding. My worse fears came stopped responding only to the keys and became a 1 note drone. I have spent so much time and money to only to finally come to terms I have secured a very bad deal..

I paid so much for a faulty maxikorg...
It's really bad, all is coming to bits.

Saturday, September 13, 2014

Cosmetically restored Maxikorg DV800

Here are the photos of the cosmetically restored DV800.

Paint job by my dear father, I did a relatively less than ideal patch job that resulted in less than ideal finishing for the side panels.

Depending on my remaining budget, I may get a carpenter to refabricate a new set of side panels.

That's all for now, I will update again after checking the synth with the technician next week.

Tuning the Maxi Korg Dv800

I unscrewed the top panel of the DV800 to access the tuning pots. I am a newbie and so I did some calculated risk and by trial and error as info my friends from vintage synth forum...

Warning- I do not accept any responsibilities for any mishap or loss of lives and equipment, I am not a professional, I am just documenting my findings here.

Take all precautionary measures while tuning. 

I used a test pen to do my adjustment and wore rubber slippers while tuning.

I located the VCO circuit board located on the left (upper deck sounds). The right controls I tested were for the right (lower deck sounds).

Use the test pen and I tuned the 2nd, 3rd and 4th pot. I tuned taking reference from the c key of my minikorg and also with an tuning app for my ukelele on myiPhone.  

Tuning the MaxiKorg

Tuning Pots Adjustment for Maxi Korg DV800

Warning: I do not accept any responsibilities over any damage to any of your equipment or loss of lives/ injury should you service your synth using my steps. 

I am just documenting what I have done, it does not represent any professional standpoint or advice.

Please take all precautions while servicing your synth, especially when it comes to live electricity.

Precautionary measures

I make sure I do not touch any electronics with my bare hands. All tuning is done using a test-pen and I made sure I wore rubber slippers while servicing the synth with live current.


I took apart the top panel of the DV800 and located the pots for VCO on the top left hand corner. I am a newbie so by trial and error and advise from friends from the vintage synth forums, I  adjusted the 2nd, 3rd and 4th pots on the left VCO circuit panel. I tested and noticed that the right VCO panel, which is identical is for the lower deck.

I tuned the pots and played the notes against my MiniKorg to tune, I also tested the tuning against my Ukelele tuning app on my Iphone.

The previous owner has marked with a sharpie pen the position of the pots. I tuned it all the way to the extreme end just to get the synth in tune.

I noticed that this helps to alleviate my out-of tune upper VCO deck, but does not solve the problem 100%, it still takes time to warm up to get in tune and some extreme low notes (low G and C) are still out of tune by a cent.

I have made an appointment with a local vintage sound gear technician to troubleshoot and service it next week.

Saturday, September 6, 2014

Sanding down the hardened putty

Here is a picture of sanded plywood ends. The plastic wood has harden and sanded down. This is it looks like before painting

Oh boy, sanding is hardwork 😞

Restoring the wooden end panels of Maxikorg

I decided to try restoring the original plywood ends, my last resort will be re-fabricating new ones using plywood or any wood I can find in the lumber merchants near me.

I searched the net on how to 'repair chipped plywood'. I stumbled upon a website where someone recommended using wood putty to restore chipped off edges of a hotel TV cabinet.

I made a trip to the local Home-fix. I showed the salesman the work out end panel and he recommended me 'plastic wood' to patch up the plywood, he also recommended me Ronsend woodstain.

Here are the pictures of the putty repair work. I used Tamiya plastic strips as shoring

Here is the Maxikorg without wooden panels.

You will need to remove the synth cover (2 screws on each side, under the wooden side panels) to remove the wooden panels on the keyboard section.

I took this opportunity to remove the cover to explore around the innards and more importantly tune the maxikorg

The chaps from vintage synth forums recommended me to open up the synth and tune the pots. By Trial and error, I managed to get the maxikorg a lot more in tune than before in one evening...not perfect but at least 98-99% in tune...maybe a couple of cents off. 

I will talk about the tuning in another post next time.