Good news from my amp tech! Bias content...

[cvogue]

My Blackstar HT40 was sounding lousy and I couldn't get a real clean sound out of it at a gig last Friday... :(

Took it in and today he told me that the amp was horrendously overbiased... tubes were running way to cold which caused the amp to have distortion (not the good kind) as well as inconsistency and volume issues.

Got it from Musicians Friend and it wasn't like that before... can amp bias change over time?

Anyway, can't wait to hear it, should be back in my hands this weekend.

 

[jp_nyc]

Does the clean channel on yours tend to be louder than the overdrive channel? My HT40’s clean channel can get painfully loud at a much lower volume setting than the OD channel.

 

[wagdog]

Bias can change over time due to the tubes aging. Component drift can also change the bias. An adjustable bias pot can move as well.

I'm betting yours was set incorrectly and as the tubes aged, they sounded worse and worse.

 

[cvogue]

Does the clean channel on yours tend to be louder than the overdrive channel? My HT40’s clean channel can get painfully loud at a much lower volume setting than the OD channel.

Yes absolutely... I think that's been fixed (got my amp back from the tech yesterday) although I haven't tried it with the band yet. The whole amp is louder now and seems better balanced. There's a lot more volume on the overdrive channel. Also, when I'm not playing the thing is quiet as a mouse now. Very good.

I also think I've found where the harshness was coming from on the overdrive channel. I've been using the "higher gain" voicing on OD (button pushed in) and I switched to the other voicing and increased the gain... sounds much better now. Nice rich tone without being too in your face. That OD setting was much more anemic before I had it worked on.

Anyway, still dialing things in... the sound of the amp is quite different.

 

[Modern Saint]

What Wagdog said!