By Niklas Eriksson on 11/8/2008 1:51 PM

The Moog Micromoog is probably one of the most frequently visiting types of synthesizers in my workshop. During the last two months I have had four Micromoog's on visit, all with different problems. Last week I finished the work of repairing yet another Micromoog with a bad power supply, a silent oscillator, a non-working ribbon controller and a silent LFO. It took some time to figure out all the problems but as usual when it comes down to Micromoog's there wasn't any major issues it. A couple of new opamps and some replaced parts in the ribbon controller was all it took to bring it back to life!

Despite only having one oscillator and crippled envelope generators (only attack / decay) the Micromoog is really an amazing little synthesizer. Equipped with a sub-oscillator, a variable wave-shaper and a 24dB per octave low-pass filter it sounds great! If the great sound isn't enough the instrument also have a fairly open architecture making it highly suitable for processing external audio or controlling other CV-devices.

By Niklas Eriksson on 11/4/2008 11:49 AM

Modern Moog-gear such as the Minimoog Voyager is built with very high quality so it is not every day you get the change of poking around inside one. However, about two weeks ago I got a call from a guy owning a Voyager RME which he claimed didn't sound as it should. The Voyager had previously been repaired under warranty by the dealer who originally sold it. Back from the dealer the problem at first seemed to have been fixed but after playing on it for a while it turned out that every parameter was way off.

Although the Voyager still was under warranty; the owner took the decision to hire me instead of the dealer who originally had repaired it. When I got the Voyager I conducted an initial test and it sounded horribly out of tune. The oscillators didn’t track at all and the output level was almost non-existent. Opening up the Voyager revealed that someone previously had altered every trim-pot in the synthesizer, probably in a desperate attempt to fix the initial problems with it. All trim-pots had markings of being altered and one of the screws attaching the analog-board to the frame was missing.

Going through the Voyager Service Manual it took me about 9 hours to complete the calibrating procedures of the Voyager. Most of the time was however spent on implementing a software tuning application since my hardware tuning device suddenly decided to commit suicide! Being a little rusty on the mathematics of Fast Fourier Transform (FFT) I eventually got the application to analyze the audio input stream from the sound-card. The output of the FFT was then used for calculating a the corresponding note, octave and cents of the main note. The GUI of the application still stinks but as soon as I get time to rewrite it I’ll probably make my little tuning application available for download for those of you who are interested … Please, stay tuned! ;-)

By Niklas Eriksson on 10/30/2008 3:27 PM

Although the business of NEriks Audio slowly is growing my main occupation still lies within the software industry. I’ve been an IT-Professional since the mid 90s spending most of my time working with compiler design, real-time operating systems and various process control systems. During the last couple of years my primary focus has however been on overall software design and software architecture so it is with great amusement that I currently find myself back to the roots of low-level programming due to some forthcoming products of NEriks Audio.

 

 

Some of the experimental products currently developed by NEriks Audio are heavily based on software for the controlling purposes of a device. I’ve always been very fond of pure analog signal paths so I will probably not go down the route of incorporating DSP’s into any of our products. At least not yet! One of the most time-consuming tasks has been to choose a hardware platform with a suitable micro-controller both performance-wise and I/O-wise. Once the platform was chosen I started to develop a framework which approximately 400 hours later had evolved into a full operating system with support for both multitasking and networking. Whether I will use all the features developed for the operating system is still very uncertain – However, I had a great time developing it!

By Niklas Eriksson on 10/12/2008 10:45 PM

Yesterday I finished the repair of an old Moog Micromoog. The S-TRIG input didn't work and my initial though was that it probably would be rather easy to fix. However, it turned out to be more difficult to fix than initially expected. One of the first things I discovered when measuring the trigger-oscillator of the keyboard circuit was that one of the opamps was faulty. I replaced the opamp but the problem with the S-TRIG input still remained. To my surprise the problem got even worse since the keyboard also stopped working. I started to troubleshoot the keyboard circuit and discovered yet another bad opamp. I replaced the opamp and tested the synthesizer once again with no luck. After approximately one hour of troubleshooting I slowly begun to suspect that the new opamps didn't work either. A quick check revealed that both of the new opamps was bad so after I replaced them once more the synthesizer finally started to work as expected.

 

By Niklas Eriksson on 10/8/2008 8:01 PM

I've just finished the repair of a Sequential Circuits Pro-One that have been in my workshop for some time. The main problem was that the modulation of oscillator A couldn't be altered by the modweel and that the output of synthesizer distored badly even at moderate levels. The problem with the modweel turned out to be a broken slide-switch in the modulation section of the synthesizer. The switch was probably broken by someone who previously had tried to replace it. Some of the PCB tracks had also been damaged in a way that several functions of the modulation section didn't work. A got some new slide-switches from Vintage Planet and managed to fix the problem rather easily.

