The Silk AC Filter
The concept of filtering used in SILK filter was conceived by me in the 90’s when I worked for a giant Pittway group doing many Fire Alarm EMC approvals following German VdS norms. I spent hundreds of hours in various EMC labs assisting the officials in their test. They used low energy, high energy and static discharge and radio frequency and magnetic field tests - tens and tens of tests. The fire alarm panels are one of the best tested devices in the world, and they have to withstand conditions, which would normally “kill the horse”. Being an engineer in the field of high voltage physics - I learnt a lot from these tests and I applied the know how to this filter.
My general finding after applying the filter concept to Audio - was that we don’t need to influence the sine wave per se, we don’t need to make anything about the AC as long as the radio frequency content is removed. We are not talking about the AC sine distortion, being out of shape etc. The RFI is by a magnitude of million faster than AC and it is invisible on any oscilloscope however fast.
The key to success is NOT OVERFILTERING - just gently removing the RFI and keeping all AC wave intact.
The RFI can penetrate the audio circuits and influence the chips, clocks, voltage regulators, transistors, opamps, etc. The RFI can blend into the feedback loop and also it can be amplified together with the signal.
The listening test show that the filter improves all kinds of stereo systems from 1000 Euro to 100 000 Euro, and nobody ever found any down-sides. We do not choke the energy from the music the way the power regenerators and conditionets do. We don’t use transformers either. We do not want lifeless, pale, un-involving music.
SILK filter lets the music be with full energy and dynamics but sounding more analog like, more clear, with better definition and tonal accuracy. The end result is so nice - that noone ever returned the SILK on loan. And as far as I know - nobody who bought it - ever sold it. I made around 40 units back in the nineties under ESA brand and now I resurrected the design under my LampizatOr brand.
The filter is in a full size box, so it can be nicely stacked with other gear. It is not a power strip wallowing in dust behind the rack. It is proudly participating with full membership rights as a vital rack element. Apart from filtering - the SILK nicely arranges our AC cables behind the rack.
The short definition of this filter is: NO-NONSENSE design, timeless device, can’t live without it.
Lampizator DAC box size - 43 wide, 34 deep, 13 high [cm]
Front panel black or silver, the eye ring is red.
Standard IEC Shurter inlet (no fuse - all hard wired)
Four identical outlets with SCHUKO or French/Polish style, or USA or UK receptacles
AC voltage from 110 to 240 V
one CLC filter individual per each outlet (not only filtering the incoming AC but also separating your gear from one another. Many gears like transports or computers do inject back the noise to the AC)
15 A per each outlet but 25 A combined - sum of four.
(typical transport consumes 0,05 A and DAC with tubes consumes 0,1 A and GM 70 mono block amp consumes 0,9 A. )
RFI attenuation from 100 kHz upward
PRICE: (add 23 % VAT tax in EU)
490 Euro plus VAT standard version without phase flippers.
590 Euro plus VAT with four- way phase flipper.
Warranty is 5 years
One week of test period applies (with full refund less shipping cost)
Weight 5 kg net, 8 kg packed gross.
We added to the standard SILK four independent toggle switches that change the phase of each outlet individually. THIS IS A MAGIC FUNCTION. We learned that if you fip the AC phase to each member of your stereo rack versus the others - the sound can improve. So after adjusting all four devices - the magnitude of improvement is quite shocking. The center image becomes more solid and the 3-D stereo effect is slightly improved. Even adjusting the DAC to transport can be audibly better. So on top of the filtering effect you get the ability to flip the phase WHILE YOU ARE LISTENING and without interruption of even CD transport during playback. This enables you to make a decision about the phase while your friend throws the toggle. Otherwise it is impossible to make a decision when the change takes 1 minute to reverse the AC cable and reboot the transport, DAC or amp. This phase flipping procedure adds 50 % of perceived “price” to your system’s overall sound quality.
As you can see, the SILK filter is “just” a CLC PI type filter with lopass function. The caps are superfast hi-voltage ceramics 2 nF / 275 VAC and the ferrite ring cores are of very high core density.
I use thick wires - 2,5 mm pure solid core copper (Polish copper, not contaminated like the Far Far Away made copper from recycled scrap. )
The AC outlets on the pictures above are SHUKO type .
