Electro Harmonix KT88 ?

[quadra]

FWIW to the thread. I've bought two Orange AD200 heads, one made in 2006 and one made in 2010. Both came with stock EH 6550's.

I was lucky to find a matched quad of vintage RCA 6550s with very low usage and fairly cheap. I put them on my first AD200 (2006) and the difference was enormous. The definition of each string with the new (old) tubes is great. And they sound a little bit more warmth and trebly at the same time. Much better overall.

I haven't compared them to any other tubes out there, I'd like to get a set of Gold Lion KT88s for the 2nd Orange and compare at some point.

Anyway, the EH 6550s are muddy and I would never recommend them.

 

[Dallyd31]

FWIW to the thread. I've bought two Orange AD200 heads, one made in 2006 and one made in 2010. Both came with stock EH 6550's.

I was lucky to find a matched quad of vintage RCA 6550s with very low usage and fairly cheap. I put them on my first AD200 (2006) and the difference was enormous. The definition of each string with the new (old) tubes is great. And they sound a little bit more warmth and trebly at the same time. Much better overall.

I haven't compared them to any other tubes out there, I'd like to get a set of Gold Lion KT88s for the 2nd Orange and compare at some point.

Anyway, the EH 6550s are muddy and I would never recommend them.

I found the same for my SED 6550 in my AD200....they are muddy. It came with the SED as stock, and I borrowed a set of JJ KT88 to try them out to see if it made enough of difference to buy a set. Biased them and tried them out...BIG difference. Much less muddy, more clarity and more mids. Not sure if the JJ's are the best KT88 for this amp, but it sure made a big difference vs the stock SED6550. Seems that perhaps the Orange is fairly sensitive to power tubes.