A small update on my iDSD Pro tube rolling. I purchased my unit second hand, and it had to my great excitement Western Electric 396a already rolled into it. Unfortunately, they were very gassy tubes, and at higher volumes caused nasty, nasty noises. The iDSD as a whole hated the whole experience. Everything would go haywire when those tubes acted up.
Got my hands on a true NOS pair of 1960's vintage RCA next. I liked them just as well as the WE (when the WE was actually working properly)
But today I decided to try a pair of Sylvania 5670 Gold Labels. WOW. Best sound yet out of the iDSD Pro. Oh my goodness. Tube sweetness with increased bass authority and definition and a treble even more airy and sublime and smooth without any harshness or unwanted harmonic distortion.
BUT PLEASE TAKE NOTE. If you have no experience tube rolling, I suggest you leave this unit well enough alone. The tube sockets are easy to break if you are not especially careful, and the Wifi Antenna cable MUST be accounted for with great care during the disassembly and reassembly. I don't want to be responsible for anyone hurting their unit and voiding the warranty on this most incredible piece of gear.
The RCA I just took out
The Sylvania I rolled in
My NOS GE STASH... so I keep this 'End Game' DAC/head-amp running on her tubes for as long as she decides to live lol
And here is an interesting vintage pair I picked up. I am not familiar with CECO. Any one have knowledge who made these and when? I am reading up all the sparse info I can find on this company. It seems they were absorbed by Gold Seal, which I believe was then absorbed my RCA, so I feel fairly safe proclaiming these are RCA tubes as well.