but I couldn't bear to sell it because it's such a good little amp.
Same here, even tho I spent thousands more upgrading to bespoke stuff, it's one of those audio devices that I just couldn't bare to sell.
It's just that good. I eventually sold it to my friend for $500 just to keep it local if I ever wanted to listen to it again.
6BX7.... Maybe I should give it a try after all.
It really comes down to preference at the end. I agree with
@Xcalibur255 that you don't need expensive tubes, sometimes it's just finding what you personally like.
For me, I rolled a few different types of both 6BX7 and 6BL7, never really liked them as much as standard 6sn7. But they do have a unique tonal signature one could like more.
Iha-1 can also take 6SL7, but again never preferred those, they have extra sparkle in the treble, but wasn't a fan.
One of my favorites was 6f8g Tung-Sol black round plate. I also have the square plate Tung-Sol 6f8g as well.
The black round plate 6f8g doesn't have a lot of bass tho, so I could see many people not liking it.
If you want to spend a stupid amount of money, you can get the Tung-Sol 6sn7 black round plate, they go for around $500 a pair if you can even find them.
They are similar to the 6f8g black round plate, but much better lower end impact and tightness.
I'd say 100% skip tho, not worth the money, stay cheap like
@Xcalibur255 mentioned.
The amp is slept on for two reasons. #1 Planars sound like trash from it, and planars are a big trend right now. #2 Even with dynamics like hd800, or Verite, it's a bass light amp compared to SS counterparts. Many people will immediately dismiss the iha-1 because of that.
What the Iha-1 does better than most any other amp at it's price point, is giving that pure SET OTC class A no feedback sound.
It comes from higher levels of second-order harmonic distortion. One might read "distortion" oh no, screw that, gimme the THX 789. Thing is, the second-order harmonic for me, and other tube lovers, is what gives music life and emotional impact. It sounds real, compared to an extremely detailed representation of what music should sound like. That's my take on it.