ShippingDelivery method : DHL or Fedex or JapanPost*After shippment,It will arrive in approximately 3-7 days.?*With tracking number.***Depending on the buyers address, you may be charged DHLs remote area fee.International Buyers - Please Note: Import duties, taxes, and charges are not included in the item price or shipping cost. These charges are the buyers responsibility. Please check with your countrys customs office to determine what these additional costs will be prior to bidding or buying.

Tubes light up great. See photos for contents and condition. Includes Power and usb cable.

Item is in outstanding condition with just a small mark on one of the transformers. Amp has the following tubes, 7 cayin kt88, 1 gold lion kt88, 2 nos mullard 12au7a, 1 nos mullard 12ax7, and 2 Raytheon 6cg7. Amp sounds wonderful. This weighs 70 lbs, so shipping will be high. Local pickup is preferred. Manual, remote, and power cord included.

Cayin iDAC-6. Very dynamic, smooth tube output stage. good soundstage. good detail. lots of options for very subtle tweaking. Five filters that are native to the AKM 4490 chip are use selectable. This was very interesting to me, because although Ive had several DACs that use this chip, this is the first time Ive had one that just used AKMs filters unchanged. The Grace m9XX only uses 4 filters, and as best as I can tell theyre slightly altered versions of the 4 AKM filters. The Schitt products that use the AKM4490 do not allow the user to select the filter, and seem to use the Slow filter always. The f filters are: Super Slow Roll Off, Short Delay Slow Roll Off, Slow Roll Off, Short Delay Sharp Roll Off, and Sharp Roll Off. Here is a picture that AKM has released describing them:

Cayin N8ii Master Quality Digital Audio Player Dual Vacuum Tube player with box case in great condition waranty expired!!! only one left pls ask before placing bid $100 for EMS international shipping Serious buyer only No Return ???64Audio Tia Fourte Audiophile IEMs pre ownedwith box case latest Ver!! Bought at 2021original cable includes!! only one left pls ask before placing bid $60 for EMS international shipping No Return ??? 64Audio Tia Fourte Audiophile IEMs pre ownedwith box case latest Ver!! Bought at 2021original cable includes!! only one left pls ask before placing bid $60 for EMS international shipping No Return ???

Cayin iDAC-6. Very dynamic, smooth tube output stage. good soundstage. good detail. lots of options for very subtle tweaking. Five filters that are native to the AKM 4490 chip are use selectable. This was very interesting to me, because although Ive had several DACs that use this chip, this is the first time Ive had one that just used AKMs filters unchanged. The Grace m9XX only uses 4 filters, and as best as I can tell theyre slightly altered versions of the 4 AKM filters. The Schitt products that use the AKM4490 do not allow the user to select the filter, and seem to use the Slow filter always. The f filters are: Super Slow Roll Off, Short Delay Slow Roll Off, Slow Roll Off, Short Delay Sharp Roll Off, and Sharp Roll Off. Here is a picture that AKM has released describing them:

Cayin HA -1A valve/tube headphone amplifier / line level preamplifier Tested and fully operational Preowned very good condition with minor blemishes Free UK post, international shipping via eBay GSP

Cayin A-50T Tube Integrated Amplifier. Good cosmetic condition with some minor cosmetic wear including a small nick on the faceplate and some light scratching on the top surface including some paint chipped off on two of the transformers covers. What is Included: Amplifier, Remote, Four Mullard EL34 tubes, Four Mullard CV4003 tubes, Power cable Functional Notes: Operational condition of this item is excellent, fully tested and no issues found. The Cayin A-50T is an integrated amplifier with two push-pull pairs of Mullard EL34 tubes that can be operated in 35Wpc Ultralinear or 16Wpc Triode, the modes switchable via the included remote control. The A-507 features point-to-point wiring, a toroidal power transformer, and two El audio output transformers, all specially manufactured for Cain in an attempt to achieve low magnetic leakage, wide frequency response, and low impedance. The amp also has two 12AX7EH and two 12AU7EH tubes (the EH stands for Electro Harmonix), four line-level inputs, and 8 and 4 ohm output taps. Its snap-on tube cage is easily removable.

