Rocker 30 Bias mod and MM vs Demeter transformers.

[InX]

Any folks install a pot to get the bias up higher?

I like the amp, just need to overdrive the power tubes a bit more. They sit at 22/24 watts, want them at 28/30 at idle. I know it's not "safe" or whatever, but this is key. Could get a hotter set, may try that first.

Anyone? Beuller?

Also, what's the consensus on the Demeter vs Mercury Magnetics OT's in these?

[InX]

That is, they're @ 70/76ma with 320v B+. With the master dimed, I see around 100ma/300v peaks, which is the sauce, but le glory toanz only happen when you start there and go higher.

My dad's Guytron GT-100 F/V runs the EL84's at over their 100% dissipation spec and thus require replacement every 3-6 months. This is the sacrifice on the altar of tone.

I need my KT77's at 28+ for sweet action.

[Jondog]

I've never really messed with the bias, I've always been quite content with it. I've actually considered running it cooler if anything. I put MM transformers in the Rocker once. Some change in tone. I used the MM Rockerverb PT on the Rocker which has a slightly higher voltage than the Demeter so the head room is increased a little which you may not want if you're looking for hotter bias. I put the Rockerverb OT on it too and I feel like it gave a smoother sound, not as edgy. The Demeter's are good transformers, maybe not as fancy looking as the MM's but I don't feel a need to invest in MM's over Demeters. My current Rocker is using the stock Demeters.

[InX]

Higher plate voltage would be good! What are you getting???

[Jondog]

Higher plate voltage would be good! What are you getting???

I don't recall. I don't have that amp anymore. But the MM PT puts out 307vac off each secondary lead. The Demeter is a little less. But it's all relative to what the primary is seeing and therefore the rest of the amp.

[InX]

Got some higher-draw JJ's from Tubedepot.com and they run around 79/82. Slight redplate, but sweet Jesus the tone! My god! Orange glow in the creases of the plates, but FFS it sounds GODLY!

Russian 6P3S-E's sound just about as good, slightly less bias (74/76) and will prolly take the live beating much better. Looks like I've found my studio/live tube configurations. GLORY!

See also: Try the 8 ohm tap into a 16 ohm speaker when playing at low levels/bedroom. VERY NICE!