What a coincidence. Let us explain to you our rules for our model naming.
We have named our models after our brand name Cayin of which there are five characters C, A, Y, I and N. One letter will represent one series of products. Now we have used C, A and N.
C represents our portable headphone amplifiers for which we already have C6, C5, C5DAC. A represents our WIFI speakers for which we have A6. N represents our digital audio players for which we have N6. Maybe you have already found a rule for our model name that as for each series of products we are naming the first model of the series after Number 6. It relates to Chinese culture. In China number 6 has a meaning of Luck, Sucess and therefore we often prefer to use the 6.
Next let's go to the line of our portable headphone amplifers. Our first model is C6 and why we have name our second model as C5. It is because C6 is a model with the DAC for Appple devices but the C5 does not have any decoding function. C5 is a pure headphone amplifier which we can see it a product "lower" than the C6. Therefore have used a number smaller than 6 and we take 5. In future if we are developing even lower version of such series of products we may name them after C4, C3, C2, etc. Why we have taken C5DAC then. Maybe you can see the reason from the response my Collegue Thomas has made above. It is because our C5DAC has the same look as our C5 and developed based on it. But we have added a new USB DAC funtion for Android system of phones and PC into the new model and then we have named it C5DAC. In fact originally we planned to name it C8 but we have a worry that some customers may question us that why Cayin would name a similar products with two totally differnt model names.
That is the story of ours and in future you will see more products of ours named after the characters of C, N, I or A and Y.