I don't believe that a 6dj8 or 6922 is an equivalent of a 6n1. The 6922's, 6dj8's, and even the 6n1p are said to draw more current and eventually damage your transformers. I "googled" 6n1 equivalent and found Tube Depot saying that the 6aq8/or ecc 85 is an equivalent. Please check with your manufacturer before "tube rolling for damage" occurs. (Just my 2 cents worth).
That 6N1, 6N11, & 6DJ8 will all work. No mention is made of 6N1P.
Oops. I meant to say that the manufacturer states that 6N1, 6N11, & 6DJ8 will all work. However, no mention is made of 6N1P.
Well, then are you absolutely sure that the Amperex's are good tubes? Maybe after they settle in a bit, they will improve, but something sounds amiss.
The label was pretty much rubbed all off so the price on eBay was very good. I decided to burn in the tube for 36+ hours on the outside chance it was actually new and it seems to be settling in. I will have to reassess it after that time.
In my own personal experience, EBay tubes are for the most part, used junk. I have a tube tester (BK DynaJet), and would have to say that over half the time I buy tubes on EBay they are worthless, so cheap is the key to an EBay purchase. Also, I have found some of the so called "reputable" tube sellers on the 'gon to sell questionalbe stuff that they claim is still good. See if you can find someone in your area with a good functioning tube tester (electronics repair services may know of someone or have one themselves).
I am begining to think that the answer may be that the Yaqin tube buffer is supplied with a Chinese 6N1 and was probably designed for that tube. While the 6DJ8 may work, it and 6922/7308 tubes have different heater elements etc.
In fact, in the reverse case, many do not recommend 6N1 & 6N1P (Russian equivalent) in circuits designed for the 6DJ8.
So, maybe what I am hearing is the result of this.
try 5654 tubes or mullard ef95 or 6ak5.i have had excellent results with all of those however i recomend getting russian american and tung sol [which can be found esaliy on ebay or anywhere] is pretty warm very warm to soft for me but when the supplied tubes break in 100 hours or so they dont sound bad even for the price! dont cry because the miracle dosent happen for 150$ LOL!!! great product.
I'm currently using Western Electric 6AK5 1940'S with great results, great improvement over stock chinese tubes. The unit with the tube upgrade alone sounds more cohesive with smoother top end. Consider doing some mods, it will transform this buffer. I have have replaced the output caps to Mundorf M-CAP Supreme Silver/Oil 1uf and removed the input capacitors now wired directly.
The unit I own is the Yaquin CD-2 which uses two 6j1.
I own the single tube version of the Yaqin and was one of the early advocates of the JAN6922 and it does work quite well. That said I have moved on to the Russian 6N1P with even better results. Cleaner mids, tighter bass and equal highs.
Incidentally the tube socket on my Yaqin is labeled with numerous tubes that can be used and the 6N1, 6922, and 6DJ8 are all included. Currently my buffer is in use between a Cayin MT12A amp and Denon multi format DVD/CD player to remove/smooth some of the harshness from the output and does so quite well.
I have heard many other people complaining abot the 6d orange so I think its just that tube.Try any 6922 or a JJ works just fine.
As one of the original posters of the Yaqin tube buffer using the JAN Phillips green label 6922, I have found using the 6H23 with the "Rocket" logo best the JAN Phillips. Better detail, imaging and depth over the JAN Phillips. You can find this tube very cheaply on eBay.