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?
Rocker 30 Bias mod and MM vs Demeter transformers.
Moderator: bclaire
Re: Rocker 30 Bias mod and MM vs Demeter transformers.
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.
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.
Re: Rocker 30 Bias mod and MM vs Demeter transformers.
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.
Re: Rocker 30 Bias mod and MM vs Demeter transformers.
Higher plate voltage would be good! What are you getting???
Re: Rocker 30 Bias mod and MM vs Demeter transformers.
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.
Re: Rocker 30 Bias mod and MM vs Demeter transformers.
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!
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!
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