Wizard KT150 with 6550’s?

[braintheory]

6550’s cannot handle a large screen grid voltage. You have to supply a second supply voltage as it’s too much of a drop to triode strap with just a resistor at the rated power levels.

What about KT90’s?

 

[braintheory]

It’s strange that others here were ok running 6550’s in their’s, but I guess they were either MC or MTL KT150’s. Maybe the Hell Razor KT150 is different

 

[hopkinWFG]

Why swap to 6550 where its originally loaded with KT88?

Conversely i have a KT200 which i gotten and i was wondering if i could scale down the power to using KT88s instead of KT120 tubes...

 

[braintheory]

Why swap to 6550 where its originally loaded with KT88?

Conversely i have a KT200 which i gotten and i was wondering if i could scale down the power to using KT88s instead of KT120 tubes...

Because in other amps where it's an option I often prefer the tone of 6550's to KT88's

 

[Dale B]

I don't own and never have played a Wizard. I'm sure they're great amps. I did have a matched Octet of GE 6550s that I ran in an Ultra-Lead. They're basically a higher headroom 6L6GC. They were very similar in tone to a =C= 6L6GC, but they sounded a bit bigger and felt harder.

I haven't run KT77s, but I've run KT88s and KT66s in amps. The KTs always had a light squishy feeling. The 66s were springy feeling. I always liked that feel. I love KT88s!

It all depends on the actual circuit at the end of the day.

 

[VonBonfire]

The same site described 6550's as a big big bottle 6L6 that can handle more plate voltage and more rugged, 6550's are quite linear and balanced in the sonic spectrum much like a 6L6 and my ears also agree with that description.

My ears also agree with that description. I had 6550's in a 100 watt Plexi RI for many years. Big sounding, punchy, clean with glassy 3-D highs and not as smooth in those highs as a EL34 when driven IMO. Granted I was using a traditional strat at the time but it could def get those Jimi-SRV tones and had quite an amazing clean tone through a 4x12 GB loaded 1960ax cab. Bold and rich. And man was it loud. Louder than a triple rec, not even close. It was good with a tubescreamer in front of it. I used a VS J&H for that part, Cranked past 6 with a 498t in the bridge of an ES it had a killer rock bite to it.