Second Order Harmonics

01/07/2026

early draft:

working on something new! don’t expect a classic VCA compressor — expect something that does more than an ADR but with a modern twist; being digital/analog combined but physically separated PCBs, independently configurable and analog/digital circuits safely electronically separated. with a possible option for total recall on any switches or faders.

Thinking about adding motorized switches, multicolor encoders and multiple front panel design versions as well as an optical LDR mode any input or feedback? what would you like to see on your compressor? Parallel compression? Configurable knee? what do you need to configure usually on a compressor in a studio session during tracking or mixing? What’s the most valuable feature? You have on your favorite compressor? What sets it apart? Transformers or operational amplifiers? Both? Switchable, relays?

We would love to have your input!


01/02/2026

Llimited time special offer for 2x 10 Slot Fredenstein 10S 500 Series Chassis from for 800EUR excl. Tax/Shipping. Used, in working condition.

10% off if you order via our website instead of eBay or Reverb.

2x Fredenstein Bento 10S 10-Slot Chassis (500 Series) | Musikinstrumente, Pro-Audio Equipment, Signalprozessoren & Effekte | eBay!

31/01/2026

when is the last time you've seen this in a service manual for a mixing desk? this is why we love old consoles -- the EQ frequency ranges and curves are described by TEAC like this (classical orchestra sections, human voice, synths and a elementary music theory like keys/octaves included). this is excellent!

31/01/2026

XQP/DIYRE Colour-upter optical disruptor colour module

31/01/2026

Building another colour module from DIYRE: JFT Class A JFET Colour

31/01/2026

We're starting to offer retrofits for analog audio hardware (mostly studio, but also synth, drum machines etc): MIDI over Ethernet and Bluetooth for remote control from your DAW, tablet/iPad or smart phone. These use tiny microcontrollers interacting with control voltage (CV) or specific parts of circuits for example in a studio equalizer you could change resistance of a switched k**b thereby remotely controlling the position without having to turn anything on a unit that may be further away/outboard in a rack. This also adds easy recall via MIDI. get in touch with us for details about specific products you may want to retrofit and if it's possible on a given unit/price of the HW upgrade. MIDI because it works for 98% of use cases and is universally supported, lots of MIDI routers, hubs and MPE now also widely available due to DAWs. Of course you would also be able to pair or directly connect any MIDI controller you prefer. For older units or such that only support classic MIDI cables we can fit new MIDI in/out & through on most mentioned hardware but please don't hesitate to ask in detail!

https://secondorderharmonics.com/all_posts.html

12/01/2026

We currently have a lot of studio and production gear to sell at the moment! We need to make space for new projects, get a bigger R&D budget for upcoming projects on the side and thought about selling most of these units for a while now (if they weren't already up on local platforms for some time like the 500 chassis), and now put everything we want to part ways with at the moment - even if it hurts a bit - on the relevant platforms.

For sale:
=======

*) ASM Hydrasynth Desktop in almost new condition
*) Eylsia Karacter 500 Series Stereo Saturator with original packaging, used only twice in a rack, like new.
*) 2x Fredenstein Bento 10S Chassis for 500 Series: 10-Slot Chassis with internal PSU. One with studio labeling stickers on it (easily removed), one with some rack burn from a touring case on the front panel (which made some of the LED writing less intelligable but works fine) - both cleaned, tested. One used to be rented out, the other one used to be one of our personal testing units and is in very good condition.

>> All hardware had been previously stored in a temperature and humidity controlled high-security storage unit with constant online climate monitoring, fire alarm etc. in rugged, shock-absorbant flight cases or in small non-smoking home to mid-sized studios or recording sessions of friends (where rental gear is concerned) as well as our R&D workplace at times depending on the unit in question: please just ask us directly if you have any questions or want to inquire about details about a certain device via [email protected]

10/01/2026

Love having to hack a virtual COM (RS232 over USB) issue not from mac or linux where it's detected instantly, no the vendor decides to give you a windows binary from 2001 to "programmatically" work with your lab PSU. it can execute excel/csv files in a row and set static values, right, very programmable. unfortunately the command reference is undocumented. so, yeah. reverse engineering and searching turned out to be quicker than waiting on ticket replies and begging for documentation.

-- [AZ (Aaron Zauner)]

10/01/2026

Yeah. Reading datasheets and building test pipelines is 85% of the work here right now.