Crackling HT Stage 60

[pimschreurs]

Hi guys,

I hope you can help me with my problem.

After a while of playing, the amp starts giving very loud crackling noises. My playing gets louder. I play at low volume. No pedals, used diferent guitars, diferent cables, so sould be the amp.

When i switch the standby-knob off, it still gives loud crackling noises. Maybe the tubes? But when i gently hit the amp on the top, nothing happens... I mean that the crackling doesnt start or end wenn i hit it.

I'm was going to change all the pre-amp tubes. The tubes will arrive next monday or thuesday.

(sorry for my english, i'm dutch )

Can you help me?

Thx

[KKND]

Hello there, well i guess a member suggested that that is related to power tubes warming up...he claims hat its gone once he changed the power tubes. i get the crackling noise on my stage 6o every now and then put heard nothing recently......i could be wrong though.

[dangerbro]

I had the same problem. It started about 3 songs into a gig and was almost unplayable. It also didn't make any difference if you gave the amp a bang on the top, but it was definitely a tube problem.
I changed all the tubes for better quality ones, and it has been 100% reliable since. I suspect it was the power valves but I changed them all because I didn't trust them after that!

Hope this helps!

[Barreldog]

I had the same thing happen with my stage 60.
I had the amp about a month. It happened maybe three or four times & it hasn't happened since.
I now have it about six months & everything is working good.

[pimschreurs]

If i change the power tubes, do i need to bias the amp? I know that i dont have tot bias the amp if i change the pre-amp tubes.... Is it even possible to bias the amp?

Then if i change the power tubes, what valves are perfect for metal sound? I dont have a clue about this subject. I was always told that the pre amp tubes are there for the sound, and the power tubes for the volume... Me noob... so...

If i do need to bias the amp, at what voltage level do i need to be?

Thanks...

[KKND]

You have to bias the amp if you will re tube the power amp tubes, what is biasing....? i dont know, matter of fact that is giving me i nightmare already, when the time comes and i have to re tube my amp,don't know how am i going to do it, cause i have ti do it my self....

EL34 will be just fine for metal.....i guess

[pimschreurs]

Well... Amp died. Fuse was burned. Just the 630 mA one. I'm still gonna change the power tubes and the pre amp tubes.

Will keep you noticed.

Thx

[jshaffer23]

Well... Amp died. Fuse was burned. Just the 630 mA one. I'm still gonna change the power tubes and the pre amp tubes.

Will keep you noticed.

Thx

Bummer! I bet the one of the power tubes went causing the fuse to blow. Thats usually the case when a fuse blows like that. Hope you get it sorted out!

[pimschreurs]

Is it nesecary to bias the amp if the power tubes are changed? Has anyone done this with the ht 60 stage?

[jshaffer23]

Is it nesecary to bias the amp if the power tubes are changed? Has anyone done this with the ht 60 stage?

Yes, it needs to be biased. It is VERY easy to do. There is a very small two prong plug on the PCB board that the power tubes are mounted to. Just hit the two prongs with the probes on the multimeter and adjust the bias pot to read around 50ma. I am pretty sure that is where mine is set. There is a thread somewhere showing pictures of how to do this. I will try to find it for you.