Psionic Audio Excalibre 15 | Big Progress Report

[@PsionicAudio]

Dammit, I forgot to show the two images showing the alignment between the tube sockets and the final boards vs this first board. I'll add those photos in a post rather than a video. Look on this page - I think under "Community" or some noninutitive name. I'll do that now.

[@JRFarmercom]

Link for convenience kzbin.infoUgxPSsveiHJuQ0GWlq14AaABCQ

[@PsionicAudio]

Just realized I said the radial electrolytics here are Nichicons, but they'rere actually Panasonics. The 105 C 10,000 hour specs are correct. Sorry, brain fart, confused my really good capacitors.

[@goodun2974]

Panasonic makes excellent electrolytics. Its impossible to know how many I've installed in the past 15 years but it's many thousands; every time I refurbished a 1970's stereo receiver like a Pioneer, Marantz, Sansui etc I'd typically install 30 or 40 new Panasonic electrolytic caps. I did have just one defective, open, brand- new Panasonic cap. I've also blown up a few small caps by installing them backwards!

[@jancreighton]

wow, this is really shaping up - this circuit isn't being designed, it's being sculpted! - nice.

[@barbmelle3136]

From Leo: Your attention to even the smallest detail is amazing, and usually unseen even in premium gear. I applaud your work.

[@shanedolman1368]

Looking great Lyle! Its gonna be one of those amps that as a service tech you open and think this is going to be a joy to work on. Though that's something that probably wont happen for 15 years or so! Dont know if you're anything like me but when I build an amp it never quite turns out exactly like I imagined it would, theres always something I can do better next time. I am definitely learning a lot from your layouts and from your choice of parts. Thank you so much for sharing this👍🖖

[@PsionicAudio]

Thanks man! I'm never 100% satisfied with anything I do, but I've done minor service in amps I did 10-15 years ago and was ok with the choices I made then, though I would do some stuff differently today. This first build will make subsequent ones easier to do. Not just big things like knowing the actual hole layout in the chassis now but things like doing the beneath the board wiring here let me see a more efficient way to do the next ones. Or changing the order of the Colour and Level pots will make the wiring shorter and easier. Designing a circuit is one thing; making it efficiently is a different skill set, and the right approach can vary from design to design. My real preference would be to do these with really high quality PCBs, which would allow me to reduce labor/price by a lot and lock in the exact right lead dress, etc. But PCBs are expensive in low quantities and there is the perception of them being inferior that I'd have to fight. But it's all in the attention to details. Taking the time to read and having the ability to understand datasheets is crucial. Meanwhile the market is flooded with sub-par kit builds and hunks of junk that get glowing reviews. It can be discouraging.

[@Toymortal]

Really enjoying your excellent videos. It's a pleasure to see someone who passionately cares about the design, build quality and component choices in a guitar amp - and who has the knowledge and personal experience to back those choices up! Some great information here regarding capacitor choices, and busting some myths. If I wasn't totally flat broke I would be pestering you for an amp in a heartbeat! Wishing you all the best for Psionic - from here in the UK.

[@matthewf1979]

Looking great Lyle! I like those radial Panasonic caps in the signal path. Perfect replacement for tropical fish caps.

[@PsionicAudio]

I like them too, and if the Vishays become unobtainable they will be my choice. Really good sounding polyesters.

[@kentjackson3830]

Thought I'd look through your uploads and see if there was any news on the Excalibre. Not new but I guess I missed this one.Beautiful work! Hope to be a customer when you make these available. Saw you on Tone Talk, very enjoyable episode. Hoping you had several productive conversations with Dave later pertaining to chassis/parts supply and the like. Decided treat myself to one of Daves Little Sister amps. technically a Christmas present from the wife that i'm not allowed to even open until Christmas morning. After watching your Runt video I felt confident that it would be a quality piece of gear. So appreciative that you and Dave choose to share all this information. Really, Thank you.

[@Sioux177]

As always, the most interesting tech audio videos. Staying tuned!

[@halhawkins7641]

On the first Psionic Audio T-shirt...."I've tested my assumptions". Then the Psionic Audio name/logo....

[@weschilton]

This is really looking great, Lyle. Its clear that you have definitely put a lot of thought into it. I really find it interesting hearing the reasoning behind all of your choices!

[@halhawkins7641]

Your attention to detail is awesome!

[@paulholmes8885]

Mate, l want one. I don't care if l can't afford it.....a work of art!!!

[@Irkin_Bollikans]

I use the belton spring style retainers for anything with el84s. Same ones found in the Epiphone valve junior. Thanks again for the time you put into your channel

[@PsionicAudio]

Thanks. I find the Belton spring clamps to be overkill. I don't like that much pressure from metal against glass.

[@peterburi2727]

If you could find them Viton is more resistant to heat than neoprine. Just food for thought in the future. Very nice job a masterpiece.

[@astr0brain]

Can't wait for the grounding videos! I'm planning on laying out my amp again so I'll wait for the videos before doing the grounding

[@daviddaniels6473]

I'm praying for the day you decide to build a gig-able bass amp! That should be Amazing!!

