6V6 JCM800 PUNCHPLATE Amp Build (Free Plans) 

Thanks Alan. Indeed, all true and valid points. One major advantage however, of building your own is the satisfaction of a) building something yourself that works and adding your own flavour, b) the experience gained, and c) knowing exactly what is in there. Even big name Amps these days include parts of dubious quality. A hand made tube amp that includes quality parts is going to cost many many thousands. I would wager that making your own with half decent components can save a decent amount. However, like you outline, you have to either have a bit of experience, or accept the fact that you will make errors and will learn from them. Like you say, its a hard road, but rewarding should you decide to go there. I am glad I did. Cheers

Thanks Greg! I can't believe it took so long, but got there in the end. Thought it was going to take longer than your fantastic Porsche restoration. Good things take time. Hope all is well on your end, cheers..

Many thanks!

Thank M! Thats my mate Tez playing. I wish I had half his talent. My mind boggles watching him play.

Thank you, really appreciate the kind words. I'm not sure if my OCD is a curse or a gift, however its something I must deal with ha ha. Have a good one!

Hey, thanks!

Thanks for kind words Romeo. Not sure I deserve those accolades however very much appreciated. Although it's a difficult road to head down, it's very rewarding. Although many mistakes are made along the journey, you'll get there in the end, all the best!

Thank you! Thanks for checking in again!

Just finished watching the whole thing. Amazing as usual. Love the he chassis plunge; vintage elams madness ahahah. Love the ocd and the zen patient mind. The little fx boards with the headstock inlay logo from the epic 1 piece LP is beautiful also. And thanks for having kept the little mistakes; You're human then ahahah. The cinematic is always top notch. And very cool string configuration your friend has. He plays great. Please tell me we don't have to wait 2 more yrs for another video ahahah

Yo G!! Nice to hear from you dude, thanks for kind words!! Way too kind as usual. Well spotted on the logo! Indeed, resurrected from Bad-News Brown LP headstock. This was never supposed to take 2 years, but too many errors kept surfacing and the FX loop blew my brains out. Now that the loop is finished it seems fairly straight forward, but sheesh, that was a long hard road. Then all my video/audio interface gear crashed and burned. So things just kept on going going, nuts.. Hopefully it won't be another two years 😂

How's it all going in beautiful Italy? Hope all is smoothing out. Time has flown..

​@@elams1894 ahahaah what a bumma. Well repaid effort tho. It sounds veeeeery very good with my yamaha studio monitors. I wish I could test it. If it just wasn't for literally half of the earth in distance ahahahah. Everything is going great here my dude. Hope you, wife, kids, billy, ma and everybody else are doing good as well

Family is all doing good thanks G. Hope yours too. How are your beautiful guitars going? That last black and white one was something else man. Glorious.

BTW: you’ve got a new subscriber after this viddy!!

I hear you brother. The whole phase thing wrecked my brain. Its a bit silly having pedals that invert phase as it throws all attempts at a parallel mix into chaos. A phase invert switch on an FX loop in the amp is a simple affective fix. Then you don't need an external device that does the same thing. I was also staggered at the amount of noise some pedals produced. They were big name pedals too, and were almost unusable. Cheers, good insights.

@@TheSizzlingBadger Thanks Badger, good points. There is a Bypass switch on the FX loop which takes the loop completely out of circuit. I would wager very few pedals are out of phase much more than 180 degrees. At least with a phase invert switch on the loop, you can use almost all loops, whether inverted or not, in a parallel setup. I don't understand the obsession with series loops. Why have a tube amp if one is going to put the WHOLE signal into silicon after the preamp? Makes no sense to me, however horses for courses I guess.

I am happy with the Hammond transformers. The Hammond power transformers are well built and well priced. I built another version of this amp also with Classic Tone trannies to compare, and although the Classic Tones to my ear are slightly more pleasant with a distinctive note separation, the Hammonds are perfectly fine. The Hammond output transformer I chose for these amp plans packs a heap of punch for the size and cost. The Hz start off at 100 and I havent really missed the extra bass of a more expensive OT that goes down too around 50-70Hz. Certainly the Drakes will be very nice, and if you want that extra bass, go for a bigger OT in terms of Hz range. 25Watts should be more than enough for anything. cheers!

@@MarhtiSan thanks for research. That's what I found also, a dead end. An amazing tool all the same, extremely handy to reach in tight places and cut close. It's the amp builders dream tool. Cheers

Thanks Redkurn. Yes Tez plays backwards back to front Jimmy styles. Thats how he learned as a kid and it stuck. Very awesome for the brain to contemplate. The reason for the feedback was that the primary cables of the output transformer were connected reverse. That is, eg, instead of the blue cable going to V4, and brown cable going to V5, the brown cable was connected to V4 and blue to V5, or vice versa, cant remember exactly, however you get the idea. Every output transformer seems to be different in this regard, so reversing these cables should be one of the first things to check if you get screaming feedback on initial start up. Its very common for this to occur. Cheers

Really appreciate the kinds words and glad it was of some help. All the best with your projects!

Thanks for the intel. Cheers!

Thank you!

Thank you, much appreciated!

No probs, glad you enjoyed it and it might be of some use, cheers!

Thanks SK! Really appreciate it!

Its the exact same preamp circuit as the JCM800, same voltage. You can swap in 6L6 or KT66 tubes. But certainly slightly different sound from the EL34. Going by the schem, it is closer to an 800 rather a Princeton however. Cheers!

@@elams1894 You are so kind...lol

Thanks for great question. The electrolytics of nodes 4 and 5 filter the preamp, and in this layout, they are separated from the power-amp. I have designed the amp in this configuration as I have found it advantageous in terms of unwanted noise, both hum and hiss. I have a number of circumstances in the past when I have detected unacceptable parasitic noise (mostly hum), and after much experimentation I found that when the preamp is separated from the power-amp, the unwanted noise was significantly reduced. As to why this occurs, I am not certain. Now, as a matter of practise, I layout all of my amps in this fashion. Grounding is indeed an enigma wrapped up in an enigma. Fields (magnetic) is a subject that has been of great interest to me for a long time. I think it is important to consider first, that perhaps there is no 'current' flowing anywhere in an amplifier. There is only either the creation or the elimination of magnetic fields. Whether or not one subscribes to this is of little importance, however one thing is certain, a magnetic field is first presented to the amp (signal), it is then induced by a larger magnetic field (mains supply) which is ultimately displaced by the speaker magnet voice coil. It makes sense to star ground each tube with its corresponding filter capacitor, as well as any shielding. I split the filter caps to either preamp or power-amp as explained above. As long as the mains earth and secondary centre taps are grounded near the mains entry, and the signal star grounds (with filter electrolytics) of the preamp are grounded at the signal input, generally this is an acceptable scenario for low noise. As I have found, this is not always the case. If you have experimented and found that favourable results are achieved by separtating the grounding of ALL filter electrolytics from the signal path, then that is great. Experimentation and results are what counts. I would add that, in my eyes, the fewer the grounding points the better. Maximum of two. Nothing is set in stone when it comes to magnetic fields. I do not subscribe to 'currents'. I do not think in terms of currents, nor electron flow. I try to look at the system as a field based entity and go from there. Cheers!

@@elams1894 What I am trying to bring out is that for example IF (I don't know if they do, and that's why I asked) those capacitors 22 and 23 share the same a few inches long wire which is not supraconductive and has some resistance, going finally to the center tap of the PT secondary, for example the ripple current of C23 causes ripple voltage into that shared part of that wire. In that situation the next amplifier stages which are involved, do not only amplify the audio signal which only should be amplified, but instead they amplify audio signal + the ripple voltage in the ground path between those stages created by the ripple currents in those caps if the cap grounds are not star grounded . And the stage fed by node C plate voltage will amplify ( if it's gain is >1) that ripple voltage as well. When using a perfect star grounding, those ripple voltages caused by ripple currents of minus leads of main filter capacitors are totally eliminated from the audio ground path, and so cannot be amplified unintentionally either. And those ripple voltages between grounds of different stages cannot be measured either because it is like you are trying to see what you AC millivoltmeter shows when its clips are shorted together! 😁 That is the idea of star grounding. The presence of those ripple currents causin ripple voltages in audio signal ground is totally eliminated because those ripple currents of minus leads of all main caps are flowing to the PT center tap only in that one single node, creating no any existing or measurable ripple currents whatsoever into the grounds of the audio path because the ground of audio path is kept totally away of the path of all ground ripple currents of main caps. Star grounding works like traffic control when heavy truck traffic (ripple currents) is tracked away from residential areas (preamplifier stages) going there where it does not cause noise to people who want to sleep. 😁

Thanks Z. I havent gone there yet with HiFi design. Different kettle of fish indeed. I may drag out my fathers HiFi designs a bit later, lets see. cheers!

Thank you very much!

Youll need the bigger chassis, 14 inch, to add a 12ax7, however indeed a 4th preamp tube opens a heap of high gain opportunity. Cheers

Awesome! Very handy skill to have. Many are scared about solid state stuff mixing with tubes, however opamps can be incredibly beneficial in tube circuits as you are obviously aware. I'm a big fan and love PCB design also. Integrating pedal type circuits in amps is real fun.

@@elams1894 yeap, every time I mention to my more traditional minded friends that I bias my tubes using LEDs, they frown 🙁 😀

Thanks D!

Great question. I hope to have a comprehensive BOM for this amp on my website. Cheers!

For me in Australia.....$1000

Some lefties can just take a right handed guitar and play it left handed like that.

@@bltvd That is a left handed guitar though. That's why I am asking. I have left handed friends that are used to playing the guitar upside down if it is a right handed guitar but never a left handed guitar.

@@matthewearl9824 if you play that way then it would make sense to have left handed guitar strung backwards. I have a friend in Chicago that is the best guitar player I know that does this as well.

Thank you!

Thank you! Cheers!

Thanks H. For sure, Tez has got the upside down-backward playing skillz honed. That's how he started and that's how it is. He plays a million times better than me and I can only look on with a boggled brain. Cheers!!

That's very interesting. Indeed, not many functional opamp based loops out there, as it ain't easy. I'll have to check out the Egnater schem. Glad it worked out well, a total win!!

Really appreciate the kind words. Far out it has been a long time, I'm very slow as you are well aware I'm sure. I like to try to get things right. Thanks for tuning back in and hanging in there. You can do it! All the best!

Indeed.

Thanks for tuning back in!

I'm actually also starting to build amps too 😎😎😎

Much appreciated, thanks!

@@dr.q332 Thanks for stopping by again, cheers!

@@MidnightVisions I am not using wire wrap DIP sockets. The ones I'm using have pins of standard length. I'm not quite sure what you are referring to?

Thanks Frank! You can do it!

That's fantastic to hear Marc, glad all is working out. Thanks for checking back in, much appreciated.

Thank you, much appreciated!

I'll leave the faceplate up to the individual builder. The cabinet and faceplate are up to you guys. Cheers!

Thank you!

Thank you, way too kind..

Yeah man, Tez is a legend!

Thanks for kind words. I checked out your channel. Very nice work on the boost pedal. Love the BIG knob. regarding some of your other posts, I suffer big time from many similar conditions of the brain. Gift or a curse, depending upon the day. Hence I took years to design and build this amp. It was in aheap in the bin. more than once. Shes a hard road, but rewarding indeed. Keep up the fine work, great to see other determined builders out there!

Thanks for checking in Daddeo, all the best.

This type of work needs to be displayed in a glass (or lexan) box.

Thank you!

I'm like cheese, I take a lot of time. It's a curse.

Indeed, that is the way. I like to do things in reverse ha ha. Instead if deceiving people with a shiny package, I bamboozle them with a bland exterior. With tube amps, its all about whats going on inside. Cheers!

@@elams1894 Of course. It's a prototype, too. Didn't want to sound to judgemental or rude. Great work non the less.

​@@mead1353 look back at his other videos if you haven't yet. You are in for a beautiful shiny surprise. Some of the most tasteful elegant/exotic design work.

Thanks for watching!

I'm slow for, however glad you could stop by again!

Thanks!

Too kind, cheers

Therein lies the beauty though, and aint it just the way. May be the Laney AOR50 is next?? 😂

That's Tez's LP standard, a very nice piece. Sounded beautiful to my ears as well, esp with the G12T75's, one seriously underated Celestion in my opinion. Cheers!

Totally agree Thomas! Tez is very particular with his gear, and he has a fine ear. Thats why I get Tez to both play the demos and provide feedback. He lets me know when things are on track and also when things are not good. Invaluable information. I only wish I could play half as good as him. That burst LP of his is my pick as well for tone. Not sure what it was about it however it seemed very thick and luscious to my ears. Cheers!