Cayin CS-1H - Neuwertig inkl. Original Röhrensatz, Anleitung und Rechnung Der edle Röhren-Kopfhörerverstärker von Cayin CS-1H (UVP = 1.298,- €) ist in jeder Hinsicht (technisch & optisch) neuwertig! Die Röhren sind maximal 10 Stunden gelaufen. Mit dabei ist neben der Rechnung (ich bin Erstbesitzer!) auch die Anleitung und die Sicherung, die dem Gerät beilag. Wir sind ein strikter Nichtraucher-Haushalt und haben keine Haustiere. Aufgrund eines anstehenden Umzugs und der Notwendigkeit uns zu verkleinern, muss ich schweren Herzens unter anderem einige meiner Kopfhörerverstärker verkaufen. WICHTIG: Der Verkauf erfolgt unter Ausschluss jeglicher Gewährleistung und ich schließe jegliche Sachmangelhaftung aus.

One slightly used Cayin CS-88a tube amplifier with KT-88 power tubes in Black. I purchased this tube amp 7 months ago to pair with my Klipsch Heresy IV speakers. The amp only has approximately 40 to 50 hrs max on it! This model is impossible to find in stock and retails for over $3500 new. The amp sounds absolutely amazing! No issues at all with the unit and I have since moved to a McIntosh amplifier. The factory tubes that it shipped with are brand new and were only used once when I unpacked it as I immediately upgraded it to Gold Lion KT-88 tubes and NOS preamp tubes. It comes with the manual, tube cage, and power cord. The original box was discarded by my wife, but I will ship it in the same fashion that I received it, in a well packed box. If you would like Me to ship it with the matched Gold Lion KT-88 tubes in place of the Cayin kt88 tubes i can for an additional $300 otherwise it will come with the brand new factory Cayin Labeled tubes that I received it with when it was unboxed new. Buyer pays shipping as it weighs approximately 65 lbs total. Here are the specs of this amp Cayin has been dedicated to great sound since 1993, and theCS-88A delivers a step up in audio performance.This integrated tube amplifier features a purist design withmusicality,headroom, and stability. CS88A features two 6SL7 and two 6SN7 tubes in the preamp stage, along withfour KT88 tubes for AB1 push-pull amplification. Youll enjoyspacious soundstage, great midrange, breathtaking vocals, and punchy power, creating a system that sings when paired with the right speakers. CS-88A also allows theoutput stage to be instantly switched between Triode and Ultralinear modes to customize the sound.The difference between these two modes is the number of electrodes used by the tube. Triode:only 3 electrodes are used, for transparent and nuanced sound ideal for jazz, classical, and more Ultralinear:the tube works at higher power, for bolder sound that excites with pop, rock, and more CS-88A is designed with pure simplicity in terms of inputs. It includes abeautifully designed and implemented MM phono input, along with2 line inputs for analogue sources and 1 preamp-in that allows the CS-88A to be used as a power amplifier. The build quality is hefty, weighing62 lbs,thanks to carefully considered parts inside and out. A specially designed toroidal transformer can be found in the power supply for more dynamic headroom and load stability, while broadband output transformers deliver even more fine detail from your music. The CS-88A features a fully anodized aluminum front in your choice of black or silver, a vented chassis with a gorgeous finish, hand-made point-to-point wiring, and a 30 second soft-start circuit to enhance the life of the toroidal power transformer and output transformers. Turntable phono input with support for MM pickup 2x analog inputs for other sources Preamp-in for use as a power amplifier Switch between KT88 or EL34 tube mode using the rear switch External user bias adjustment with meter for monitoring Choose between 4 ohm or 8 ohm output impedance to work with your speakers Switch between Triode and Ultralinear mode with a button on the remote Hand-made construction with fine point-to-point wiring High-quality Japanese ALPS motor potentiometer Includes aluminium remote control for volume, mute, input selection, and triode/ultralinear mode switching Includesremovable snap-on protective tube cage Dimensions 420 x 382 x 195 mm | 16.6 x 15 x 7.7 in Weight 28 kg | 62 lbs Tubes 6SL72, 6SN72, KT884 Frequency Response 10Hz42kHz (-3dB) Power Output 27W+27W (Triode) 48W+48W (Ultra-linear)

