Saturday, 13 May 2023
Elk Elektroniks - next meeting
...
Unit 2, 1-5 Miller St , Wollongong, NSW, Australia, New South Wales
Ph: 0417 203 283
https://www.elkelektronik.com.au
Friday, 12 May 2023
Coffee Group-heads
The group head, also known as the brew head, is the part of an espresso machine where water from the boiler is dispensed into the coffee filter basket.
Espresso machines utilize different types of group heads, which are essential components responsible for delivering pressurized water to the coffee grounds in the portafilter for extraction. The design of the group head can affect factors such as temperature stability, water distribution, and espresso flavor.
It serves as a meeting point, connecting the machine to the group handle and the hot water to the coffee grounds.
I think that the he most significant difference between different group head designs is how they are heated.
The group head essentially consists of two main components: the portafilter and the water distribution system.
Most commonly, group heads come in 8-hole (single), 12-hole (double), and 20-hole (triple) configurations.
In all group heads you will find a gasket & a shower-screen.
The gasket is a thick rubber band that creates a seal between the portafilter and the group-head.
The shower-screen distributes or showers water evenly over the puck.
(As an aside, cleaning your gasket & shower screen regularly is impt)
There are many types of group heads. Technology is constantly evolving
and its difficult to keep up with new improvements.
It is not that straightforward to classify them into simple categories. Some may share the same name but with a slightly different mechanism, while some have different designs but works the same.
The main types of group heads that you will come across are :
Conventional.
Saturated.
semi-saturated
E61.
Lever.
Electrically (electronically) heated
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Conventional.
Also known as traditional or commercial group heads, these are the most common type of espresso machines. They are simple in design making them straightforward in brewing espresso
and giving you a sleek no frills look.
The inner pipes are housed inside, so the external casing isn't hot to the touch.
They use 3 way solenoid valves to reduce excess pressure after brewing.
These group heads are not heated so aren't the most thermally stable when compares to E-61 or saturated groups.
Standard group heads typically have a large, circular design with a central dispersion screen or shower screen. While it may not be the best group head for thermal stability,
it is a proven tech with simple construction, and is cheaper to produce and maintain than other more complex group heads.
Examples are Rocket Boxer, Nuova Simonelli Musica/Osca, and Rancilio Silvia V6.
Saturated
The water circulates continuously around the group head from the boiler.
The entire group head is thus heated, ensuring that the brewing water remains at a consistent temperature throughout the extraction process.
This results in improved temperature stability because the group is saturated with the same body of water whose temperature is being controlled in the boiler.
These types of groupheads usually heat up much faster that E-61 groups.
Synesso and La Marzocco both use saturated groups. Obviously, a saturated group can only work with machines that have separate steam and brew boilers.
Note that this water in the saturated group head is not used to brew. It just circulates.
Saturated group heads are often found in higher-end espresso machines and are favored by specialty coffee enthusiasts.
Left is a "ring style" saturated group head.
examples: La Marzocco GS, GS2, GS3 (GS = Group Saturated) machines. GB5, Linea Classic, La Marzocca GS3 or Slayer, Synesso, Rocket R Nine One, and Kees van der Westen.
The La Marzocca "goosehead" style is found on many of their machines like the GS3.
Some cheaper machines like the Gaggia Classic pro employ a similar idea. The Gaggia's boiler is right above the group-head. So heating the boiler will heat up everything (including the group-head).
Semi-saturated
The group head is separated from the boiler by a heat exchange mechanism that directs water flow around the group head.
A semi-saturated group head features a separate water path from the boiler to the group head, which allows for precise temperature control and consistency. .....maybe the temps are a little less stable than a saturated head.
Lever
There are two sub-categories within this type: spring piston and manual piston. With a manual piston group head, the user has direct control over the water flow through the coffee grounds to brew the espresso. On the other hand, a spring piston group head uses a lever to compress a spring, creating pressure to force water through the coffee grounds. Both of these types offer varying degrees of control to the barista and may impact the espresso quality.
Examples; Pro 800 by Profitec and Leva by La Marzocco , Robot Barista by Cafelat
E61
The Faema got its name from a solar eclipse that occurred in 1961.
It's a design that is very tried and true and is one that is used on many prosumer grade espresso machines and even some commercial machines like the Faema Legend and the Faema Jubile.
This design uses a thermosyphon heating system where heated water circulates between the boiler and the group head to maintain a stable temperature.
