BLACKSTAR HT20RH MKII POWER TUBE REPLACEMENT

HT-1R MkII, HT-5R MkII and HT-20R MkII Head and Combos.
Post Reply
KSBlackstar1
Posts: 1
Joined: Thu Jan 02, 2020 1:30 am

Thu Jan 02, 2020 2:42 pm

I'm hoping to get a definitive answer regarding replacing the EL84's in my HT20RH MKII.

Do they or do they NOT need to be biased? (I know that the pre-amp tubes are plug and play).

I have found nothing online or in this forum regarding this particular amp.

Thanks in advance for some constructive feedback (no pun intended).

Fauxsuper
Posts: 7
Joined: Mon Feb 24, 2020 12:39 am

Tue Feb 25, 2020 6:55 am

I would also like to find out the same information, as I'm in the dark about this. One of the fun things about tube amps is trying different tubes. I can understand why a manufacture might not want to encourage people to expose themselves to potentially lethal voltages, but I've been messing around with tube amps for over 50 years, and I'm still here.

Hankon6
Posts: 2
Joined: Tue Dec 31, 2019 9:45 pm

Wed Feb 26, 2020 5:03 pm

There is usually no reason to bias small amps that are cathode biased. Amps below 30 watts are usually in this parameter. I am about to roll the power tubes myself with EL84 Tungsols. :D :D
I recently put in some 12ax7 Genalex pre amp tubes and they ROCK! There is still burn in time to go...but it gets sweeter everyday!
If you buy a matched pair that fit in the manufacture's bias parameters you are putting the exclamation point in BOLD! No need to re-bias unless you would like to run your tubes a little hotter or colder to fit you tone
a bit better.

Post Reply
  • Information
  • Who is online

    Users browsing this forum: No registered users and 7 guests