Next Build: Modded Blackface Vibrochamp

[matoni]

Hey all,
I have a couple of questions before I begin my next build. I plan to build a PCB like Ryan Colgan's PCB for the JM sig. I already emailed him, but if anyone has any recommendations on programs to use or part libraries, please send them my way. Next, this is the schematic I plan to use. I have added a one-tube reverb circuit I found on another forum. This brings up my first question: Where should I put the reverb? I was thinking after the second preamp tube, but I'm not sure if this will put it after the tremolo, as I am not yet the best at reading schematics. I will also post the reverb circuit I am planning on using below. Also, what voltages do I attach the C and D seen on the schematic? Finally, I want to use a diode rectifier, and everything I have seen on converting to a diode rectifier has confused me. What kind of diode rectifier do I need to use (standard, bridge, etc)? Do I need to change the power transformer to a different type, or am I fine with the one speced that I found on amplified parts? Im so excited to start this build. I think I am going to use a fender Princeton chasis from Mojotone. This is my first time designing PCBs (or turret boards if I decide to go that route) from scratch for an amp so I am excited to see how that goes. I will keep you posted with updates as the process further progresses, I just wanted to first make sure that everything I wanted was possinle. Thanks for all the help!!

[thetragichero]

kicad is pretty easy to learn

[matoni]

I already know how to use eagle. That’s what I think I’m going to use.

[10thTx]

Look this over

With respect, 10thtx

[matoni]

I like that, but a one tube reverb might be easier. I’m open to anything though. Thanks!!

[matoni]

What is the difference between the one and two tube reverbs? And can I add a dwell control on the front end like in the one tube option?

[Stevem]

If you are going to bother to have reverb at all and want it to sound good then the input side of the pan needs a lot of current drive.

This is why Fenders and Ampegs and a few others have such great sounding reverb!

The Fender set up uses both sides of a 12AT7 in parallel to produce a big current drive, and the Ampegs use a big plate Octal 6SN7 tube.

I have never liked the sound of a reverb pan drivin by just one half of a 12AX7,period!

If I was to find I had to go that route to get reverb into a amp I would sooner use one of the SS brick type reverb effects that only need 5 volts from the power supply.

[10thTx]

What is the difference between the one and two tube reverbs? And can I add a dwell control on the front end like in the one tube option?

Did you count the number of 12Ax7's in the schematic I posted? If you used a one tube reverb, what will you do with the left over triode?

I usually prefer a one tube reverb. I don't use much reverb and it saves me a triode and accomplishes what I am aiming for.

I have two amps here at home with reverb. One has the Fenderish two tube reverb and the other is a one tube reverb using a 12DW7. I like them both. And the reality is that I them both set with about the same amount of reverb on each amp as I don't really care for alot of reverb in my tone.

Yes, you can add a dwell to the Fender two tube reverb.

with respect 10thtx

[thetragichero]

What is the difference between the one and two tube reverbs? And can I add a dwell control on the front end like in the one tube option?

standard fender reverb uses three triodes plus a reverb transformer. it really is the way to go if you like really wet reverb in the amp but i tend to shy away from them mainly because while i can usually spare a triode. the extra transformer takes up space and extra dollars (unless someone has found a cheap source for em) that i may not have to spare. plus my fathom takes care of most of the reverb sounds i want anyway and it's right there controllable at my feet

[matoni]

Ok, I think I might just go for the 2 tube fender-type reverb. Could somebody let me know how I can put a dwell control in the 2 tube reverb, because I find that really helpful in crafting my sounds.

[sluckey]

Replace the 1M on V2-2 with a 1M-A pot. Wire it exactly as shown on your 1 tube circuit.

[matoni]

Thanks so much!!! Now what do I do about the diode rectifier because I’m completely lost. If it’s not possible I can use a tube rectifier, but I like the quick reaction times of a diode rectifier better. Thanks for your help so far. I’m far enough now where I can begin to work on my PCB

[sluckey]

Thanks so much!!! Now what do I do about the diode rectifier because I’m completely lost. If it’s not possible I can use a tube rectifier, but I like the quick reaction times of a diode rectifier better. Thanks for your help so far. I’m far enough now where I can begin to work on my PCB

The PT you choose will dictate which type of diode rectifier you must use.

[matoni]

I was thinking this type of pt https://www.amplifiedparts.com/products ... nder-120-v. How do I substitute a diode rectifier in for this. If you scroll down to the description you can see the specific model number for the Vibro champ. Thanks again for your help.

[sluckey]

I was thinking this type of pt https://www.amplifiedparts.com/products ... nder-120-v. How do I substitute a diode rectifier in for this. If you scroll down to the description you can see the specific model number for the Vibro champ. Thanks again for your help.

https://www.hammfg.com/files/parts/pdf/290AX.pdf

Put tape on the ends of both yellow wires. Put tape on the ends of both red/wht wires. Tuck these four wires out of the way. They are not used.

Connect the red/yel lead to ground. Connect one red lead to the anode of a 1N4007 diode. Connect the other red lead to the anode of a second 1N4007 diode. Twist the two diode cathode leads together and connect to the first filter cap.