Sunday, September 3, 2017

Don't give up on those old drum machines


I love old gear. But sometimes parts degrade or stop working and you wish you had a brilliant friend who knows how to find problems and fix them. As it happens, I have such a friend -- one Curtis Rochambeau of Rochambeau Musical Apparatus -- and was stoked when he agreed to come check out my ailing Korg SR-120 drum machine. It wasn't outputting any low end. So no bass drum and no tom sound.

My own suspicion was that some part involved in producing low end sounds was toast: besides there being no bass drum sound in each of the built-in patterns, there was also no bass drum or tom sound happening during fills invoked by the manual change button. Just silence during the hits that should have been there, while the crispy snare and hi-hat continued doing their jobs. But that was the extent of my ability to troubleshoot.

Consulting the service manual (thank you, internet), it was easy enough to spot sections of the circuit that performed certain functions. Well, I say "easy" because those sections were labeled with things like "B.D." (bass drum), "S.D." (snare drum), "Equalizer" and "Power Supply", and so on. But Curtis can look at those diagrams and understand that this chip is doing that, and this cap is needed here for this, and these 100 ohm resistors do that. He quickly identified where the triggers for the various sounds originated, so he used his probe to watch the oscilloscope for electrical triggers being sent from each pin on a particular chip. 

We could see a pretty obvious trigger coinciding with the snare sound, and we knew where the bass drum sound should have been occurring. So with the drum machine playing through the sound system we watched for triggers on the 'scope that happened where the bass drum should have been.


Once Curtis identified the pin for the bass drum trigger, he followed the trace on the circuit board to the point where the received trigger would hit the part responsible for producing the bass drum sound. Except that the trigger wasn't being seen on the other end. At this point Curtis declared, "This should be an easy fix."

He proceeded to flip the circuit board over and back, over and back, following circuit traces with his eyes and fingers, looking for possible reasons why the trigger signal wouldn't be making it to the next hop along the path. "Well, that's no good," he said, pointing to a spot of corrosion at one of the connection points. In fact, there were two or three other spots of corrosion around the board, and they all corresponded to capacitors. Ah, so that's why people have to re-cap old gear after a time...

Curtis scraped away the corrosion from our suspected trouble pin, saying that if the corrosion hadn't eaten away at the circuit trace itself, then he could simply re-solder that spot. As long as the electrical signal could pass that spot, we should see the bass drum trigger downstream. So he gave that a try. Alas, the signal did not pass. He then reluctantly tried to finesse some solder before and after the pin to try to bridge the gap, but that didn't work either. So he undid that, and said, "We could just bypass this cap altogether, and then someday when you re-cap this thing, you can remove the bypass and put the new cap back in play (assuming the trace isn't corroded too)."

He probably explained why we could bypass this particular capacitor, but my arms were getting tired from holding a light for him and my beer was out of reach for the moment. OK, Curtis, so what do we use to bypass the cap? "Just a little wire." Well, since we're ad-libbing here, do I have something lying around the house that could do the trick? "Do you have some CAT-5 network cable? We could steal a wire out of that."

Blip. Blip. That's the sound you make when you just soldered two points, connecting a little wire from point A to point B, bypassing a bad cap. In this photo, the small orange wire is our bypass, and you can see the corrosion at the point where the bypass wire bends to the left.

We flipped the whole thing over and fired it up. BOOM.... BOOM BOOM... BOOM... BOOM BOOM... We have bass drum!

Thinking about it later, I asked Curtis to explain to me again how he knew he could just bypass that capacitor. He wrote back:

"Most big caps you see are just doing power supply decoupling, so any noise or cycled waveform created by an adjacent circuit does not bleed through the power rails and affect other circuits. They perform this function because they pass AC (signal and noise) while blocking DC, so you strap a cap from the power rail to ground in hopes of limiting the available voltage to just DC. Those 100 ohm resistors separating sections in the power rails provide a small enough "incline" that spurious signal has an easier path through the cap, so it doesn't wander and bother the neighboring sections, so to speak.

