Pharmaboy
Headphoneus Supremus
Great write-up! Welcome to the very select HP8 club (not really ... I just like typing that).Hello, please let me present my candidacy to join this select and iconic group.
After much reading and researching (surely you all know what I’m talking about) I decided to go with the Icon HP8 for my first tube amp. I got this one from the classifieds last week. It’s not the Signature version, just MKII, but if it sounds this good, I can't imagine how fantastic the Signature version will be. My intention though is to update the Caps at some point, but for now I'm not letting it go anywhere
The HP8 MKII came with its original tubes, 2 x David Shaw and 1 x JJ 12AX7, but I also got two additional NOS tubes from the seller (well, NOS but used), one RCA 12AX7 from 1970 made by Mullard and one RCA 12AX7 Black Plates from 1950 (long plates)
I have tried the 3 driver tubes and to my ears there are subtle differences but always maintaining the wonderful sound signature of this fantastic amp
My first Wow moment came with the stock tubes, with that thick and bold sound yet very detailed, deep and tight bass, lush and liquid mids and very pleasant and controlled highs. Great holographic image with a good soundstage. The soundstage was not as huge as I expected, but it was still a very good size.
The RCA Black Plates brought more detail and air, with better separation and bigger stage. Also (even) better bass and extended treble. This tube works very well with rock, blues, etc, but with Classical the high frequencies are a bit harsh sometimes (violins for example) to my ears (maybe this is due to my chain too)
And finally, the RCA 12AX7 made by Mullard, that is my favorite now, gives a smooth, musical and detailed sound, with nice warm mids, which works very good with Jazz, acoustic and Classical, that are the main genres I tend to listen
I have read entirely this thread and there are plenty of tube recommendations (thanks for that!) But, among all of them, which would be your choice to get a smooth, musical and warm yet detailed sound with big and holographic soundstage? (Both power and driver). I think my next purchase will be Brimar 12AT7 CV455 KB/FB to get a bit more headroom in the volume pot, but I don’t know which is the sound signature that this tube can provide
Well, and that’s all. I’m very happy with this little but powerful amp, and now I can see how many people loves this lush and euphonic sound coming from theses little glass bubbles made 50-60 years ago
Brimar CV455s are among the best 12AT7s I've tried. I have a couple of Mullards -- I've never heard a NOS Mullard input tube I couldn't like. I didn't care for any 12AX7s until a friend sent me an Amperex ‘fisher’ 12AX7 (1959). It's an impressive tube that really locks in with the matched 1951 Sylvania 6SN7GT/GTAs I've used as power tube for the past year. The Sylvanias slam & do bass like crazy, plus big mids and not expecially extended treble. The Amperex/Fisher tube also slams, too, top to bottom. I like the resulting synergy.