Mini Dirty Shirley power tubes biased?

Hi

I recently purchased a mini Dirty Shirley head and cab, unfortunately the delivery driver threw them over the back gate when they were delivered and they landed upside down!!!!

They seem ok but i think the tubes are dead, i was getting a thick fuzzy like & the low end was breaking up and kind of rummbly is the best way i can describe it that didnt sound rite to me. Kind of like if i was running a fuzz face through it.

Ive changed the pre amp tubes but i think i need to change the el84's (they have a burnt residue on the glass i can see)
Do i need to bias the el84's or can i just buy the same tubes and put those in?
Im not sure if the head is self biasing etc

Thanks Dave for the awesome gear you build

Thanks
Pete

Pretty sure EL84's don't get biased

The Mini Dirty Shirley is a cathode biased amp, so no tube biasing required. I have seen Dave post that he recommends JJ brand EL84 tubes.

Send that shit back on ups dime. Brand new amp and your trouble shooting. No way.

Thanks for the help all.
New tubes already on there way.
Apart from the tubes the amp held up good, quality build from the Friedman camp
Heres how it arrived lol! (i have to laugh)
A testament to how well made Friedman's are

Defiantly bias the tubes. First thing I do on any head/amp is take it right up to my tech, should have a tube tester and have the whole circuit checked and screen voltage adjusted. Shouldnt take more than 20 mins

I can't see the delivery causing a problem. If were packed correctly. Not sure how that would effect the tube inside the head anyway. I think it would have to go back for a new one considering the price that you pay for amps. Also I would held at the facilitie to pick up instead of having it bounce around in a delivery truck all morning then thrown on my step

Sickriverlespaul":1svxjw74 said:

I can't see the delivery causing a problem. If were packed correctly. Not sure how that would effect the tube inside the head anyway. I think it would have to go back for a new one considering the price that you pay for amps. Also I would held at the facilitie to pick up instead of having it bounce around in a delivery truck all morning then thrown on my step

Click to expand...

Sounds to me like you've never owned a tube amp.

Owned plenty ... I just take care of them

How would that situation affect a well packed tube amp?

I'm not sure how a box upside down would affect that too but the from the pictures that I've seen that there's no damage on the box so I'm not sure how that would affect the tube