It's basically a radiator. Hot water leaves the top section of the boiler and enters the top of the e-61 group head (the mushroom). It begins to cool.... then travels back to the bottom of the boiler.
There is no pump running. The thermosyphon is a passive heat management system.
That big chunk of metal radiates water around the machine to impart thermal stability.
These are easy to spot as the portafilter sits outside the machine and is connected to a brew lever that operates it. Lots of people love these as they look great and do a decent job.
Plus, it is a very simple and reliable design. For example, it incorporates a mechanical 3-way valve with no need for a separate solenoid.
This design helps to prevent temperature fluctuations during brewing and ensures consistent extraction. Thermosyphon group heads are commonly found in high-quality commercial espresso machines.
The E61 became a group head template for manufacturers, each making slight variations on the design to suit their own requirements leading to the introduction of multiple boilers to their machines.
It takes about 25 minutes or longer to heat up an E61.
The Rocket Apartamento is an iconic E61 machine, followed by ECM Classika, Profitec Pro 400, and Lelit Bianca.
Electronically heated.
The group head is electrically heated with heating elements that are inside the group-head itself. These elements are usually controlled by a thermostat, or PID. Since the heating elements are embedded in the group head they are very efficient in maintaining thermal stability.
You often see these in entry level machines (though not always).
The Bezzera BZ-10 has a electronically heated e-61 style group head. Other examples are the Profitec Go & Move, Rocket Bicocca and the Stone espresso.
They are very fast at reaching brewing temperatures
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Coffee index. Click here :
Tuesday, 9 May 2023
Symi - Greek Island
On my way to the Island of Symi.
One of the main characteristics of Symi is its traditional neoclassical architecture. The island's main town, also called Symi or Gialos, is built amphitheatrically around a natural harbor, creating a stunning view. The colorful two- and three-story houses with their red-tiled roofs, wooden balconies, and ornate facades give Symi a unique and charming ambiance. The town's narrow, winding streets are lined with quaint shops, cafes, and taverns, creating a delightful atmosphere for leisurely walks and exploration.
Symi Island has a rich maritime history, and its main source of wealth in the past was shipbuilding and sponge fishing. The Naval Museum of Symi, located in the town's old market, showcases the island's maritime heritage, displaying various artifacts and exhibits related to Symi's nautical past.
Apart from its architectural beauty, Symi also offers stunning natural landscapes. The island is characterized by rocky cliffs, crystal-clear turquoise waters, and numerous secluded beaches and coves. Some of the popular beaches on Symi include Nos Beach, Marathounta Beach, and Agios Georgios Disalonas. These beaches offer visitors a chance to relax, sunbathe, swim, and enjoy the peaceful surroundings.
So quiet in the afternoon. Everyone is asleep
Cats having a nap on a hot day.
Symi Island is also home to several notable landmarks and attractions. The Monastery of Panormitis, located on the southern part of the island, is a major pilgrimage site dedicated to the Archangel Michael.
The monastery is known for its beautiful Byzantine architecture and its unique icon of the Archangel Michael, which is believed to have healing powers.
,,
Below is a view from the Kastro of Symi.
The Kastro of Symi offers panoramic views of the town, the harbor, and the surrounding landscapes. Visitors can explore the remains of the fortress, walk along its walls, and enjoy the scenic vistas. Although the Kastro itself is not as grand or extensive as some other fortresses in Greece, it provides a glimpse into the island's history and offers a serene and picturesque setting.
Monday, 8 May 2023
Kibbutz - Israel
Some old pics of the restaurant of a Kibbutz I visited while in Israel back in 2015.
I can't remember the name of this Kibbutz, but the food was great. If anyone can help me identify the place I'd be most greatful. I think it's in northern Israel near the sea of Galliee.
The name comes from the Hebrew word kvutza, meaning “group”
Today there are approximately 250 Kibbutzim in the country, where about 125 000 people live. The majority of Kibbutzim are secular, but there are about twenty religious Kibbutzim, as well as Kibbutzim connected to both the Conservative and Reform streams.
This Kibbutz was founded in 1928.
People live on egalitarian and communal principles.
in a social and economic framework.
It is based on the principle of collectivism.
All income generated by the Kibbutz and its members goes into a common pool. This income is used to run the Kibbutz, make investments, etc.
Though this sounds a bit like communism, its governed by a system of "direct participatory democracy".
Here, the individual can directly influence issues and events in the community.
I think the hebrew translates as "Aware"
And "70 years".
Founded 1928.
