Octave Audio V70SE tube recommendations

I am personally not a fan of the 6550 tube at least not new productions, you may want to try EL34's if you want a warmer sound.

So, the output tubes are fully burned in. I believe the input tube in the gain stage (12AX7) has the most influence on sonics followed by the drivers/phase inverters. If these were true NOS tubes, which are a rarity these days, they might take 50-60 hrs for burn-in. You're at a point that you should be hearing the sound settling in. I've used the black plates for years, the highs should become smoother and less sharp (there will still be some detail up top), but it shouldn't sound harsh. The soundstage should be opening up and the bass will become deeper.

FYI, all amp designs are different and a certain tube type can have a different presentation in that circuit. These are some of the sonic  attributes you should start noticing.

Thanks for the input. I purchased the octave about 7 months ago. Probably have about listening 300-400 hrs on the stock tubes, and 20-30 hrs on the new input tubes. But, seems like the consensus is, I need to burn in the new, input tubes longer, Before changing out the output and/ or exploring the super black box option.

Again, thank you all !

Some good advice here from @tpreaves ​​​​@lowrider57 

 I agree that you need some more time on your tubes.Don't be in a hurry to start changing things.

Congrats, great amp. I agree with lowrider on burn-in. I started with the V40se went up the ladder and now have the V70 Class A. Your heritage specials could benefit from the Octave Super Black Box which improves bass response and grip. I personally am not a fan of JJ’s. In terms of warmth look to Mullard or Amperex. Either way you have a fantastic match with the Octave/Dyna.

I prefer Gold Lion KT-88's in my V70SE over the 6550's. I agree that you need some more time on your tubes.Don't be in a hurry to start changing things.

You'll get warmth and some good detail from the RCA blackplates. They need more burn-in, in fact the entire amp needs burnin time if new. A bright sound with a lack of low-end often means it needs to be run-in. You may also find the JJ's aren't for you, but give them some more time.