Your template | Trixum Cayin CD-Player - Gesetzliche Gewährleistung! - mit Rechnung vom Händler - alle Fotos sind vom angebotenen Produkt - sehr guter technischer Zustand - Alle Geräte können bei ernsthaftem Interesse in unserem Hörraum getestet werden und Sie können sich von der Richtigkeit unserer Angaben überzeugen. Preisnachlaß bei Selbstabholung möglich! Infos gerne auch per Tel. Unsere Nummer finden Sie unten in den Pflichtangaben. Informationen zum Produkt / Product information Beschreibung: Dieser CD-Player von Cayin gilt als eines der besten Geräte, die das Unternehmen jemals hergestellt hat. Es ist bekannt für seine außergewöhnliche Audioqualität und die erstklassige Verarbeitung. 16 KG - Panzerschrankqualität! Das Gerät bietet eine Vielzahl von Funktionen und Features, die audiophile Enthusiasten ansprechen werden. Es ist jedoch wichtig anzumerken, dass eine vollständige Beschreibung des Players den Rahmen hier sprengen würde. Interessierte können eine umfassende Beschreibung und technische Details im Internet finden.. Dort finden Sie auch begeisterte Testberichte! Mit Metallfernbedienung. Zustand: Der Zustand ist sehr gut, mit minimalsten Gebrauchspuren. Technisch sehr gut. Der Laser reagiert schnell und zuverlässig. Siehe Video. Versand: In Deutschland: Kostenlos! Mit TOP-Verpackung. Description: One of the best players, Cayin ever built. You can find many informations and tests about this fantastic item in the net. Condition: The optical condition is very good with very light wear. The laser is very fast. Technically perfect. With metal remote control. Shipping: In EU: 29,99 Euro with insurance and very good packaging. Worldwide: 185,99 Euro with DHL. Sicher einkaufen Bei einem Händler sind Sie auf der sicheren Seite! Seit dem es das Internet gibt, gab es noch nie so viele Betrugsfälle und Betrugsversuche, wie im Moment! Die Methoden der Betrüger sind mittlerweile so ausgefeilt, dass selbst Profis darauf hereinfallen können. Ein Gewerblicher Händler bietet Ihnen davor Schutz. Er ermöglicht Ihnen:einen persönlichen Telefonkontakt (Nummer im Impressum)eine persönliche Besichtigung vor OrtSelbstabholungBarzahlung nach ProbelaufPaypal-ZahlungRückgaberecht gemäß Fernabsatzgesetzgesetzliche Gewährleistung (AGB´s beachten)Möglicherweise eine Garantie (AGB´s beachten)einen sicheren Versandprofessionelle Verpackung... und viele weitere Serviceleistungen Garantiebedingungen und Allgemeine Angaben In unseren Rechnungen wird wegen Differenzbesteuerung KEINE Mehrwertsteuer ausgewiesen.Fragen versuchen wir so schnell wie möglich zu beantworten. Im Einzelfall kann es aber mal zwei bis drei Tage dauern.Keine Garantie für die Angaben im Ebay-Produktkatalog. Für Fragen bitte den entsprechenden Button hier bei Ebay benutzen nicht das Telefon.Verwendete Markennamen sind Eigentum des Herstellers und werden nur verwendet um das Produkt uns seine hervorragende Qualität zu beschreiben.*GARANTIEBEDINGUNGEN:Wenn in unseren Angeboten eine Haltbarkeitsgarantie angegeben ist, dann bleiben Ihre weiteren gesetzlichen Rechte (z. B. Gewährleistung davon unberührt. Die Garantie umfasst alle technischen Fehlfunktionen, soweit diese nicht durch falschen Gebrauch hervorgerufen wurden. Ausgenommen von der hier dargestellten Garantie sind Batterien, Lautsprechersicken, Laser, CD-Laufwerke und Akkus (auch festinstallierte). Der Garantiegeber ist Harald Leichtle, Schweppermannstr. 5, 90408 Nürnberg. Die Garantie ist deutschlandweit und ist auf den oben im Angebot angegebenen Zeitrahmen beschränkt. Zur Prüfung und Abwicklung des Garantiefalles setzen Sie sich bitte telefonisch oder schriftlich mit uns in Verbindung. Zur Prüfung und eventuellen Schadensbehebung muss uns der Kaufgegenstand und eine Kopie der Rechnung kostenfrei zur Verfügung gestellt werden. Ist eine Reperatur oder eine Ersatzlieferung nicht möglich, erhält der Käufer den Kaufpreis zuzüglich Rücksendekosten zurück.Hinweis nach dem Batteriegesetz: Im Zusammenhang mit dem Vertrieb von Batterien oder mit der Lieferung von Geräten, die Batterien enthalten, sind wir verpflichtet, Sie auf folgendes hinzuweisen: Sie sind zur Rückgabe gebrauchter Batterien als Endnutzer gesetzlich verpflichtet. Sie können Altbatterien, die wir als Neubatterien im Sortiment führen oder geführt haben, unentgeltlich an unserem Versandlager (Versandadresse) zurückgeben. Die auf den Batterien abgebildeten Symbole haben folgende Bedeutung: Das Symbol der durchgekreuzten Mülltonne bedeutet, dass die Batterie nicht in den Hausmüll gegeben werden darf. Pb = Batterie enthält mehr als 0,004 Masseprozent Blei. Cd = Batterie enthält mehr als 0,002 Masseprozent Cadmium. Hg = Batterie enthält mehr als 0,0005 Masseprozent Quecksilber.Bitte beachten Sie auch unsere AGB´s und unser Impressum. Beide sind auf dieser Seite hinterlegt.Photos are original. We will try to answer your questions as soon as possible. No guarantee for the informations of the Ebay-catalogue. For questions please use the button here on Ebay.