Kibbutz members receive the same budget (according to family size), regardless of their job or position. In terms of education, all children start equally and are given equal opportunity.
Kibbutz members receive the same budget (according to family size), regardless of their job or position. In terms of education, all children start equally and are given equal opportunity.
I wish we could have stayed longer.
Coffee machine manufacturers
A brief list of some of the major coffee machine manufacturers.
ACS coffee machines - Naples - Advanced Coffee Solution
1962?
Ascaso - Spain, Barcellona. Est 1962.
The founder, Jesús Ascaso, worked at Gaggia Spain
Aremede - Australia
Arrarex - Mid 1950 - Milan - famous for the caravel - known as the VAM
(Vetraria Ambrosiana Milano) .
This machine was created in mid to late 1950's 1960 by Dr Emilio Salati of Milan.
The design of the machine is an absolute masterpiece, tastefully blending elements of
Dr Salati created the Caravel for one specific purpose: to produce small
shots of perfect espresso.
Bellezza - 1975 - Heinz Berberich founded Berberich Kaffeemaschinen in Ketsch, Germany.
Bezzera - It was in 1901 when Luigi Bezzera patented the first espresso coffee machine
introducing a new way of drinking coffee, starting the Italian Espresso Coffee culture.
Luigi Bezzera (born in the 19th century; died in the 20th century)
was an Italian mechanic and innovator.
He is the inventor of the first removable portafilter espresso machine,
In 1901, the first patented espresso machine was invented by Luigi Bezzera,
who almost immediately sold his patent to Desiderio Pavoni
(whose name is synonymous with Italian-built espresso machines to this day)
BFC - Brutti Fullin Costruzioni - 1998
all of BFC's coffee machine components are manufactured at the
Scomigo di Conegliano factory in Italy.
Boema - established in 1956, Sydney Australia
Signori Bordignon and Emer were two Italian immigrants that
decided to start there own coffee business,
hence, how the name Bo-ema name came to be.
Breville - Founded in Sydney, Australia in 1932 by Bill O'Brien and Harry Norville,
who combined their two surnames to form the company name.
The company originally manufactured radios.
During World War II, it made mine detectors.
Also known as Sage in the UK
Cafelat - Hong Kong - Famous for the Cafelat Robot Lever machine.
The founder of Cafelat is Paul Pratt.
Cafelat’s design is due to the involvement of Danish artist and designer Karina Mencke.
Cafello - China - (Tutto)
Casadio - Bologna Italy 1950 (part of the Cimbali group).
Nello Casadio was born on January 1, 1907.
closely related to Bologna is the choice of the company's trademark:
the neptune with the trident, a famous sculpture by Giambologna that, in 1950,
became the official symbol of the Casadio company
CIME - Machine Espresso Italiane . Founded 2012.
De'Longhi - Founded in 1902 in Treviso, Italy.
ECM - Espresso Coffee machines (Monteriva)
The original company ECM was founded in 1995 by Friedrich Berenbruch in Milan.
Wolfgang Hauck founded ECM GmbH in 1996
All of their machines and grinders are developed and designed in Germany
and produced in Germany and Italy.
Elektra. Founded in Treviso Italy in 1947.
El Rocio - South Korea - founded April, 2013
Models: Manus, Zarre.
Espresso Deck - Australia - They invented the "undercounter coffee machine".
1990s ? These are custom built.
Expobar - Founded by Rafael Olaso Peirò in Spain - 1985.
Located in Gandia Valencia, They are part of the Crem group.
Crem has produced coffee machines for more
than twenty years including the brand Expobar
than twenty years including the brand Expobar
Faema - 1945 - Milan - the "Factory Electro Mechanical and Associated Equipment"
("Fabbrica Apparecchiature Elettro Meccaniche e Affini” - FAEMA).
In the 1950s, Faema began with horizontal boiler, lever piston machines,
which were typical of the time. ... In 1961, however, Faema released the E61
(part of the Cimbali group)
Flair - California, USA - lever machines
Francio - UK - 1962 - Fracino are the leaders in dual fuel espresso coffee machines producing commercial machines that can run from LPG gas , Electricity or
a combination of both.
Futurmat - Spain 1978 eg Rimini
Gaggia - Founded in 1938 in Milan, Italy.
The Gaggia S.p. A company was purchased in 1999 by fellow Italian competitor
Saeco International Group, which in turn was purchased by Dutch manufacturer
Philips in 2009.
