Wednesday, 9 July 2014

Metasonix R-56 Tube Reverb.

A few test videos of the Metasonix Vacuum Tube Reverb. - R56.


The videos are a bit low fi- recorded on a mobile phone.
So my apologies for the audio quality.
Here we (Cobramatic & I) are testing the R56 with a Buchla music Easel)

The feedback dial is EVIL.if you love distortion like I do.
In this video we are running a Endorphin.es Furthrrrr Generator
through the R-56. The Furthrrrr is a Buchla 259 inspired eurorack module.

Here is the blurb from Metasonix


Monday, 7 July 2014

Buchla Music Easel & Vermona Drum

Playing with the BEMI Easel.

The Easel is clocking the Eurorack TriggerMan (Delphtronics) which is in turn
triggering the Vermona DRM 1 (Mark III).


Some pics:





Who's the girl (playing that 1960ish Moog Modular)?

Does anyone know who this girl is?

I'd love to know her name? Is she a musician?

I understand that The R.A. Moog modular that she is playing is this one (bar some different modules in the upper right of the top case and the absence of the second keyboard):


The system includes:- three 901 VCOs, 901A VCO driver, four 901B VCOs, 903 White Sound Source, two 904-A LPFs, 904B HPF, 904C filter coupler, three 902 VCAs, three 911 envelopes, 911A dual trigger delay, 907 10-band fixed filter bank with a unique original switching system, and a five-octave keyboard
with portamento.

The basis of the system dates from August 3 1967. I understand that the picture with the girl was taken in the summer of 1969. There is a record of a second service being carried out at R.A. Moog when the extra cabinet & modules were added).

This modular is the 10th proper system sold by Moog since they started keeping records (based on serial numbers) at the beginning of 1967. Professor Emerson Meyers of the Catholic University electronic music studio used it  to create the late 60s LP "Provocative Electronics".

Friday, 4 July 2014

Monte Albán - Mexico

Monte Albán is a large pre-Columbian archaeological site in the southern Mexican state of Oaxaca.
It was one of the first major cities in Mesoamerica and the center of the Zapotec state.
Zapotec culture goes back at least 2,500 years.


Zapotec civilization originated in the Central Valleys of Oaxaca in the late 6th Century BC. The three valleys were divided into three different societies which were separated by 80 km2 “no-man’s-land” in the middle. The 3 societies originally competed with one another, but in the end one ruled them all, and they made their capital in Monte Alban.


The site is situated atop an artificially-leveled ridge, which with an elevation of about 1,940 m (6,400 ft) above sea level. (To flatten an entire hiltop was some feat in those times).
...

 This central monument (building J) is made from stone slabs that bear inscriptions from foreign nations.
A symbol of  Zapotec domination. It's an odd shape.. has a roughly pentagonal outline.

It's orientation is thought to point to the location of the star Capella. Capella is indicated by the orientation point of the building on May 2, when the sun reaches its zenith and passes directly overhead.
 Possibily, building J follows the shape of the five brightest stars of a constellation known to us as Auriga, in which Capella is the brightest star.



The main plaza and surrounding temples however are aligned from north to south.....with the rising and setting sun as well as constellations. Was this to track time and make offerings to the Gods?


The city was founded around 500BC making it one of the earliest cities on MesoAmerica. The ruins are very impressive. Why was the city built so high ... above the farmland, and water? The people who founded this must have had defence in mind. Zapotec civilization.

Ancient Mexican Football.
 Notice the shape of the stadium ... its  like a capital "H"..... a symbol of Zapotec culture??



 This group of stones are the so-called "Danzantes" (literally, dancers), found mostly in the vicinity of Building L.
They represent naked men in unusual poses. The original explanation that they are dancers has been discredited and they are today believed to represent captured & sacrificed prisoners. They were most likely tortured which explains their twisted bodies. Some of them are genitally mutilated.

"By 200 AD, the Zapotecs had extended their influence, from Quiotepec in the North to Ocelotepec and Chiltepec in the South. Monte Albán had become the largest city in what are today the southern Mexican highlands, and retained this status until approximately 700 AD".
(Wikipedia)





You can view more of my Mexican travels here

For more travel postcards click here:

Thursday, 3 July 2014

Vermona DRM - How to install CV triggers

I've owned a Vermona drum for many years. It's a DRM 1 - Mark III.
I love it to bits but purchased it in the days when I was only interested in midi triggering.