[@edwardhannigan6324]

Just lookin' Fab..! Perfect fabrication and attention to detail..Could never afford it, but I'd love it when finished..! Ed..uk..😀

[@markarita3]

Coming along nice. 16:14 A true blind test in my opinion is always (and should always be) the real test for sure. It's so easy to "let" yourself be influenced by other factors. Btw, your soldering is bordering on jewelry level.

[@dennisflock3958]

Looks fantastic!

[@lionscircle4700]

Thanks for the walk through, that was amazing! I've seen vox use the ef86 as v1 but more recently they went to 12ax7 on the reissue amp so I thought maybe it had become a tube of the past like the 5u4.

[@PsionicAudio]

EH is still making one and there are still a lot of NOS for reasonable prices, but it is a specialty tube that needs to be babied. When people want one, I will explain the cons as well as the pros.

[@lonniezamarripa959]

Looks great!

[@kbkman7742]

Looks awesome

[@jonnybeck6723]

Don't EF86's have internal shields, and do designers sometimes decide not to use them? * Enjoying your vids. Might I venture to say you're in a class w/ the GREAT Uncle Doug? *1 more minute and you answered (for Pete's sake)

[@ernestobarechesto1541]

Awesome work as always, looking forward to seeing it complete. Question: Turret board is ultra clean wired but you apparently don't do milspec wiring - putting strain relief bends on all the component leads. There are whole government manuals with all the minutia (as would be expected). We're obviously not putting this in the space shuttle but would still be interested in your opinions . . . .

[@PsionicAudio]

Full milspec would buy us nothing here except a much more expensive amp. These are low mass components and there will be no strain as I have implemented the soldering. I'm building better than Marshall or HiWatt in their heydays. I think that should suffice. This is a very high quality amp, but it will never have to deal with what an F18 goes through. ;)

[@PeachEater81]

What is the model on the film caps? I scanned the comments, but didn't see it mentioned. Thanks for the videos! Also, I've been building pedals with ELNA Silmic II electrolytics, great sounding radial caps available at MOUSER. Update: it looks like a Vishay MKT1813 series, which is polyester film? What are your thoughts between Polypropylene and polyester? I've found that the polypropylene seem to have more bandwidth, maybe more hifi than polyester....

[@voxpathfinder15r]

In the future there won’t be any through hole components, smd makes me really sad. Although they have been saying tubes would be extinct for the last 40 years. Great build. A Chicago transformer company went out of business last year, they were a great source of aftermarket transformers. I had to race to grab up one of the last two they made for the jcm2000 with extra plates I need to complete my Kustom ‘72 Coupe amplifier. And I absolutely had no budget to buy it, but if I didn’t buy it - I would have been stuck with an amp project forever without parts to complete it. I think the future is sad for guitar amplifiers

[@ernestobarechesto1541]

Alas, ClassicTone shuttering was a loss but I would expect Hammond, MojoTone and others to see an increase in sales because of this. I would expect all but the most arcane and unusual iron to continue to be available as long as there's a market for them.

[@voxpathfinder15r]

@@ernestobarechesto1541 true but wasn’t magnetic components an old company with great history? If they can go out of business, why not another company?

[@goodun2974]

Aren't Nitrile O-rings and grommets supposed to be more resistant to heat, grease and solvents than Neoprene? And what about Silicone grommets? By the way, just a cautionary note for everyone here: ordinary hardware store grommets, gaskets and such might not be the best choice; I have some rubber stoppers from True Value, and I used to cork a small bottle of white vinegar ---- the rubber stopper swelled so much that I could barely get it out of the bottle. I suspect it's actually a latex compound. (Vinegar is really good for foaming away battery-compartment leakage and corrosion, BTW).

[@jacobbockover1628]

Didnt know about this. So you will be selling these one day?

[@chokkan7]

Beautiful layout and execution, as we've all come to expect. I do have a question: I'm unfamiliar with the neoprene grommets such as you use under the nuts, and have been using a 3/4" neoprene O-ring for the same purpose with good results...is one method superior to the other? I have a bag that will last me, but I'm always open to improvement...

[@PsionicAudio]

The grommets let you isolate the mounting hardware from the chassis too.

[@megwatts1903]

Amp porn. I'm eagerly anticipating the "money shot".

[@justovision]

When you say these "carbon film resistors sound great" what do you mean?

[@PeachEater81]

What brand are the 1/2w carbon film resistors? Thanks

[@PsionicAudio]

Koa Speer

[@PeachEater81]

@@PsionicAudio thanks. I read further down and saw that you had already answered that. I've been using those resistors and the wmf cde caps. They are pricey, but cheaper than the Jupiter's. They are the only film and foil polyester axial caps on mouser. The 1813's and m150's sound good too. Thanks for your videos. I watch all of them

[@jonnybeck6723]

Please forgive this critique but do you think a bigger fancier indicator light is not only cool looking (IMHO) but could maybe help as a reminder, not to leave precious custom amp on when not in use (?)

