BYOC Champlifier Build Process

[chongmagic]

Check all of your solder joints. When the temperature rises, things move around. Make sure the tube pins are clean and the sockets are tight. Retorque any screws that have solder lugs on them. That 25uF electrolytic up against the 470Ω heater is another possibility.

They had it placed that way in the build docs, but I can try moving it. What is the best way to discharge the amp after it has been turned off?

 

[Chuck D. Bones]

Ground pin 1 or pin 7 on the 12AX7A and let its plate resistor bleed off the HV caps. Wait 30 sec, then verify that each of the HV caps is under 10V. If you want a permanent bleeder, install a 470K to 1Meg 1W resistor across the 16uF cap.

 

[jjjimi84]

CM, check out trinity amps they have an impressive range of amp kits.

My first amp build was 12 years ago and was a metro amps kit, it still sounds great. Metro stopped offering kits but valvestorm took up the slack and you can get almost all of the parts from them to do plexis.

I did that for my last build, which is the loudest 50 watt plexi i have ever played.

Allen amps is another great site, I built an accomplice and use it to record all of the time.

It is so addicting just like pedals.

Looks great, I wanna hear some clips

 

[chongmagic]

CM, check out trinity amps they have an impressive range of amp kits.

My first amp build was 12 years ago and was a metro amps kit, it still sounds great. Metro stopped offering kits but valvestorm took up the slack and you can get almost all of the parts from them to do plexis.

I did that for my last build, which is the loudest 50 watt plexi i have ever played.

Allen amps is another great site, I built an accomplice and use it to record all of the time.

It is so addicting just like pedals.

Looks great, I wanna hear some clips

I will definitely post some clips.

 

[HamishR]

I miss those Metroamp kits. George was great to deal with. Trinity amps are good.

I like to keep those green filament wires tucked inside the front lip of the chassis, well away from the circuit. The filaments are AC voltage and the circuit runs on DC. If you get the filament wiring too close to the board it can cause a bit of hum if you're unlucky. I like how you've twisted the pairs around each other - that helps keep the noise down.

The good thing about an amp like that is that it's not hard to troubleshoot because there's not much there! Be careful because it is extremely addictive. My suggestion for a "next build" would be a 5E3 Deluxe or a 5F11 Vibrolux. Very usable amps. The only thing i don't like about kits is that I like to use something different in all of them! The Mojotone kits are pretty good. I like to use F+T electrolytics, Sozo coupling caps and carbon film resistors. Carbon comp are the mojo choice but can be noisy and can drift in value.

 

[chongmagic]

Here is a little clip of me doodling around with it. Had some static but I believe I have it all worked out.

 

[jjjimi84]

If you put it in the cabinet with the completion of the faraday cage does the hum go away?

Either way it sounds really nice, great job.

 

[MightySmallElectrons]

Sound good Chong! Love a Champ and now there’s one more thing I envy that you can do!!

 

[Barry]

Sounds nice when it's not fizzing

 

[Chuck D. Bones]

Sounds bitchen! Nice playing. This proves you don't need a 100W amp with a dozen knobs to get a great tone. That intermittent noise sounds like a loose ground to me, in the input side of the circuit. Or a funky 12AX7A. The Volume pot is suspect too. CC resistors have mojo, but they also have reliability issues. Put an audio probe on Pin 1 or pin 6 of the 12AX7A when the noise is happening and see if you hear it there too. Make sure the cap on the audio probe is 400V or higher and be careful.

One more suggestion: the video could be longer.

 

[chongmagic]

One more using the Chalumeau.