Friday, 30 August 2019

Balter - NLC - Build notes

Some pics of a recent nonlinear circuit module build.
Its a delay -- for gates .. will help to loosen up my rigid drums.
The CV controlled delay  has a huge range..... from 7 milli-seconds to 1 minute.

You can get longer times by replacing the 1uF caps with larger values, say 10uF

This module is in Eurorack format.
gET  the SMD stuff on first.

RL = 10k

José Luis Torrente is a fictional character created by Spanish actor and director Santiago Segura and the main character in the Torrente scatological and dark comedy-action film series.

+ Wiki NLC
+ NLC Build Guide & BOM

+ Wiki NLC
+ NLC Build Guide & BOM

Click here to return to the NLC Build Index: 

Roland SP 808 Groove sampler

The 808 groove sampler came out in 1998 ... it's 21 years old.
There is a whopping 100MB of memory on a zip drive.

The SP 808 shares the same digits are its illustrious  brother the famous TR 808 drum.
This however was marketed as a workstation
You can still pick these up on Ebay quite cheaply.. if you are into vintage gear, this is still a good buy.

I think the machine is very underrated and I really like how it sounds.

It's a phrase sampler, sequencer, synthesizer, hard disk multitrack recorder with lots of studio quality effects. I think the market were DJ remixers ... musicians who wanted to sample.
In 1988, computers were basic and computer based sampling really difficult and expensive.
Plus, there is nothing like a real hardware machine that hardly ever crashes.
Daft Punk and The Prodigy used this on stage back in the 1990s

 The 16 pads reminded everyone of the AKAI MPC
The Sampler is 44.1kHz and 32kHz. It can  hold up to 1,024 samples. 
This is spread over16 pads x 64 banks.
Max sampling time is 25mins (stereo) at 44.1.
32 mins at 32khz

Roland used zip disks to store the samples. ... this is one of its weaknesses .......the zip can break down and be hard to repair. sadly WAV and AIFF formats aren't supported.

 The D-beam controller -- ITS A BIT LIKE A tHERMIN,
Just wave your hands above it.
You can  tweak effects,  pitch and volume

tHIS is the zip drive
Back in the 1990s, 100MB was a big deal.
Only SCSI drives could compete with this.

 The drive is both a blessing and a curse.
Over time , these break down, Its the Achillies heel.


For more info on the history of Roland Drum Machines click here

Thursday, 29 August 2019

Jaipur - Hawa Mahal - The Palace of the Winds.

It's a beautiful city with wide boulevards. It's the capital of the state of Rajasthan.
Founded in 1727 by Jai Singh II., it was designed during the British Colonial Period.
It's also one of UNESCO's world heritage sites.

It's often know as the Pink City because it was pained that colour to welcome Albert, Prince of Wales in 1876. Albert, later was crowned King Edward VII. One of his many titles was Emperor Of India.

There are lots of attractions to see when visiting Jaipur.
It's also a good base to visit other parts of Rajasthan such as Jodhpur (348 km), Jaisalmer (571 km), Udaipur (421 km)

A must see when visiting is the Hawa Mahal

This is the front. It's constructed of red and pink sandstone.
There are 5 stories. to this pyramid structure.
Built in 1799 by Maharaja Sawai Pratap Singh, the grandson of Maharaja Sawai Jai Singh, who was the founder of Jaipur

Its been described as a behive. There are 953 windows (Jharokhas). Notice the fine latticework..
Royal ladies were not allowed to be seen by the public without face coverings. This latticework allowed them to view the street, and not be seen.

These pics are the inside
Hans A. Rosbach (Attribution ShareAlike 3.0)
Sameer Goya

Ziaur Rahman 

Midi triggering the 1010 bitbox

I'm loving the bitbox.

It's a great sampler ... reminds me of the Roland SP 404 or a AKAI MPC
I've been searching for the best midi sequencer to pair with this module.
I've had success with the Arturia Beatstep Pro (the drum sequencer section) and the Roland TR-8

Midi note numbers output from the tr 8.
The Roland TR-8  outputs midi from channel 10. The midi note numbers are as follows:
Bass Drum - 36
Snare Drum - 38
Low Tom - 43
Mid Tom - 47
High Tom - 50
Rim Shot - 37
Hand Clap - 39
Closed HiHat - 42
Open HiHat - 46
Crash Cymbal - 49
Ride Cymbal - 51

Luckily, the bitbox also responds to midi on channel 10.
Midi input can also be used to modulate some parameters in the bitbox.

Ive seen the cirklon sequencer also used very effectively on the 1010.

Let me know if you of any other sequencers that pair well with the bitbox

Synthesizer Power Supples ----- Linear Vs Switching

When building a synthesizer power supply, there are two choices:

1. Regulated Linear Power supply
2. Switch Mode Power Supply (SMPS)


1. Regulated Linear Power supply.

These are quite simple in design.
Low noise ... most supply types produce no high-frequency interference.
But they are inefficient when compared to a SMPS . Output voltage is regulated by dissipating excess power as heat resulting in a typical efficiency of 30–40%.
Often uses heavy line-frequency transformers

It's hard to find AC Linear Wall Warts larger than 2A. This is a problem if you are building a large modular.
 This is a NLC linear power supply. It's very easy to build.

 aND ANOTHER example of a DIY linear PSU. One advantage is their ease to build. The components are cheap.