[@PsionicAudio]

Wait until you see the real thing. I'm using a fresnel lens which will make it seem bigger than it is. And you will never have to replace a bulb this way.

[@frostedhead]

Is there a reason why many amp companies don't hard wire in the AC cord?

[@PsionicAudio]

Yes. Different countries use different plugs. The IEC stands for International Electrotechnical Commission.

[@viktor86bt]

Sweet. Are those resistors Xicon? Are all the brands on Mouser good, or are there any to stay away from. TE, KOA Speer, Yageo? Thanks

[@PsionicAudio]

These are Koa Speers. All the brands are good, but read the data sheets to make sure you have the right resistors for your application.

[@JRFarmercom]

Is "Colour" just a creative name for the hi cut, or is it doing something unique?

[@PsionicAudio]

It's the high cut circuit but will be wired so that clockwise=brighter.

[@diegocastro5114]

What is the brand of the radial eletrolítics? And what you think about non eletrolitc cathode bypass on preamp?

[@PsionicAudio]

Nichicons. Film are great for smaller values. I've learned not to trust tantalums.

[@oldguy5381]

You could put a hour meter on board. I don’t think I have ever seen on a amp. Is this possible? Or would it cause some noise? At that, would it even be helpful to a technician? I guess I’m thinking to hard. Can’t wait.

[@PsionicAudio]

It would make fly dates really difficult with no upside.

[@goodun2974]

@@PsionicAudio, In another comment a while back I may have mentioned some Chinese built Hurricane hifi amps with *eight* 6550 output tubes per monoblock that I've repaired a few times for one of them "golden-eared audio-fools". The ONLY thing I like about these amplifiers is that they have individual, user-adjustable bias pots for each tube, a digital display, and an 8 position switch to select V1 thru V8. Very easy for the owner to adjust, and periodically check, the bias on each tube, and to spot a tube that is weak, acting flaky or in danger of going into thermal runaway. Just adjust bias pots so that the meter reads 480 millivolts across the individual 10 ohm cathode resistors, which equals 48 ma total plate/screen current). I bet some players would appreciate that sort of feature. How much it would increase the cost of the amp is another matter....

[@shckltnebay]

@@goodun2974 This is a cathode biased amp

[@goodun2974]

@@shckltnebay , ah yes; I was thinking more about the Marshall-style amp that Lyle has been planning. What I described is still possible with cathode-biased amps, for monitoring the current externally (add a 1 ohm or 10 ohm resistor in series with the main cathode resistor, and measure across that additional resistor, with a built-in meter or external test points for your own meter), but overall it makes more sense for a fixed bias amp.

[@shckltnebay]

Whats the best choice el84 for a 1964 AC15?

[@PsionicAudio]

Current production? Tube Store Preferred Series 7189s. NOS? More about the trusted vendor than Mullard vs Brimar etc.

[@shckltnebay]

@@PsionicAudio Thanks was looking a Matched Pair (2) Genalex EL84 Reissues, also is really worth nos? Im starting to think what really matters is input tubes, transformers and speakers

[@PsionicAudio]

NOS isn't worth it unless the amp will always stay in a really nice studio. Otherwise you're spending a ton more for differences that won't be heard in most clubs. And it makes potholes very expensive. Genelex isn't worth the upcharge. It's just a rebranded something else. Same for Gold Lion, Groove Tubes, Ruby, and many others.

[@shckltnebay]

@@PsionicAudio Thanks

[@johnsweda2999]

Claritycap make axial and their replacement electrolytics for film capacitors are good. so does alcap axial I think that's a bit misleading don't operate the amplifier, it should say do not turn on amplifier without speaker connections. It's not very clear the way it's worded to somebody who doesn't know what it means!

[@mergatroid1212]

I can't understand the whole freak out about capacitors, why are guitar player so special? Almost all amp building/repair videos on KZbin talk about caps as if they are something ultra special? it is an electronic component, it has a life span, they do not last forever, when they fail they need to be replaced, they have no sound they do a job based on their measurements. The old caps where made of basic materials, paper and oil all rolled up in a plastic tube, painted in pretty colours and given cute nick names "Bumble Bee" for example .........wow! All Nichicon has to do is paint their caps in pretty colours and give them cute nick names too and every guitar player will fall in love with them, then we can get on with what is really important, playing good tunes! Paint them in a red and white twisted stripe like a candy cane lolly pop and call them "Candy Stripe Caps" everyone will want them! Or paint them in a black and metallic blue like the blue monarch butterfly and call them "The Butterfly Effect Caps". They will make any amp sing!

[@PsionicAudio]

I think you and I are saying much the same thing. I chose the Vishay MKT1813s here because they are inexpensive, reliable, low mass, have thick leads, and sound great. All pragmatic reasons, no "mojo" mumbojumbo...

[@goodun2974]

"I like low profile"..... but, but, you have a KZbin channel and your subscriber and viewer numbers are increasing....🤔