Isomac - 1977 - Monteriva - founded by Giovanni Fontana
The company is now owned by Pavoni
Izzo - founded in Naples, under the shadow of the famous Mt Vesuvius, in 1979 by Vincenzo Izzo
Jura Elektroapparate - Founded in 1931 in Switzerland.
KEES VAN DER WESTEN - Espresso machines built by eye in The Netherlands.
1984 - founded
High precision, high performance. Unique design. Sculpture meets coffee
La Marzocco - Founded in 1927 in Florence, Italy.
They specialize in high-end espresso machines.
La Pavoni - Founded in 1905 in Milan, Italy
aquired by Smeg in 2019
La Cimbali - 1930 - Italy .
With more than 900 employees worldwide, Cimbali Group currently comprises
six primary brands: espresso machine and equipment brands La Cimbali,
Faema and Casadio; United States-based espresso machine brand Slayer
(acquired by Cimbali in 2017); the Mumac coffee machine museum;
and the Mumac coffee academy
Lelit - Lelit was founded by the Epis family in the 1980s in Baitella, Italy
Headquarters - Brescia
Purchased by Breville in 2022
Londinium - Founded 2012. Birmingham UK.
Focus is on making modern lever coffee machines.
Miele - Founded in 1899 in Gütersloh, Germany.
They produce a range of household appliances including coffee machines.
Meraki - founded in Shenzhen, China -
A Greek word meaning to do something with soul, creativity, and love
Muvna - founded 2020, China. famous for their hand cranked coffee machine (MACH)
Nespresso (owned by Nestlé) - Nespresso machines were introduced in 1986.
Nuova Simonelli - 1936 - Nuova Simonelli is an Italian company that can trace
its history back to 1936 when Orlando Simonelli made his
first espresso machine, which was seen as one of the most
technologically advanced units of its time.
Odyssey - 2019 - famous for the Argos Lever. Denver, Colorado
Olympia - 1928 - Switzerland.
Profitec - 1990 - German/Italian Company.... started in Bammental Germany
The Profitec brand was started by Michael Hauks father, and ECM
started by Michael himself…they are both part of the same company run
by Michael. There is a different look, but very similar construction
and components with ECM being the more premium brand.
QuickMill - 1945 - Senago, near Milan.
Rancilio - founded in 1927 by Roberto Rancilio in Parabiago, Italy
Rocket - 2007 - Milano Italy
Giotto - The first classic model produced by ECM
Their top of the line R Nine One - PID, infusion control -- great for profiling
The company was originally purchased from the financially troubled
ECM in 2007 by two New Zealanders, Andrew Meo and Jeff Kennedy,
They were responsible for the distribution of the ECM brand in New Zealand
prior to taking control of the failing company.
Rocket is now independent
Production method: “fatto a mano,” translated to English as “made by hand”
ROK - UK - (2002 . Named Presso untill 2012)
Simple Lever machine. No power ... water is heated in a kettle and poured into the grouphead.
Slayer - Seattle USA - 2007. Owned by La Cimbali
Handcrafted, excellent quality and very expensive.
SAB - San Vittore Olona, Milan, Italy - since 1998
Saeco - Founded in 1981 in Italy.
SanRemo - located in Treviso Italy, near the city of Venice.
Strietman - 2011 - Dutch - specialises in open boiler lever machines.
Stone - Milano Italy - Famous for their fast startup times.
Synesso - Seattle USA 2004
Thermoplan - Swiss -
The Black&White4 CTS qualified for the 2024-27 World Latte Art Championships.
Unica - Swiss - Lucerne - 2023. Precise, accurate, quiet, fast heatup.
VBM - Vibiemme Coffee Machines.
Founded on 12 January 1976, at Via Mauro Macchi, Milan.
by three ex-Faema executives .The company name came from the
names of the executives who left Faema: Valente, Biancolini, and Meroni. (V, B, and M).
It is pronounced like the letters of the Italian alphabet: Vee-Bee-Em-may.
Towards the end of the 70s, VBM started making machines for home use,
creating the first domestic espresso machine in history: Domobar.
Victoria Arduino - 1905 - the modern Black Eagle
Wega - WEGA was founded in 1969 by Nello Dal Uncle, heir to the Astoria CMA Group.
Then, in 1985, the name WEGA Macchine per Caffè was established.
In 2007 the company's headquarters were opened in Susegana (Treviso) -
incidentally the largest site for the production of espresso machines!
Wendougee - Mandarin for "Warm Bean Session". Flagship machine = DATA.
