Update on Cayin i5 DAP: Schedule and Design Revision
To transfer Cayin i5 DAP from R&D phase to production, we have proceed to procurement of material for mass production and started pilot production. Unfortunately we have identified new problems that have not surfaced in previous 6 rounds of prototyping: noise interference were detected when WiFi is connected. After cross-checking the prototype vs trail production samples exhaustively, we have traced the problem to two op-amp from TI. During the prototyping process, we used LME49720 (MA) in Low-pass filter and voltage amplification, unfortunately this op-amp has ceased production and we have used the revised model LME49720 (MAX) as replacement and turned out the LEM49720(MAX) is more sensitive to WiFi interfere.
While we have the option to proceed i5 as planned, and claimed that WiFi interference is inevitable, Cayin feels obliged to deliver a product that is fully functional on all primary features, and facilitation of streaming applications is a primary feature in our project plan. To remedial the situation, Cayin goes back to drawing board and improved the WiFi-related design from the ground up, and come out with the follow design revision:
All actions comes with a cost, and in this case Cayin has scrapped 500 sets of stuffed PCB, throw away /remodeled all the chassis from pilot production and developed new tooling for the revised structural design. Our R&D and Production team has been working round the clock to get back on track since the press conference in Bejing, and we are pleased to announced that the Cayin i5 will be available at Mainland China from 6 June 2016. Our plan to overseas markets remains unchanged and we expect to ship the Cayin i5 to Asia markets by late July 2016, and other areas at around 2 months after official launch in domestic market.
Cayin will keep everyone well informed in due course, and we promise to deliver a DAP that will make your music “Never Be The Same Again”.
To transfer Cayin i5 DAP from R&D phase to production, we have proceed to procurement of material for mass production and started pilot production. Unfortunately we have identified new problems that have not surfaced in previous 6 rounds of prototyping: noise interference were detected when WiFi is connected. After cross-checking the prototype vs trail production samples exhaustively, we have traced the problem to two op-amp from TI. During the prototyping process, we used LME49720 (MA) in Low-pass filter and voltage amplification, unfortunately this op-amp has ceased production and we have used the revised model LME49720 (MAX) as replacement and turned out the LEM49720(MAX) is more sensitive to WiFi interfere.
While we have the option to proceed i5 as planned, and claimed that WiFi interference is inevitable, Cayin feels obliged to deliver a product that is fully functional on all primary features, and facilitation of streaming applications is a primary feature in our project plan. To remedial the situation, Cayin goes back to drawing board and improved the WiFi-related design from the ground up, and come out with the follow design revision:
- Structural design: modify the CNC framework and carbon fiber back panel so that the WiFi components will be covered by plastic sheet instead of carbon fiber/metal frame. This will enhance the WiFi connectivity of i5 without affecting the look and feel of the façade design. The revised design will reduce the internal interference caused by reflection and minimize channel effect. The diagram below illustrates the back panel before and after the revision.
- Analogue Circuit: the LME47920 will be replaced by AD712 (Low pass Filter) and OPA1652 (Voltage amplification), we believe this will further enhance the audio performance and immunity to interference. The revised audio circuit is as follows:
- PCB layour: while we change the components, we have taken the chance to further enhance the system performance by separating the ground circuit completely. The new PCB is clean and quiet now.
All actions comes with a cost, and in this case Cayin has scrapped 500 sets of stuffed PCB, throw away /remodeled all the chassis from pilot production and developed new tooling for the revised structural design. Our R&D and Production team has been working round the clock to get back on track since the press conference in Bejing, and we are pleased to announced that the Cayin i5 will be available at Mainland China from 6 June 2016. Our plan to overseas markets remains unchanged and we expect to ship the Cayin i5 to Asia markets by late July 2016, and other areas at around 2 months after official launch in domestic market.
Cayin will keep everyone well informed in due course, and we promise to deliver a DAP that will make your music “Never Be The Same Again”.
we have more then one i-series DAP in our product roadmap, I sure hope we can beat the timeline and offer more choice to i-series users down the road ASAP. 
I don't have an answer to this, I just know you guys will raise out very soon. 