"So that cap’s only function is to sluice any noise (or signal, because when a section is generating a wave form it pulls power in a way that reflects the waveform onto the power rail) originating at the bass drum and tom section from rippling out and affecting other sections. But we're dealing with small signals here, not power amp level draw, so the likelihood of the bass drum modulating other sections is minimal - because in order to do so, it would have to pass through the localized filtering supporting the neighboring sections as well. It's kind of a redundant system. Plus, we only know that the power rail was severed at the cap, IF one leg of the power rail is still attached to the cap, the cap is effectively still in circuit after bridging the severed trace. I didn't have tools to measure that on hand, and at the end of day, it sounds awesome - so even if the bass drum is pummeling other sections when it hits, it does so in a musically valid way.

"The caps that really affect the sound of something are either interstage DC blockers (when they leak everything sounds worse), or a tuning/timing constant on an oscillator or filter, but those are rarely electrolytics, and enjoy a much longer lifespan."

Thursday, September 8, 2016


BlRR Recommended. Edition of 250 copies with the first 100 numbered.

Available Sep 15. Split release by square_wave / Prajna. Two long lovely, floating tracks.

1.  square_wave - Lovers Slumber  (21:59)
Ty Hodson - monome, estate sale records, synths, percussion, vocals, mix
Prajna - supine presence, rummaging
Drifting through mists hanging heavily on forests coming to life under sun-kissed clouds, playful Oni lure lost children. 

2.  Prajna - Want to Need  (20:34)
Prajna - bowed and tapped violin, gas tank bells, vocals, processing, mix
Ty Hodson - field recording, processing, mix
Slipping like ghosts through thousand-year-old monastery walls, crossing hidden courtyards where Buddhist monks make their cell phone calls.

Ty Hodson has released music under the square_wave moniker since 2007, having released four albums on his sublevel9 studios imprint. On the side, he writes and records under the name gradenko, with a post-rock/prog album slated for future release on Beta-lactam Ring Records. Ty also represents one half of Armchair Migraine Journey.

Prajna has appeared previously on Armchair Migraine Journey’s ‘Blood Coupling Magnet’ on vocals alongside Soriah. "Want to Need" is her first published solo work.

Mastered by Randall Frazier at Helmet Room
Chris: artwork, design, layout

Edward Ka-Spel / Armchair Migraine Journey - Transmit Acoustique Abstraction Three



Issued Sept 15th to coincide with the N. American tour of The Legendary Pink Dots and Orbit Service. An edition of 111 copies available on the tour with 39 copies available via the label mail-order (first edition of 150). Packaged in a French Black six panel CD case. Two years in the works and finally seeing the light of day. 

“Infernal Machine” a collaboration with Edward Ka-Spel and Armchair Migraine Journey delves deep into a psychedelic swirl of sounds. 

“Strands That Bind”, a new track by AMJ dives slowly into a sea of ambient drones and passages and develops along its 24-minute journey into an almost metal machine music dirge. 

1. Edward Ka-Spel / Infernal Machine: 
Edward Ka-Spel - vocals, synth noodling 
AMJ - drones, synths, processing 
Ty Hodson - drums, vocoder, processing 
Mixed by AMJ and Ty Hodson

2. Armchair Migraine Journey / Strands That Bind: 
Ty Hodson - guitar, drums, synths, processing 
AMJ - synths, drones, theremin 
Randall Frazier - The Voice of …? 
Mixed by AMJ and Ty Hodson 
Includes deconstructed elements of ‘Magnetic Blood Drowning’ with Peat Bog (Earthmonkey) and Randall Frazier (Orbit Service)

'Infernal Machine' by Edward Ka-Spel, AMJ, Ty Hodson 
'Strands That Bind' by Ty Hodson, AMJ
Mastered by Randall Frazier at Helmet Room

AMJ to open for select LPD shows Sep/Oct



The Legendary Pink Dots are about to begin their Tour Aquarius 2016 with Orbit Service. Armchair Migraine Journey will also open for select shows, beginning with the first two shows of the tour: Portland (Sep 15) and Seattle (Sep 16). Other dates to be announced. The full Tour Aquarius schedule can be found at legendarypinkdots.org.

