ASK-HBS – Blackstar HT-20R MkII Tube Swap

Question

Hi,

Thank you for your website.

I am currently playing a Blackstar HT-20R MkII and am looking to clean up the overall tone of the amp. I’ve been reading about some possible tube swaps and am wondering if 6L6’s would be an option for this amp. Or, if there are other power or preamp tubes you might recommend.

I’ll await and look forward to your response.

Michael

Answer

Hello Michael, thank you for the great question. Unfortunately, you cannot substitute the 6L6 for the EL84s in your Blackstar because they have a different number of pins. There are a few options, like the EL82, Russian 6p14p, 6p14p-EV – Military, and 6BQ5, but they might not work as well or sound as good and will need you to adjust biasing, etc. Some others might work with some mods to the amp, but I’m not sure how easy it would be on the Blackstar and it’s probably more than you’re looking for.

While there isn’t a good alternative to the EL84, several companies make them, and the finished tubes all sound different.

• Standard JJ EL84 tubes are a popular choice in many amps and sound great.
• The JJ EL844 is a modern tube that breaks up quickly, so it’s probably not what you are after.
• The EH EL84 is a great all-around tube that might work for you.
• Sovtec EL84 tubes are usually inexpensive so try one to see if you like the sound.
• Mullard EL84 tubes are expensive but sound really nice and might give you the clean sound you are after.
• RCA EL84 tubes are another good option for a cleaner sound.

I’m not sure what brand the Blackstar comes equipped with but trying different brands is likely your best option to find the tone you want. Even tubes of the same brand will sound different, and the sound changes as they age, so experimentation is key. Hopefully, you will be able to find them at a reasonable price.

Sorry I couldn’t be more helpful. Let us know if you have any other questions, and thanks for reading Humbucker Soup!

Follow-Up From Reader

Thank you for this great response, Ed.  On the contrary, this is very helpful and I appreciate your input.  I think part of my issue is that I am trying to get one amp to perform well in (at least) two different genres – classic funk with a 21st-century edge and straight-ahead/50s-60s (dead guy) jazz.

Based on the “thetubestore.com” descriptions I purchased (2) TungSol 7189s and (2) Reflector EL84s.  But, I definitely appreciate your input here…

Michael