Since getting into modulars I started to regret not buying the version with the CV triggers.
I've read that adding the triggers is easy but could never find info on the web relating to this.
Hopefully these pics will help others wanting to do this mod on their own.
Once you see how easy it is you will prob want to get to it right away.
The triggers are placed  into the spot on the left with the 10 caps.

Once you have opened the drum, remove these caps.

These are the trigger modules. You will need two (there are 5 trigger inputs in each).
 The underside of a trigger module.

This is the inside of the DRM.   Beautiful to behold!!

The CV trigger modules have a ribbon cable that simply plugs into the PCB as shown.


That's all that is really needed. No soldering :-)




Many thanks to Matt of "RhythmActive" for supplying the trigger modules.

Sunday, 29 June 2014

TTSH - ARP 2600 Replica - VCO 1

This is the 4th part of my TTSH (Two thousand six hundred) build.
You can see my full build thread HERE
There are two awesome TTSH threads in Muffs.
2600 clone - Two Thousand Six Hundred (TTSH)
and
Two Thousand Six Hundred (TTSH) Project General Build Thread
The DSL-Man site has a very good TTSH thread
And of course the official build thread is here
------------------------------------------------------------------------------




 The unpopulated rear section of VCO 1

Install the IC headers,  resistors & caps first.

This is the front view of VCO 1



These headers connect the VCO submodules to the motherboard.
I'm installing these on the motherboard as high as as I can to 
provide as much room as possible between the two boards.



Connecting VCO1 to the PSU.

I'm soldering the connections directly to the PSU, though you many wish to use MTA connectors.

The red wire to the base of the resistor is temporary only.
+15V needs to be applied there for testing.

If all is working you should see a square wave from this pad and a saw from the pad above.

The VCO uses fairly inexpensive LM301 op amps which can be found in many vintage ARP 2600s:


This is the pinout:

I might in the future try replacing these with more modern 711's, LF351s or 411s. ???
It's probably not a matter of simply swapping the chips. Maybe the 301's are better left in the VCOs and changed in the filter ??? These 301s are everywhere. They can be found in the VCOs, the filter, the EGs and the VCA.

This modification is just a personal idea and I haven't tested it yet.
I don't recommend any modifications unless you are a qualified technician. 


In Mark Vail's book "Vintage Synthesizers" he discusses the SL19986 describing it as "nothing more than a selected LM-301. He goes on to say that" The reason ARP selected them was for their DC performance. But because they aren't of very high input impedence .... they are not as good as an LF-351,411, or other high-performance op-amps."



Anyway, I'm a bit undecided about changing op-amps. New op-amps may clean the path but I kinda like dirt and noise. Maybe ill keep the old 301's in the end. 





Another ARP guru, Phil Cirocco, has some great info on this website:

 To quote him:
"...The 2600 uses microchip technology in all of its gain stages! The first 2600's .......used hi-fi chips (Teledyne 1339 octal op-amps) with a high slew rate. Although these chips sound great, they were very unreliable and prone to latch up. Around 1972, plagued by failures in the field, ARP was forced to change these chips to a much more reliable type (National Semiconductor LM-301 or SL-1998) The problem is that they slew the wave shape producing a muffled sound. The LM-301 is classified as a general purpose amplifier, and is considered inadequate for audio by present standards. Nearly all the standard production gray-face 2600's use the LM301. This is the main reason why the legendary Blue Marvins sound better!

So I wonder what he replaces the 301's with today ??? 

***********************
Many thanks to "unknown" for his comment re the MC1439
"I've seen picture of 2500 modules where the 301s had been
replaced by MC1439. The PCB looked like it could accommodate
either; the 301, according to the older schematic only used
a cap whereas the 1439 looks like it use series RC for
compensation."

 
Yes it looks like the pinouts for the LM301 & the MC1439 are identical. Ins are on pin 2 & 3. Out on pin 6.
I'll give this a try on one of my next builds.