One slightly used Cayin CS-88a tube amplifier with KT-88 power tubes in Black. I purchased this tube amp 7 months ago to pair with my Klipsch Heresy IV speakers. The amp only has approximately 40 to 50 hrs max on it! This model is impossible to find in stock and retails for over $3500 new. The amp sounds absolutely amazing! No issues at all with the unit and I have since moved to a McIntosh amplifier. The factory tubes that it shipped with are brand new and were only used once when I unpacked it as I immediately upgraded it to Gold Lion KT-88 tubes and NOS preamp tubes. It comes with the manual, tube cage, and power cord. The original box was discarded by my wife, but I will ship it in the same fashion that I received it, in a well packed box. If you would like Me to ship it with the matched Gold Lion KT-88 tubes in place of the Cayin kt88 tubes i can for an additional $300 otherwise it will come with the brand new factory Cayin Labeled tubes that I received it with when it was unboxed new. Buyer pays shipping as it weighs approximately 65 lbs total. Here are the specs of this amp Cayin has been dedicated to great sound since 1993, and theCS-88A delivers a step up in audio performance.This integrated tube amplifier features a purist design withmusicality,headroom, and stability. CS88A features two 6SL7 and two 6SN7 tubes in the preamp stage, along withfour KT88 tubes for AB1 push-pull amplification. Youll enjoyspacious soundstage, great midrange, breathtaking vocals, and punchy power, creating a system that sings when paired with the right speakers. CS-88A also allows theoutput stage to be instantly switched between Triode and Ultralinear modes to customize the sound.The difference between these two modes is the number of electrodes used by the tube. Triode:only 3 electrodes are used, for transparent and nuanced sound ideal for jazz, classical, and more Ultralinear:the tube works at higher power, for bolder sound that excites with pop, rock, and more CS-88A is designed with pure simplicity in terms of inputs. It includes abeautifully designed and implemented MM phono input, along with2 line inputs for analogue sources and 1 preamp-in that allows the CS-88A to be used as a power amplifier. The build quality is hefty, weighing62 lbs,thanks to carefully considered parts inside and out. A specially designed toroidal transformer can be found in the power supply for more dynamic headroom and load stability, while broadband output transformers deliver even more fine detail from your music. The CS-88A features a fully anodized aluminum front in your choice of black or silver, a vented chassis with a gorgeous finish, hand-made point-to-point wiring, and a 30 second soft-start circuit to enhance the life of the toroidal power transformer and output transformers. Turntable phono input with support for MM pickup 2x analog inputs for other sources Preamp-in for use as a power amplifier Switch between KT88 or EL34 tube mode using the rear switch External user bias adjustment with meter for monitoring Choose between 4 ohm or 8 ohm output impedance to work with your speakers Switch between Triode and Ultralinear mode with a button on the remote Hand-made construction with fine point-to-point wiring High-quality Japanese ALPS motor potentiometer Includes aluminium remote control for volume, mute, input selection, and triode/ultralinear mode switching Includesremovable snap-on protective tube cage Dimensions 420 x 382 x 195 mm | 16.6 x 15 x 7.7 in Weight 28 kg | 62 lbs Tubes 6SL72, 6SN72, KT884 Frequency Response 10Hz42kHz (-3dB) Power Output 27W+27W (Triode) 48W+48W (Ultra-linear)