I use a 2A  AC brick with both of these.
Something like this:
I find that powering 3U to 6U (max) of Eurorack is OK with these ... check your modules power requirements of course.

You could of course use something like this if you needed more juice:
 This is a power one HCC 15-3A
This transformer based design has a center tap to give the centre ground. Both voltage outs are rectified and regulated to create dual voltage rails

Its very very heavy and would be hard to fit into a eurorack case. I used this in a Serge case.

Above is a doepfer A-100PSU2
Its a Linear PSU with ring core transformer
Output voltages/currents: +12V DC/1200mA, -12V DC/1200mA
Input voltage: 230V AC or 115V AC

Below is the L1 linear PSU
 It's a great kit.  1.5A per rail. 5V regulator on busboards.

2. Switch Mode Power Supply (SMPS) 

These first came out in the 1970s They are very efficient and their performance is much higher than linear regulators. SMPSs use PWM (pulse with modulation) to regulate the output voltage.
Their efficiency is very high, but the process is extremely complicated & creates high frequency noise.
They use diodes & capacitors to produce high voltage DC. This high DC voltage is then decreased and converted into a steady DC output using a system of transistors, capacitors, diodes, inductors & ferrite transformers.

The power bricks (wall warts) are a modern example of SMPSs. You will find them powering computer laptops and mobile phones.

This is a ATX SMPS from a desktop computer.

The advantages of this type of regulated PSU are that its smaller. There is very little heat generated.
Noisier due to the switching frequency of the SMPS. An unfiltered output may cause glitches in digital circuits or noise in audio circuits.
Above is the Doepfer A-100SSB. Its a small switcher PSU, suitable for up to 8 modules. (380mA)

Below is the Doepfer A-100PSU3
It's a +/-15V switching supply (wide range input 100...240V for mains voltage) followed by a linear regulation circuit that generates +12V and -12V. The +5V is a pure switching supply without linear regulation.

Really interesting design as it combines both linear & switching supplies. The black boxes are
Meanwell switching supplies. They create +15v, -15v, and +5v. The +/-15V must be passed through linear regulators to get +/-12V. I can't see the regulators in the photo ...maybe they are under the heat sink fins ???

The transformer in a switching power supply is also smaller than a traditional line frequency (50Hz or 60Hz depending on region) transformer,

If you need a high current wall wart a SMPS PSU will be easier to find. I use a 10A brick to power one of my Buchla cases.(though the OEM brick is expensive).

Meanwell RT65B.

A great switching PSU which seems ideal for a small eurorack case (around 200HP)

5 VDC(5A)
12 VDC (2.8A)
- 12 VDC  (0.5A)

You can use a Bus board with filtering  to remove the PSU ripple noise.
Use something like a LC filter.
This consists of an inductor ( represented by the letter L) connected in series with the power flow and a capacitor (represented by the letter C) from the filtered voltage to ground.

I guess before you do this you need to ask the questions;
  1. Are you better off filtering the noise, or preventing noise in the first place?
  2. Is there actually much noise ?
  3. Is the LC filter making more noise than it is removing?

Below is another example of a switching PSU
Its a Meanwell PD2515
Mouser: 709-PD2515

 It supplies : 24W 15V/0.8A -15V/0.8A 
iTS ok FOR a small buchla system

Finally, this is the PSU for my amalgamod Eurorack system:

Plenty of juice for  this:

+ NLC Build notes - Linear PSU 

Monday, 26 August 2019

Portishead - dummy - 25th anniversary

A landmark album.
This was part of my growing up
I can't believe its 25 years.

The group comprised sampling guru Geoff Barrow, guitarist Adrian Utley, and vocalist Beth Gibbons.
The album is all about atmosphere and texture.

Some of the tracks used material that was first recorded to tape, then pressed to vinyl which was stomped on and kicked around to give that crackling sound.
It seems they recorded a lot to tape which imparts compression & frequency distortion.

No.    Title            Length
1.    "Mysterons"    5:02
2.    "Sour Times"    4:14
3.    "Strangers"    3:55
4.    "It Could Be Sweet"    4:16
5.    "Wandering Star"    4:51
6.    "It's a Fire" (not on vinyl LP or original UK & Europe versions of album)    3:48
7.    "Numb"    3:54
8.    "Roads"    5:02
9.    "Pedestal"    3:39
10.    "Biscuit"    5:01
11.    "Glory Box"    5:06

Some of the synths used on the album were the  :
Roland 808 drum.("It Could be Sweet")
Akai S 1000 sampler
Roland SH 101 ( "Mysterons") ???
Fender Rhodes (Roads, "Biscuit", "It Could be Sweet" )
Vox Continental Organ ("Numb," "It's a Fire," and the end of "Wandering Star." )
Hammond Organ ("Numb," "It's a Fire," and the end of "Wandering Star." )
Roland Space Echo - RE 201 ( "Mysterons", "Pedestal", "Numb")

This is by no means a complete list...
(I haven't of course mentioned any of Adrian Utley's Guitars)