Seeholzer Engineering

Offering experienced technical services in the fields of repair, modification, and service/maintenance of vintage and modern electronic musical instruments

Seeholzer Engineering is an engineering consulting firm and repair operation located in Olympia, WA. We offer a number of services including repair, modification, and service/maintenance of vintage and modern electronic musical instruments including, but not limited to, synthesizers, drum machines, sound modules, keyboards, pedals, and rack mount hardware. Additionally we provide consulting regarding mechanical and electrical engineering, and electronic music studio infrastructure. In all areas we strive to provide the utmost in terms of quality, professionalism, and customer satisfaction.

With three years of experience as the lead repair technician for Buchla, we have worked on every model of 200e module that has been in production.

We have a high level of competency in working with surface mount technology, and are comfortable doing repair work on anything other than BGAs and chip-on-board hardware.

In all our repair work it is our goal to return all instruments to the customer in the best condition possible. This includes a thorough inspection of the functionality of the instrument(s) in order to detect any additional issues that might not be known to the customer.

The conditions of vintage electronic instruments vary drastically based on age and the life of the instruments, which can lead to large variations in bench time for different repair jobs. Because of this, we work with our customers to come up with a plan to fit each customer's budget and timeline so they can get their instruments back up and running as quickly as possible.

Please contact us to discuss our repair rates.

While we specialize in repairing Buchla instruments, we have done work on hardware from many different manufacturers, many of which are listed below.

  • Access
  • Alesis
  • Arp
  • Clavia
  • Elka
  • Jomox
  • Korg
  • Moog
  • Roland
  • Sequential Circuits
  • Tascam
  • And more...

With the lengthy history of many vintage electronic instruments, curious musicians and users have come up with many augmentations to add to their instruments. We are happy to work with customers to provide these modifications for their instruments.

Additionally we provide DIY kit assembly services. There are an increasing amount of DIY synthesizer kits available every day. Some of these kits are the only way to acquire this hardware, and not everyone is capable of assembling them. We hope to provide access to these instruments for people who are unable to build them themselves.

Our rates for modifications/kit assembly vary based on the hardware being modified or built. Please contact us to discuss pricing.

Here are some of the modifications that we offer:

  • MIDI Retrofits
  • Control Voltage input/output modifications
  • Cosmetic Modifications (LEDs, etc.)
  • Sustain/Latch on Buchla 218e Modules
  • Noise Fix on Early Buchla 210e Modules
  • Contact us for more...

Many amazing electronic musical instruments are getting up there in age. With this can come some not great things, like inconsistent behaviors, decrease in sound quality, low output levels, and complete lack of functionality, to name a few.

We are happy to thoroughly service any vintage instrument. This includes cleaning of all controls, replacing any of them that are faulty, replacing electrolytic capacitors (these tend to dry out after 20 years or so), replacing tantalum capacitors in power supplies with electrolytics (this can avoid the tantalum capacitors from failing catastrophically), and cleaning the instrument inside and out to get it looking and working like it did when it left the factory; or as close as is possible!

Please contact us to discuss our service/maintenance rates.


Suzanne Ciani

“Charles is a pleasure to work with, capable and kind.  He’s been very helpful with my Buchla 200e issues and has built a 291 clone that is great. I highly recommend him.”

Suzanne Ciani

Alex Vittum

"Charles has worked on many of my instruments and no matter how mysterious the issue he solves it effortlessly. He communicates clearly, has great rates and ships right away. I feel so fortunate to send my synths to someone I can trust and who I know is passionate about music and the instruments he works on. Can't recommend him enough. Thanks Charles!"

Alex Vittum

Randy Adams

"My 291e bricked and had it's screen damaged. Charles repaired it quickly and with an expert's touch. I'm glad that 200e users have Charles Seeholzer service to keep our systems in top condition."

Randy Adams