Monday, September 28, 2015

Armchair Migraine Journey - Blood Coupling Magnet


New album! Spacerock guitars, juicy dark drones, psych drums, dense otherworldly atmospheres, Tuvan throat singing, evocative Eastern drones, a lilting mantra for rebirth... A sonicosmic journey of endings and beginnings... Two epic tracks featuring guests Peat Bog (Earthmonkey) and Randall Frazier (Orbit Service) on one, and the vocal talents of Soriah and Prajna on the other. Edition of 450 numbered copies packaged in a custom gatefold book bound sleeve. Also, an edition of 50 numbered and signed copies with a bonus CD-Record of exclusive music (CD playable with an included adapter on a turntable) plus an original art print by AMJ. Available to order at Beta-lactam Ring Records.

"The emphasis is definitely on the “Journey” as mysterious drone-meets-psychedelia act Armchair Migraine Journey embarks on this new trip. Beginning with a medley of dark ambient drones, buzzes, fades and washes, MAGNETIC BLOOD DROWNING, the initial offering on the two-track Blood Coupling Magnet, lays on thick atmosphere before coalescing into a dark psych-rock jam backed by distortion-drenched drums. In the fashion of the best and most “out there” prog, it effortlessly skirts the line between noise and melody; just when you think things are turning into a morass of self-indulgent feedback, the guitar pulls back just enough to get your head nodding again to the moody Krautrock-inspired rhythm. The second composition, REBIRTH BLOOD ΩM, shifts even more drastically, traveling further out into the sonic and philosophical void. Industrial rock drums and heavy overdriven guitar chords straight out of some early Pigface demo open things before suddenly giving way to the gentlest ambient, delicately drawn out chiming tones over a quiet heartbeat punctuated by heavy breaths. Soon, the otherworldly growling trance-drone of Tuvan throat-singing—courtesy of Soriah's Enrique Ugalde—brings the ethereal down to earth. A Buddhist mantra, sung by Prajna, forms the backbone to the song's latter half, as the throat-singing takes turns with a fuzzed out, effects-drenched tanpura to follow the melody of the chant, drifting in and out of harmony with Prajna's voice. Cosmic, earthy, ominous, uplifting and even spiritual, Blood Coupling Magnet is sonically fascinating, but more than that, it's emotionally affecting. Plenty of experimental music can manage to do interesting things with your head (especially if you're that breed of music nerd that likes to spend time thinking about experimental music) but Blood Coupling Magnet works its way into your gut, too.” --Matthew Johnson

AMJ: sounds electronic, sounds imaginary, sounds found
Ty Hodson: rock and roll music, electronics, analogue processing
Peat Bog (Earthmonkey): guitar, atmospherics on MBD
Randall Frazier (Orbit Service): atmospherics on MBD
Soriah: vocals on RBΩ
Prajna: vocals on RBΩ
All songs by Ty Hodson/AMJ 
Mastered by Randall Frazier at helmet room 
AMJ: Artwork, design, layout

Thursday, September 17, 2015

Un Festín Sagital - Moesta et Errabunda


Happy to contribute drums via Armchair Migraine Journey on the latest EP by Un Festín Sagital, with arresting artwork by Jesse Peper. Available on UFS's bandcamp page and in physical form on Beta-lactam Ring Records.

Game release: Thief of Baghdad [square_wave soundtrack]













I contributed music from the earliest square_wave archives for this beautifully rendered and wickedly difficult game called Thief of Baghdad

From the game creator, Michał Rostocki:
TOBAFCASS is a side shooter with unique visual style and characteristic electronic music. For both the story and visual style I took inspiration from "The Thief of Bagdad" a 1924 classic silent adventure movie with Douglas Fairbanks. Game mechanics are of classic ultra-hard side shooter. In particular I was inspired by "Agony" a beautiful yet unforgiving Amiga game from the 90s. Finally most of the enemies come from "Kunstformen der natur" a book by Ernst Hackel full of litoghraphic illustrations of bizzare creatures perfectly organized with Prussian precision and devotion to symmetry.

Downloadable for free here. UPDATE: I received a newer link here.