Read below about the SCHUKO standard from Wikipedia:
The Schuko system originated in Germany and goes back to a patent (DE 370538) granted in 1926 to Albert Büttner, a Bavarian manufacturer of electrical accessories. It is used today in more than 40 countries, including most of Continental Europe.
France, Belgium, the Czech Republic, Slovakia and Poland use a type of plug and socket (CEE 7/5) with the same size and spacing of the main pins but with a male protective-earth pin on the socket instead of the earth clips and without the guiding notches at the sides. Most modern moulded-on Schuko plugs, and good-quality rewirable replacements, are a hybrid version with an extra hole ("CEE 7/7") that also accommodates the earth pin of French sockets.
•Denmark (CEE 7/17 and and Dainish standard 107-2-D1 are widely used, they accept CEE 7/7 plugs but without compatibility for earth connections. CEE 7/5 and CEE 7/4 sockets with child-proof shutters has been allowed since 2008/2011, but people are not using them yet).
•Ireland (BS1363 / Equivalent Irish Standard: IS 401) but see below,
•Italy (CEI 23-16/VII),
•The United Kingdom, including Gibraltar (BS 1363)
In Italy, CEI 23-16/VII is the dominant standard, though Schuko is also an approved standard and is in common use. Appliances are sold with either Italian or Schuko-type plugs. A minority of sockets accept both types, the remainder accepting one or the other. Schuko sockets are most commonly used for larger-rated appliances such as washing machines, and are particularly common in South Tyrol, with its cultural, economic and tourist connections with Austria.
Although Schuko has never been a standard (or the de facto norm) in Belgium or France, it is sometimes encountered in older installations in eastern regions of Belgium and Alsace. Newer installations adhere to national standards.
In parts of the Republic of Ireland, Schuko was commonly installed until the 1960s. For safety reasons and to harmonize with the UK (with which Ireland has a long-standing free travel arrangement) and avoid having a different outlet type in Northern Ireland and the Republic of Ireland, the Republic standardized on BS1363 (transposed into Irish Standards as IS401 (Plug) and IS411 (Socket outlet). Schuko has been phased out of use in Ireland and will be encountered very rarely. Some hotels provide a Schuko outlet alongside BS1363 outlets for the convenience of visitors from the Continent.
Russia, while maintaining its own mains connector standard, has it largely harmonized with the relevant European regulations since Soviet times. The original Soviet standard was mostly compatible with europlug (traditional Soviet plug used straight 4 mm pins with 19 mm spacing and thus Soviet sockets were able to easily accept europlugs), and since Schuko introduction was modified to include its specifications, due to the large volume of imported appliances equipped with the Schuko plug. This was necessitated by the fact that 4 mm holes in the Soviet sockets could not accept 4.8 mm Schuko pins without modification. Nowadays most sold and installed sockets in Russia are Schuko ones, though they may lack grounding wire connection, especially in older buildings, as this wasn't required by the Soviet wiring regulations.
The PHASE FLIPPING VARIANT
For those who want to squeeze maximum quality out of their system, (for which they already paid a lot) this phase switching is a must. Of course the phase alignment of all rack components can be done by the cables but our way is safer, faster and more precise.
It is an unexplained phenomenon but two components of the stereo system (cd player, amplifier) do sound differently when one component is working from AC outlet with a given phase and the other with an opposite phase. As we know - in AC outlet one wire is called hot and the other is cold. For two components we have 4 possible combinations:
HH, HC, CH and CC.
If we have transport, DAC and amp - there is 8 combinations:
HHH, HHC, HCH, HCC, CHH, CHC, CCH, CCC
and for 4 components - we have 16 combinations.
Only one of the given set of phase alignments produces the best sound. Namely, the characteristics becomes:
-center image is more central and better defined
-stereo “wings” of the image become more naturally spread
-voices sound more natural and more “right there”
-everything sounds “more right”
-bass is deeper, stronger and more pulsating.
The extra price for four-way phase switching filter is 100 Euro.
In the middle position the switch disconnects the outlet independently of the other three. It is usually better and easier than reaching to the back of the amplifier to switch it off.