Cayin A-50T Tube Integrated Amplifier. Good cosmetic condition with some minor cosmetic wear including a small nick on the faceplate and some light scratching on the top surface including some paint chipped off on two of the transformers covers. What is Included: Amplifier, Remote, Four Mullard EL34 tubes, Four Mullard CV4003 tubes, Power cable Functional Notes: Operational condition of this item is excellent, fully tested and no issues found. The Cayin A-50T is an integrated amplifier with two push-pull pairs of Mullard EL34 tubes that can be operated in 35Wpc Ultralinear or 16Wpc Triode, the modes switchable via the included remote control. The A-507 features point-to-point wiring, a toroidal power transformer, and two El audio output transformers, all specially manufactured for Cain in an attempt to achieve low magnetic leakage, wide frequency response, and low impedance. The amp also has two 12AX7EH and two 12AU7EH tubes (the EH stands for Electro Harmonix), four line-level inputs, and 8 and 4 ohm output taps. Its snap-on tube cage is easily removable.

Cayin A-50T Tube Integrated Amplifier. Good cosmetic condition with some minor cosmetic wear including a small nick on the faceplate and some light scratching on the top surface including some paint chipped off on two of the transformers covers. What is Included: Amplifier, Remote, Four Mullard EL34 tubes, Four Mullard CV4003 tubes, Power cable Functional Notes: Operational condition of this item is excellent, fully tested and no issues found. The Cayin A-50T is an integrated amplifier with two push-pull pairs of Mullard EL34 tubes that can be operated in 35Wpc Ultralinear or 16Wpc Triode, the modes switchable via the included remote control. The A-507 features point-to-point wiring, a toroidal power transformer, and two El audio output transformers, all specially manufactured for Cain in an attempt to achieve low magnetic leakage, wide frequency response, and low impedance. The amp also has two 12AX7EH and two 12AU7EH tubes (the EH stands for Electro Harmonix), four line-level inputs, and 8 and 4 ohm output taps. Its snap-on tube cage is easily removable.

Item TitleCayin Vacuum Tube Lifier A-200P Payment Supports managed payments Please pay within 5 days after auction is finished. About Us We are located in Japan. Its our pleasure to make you happy by proposing our recommend item. If you have any questions or request about items please feel free to ask us. International Buyers - Please Note: -Import duties taxes and charges are not included in the item price or shipping charges. These charges are the buyers responsibility. -Please check with your countrys customs office to determine what these additional costs will be prior to bidding/buying. -These charges are normally collected by the delivering freight (shipping) company or when you pick the item up - do not confuse them for additional shipping charges. -We do not mark merchandise values below value or mark items as - gifts - The US and International government regulations prohibit such behavior. Thank you for your understanding.

Cayin A-50T Tube Integrated Amplifier. Good cosmetic condition with some minor cosmetic wear including a small nick on the faceplate and some light scratching on the top surface including some paint chipped off on two of the transformers covers. What is Included: Amplifier, Remote, Four Mullard EL34 tubes, Four Mullard CV4003 tubes, Power cable Functional Notes: Operational condition of this item is excellent, fully tested and no issues found. The Cayin A-50T is an integrated amplifier with two push-pull pairs of Mullard EL34 tubes that can be operated in 35Wpc Ultralinear or 16Wpc Triode, the modes switchable via the included remote control. The A-507 features point-to-point wiring, a toroidal power transformer, and two El audio output transformers, all specially manufactured for Cain in an attempt to achieve low magnetic leakage, wide frequency response, and low impedance. The amp also has two 12AX7EH and two 12AU7EH tubes (the EH stands for Electro Harmonix), four line-level inputs, and 8 and 4 ohm output taps. Its snap-on tube cage is easily removable.

Tubes light up great. See photos for contents and condition. Includes Power and usb cable.