The problem of the distorted output bugged me for a while but it eventually turned out to be an opamp that caused the distortion. The strange thing was that the opamp didn't distort at low input levels which first led me to believe that it wasn't broken. Analyzing the circuit around the opamp finally made me replace the opamp which caused the problem to disappear.

By Niklas Eriksson on 9/29/2008 9:06 PM

Today I finally got my Yamaha CP-70B tuned by a professional piano technician. The name of the technician is Lars Wahlberg and he did a tremendous job of bringing the piano back to its former glory. Lars is a member of the Swedish Piano Technician Association, SPTF. If you need your piano tuned or serviced I can definitely recommend Lars. You'll find his contact information in page below:

http://www.sptf.com/medlemsregister/malar_sthlm/index.html

For a larger picture please click here.

I currently have my Moog Minimoog Voyager Old School placed on top of the piano since I really don't have any other place in my studio where I can put it and still use it. The Voyager Old School is an extraordinary synthesizer so I definitely want it in a place where I actually can play it without being surrounded by lots of gear that interferes with the playing. On top of the piano is a perfect spot for it ...

By Niklas Eriksson on 9/8/2008 10:30 AM

Yesterday the Swedish Moog distributor (Fitzpatrick Import Group) had orgainzed a small Moog-event taking place a Kingside Studios in Stockholm. Musicians like Mats Schubert (from a Swedish band called 'Bo Kaspers Orkester') and Pamelia Kurstin participated in the event performing and showing of various Moog products.

Mats Schuber from Bo Kaspers Orkester playing the Moog Minimoog Voyager.

 

Pamelia Kurstin playing the Moog Theremin.

I was also invited to talk about vintage Moog synthesizers and for the accation I had brought along my Moog Modular. Spending the last week of preparing for the event I was kind of worried that the Moog would fail but in the end it all went very smooth. I'm not sure that the audience appriciated my presentation since I mostly talked about technical issues regarding vintage Moog's. Luckily I had some help from a good friend of mine who is an expert in using modular synthesizers (Thanks Niklas Winde!).

A very good friend of mine, Mattias Olsson also came by to experience the event.

 

By Niklas Eriksson on 9/6/2008 11:41 PM

Today I finally made a new attenuator/multiple panel to replace the original quad blank panel of my Moog Modular System 35. Since the Moog lacks a lot of multiples I decided to make a new panelen with four attenuated multiples and two normal quad mutiples. See the picture below:

For a larger picture please click here.

The panelen is made of black anodized aluminium with a thickness of 1.5 mm. The holes are milled and the text/graphics are engraved.

By Niklas Eriksson on 4/25/2008 12:38 PM

Yesterday I finally got my Minimoog Voyager Select Series (walnut cabinet with blue backlight).

Testing the Moog Minimoog Voyager Select Series.

I also bought a VX-351 CV Expander in order to be able to use all the features of the instrument in a more experimental way. Naturally I tested to run the Voyager along with the studio's grand old lady (the Moog Modular) and I can assure you that it sounded great! The Voyager definately sound as good as it looks!

By Niklas Eriksson on 2/18/2008 10:51 AM

I have spent the entire weekend working on the new analog mixing console that I'm building for the studio. Despite only having 16 input channels the console will be physically quite large. Last night we started to build the frame of the console which is mainly made out of solid oak. I hope to have the console ready by the end of May. I'll try to post some pictures of the console along the work with it. Please, stay tuned for continuous updates of the progress!

By Niklas Eriksson on 2/9/2008 3:42 PM

The core business of NEriks Audio is to provide professional repair and restoration services of vintage synthesizers and vintage studio equipment. Our knowledge of vintage synthesizers from manufactures like Moog has also resulted in some inquires about servicing, repairing and selling modern equipment from Moog. In order to provide our customers with modern equipment from Moog, NEriks Audio recently became an authorized Moog dealer. In relation to our Moog dealership we naturally decided to invest in some Moog gear for our own studio ...

Yesterday we got the first shipment from Moog. I spent the entire night installing and testing the new equipment in the studio.  Among the gear we got is a Moog Little Phatty and some Moogerfoogers. I really like the fooger's but being a analog synthesizer geek I would have prefered that Moog provider the Moogerfooger line of products in a compatible format to their old vintage modular products.

By Niklas Eriksson on 2/7/2008 12:50 PM

Welcome to the completely redesigned website of NEriks Audio. After a few weeks of hard work we are finally up and running! With the new website I also decided to start my own blog. I don't have a clue what this blog is about so we'll probably have to wait and see how things develop!