Founded China, 2014 as a coffee shop.
it opened five shops in Suzhou by 2015. In 2017,
WENDOUGEE began manufacturing its own equipment, starting with
the "Pioneer 1" coffee machine.
in 2019, WENDOUGEE expanded to Wuxi and launched the "Mantis"
machine. In 2020, it expanded its factory and introduced new products
like the "RKONE" grinder and "MILK BOT" frother.
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Coffee index. Click here :
Thursday, 4 May 2023
ARP 2600 - Filter
A bit about the ARP 2600 filter.
The 2600 VCF is a low pass filter.
The top slider is labelled "initial filter frequency".
This is more commonly calked the "frequency cutoff.
(Range is between 10hz & 10kHz)
You can fine tune this frequency with the next slider : Fine Tune.
The next slider is Resonance.
When the slider is fully to the right, it will self oscillate. ... this usually creates a sine wave.
There one filter output and 8 inputs.
The inputs are divided into
5 audio & 3 CV
The audio inputs are:
+ Ring mod
+ VCO 1, 2, 3
+ Noise
The Control section:
keyboard, ADSR, VCO2.
These inputs control the filter frequency (or cutoff)
To test the keyboard input, put the filter into self oscillation mode ( resonance slider to the right)
and play your keyboard.
Re the VCO 2 input: remember, this VCO can be audio or Low Freq.
There are 4 basic settings you'll need to make to the VCA & mixer
The audio from the filter needs to pass into the VCA.
Thus, on the VCA section
1. fully open the VCF & AR inputs.
(all other inputs are closed)
2. close the initial gain (slider to left).
The audio then passes from the filter to the mixer.
Thus on the Mixer:
1. Open the VCA input.
Note: the VCF input should be fully closed.
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There are two types of filter circuits available on the ARP 2600 synthesizer:
the 4012 filter and the 4072 filter.
The very early 2600s use the 4012 filter
(up to around 1975)
This early filter circuit was used in the metal cased Blue Marvin (2600) & Grey meanie (2600C), and the grey tolex covered 2600P & the 2601v1.0 versions of the ARP 2600.
The filter has a distinctive sound that is often described as slightly brighter, more aggressive when compared to the 4072 filter.
The 4012 filter is a 4-pole low-pass transistor ladder, very similar to a Moog ladder filter.
They were encapsulated to conceal their inner workings.
The 4072 filter, on the other hand, was introduced later in the production run of the ARP 2600, and it has a slightly different tone compared to the 4012 filter. The 4072 filter is also a 4-pole low-pass filter, but it has a maximum cutoff frequency of around 7 kHz. The 4072 filter has a slightly darker and more mellow sound compared to the 4012 filter, and it is often favored by synth enthusiasts for its ability to create warm and rich bass sounds.
Both filter circuits have their own unique characteristics and can be used to create a wide range of sounds on the ARP 2600 synthesizer. Some users prefer the 4012 filter for its brightness and aggression, while others prefer the 4072 filter for its warmth and richness. Ultimately, the choice of filter circuit depends on the sound you are trying to achieve and your personal preferences.
So both versions are 4 pole.
The "4-pole" designation refers to the number of filter stages, which affects the slope of the filter curve. A 4-pole filter has a steep curve, which means that it attenuates frequencies above the cutoff more quickly than a 2-pole filter would.
The filter on the ARP 2600 has controls for cutoff frequency, resonance, and keyboard tracking. The cutoff frequency determines the point at which the filter starts to attenuate frequencies, while resonance boosts the frequencies near the cutoff point, creating a characteristic "squishy" or "squelchy" sound. Keyboard tracking adjusts the cutoff frequency in relation to the pitch of the notes being played, which can be used to create interesting tonal variations across the keyboard.
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Even though its just a LP filter
You can configure it to be high pass & bandpass-ish
https://www.youtube.com/watch?v=kw65oO_nlQ8
https://www.youtube.com/watch?v=Nm7t3jQaOBc
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filter feedback
Patch 1 filter feedback -- patch the output of the filter back into itself via the noise input.
patch 2 - also feed the VCA output back into the VCF
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Some eurorack modules based on these filters which you make like to try:
Steffcorp VCF-12 --- based on the 4012 filter
G-Storm Electro Tonus --- based on the 4012 filter
Studio Electronics 4075
STG Soundlabs Post-Lawsuit Filter -- " not a clone of the ARP 4072 submodule.
It does, however, have an identical topology with the same transistors and operational amplifier array."
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