blackstar HT20 Combo issues

emaccarthy

New member
I have a Blackstar HT20 combo and lately when I turn it on it does not turn on "all the way." I get it being a tube amp that it won't just switch on like SS do. What is happening is that when I turn it on there is almost no volume coming through the speaker. If I CRANK up the master volume I can get sound through the speaker but its very faint. If I literally smack the top of the amp with my hand/fist (ala Fonzie) it will then fully kick on and then proceed to play like normal. Sometimes it will seem to peeter out when I play and I have to smack it again for it "wake up." Any ideas? Power tubes crapping out? Bad solder joint somewhere? Keep in mind I do not gig with it and this amp is never tossed around. It is my home practice amp so it is not abused.

Thanks!
 
Re: blackstar HT20 Combo issues

It's haunted.

You'll have to find an amp tech that is also a well-practiced exorcist.
 
Re: blackstar HT20 Combo issues

Hmmmm. Unfortunately I do not know any members of Stryper. Im sure they could help me out in this "haunted" situation. Without jiggling the tube in the socket, they appear to be tight. They are held in place with the little metal spring retaining clips so I kind of doubt they are working their way loose. I might try to open up the back and yank out tubes and put em back in hopefully that will solve it? This amp does not move and I really hope this isn't a component (transformer or something expensive) slowly crapping out on me. Any more ideas out there?
 
Re: blackstar HT20 Combo issues

Tube pins and/or sockets may be oxidized and need cleaning with deox. OR a bad solder joint could cause it.
"Keep in mind I do not gig with it and this amp is never tossed around." Hmmm, I wouldn't smack it a la Fonze. That can't be doing it any good.
 
Re: blackstar HT20 Combo issues

Blackstar has quality issues for sure... Longevity in a quality made amp is most important to me...

Peavey VK112's (first series), sound great, but prone to break down.
Fender Blues Jr/Princeton/HRD, all sound great, but poor components cause them to fail.
Bugera... the name says it all...
Blackstar HT combos... Prone to failure

Jet City.... Excellent quality, even made in China. Very killer sounding!
 
Re: blackstar HT20 Combo issues

I am back and the issue is still happening.

Updates: The issue persisted very intermittently for sometime. The amp would randomly just "fizzle out." Full sound would oscillate and change in volume until it would eventually drop to nil. I could crank the volume to the max and hear an ever so faint guitar guitar sound from the speaker. If I drop the volume back down to where I was before (loud bedroom level) and hit the top of the amp in random spots with my fist, most times the amp would wake back up and return to fully functioning awesome sound. This was so intermittent that I have a hard time repeating it. The amp could be fine for another half hour or fine for the next week plus. I assumed that maybe one of the tubes was going so I ordered a complete new set of pre and power amp tubes. Re-installed new tubes and biased the amp and flicked it on. Seemed to work fine for a little then all of a sudden it fizzled out only to be awaken again. The problem is still there and still intermittent.

Any experiences similar to this? I am pretty confident it isn't a tube issue....
 
Re: blackstar HT20 Combo issues

Jet City.... Excellent quality, even made in China. Very killer sounding!

I'll back this up. I love my JCA20H, and my HT-5 sees very little playing time because of it. The features on the Blackstar kill the Jet City, but installing an effects loop and a depth knob solved that problem. Plus, I find the Jet City much more responsive to tube changes, so tweaking it is a bit easier. That being said, the ISF is hard to beat.
 
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Re: blackstar HT20 Combo issues

Solder joint. It must go to a tech unless you are experienced and skilled in this area.
You won't find a solution here.
We'd all like to know the outcome once you have it fixed.
 
Re: blackstar HT20 Combo issues

I wouldn't go rummaging around in the amp yourself. I've heard these things are "un-repairable."
Put it this way: I own a Blackstar series One amplifier and am considered a fan of their amps. I would never buy an HT series amplifier. Prone to failure and impossible to repair.
 
Re: blackstar HT20 Combo issues

I wouldn't go rummaging around in the amp yourself. I've heard these things are "un-repairable."
Put it this way: I own a Blackstar series One amplifier and am considered a fan of their amps. I would never buy an HT series amplifier. Prone to failure and impossible to repair.
That's definitely untrue. I own one which had a bad solder joint and was repaired under warranty. I have a number of amps and the repair tech I use is authorized for many different brand amps' warranties. When asked, he responded the the build quality was on par with similarly priced amps. One problem with B* that may have prompted what you heard is that they are highly secretive about their schematics, hence only their authorized rpr. points can fix them....warranty or not. With a Fender, anyone can download schematics from the Fender web site.
 
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