The Amp Garage

What about pins 3,6,8?

Yes,you can totally eliminate crossover distortion with the appropriate zener voltage,but I think this is a trick more suited to el84 amps,plus, whenever you change tubes,if they don't bias them at the same negative voltage your zener clamping can be off.

One thing that kills these IC s is heat,if there is not enough dissipation they can blow, because in general they have short protection,post a picture of the circuit

me too,in the tonestack after a cathode follower,in the end i prefer the ceramic sound anyway

Absolutely, the speaker is in itself an eq filter,and combined with the cabinet has a specific impedance curve that makes a power amp behave different from other combination.

Yes,great amp is the way,in fact a shitty one can't translate well the guitar sound and then you start buying 1000s of pedals,then you sell the pedals and buy the good one,which,by the way ,makes every pedal sound even better.

no wonder they sound american,the TB18 is basically a clean Dumble,digital reverb and SS loop, the 35 is basically a Blackface reverb with 4x6V6s cathode bias.

Stevem wrote: ↑Tue Jan 15, 2019 5:24 pm Thanks for your time and input , but the 6505 has 6 preamp tubes and the 5150 has only 5 .

6505 is the 5150,6505+ is the 5150 II,simple as that,schematic is around the net.
They had just changed the name because of EVH trademark.
The combo is different though.

if you use 2x12ax7 at 12V it means you need 300 mA for filaments and another 100/150 mA for the SMPS that feeds the HV,i personally use a separate 12V/2A power supply for security,just in case something goes wrong it won't mess any other circuit.

Thanks Malcolm, I've one question concerning the description in the link you just posted: https://sites.google.com/site/stringsandfrets/guitar-amplifier-overdrive/evolution-of-an-od-stage/OD4.png It is clear the purpose of having different input impedances at different frequencies, so higher impeda...

i never got why in a clean/overdrive amp you have to compromise using just 2 tubes,i mean, how much is one more tube and wire a totally independent od channel? in a 3K+ amp?

The 4 stage High gain is pretty good for that Roccaforte style sound,other than that I used many bits here and there to mod various amps,champ,800,power supply mods.

there is a schematic around,if i found it i'll post it here

Mismatched impedance leads to power tubes failure first,then maybe a fuse,and after long overheat the ot goes down.
More probably a defective construction or material.

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I guess those speakers are all Celestion jb85 at this point,along with his signature twins,the guy knows marketing,and I really think he knows a lot being a nerd.

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