Monday, 8 January 2018

Roland Jam - 100m, Aria TR8, MX 1

A quick and fun jam.
I love Roland gear, new and old.

I'm using Aria gear TR-8 drum & a MX 1 mixer and some old Roland 100m modules.

Apologies for the neck cramps.Couldn't work out how to rotate the video.

Wednesday, 3 January 2018

Hyve Touch Synthesizer - Tonnetz keyboard

I'm exploring the Hyve's upper keyboard. This is not your familiar black/white piano.
Apart from it not having any moving parts, it's arranged in a lattice structure.
This is a network representing tonal space "first described by the mathematician Leonhard Euler in 1739.Various visual representations of the Tonnetz can be used to show traditional harmonic relationships in European classical music".

It's all about chords and harmonies. Each note is harmonically related to its adjacent notes.
Straight up is a perfect 5th (a interval spanning 7 semitones), up to the right is a major 3rd (a interval of 4 semitones), and up to the left is a minor 3rd (interval of 3 semitones).

So the way it's arranged is if you play any note in a straight line from top to bottom, or bottom to top, it will play in perfect 5ths.
If you play notes going up to the right you will have a augmented pattern (it will go up or down in Major 3rds).
And playing notes to the left will have a diminished pattern (Minor thirds).

This layout of neighbouring fifths and thirds also makes it easy to form major and minor seventh, ninth, 11th and 13th chords.

It seems that all the most important scales — major, minor, chromatic, whole‑tone, diminished, blues, etc — have logical and distinctive patterns that basically climb rightwards and up. 
How it forms chords is really interesting.

I'm starting by looking at how it groups the Major Triads.
These are the most common  chords and are built by adding the third and fifth notes in the scale above a starting note (root). For example, in C major, the triad built on C contains:
  • C (the root)
  • E (the third note above C; often called just "the third")
  • G (the fifth note above C; often called just "the fifth")
The 3 major white-white-white triads are: C Major, F Major, and G Major.
C major: C E G
  F Major : F A C
 G Major: G B D

Minor Triads
 In C minor, the triad on C is built the same way:
  • C (the root)
  • E♭ (the third note above C; often called just "the third")
  • G (the fifth note above C; often called just "the fifth")
This is called the C minor triad.

C Minor Triad : C Ef G
C-sharp Minor Triad : C# E G#
 D Minor Triad : D F A
As discussed earlier, this layout of neighbouring fifths and thirds also makes it easy to form major and minor seventh, ninth, 11th and 13th chords.

First the 7th & 9th chords.
The C Major 7th Chord is C E G B
The C Major 9th chord is C E G B D
The C major 11th chord is C E G B D F
The C major 13th chord (drawn in light green) is C E G B D F A
The minor chords now.

Below are just random examples.

The G-minor 7th chord interval is: G A# D F (G Bf D F)

The E-minor 9th chord interval is: E F# G B D

The C minor 13 chord contains C, E♭ , G, B♭, D, F and A♭ (C D# G A# D F G#) as on the diagram below:

Hyve Synth

This arrived in the mail today: A Hyve synth.
I've been eagerly waiting for this since Feb 2017.
It's facinating. I think the Hyve gets its name from the upper honeycomb keyboard (and it also sounds like a swarm of buzzy oscillators.... there are 60 voices !!!).

There aren't a lot of these Hexagonal Lattice type keyboards around. (Tonnetz).
It's very Buchla Easel in its responsiveness to touch.

The Hyve is a result of a kickstarter program.
Thanks Skot for this incredible instrument. It's a beautiful fusion of engineering with art.
So how does such a small synth have this huge sound? (I'll post some videos later).
The synth looks deceptively simple. The two main ICs are a SN74HC393DR & CD40106BM96
There are six 74HC393s. It's a dual 4-bit binary counter. Each chip contains 8 flip-flops.

There are two CD40106s. These are CMOS Hex Schmitt-Trigger Inverters.
Each chip consists of six Schmitt-Trigger inputs and is capable of making 6 square/pulse wave oscillators.

The upper section has a TDA1308T/N2,115 .. it's a audio amplifier & a UA78L05CPK .... a 5V voltage regulator.
If I'm understanding this circuit correctly, each CD40106 produces 6 square waves.
As there are two CD40106 we have 12 original square waves to play with.
Each square wave is fed into a Flip-flop. The flip flop outputs 4 squares waves (each a octave below the previous).

So in actual fact each of the original square waves has added to it 4 new waves at different octaves from the original. (1 + 4 = 5)

There are two CD 40106 ICs so there are 12 original square waves.
12 X 5 = 60
This I think, is how we achieve 60 voices.

(let me know if there are any mistakes)
This Octave-down effect has been used in the past in guitar pedals. The MXR Blue Box used this method to create a two octave drop by using flip-flop circuits to divide the frequency by two. 
This created a buzzy synthesizer like tone.

The Roland SH101 used a CMOS 4013 dual flipflop to give three sub-oscillator waveforms; square at -1 octave, square at -2 octaves, and a pulse at -2 octaves.
Roland just fed the main oscillator output to the CMOS 4013 bistable flip-flop circuit to give the sub oscillator waveforms. Simple but ingenious.

+ Hyve touch Synth Facebook
+ Kickstarter
+ Factmag
+ Muffs
+ Muffs - Hyve modifications

Monday, 1 January 2018

Acclimatizing for Machu Picchu

Altitude sickness is probably the biggest obstacle for treking in Peru especially if you live at sea level.
In Peru most cities like Cusco are considered high altitude and the oxygen levels drop by around 5-6 percent. Symptoms range from SOB (shortness of breath) & tiredness to vomitting and dizziness.
In extreme cases, altitude sickness can cause death. Always seek medical advice if you are suffering from severe altitude sickness.

Altitude by City in Peru
  • Cusco – 3,200 meters (10,500 ft)
  • Sacred Valley* – 2,700 meters (8,850 ft)
  • Machu Picchu – 2,430 meters (7,970 ft)
  • Arequipa – 2,300 meters (7,500 ft)
  • Colca Canyon** – 3,633 meters (11,800 ft)
  • Puno / Lake Titicaca – 3,830 meters (12,560 ft)
Lima is not a good place to acclimatize for your Andean hikes as it is only 154m above sea level.
Before heading out to Cusco, I spent some time in Arequipa and visited a few of the surrounding volcanoes to help adjust.

The locals also advised me to chew Coca leaves. They make a decent tea.
Yes, coca leaves are the raw material for cocaine, but chewing the leaves or drinking coca tea when you're in Cusco (altitude 3,400 metres) clears your throbbing head and lets you breath again.

Altitude 4885m

 Our bus group at 5000m. Lack of O2 took its toll on everyone (except the bus driver).

Peruvian Pizza helps too.

 Inca Terraces

The bird is a Andean Condor.

Back in Arequipa. Peruvian hot dogs. I can think of no better way to round off a great few days in the mountains.
For more travel links click here: