Psionic Excalibre 15 | A Dream Made Real... (well, close - so close)

[@PsionicAudio]

I meant to say doubling the distance between two components or wires more than halves the noise/interaction between them. Space yields experiential lessoning of noise. But instead I said doubling the distance more than halves the distance. Because not enough coffee.

[@bhm1712]

We knew what you meant 👍🏻

[@weschilton]

Coffee, or you could try sleep ;) Either way, this thing is looking amazing. Can't wait to hear it.

[@diegorhoenisch62]

I imagine that the intensity of an alternating current field diminishes relative to the square of the distance(e.g. doubling the distance reduces the noise by a factor of four). Your videos are always great; thank you. Regards, Alan Tomlinson

[@PsionicAudio]

To the person who gave this a Dislike: You are a poopy head. And you still helped my channel with that reaction. So suck it. ;)

[@PsionicAudio]

And I said "negative effects loop." Meant negative feedback loop. Is there enough coffee in the world?

[@weschilton]

Yes there is. I have most of it.... 3rd cup so far today. ;)

[@josephc3276]

Is there enough coffee in the world??? Short answer is NO!!!

[@butchlauer]

The Excalibre has got me on the edge of my seat. My eyes and mind are absorbing as my ears patiently wait for AC to be applied.

[@christophermarsteller8235]

Haha... listening to you talk about the Ex15 is like listening to my kid talk about Minecraft. I have almost no idea what all of it means, but I can hear the excitement in your voices! Between you and me I’d rather listen to you. Can’t wait to hear this amp! Keep up the excellent work Lyle!

[@PsionicAudio]

I don't get Minecraft either. At all. My kid happily wastes hours playing a low-res Dire Straits video... The graphics are appalling and the game seems pointless to me.

[@christophermarsteller8235]

@@PsionicAudio it does seem inane, but I do appreciate the enthusiasm it provides them? It’s about the only thing she’s interested in talking about, so I listen. I understand the vocabulary, but I realized it’s kind of along the lines of me describing one of your videos to them? It’s a lot of technical jargon that is fascinating, though I have little actual understanding of it, but I know it MEANS something and I’m very excited about it. Know this Lyle... there are many of us out here who are just as excited as you for the Ex15! I just need to figure out what to sell at this point! 🤣. Eagerly awaiting and equally as excited! Best of luck to you sir! And Happy Father’s Day by the way!

[@russellhltn1396]

@@christophermarsteller8235 I think the idea behind many games is "flow" aka "in the zone" - the ability to function without much conscious thought. That state is a bit of a drug. I get why it's a fun place to be. But the accomplishments are so trivial in real life. There are other hobbies that offer that that will give you something you can show.

[@goodun2974]

@@PsionicAudio , my electronic gaming days began and ended with Pac-Man and Space Invaders! (Which serves to show how old I am). But Pinball was king, especially pinball played on hallucinogenics ---- where I became the machine and the machine became me. And yet, I find modern robots to be extremely creepy, especially if they have been programmed for synchronized movements or dancing, and the more humanoid looking they are, the creepier they are.... it's like robot line dancing, and I find human line dancing to be disturbing enough already.

[@justdave9783]

Great object lesson in many best practices principals.

[@PsionicAudio]

Thanks for all the kind comments. I'm driving for a bit (getting gas right now). Will reply/answer questions later tonight.

[@Satchmoeddie]

GOREGEOUS WORK! Some of those European countries want every secondary on the PT fused now, including the heaters. England is I guess just England now, but I am pretty sure they want the heater supply fused. Any elevation on the heaters helps.

[@seanrmartz]

Looking great

[@sgt.grinch3299]

This is an incredible opportunity for me to learn. Thank you. I enjoy the birds in the background too.

[@philthompson9633]

Just a beautiful piece of Art! Your a protectionist!

[@shanedolman1368]

Great layout, with loads of space, easy on the eye and will be on the ear too. Fantastic job Lyle, cant wait to see and hear the finished product.😀👍

[@johntrentmusic]

Oh good I'm glad you spotlit the spider. I can see the appeal of building an amp, the build looks beautiful so far!

[@robertbarnes9745]

Sure looking forward to mine! I can feel your excitement. It is reciprocated at this end.

[@darrylritter4275]

Exciting doesn't come close to describing this! Can't wait! Nor could the spider!

[@mattjohnson6916]

I can't thank you enough Lyle for putting up these amazing videos as you have gone through the design and building process of this amp! It is all incredibly fascinating! My experience and knowledge of AC15/30 circuits and classic Vox amps in general is fairly low compared to Marshalls and especially Fenders. You just don't see a lot of old Voxes here in my part of upstate South Carolina for some reason. Watching this has certainly peaked my interest in them though so I've been geeking out over as many old schematics as I can find!

[@lonniezamarripa959]

I am impressed! It’s exciting to see an idea become a reality, a step at a time. 💥

[@jasonmcbride2737]

Love your main board layout and spacing. Really clean and looking great!

[@fiddlix]

Incredibly neat and logical layout and workmanship.

[@robertbozic4692]

Great stuff Lyle. Can’t wait to hear it.

[@markarita3]

Even the birds are pleased!

[@darrylgodfrey9604]

I just caught up with this video. What a gorgeous looking amp - you almost need a transparent top and mount it on top of a cabinet! No surprise that you took the smart decision to use radial caps - good grief the axial ones are getting hard to find! I'm reduced to using IC caps 😞

[@musherX]

I love your videos. I found a god of the amp nerd world. I'm so happy.

[@ridiculouswonk2135]

Following this project has been great! I’m learning so much about amp design and can’t wait to hear how this masterpiece sounds. I love your approach to design, based on real life experience repairing others’ design mistakes. Now to just talk my wife into another amp…

[@ja2306]

Wow that looks beautiful! Fantastic work. Next time I’m in the market for an amp I’ll be reaching out!

[@phildfisher]

Lyle, your layout design is excellent. Thanks for sharing your years of experience .... really enjoying your videos. I'm interested to see how the multi-point grounding to chassis turns out. I saw something similar in the Chris Stapleton edition of the Brownface Princeton. Keep up the great work, great videos and the playing 👍

[@chokkan7]

Another beautifully executed presentation...I had a satori while watching. I've twisted my heater wires, routed them carefully, utilized the two 100 ohm resistors, and elevated the voltage thereof in conjunction with the 6.3V CT (which I learned from RobRob...tip o' the hat) for years...and it never occurred to me until watching this that the twisting had therefore been rendered redundant...doh!

[@mamulcahy]

Bravo! Can’t wait to hear it.

[@paulholmes8885]

Looks like a work of art......l wonder what it will sound like???

[@PsionicAudio]

Thanks! See the later videos. And another coming soon.

[@jancreighton]

this is just fantastic - love it!

[@goodun2974]

Glad to see you didn't harm the spider. That was Charlotte; can Boris be far behind? PS, That's a lot of bird song and chatter taking place behind you. I would expect you'd be making this video in an air conditioned space with no open windows. I would expect Memphis to be pretty swampy this time of the year. It is definitely swampy here in Southern New England! Buggy too, gnats and deerflies, oh my....

[@edwardhannigan6324]

Lyle, you need to stop that..! It's a thing of beauty and my guitar needs to be plugged into it when finished..!! Say nothing, I'll give you my address..Just send it..! Stop tormenting us....Ed..uk..😀

[@nickdevriese]

I’ve been looking for a Vox-ish amp. Looking forward to see the final outcome. Looking good!

[@goodun2974]

Re: Pentode preamp circuits: Lyle, have you ever worked with 5879 tubes? Somewhat similar to EF86 but lower gain and a different pin out if I recall. They were fairly common as mic preamps in paging amplifiers and apparently there were a couple of Gibson amps that use them as well. I've got this massive and beautiful Webster PA amp with 4) 5879 tubes which might make for a fun conversion project into a guitar amp. When I say massive I mean it, and the knobs are very similar to the Vox Pacemaker knobs, only about twice the size! Anyway, NOS, 5879's are relatively inexpensive these days, probably a 5th or even a 10th of what an EF86 goes for.

[@efsglass]

SUPER RAD!!!

[@IL2TXGunslinger]

Lyle, when are we going to be able to get on, what I’m sure will be a long list for these Excalibur’s? Deposit ready ;)

[@PsionicAudio]

Working out the prices in the next day or two now that I have the last variables nailed down.

[@IL2TXGunslinger]

@@PsionicAudio - Thanks!

[@johnsweda2999]

What wires do you use I never see any shielded wires in the audio path ? ever thought about using silver in teflon sheath not expensive

[@goodun2974]

At 2:00, that DPST Carling switch could be wired with contacts in parallel for the US market, for greater current handling at turn-on ---- since the amp will draw twice as much current at 120VAC compared to 240VAC, and the inductive surge will be greater at turn-on.

[@jimnanos1624]

Do have any interest in working on a Gibson GA 400? There are three channels to work with and a compressor. It functions but very quiet. I know alot of techs hate working on them but it needs serious help. If have a tech who could put it back to normal but with three channels it could be an opportunity to make some changes to two channels. They are not popular so it could be a sleeping giant. 6550 in the output. It was like thunder back when I played big rooms. Thank you for your fine approach and respect for these antiques.

[@gerrickreidenbach8147]

Lyle, thanks for the video, the design looks to be coming along nicely. Are the two 8 ohm speaker connections to be used with either a single 8 ohm cab plugged into just one and two 16 ohm cabs plugged into both? Are there any other combinations possible? And what is your perspective on mismatching the connections with this design?

[@PsionicAudio]

One 8 ohm load or two 16ohm loads. I've decided that future ones will have a switch to go between 8 and 16 with a main jack (shorting) and an aux jack. Less room for user error that way. This OT can handle a mismatch fine,, so you could use a 4 ohm load using the 8 ohm setting.

[@halhawkins7641]

Beautimus!!!

[@JB-68]

Amazing job Guy :-) Not just a great job, it's also beautifull ! This black board and turret Technic are so neat ! Could you please give us some references for these knobs ?

[@PsionicAudio]

They have them at Small Bear Electronics.

[@russellhltn1396]

Is the capacitance shielded cable adds any issue? I know it's small, but this is a higher impedance circuit.

[@PsionicAudio]

Not with the right shielded cable and such short runs. Real but negligible (ie, measurable but not audible, unlike the noise that unshielded grids can pick up).

[@donclemons6802]

HA! A "The Count" reference!

[@paul.h.h]

Dear Lyle, I’d like to ask about the Excalibre’s output transformer please. Quite a few companies provide 6K for an AC15 OT, whereas I’d have expected 8K from the data sheet. (I believe the Marshall 18watt 1974 circuit uses 8K). What impedance have you chosen for the primary winding, and any thoughts on why?

[@PsionicAudio]

6 point something. I have it written down somewhere. It's a measurement taken from a '60 Woden IIRC.

[@paul.h.h]

@@PsionicAudio Thank you. It’s really interesting to hear about the choices you are making, and there is something very satisfying about watching a craftsman care about their work. All the best (from the UK), Paul.

[@russellesimonetta3835]

Uhhh , what brand of coupling caps are you using???? Like your radial cap mounting. Are they Vishay???

[@PsionicAudio]

Vishay MKT1813s. And thanks!

[@russellesimonetta3835]

@@PsionicAudio yeah I think vishay bought out mullard and they manufacture to that spec and are high guality. Umm, your critique of mojo chassis. Marshall amp diehards say that the chassis that Nik at Ceriatone builds up are the most accurate. I'm an hobbyist but spent 30 years playing next to vintage Fender, Marshall and Vox eguipment when it was brand new or just slightly used! I was a pro drummer that spent his youth in clubs and roadhouses , big bands , show bands ,,, anything that came along.

[@seanmckenna228]

Are you still making these?

[@JRFarmercom]

So that normal channel... the 2 sides of the 12ax7 are wired in parallel. You had a spare triode, so it cost nothing to do it, but what are the benefits of this approach? And this option is only possible if you get the EF86+Normal channels?

[@JRFarmercom]

I think I've seen the parallel triodes on a few Matchless schematics.

[@PsionicAudio]

Makes for a slightly lower noise floor. Still sounds like it ought to, though it will have a little more gain as it will drive the load better. I can adjust as needed once I fire it up. The little bit more gain might be just the ticket.

[@Rufko]

Hi Lyle, long time passed since you posted this last video update on the Excalibre 15 amp. Where is this project stuck now? Give us some update please. Thanks

[@PsionicAudio]

Well, there were a lot of videos after this one But it's's been a long nightmare getting the new panels, which are supposed to be here later this week. I hope. The first batch was stolen in the mail two months ago and my panel guy had some health issues. Trust me, I'm just as frustrated. At least. Once they arrive I can finish the top boost version, at which point people can hear the various channel options. Then I will announce availability (with a behind the scenes discussion with the panel guy - he was always very reliable in the past and I hope he gets back to that now that his health issue has been dealt with. There aren't a lot of laser panel services that will take on small batches).

[@Robert-xn3jb]

Have you set a retail price yet? Great job. I have enjoyed seeing this come to fruition. I am guessing $2250 for amp only….

[@PsionicAudio]

Will have that together in the next 2-3 days. That's a fairly realistic guess for a head. Maybe I can come in under that. Will find out soon.

[@TheStimpy60]

Such beautiful work Lyle. I think I see how this is like the 18 watt Marshall combo kit and how I can avoid the bus wire on the pots. Will there be more ground detail coming - or is this what you were referring to ?

[@PsionicAudio]

This is just a teaser on the ground stuff.

[@TheStimpy60]

@@PsionicAudio - the Allen Hot Fudge kit I’m finishing does the grounds this way, but now I know why and your explanations have taught me so much about that and lead dress- thanks

[@Chuffin_ell]

Ok Mr Psionic, but would you actually tell us if your B+ ~Grounding arrangement turned into a tank circuit when powered?

[@PsionicAudio]

I would. But it won't.

[@oldguy5381]

Is it time for the deposit??? Oh, happy Father’s Day

[@PsionicAudio]

Soon, and thanks!

[@BenState]

Is this amp available Lyle?

[@peterdadswell7998]

Hey Lyle, Ive built a lot of amps and I try my best with lead dress to keep it tidy but this amp is next level tidy as is the layout and this is the prototype so I know that you will make small tweaks on the next ones. As I mentioned, I have built a lot of amps, all kits so I know next to nothing about the tech stuff but I can follow a road map. I have learnt so much watching your videos and gotten to know you and your work ethic. I'm a bit of a fan and just wanted to say thanks. When you do the firing up video of this amp I promise to plug my laptop into a good system to hear it in all its glory. Oh, and hi from Australia...

[@PsionicAudio]

Thanks so much!

[@russellhltn1396]

Can't say as I'm a fan of the half-bright light for mute. Depending on the lighting situation, it would be easy to confuse the indication. I'd suggest using an RGB LED. Red is on, and add Blue when off mute. (Yeah, you could do the same with a red/green LED, but I'm trying to be nice to those with red/green color blindness. Besides, Red/Purple would be cooler.)

[@PsionicAudio]

I'm red/green colorblind. Too difficult to get red and blue to match. Blue tends to be much more directional, even with wider nominal angle LEDs. I promise this will work intuitively.

[@russellhltn1396]

@@PsionicAudio I just have my doubts that brightness will work on both a dark stage and a bright one. It will work once you're used to that stage, but I'd think that at a glance, mute might look like ready on a dark stage and ready would look like mute on a bright one. That's why I'm suggesting a different color or perhaps a second LED. No mistakes there.

[@goodun2974]

@@PsionicAudio , the color spectrum of most blue LED's, combined with their directionality, makes them pretty obnoxious. If you can get LED'S that run more towards the purplish spectrum, they'll be less glaring. Otherwise, you may find yourself using separate lenses or some type of color gel in order to tame them a little. Not specifically applicable for designing a new product as you are doing, but perhaps usefull info for other projects: I have quite a bit of experience at replacing incandescent lamps in vintage stereo equipment with LED's; matching the orangey-white color and cardioid diffusion pattern of incandescents with beamy LED'S can be a real pain, involving a lot of trial and error, as well as a resistor-substitution box for selecting a suitable dropping resistor, and a selection of color gels, reflective aluminum tape and so on. (Sometimes we aimed the LED's sideways, or even backwards, directing the light at a reflective surface, to get better diffusion and a more even backlighting of a radio dial). The electronics suppliers that serve the pinball restoration market usually have a wide variety of LED's in bayonet, fuse-lamp, and hardwire styles with leads, with built-in voltage/ current limiting resistors; unfortunately, they're all made in China, and the pressed-together bayonet-style lamps in particular need modification to be reliable. The bayonet-base lamps with a pair of COB ("chip on board") LED's that are mounted on elevated wires like a crabs' eyestalks are particularly useful because you can twist the wires and aim the light at an angle.

[@lowdownfender]

Hmm filters for bird noise ? 😜

[@deanallen927]

Is this an original design or a take off on something?

[@PsionicAudio]

What is an original design? I've never seen anything much done in amps that wasn't shown or implied in the RCA and Westinghouse tube books of the '40s. Vox and Marshall copied late '50s Fenders with a few other borrowed bits in Vox's case - are Marshalls and Voxes "original" designs? It's really a matter of degree, not of kind. In this case I am very much using the '60 AC15 as a starting point, with aspects of the '62 and '63 AC30 circuit added as desired by the owner But putting these building blocks together intelligently is where I have actual design elements in the final circuit. Not to mention layout considerations. This is not a "kit build" and a buyer would be purchasing 30 years' worth of experience in making great sounding reliable rugged amps as much as the circuit itself. To my mind, the build and the circuit and the sound are all the same thing. Get one aspect wrong and the whole castle washes away...

[@deanallen927]

@@PsionicAudio Yes I know none are REALLY original - it's been said the first Champ was peeled right out of the RCA manual in full form. I was just trying to find what it might sound like after you finished it. But using the manual as a spring board people did things that to me qualify as, for all intents and purposes original like the 2204, Boogie MK I, simul-class amps and others. My Dr. Z has stuff that's at least new to me: Preamp is 12AX7 + tone stack + EF86, power section is longtail driver with four EL 84s class A/B cathode bias which, if not new, you don't hear about much. Sounds very unique. AND WONDERFUL.

[@PsionicAudio]

I'm glad you like the Dr Z, but the power section you describe is every AC30 ever made.

[@deanallen927]

@@PsionicAudio Everybody always says those are class A?

[@PsionicAudio]

They aren't. Class A/B. Your Z has the exact same output section. www.aikenamps.com/is-the-vox-ac-30-really-class-a

[@sharkair2839]

this is based off a vox?

[@PsionicAudio]

Yes. kzbin.info/www/bejne/nJ-ThKKpj8yFhpY

[@russellhltn1396]

So, how does one pronounce "Psionic"? I don't know as I've heard you say that. I'd suggest setting the standard before someone calls it "piss-sonic".

[@PsionicAudio]

Greek. Sigh-on-ic. kzbin.info/www/bejne/Y2PCdH14ptOUi9U