Cayin iDAC-6. Very dynamic, smooth tube output stage. good soundstage. good detail. lots of options for very subtle tweaking. Five filters that are native to the AKM 4490 chip are use selectable. This was very interesting to me, because although Ive had several DACs that use this chip, this is the first time Ive had one that just used AKMs filters unchanged. The Grace m9XX only uses 4 filters, and as best as I can tell theyre slightly altered versions of the 4 AKM filters. The Schitt products that use the AKM4490 do not allow the user to select the filter, and seem to use the Slow filter always. The f filters are: Super Slow Roll Off, Short Delay Slow Roll Off, Slow Roll Off, Short Delay Sharp Roll Off, and Sharp Roll Off. Here is a picture that AKM has released describing them:

Cayin A-50T Tube Integrated Amplifier. Good cosmetic condition with some minor cosmetic wear including a small nick on the faceplate and some light scratching on the top surface including some paint chipped off on two of the transformers covers. What is Included: Amplifier, Remote, Four Mullard EL34 tubes, Four Mullard CV4003 tubes, Power cable Functional Notes: Operational condition of this item is excellent, fully tested and no issues found. The Cayin A-50T is an integrated amplifier with two push-pull pairs of Mullard EL34 tubes that can be operated in 35Wpc Ultralinear or 16Wpc Triode, the modes switchable via the included remote control. The A-507 features point-to-point wiring, a toroidal power transformer, and two El audio output transformers, all specially manufactured for Cain in an attempt to achieve low magnetic leakage, wide frequency response, and low impedance. The amp also has two 12AX7EH and two 12AU7EH tubes (the EH stands for Electro Harmonix), four line-level inputs, and 8 and 4 ohm output taps. Its snap-on tube cage is easily removable.

Tubes light up great. See photos for contents and condition. Includes Power and usb cable.

Shipping Usually it will be shipped within 10 business days of receiving the payment paid. Standard shipping ( On line Tracking Number) We send a product by DHL or FedEx. If you have bought multiple items, there is a discount of the shipping cost. International Buyers - Please Note: Import duties, taxes, and charges are not included in the item price or shipping cost. These charges are the buyers responsibility. Please check with your countrys customs office to determine what these additional costs will be prior to bidding or buying. These charges are normally collected by the delivering freight (shipping) company or when you pick the item up - do not confuse them for additional shipping charges.

New unused KT120 TungSol vacuum Valve tubes. Will consider close offers. I am a valve amplifier fan, and have a collection of spare tubes, I am currently running a Cayin 300B. These are a set I purchased two years ago and have stored, never been used, not even to test. Will be sent in original packaging. Postage is for mainland UK, highlands and islands will be extra. Please see my other auctions for more bargains. Thank you for looking

UP FOR SALE I HAVE MY PRISTINE CONDITION CAYIN N3 PRO TUBE AMPLIFIER HIGH RESOLUTION MUSIC PLAYER.IF YOU FOLLOW MY SALES YOU WILL KNOW I HAVE ALOT OF DAPS/DACS.I HAVE JUST PURCHASED A CAYIN N6II AND AN A&K KANN MAX SO NEED TO SHIP SOME OUT.I HAVE NOT USED THIS MUCH BUT ITS A BEAUTIFUL DEVICE AND IS EXTREMELY STURDY IN THE HAND.BUILT QUALITY IS SECOND TO NONE.IT ALSO UTILITIES THE HIBY MUSIC SETUP WHICH I THINK IS FANTASTIC.GREAT SOUNDING DEVICEHAS NORMAL 3.5MM JACK AND I THINK THE TUBE AMP ONLY WORKS ON THIS4.4MM BALANCED JACKAND LINE OUTUSB C CHARGING AND DATA TRANSFER.MICRO SD CARD SLOT (NO CARDS INCLUDED)COMES IN ORIGINAL BOX WITH ALL UNUSED ACCESSORIES AND ENGLISH LITERATURE I AM ALSO THROWING IN A FREE GENUINE CASE AS WELL AS THE INCLUDED SILICONE ONE.PLEASE STUDY THE PICTURES AS THESE FORM ALOT OF THE DESCRIPTION.

Cayin iDAC-6. Very dynamic, smooth tube output stage. good soundstage. good detail. lots of options for very subtle tweaking. Five filters that are native to the AKM 4490 chip are use selectable. This was very interesting to me, because although Ive had several DACs that use this chip, this is the first time Ive had one that just used AKMs filters unchanged. The Grace m9XX only uses 4 filters, and as best as I can tell theyre slightly altered versions of the 4 AKM filters. The Schitt products that use the AKM4490 do not allow the user to select the filter, and seem to use the Slow filter always. The f filters are: Super Slow Roll Off, Short Delay Slow Roll Off, Slow Roll Off, Short Delay Sharp Roll Off, and Sharp Roll Off. Here is a picture that AKM has released describing them: