Gain mods

[Sean]

Hey Guys, Does anyone know of any mods from the original schematic for more gain? Is a master volume mod the only option? I am looking for a tighter lower end with a more aggressive breakup. I was wanting to stay away from a master volume mod from fear of overheating the valves. Any suggestions? Thanks.
Sean

[zaphod_phil]

Check out the other thread headed, "18 watt shredder?" for some good suggestions. A bigger cathode bypass cap on the EL84 cathodes should also help improve low end...

[am1aw]

I was wondering this myself as all the other 18 watters have 3 preamp tubes but the 18 watt Blockhead 2x12 combo I have has 4 preamp tubes, a solid state rectifier and 2 EL84s. I was told by Blockhead this is a one-off prototype but obviously more gain can be had by adding another preamp tube. Other items may also need to be different in this configuration but as I am a newcomer to 18 watt world and electronics in general. I wish I could give you better "specifics" but I just don't have the knowledge. I CAN count to four though, haha! Good Luck!!

[Wayne_Alexander]

Rewiring the normal channel to use an EF86 tube instead of a 12AX7/ECC83 gives you a substantial amount more gain. It just requires a few different resistors and capacitors if you leave the phase inverter and power supply stock, and if you rewire those to Vox AC15/30 values it's still just a few more resistors. With that and my current speaker setup (2x12 Mojave cabinet with G12H's) I've got a lot of low end response. I've posted details about what's involved in my other posts. I really recommend this.

[Sean]

Thanks Guys, Just so happens I am building my second 18 Watt, I started this thread when I built my first and I never did any gain mods, hence no Randy Rhoads chunk. Dimebag Darrell is a world away for my bands Pantera cover. Wayne what was the name of the thread that you are referring to? What resistors and caps did you change and what was their values? Also Iam1aw's extra preamp tube as in the Blockhead sounds interesting. Any ideas on how to make this work guy's? would be an interesting option in the schematics section for something like this. We could call it the "Turbo" schematic or something. Jung gung Jung gung, wrangggg...... time to break out the Soldano!

[am1aw]

Funny you should mention Soldano. I just traded my '93 SLO for Bogner Fish (#059). I miss it already That is, until the Fish gets here! Should be here next week, woo-hoo! Can't wait!