A Commodore 64 with… vacuum tubes? Introducing the Evo64!

A brand new, high-end audiophile-oriented C64 replica - features reviewed + build + test.
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Mitch Hoffman
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William Sullivan
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FULLSET
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Joshua C. Forest
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James Taylor
00:00 Introduction
00:48 Unboxing
02:34 Project Overview and History
04:16 Features - Dual SIDs and Audio Design
05:50 Features - NuTube64
06:29 Features - Triode64
06:58 Features - ClearVideo64c and Video Design
07:33 Features - Multi-ROM
08:08 Features - QAPLA
08:50 Features - ESD Protection
09:11 Building the Evo64
14:43 Configuring the Evo64
19:09 Installing in a Transparent 64C Case
24:19 First Power On
24:52 Testing - ROMs and Cartridge Images
27:56 Testing - Adjusting the Video
29:20 Switching NTSC to PAL
30:22 Stereo Output Options
32:05 Testing - Dual SIDs with NuTube64
35:30 Triode64 Requirements
36:02 Costs
37:07 Conclusion
*Retro Bits earns money from Amazon and eBay Partner Links

[@C64EVO]

As a quick follow up to Matt and the Retrobits team, we've made solid progress with the Triode64 and it's Toroidal Power supply. kzbin.info/www/bejne/nZvLh6x-ea2porc

[@retrobitstv]

Thanks for the update Darrell! Please feel free to use this pinned comment to keep us all informed about the status of the project :)

[@C64EVO]

Updated May 6th 2023: Latest testing video of the near production-ready Triode64 module kzbin.info/www/bejne/bajYh4GcgKmMjtk

[@nyccollin]

@@retrobitstv​​⁠2 mins in and already liking it much more than 8-bit guy’s review.

[@zap2002]

Thousand bucks?! Holy guacamole, that's whole lot of dip. Nice setup though.

[@jowi_24seven43]

Frankensteins monster of C64. Total extravaganza overload. I don't see the appeal especially as you still need to sacrifice original chips. Agreed it looks good raw but who will see it under the bread box (clear plastic cases have never looked good to me)

[@rutabagasteu]

I thought it would be 2 grand.

[@C64EVO]

​@@jowi_24seven43 If you can imagine what a standard C64 Assembly 250407 might looks like with all of the add-ons and modules it would require to come even close to the feature set of the EVO, then you'd be right to call that a Frankenstein's monster. By fully integrating every feature directly into the main board, EVO is actually the opposite of that.

[@tonyfremont]

An original 64 was $600 with no accessories. A serial SSSD floppy drive was almost $400. In the early 80s, that was a big pile of money for a "toy".

[@Carstuff111]

Oh wow.... SID music in stereo is such a HUGE upgrade! This is glorious! I think stereo SID music just transformed this system for me. And that is just through KZbin!

[@angieandretti]

I'm not a Commodore enthusiast but this board is truly amazing and beautiful! I wonder when the retro community will get to the point of producing something of this quality with upgrades along ever facet of the hardware, but targeting Win98 enthusiasts! Can you imagine a brand-new Slot 1 PC motherboard built on this philosophy?! The potential is there for something mind-blowing!

[@auro1999]

thanks !

[@rarararararara9673]

Holy Schmoly the audio sounds incredible!!

[@VicGreenBitcoin]

This is so Cool! I love that the C64 is still there today! I still remember using my C64, hooked up to a CB Radio and with my own program I could send messages to my friend (No packet Radio, but my own homebrew), like a early MSN or What`s app.

[@xXTheoLinuxXx]

That is cool! I remember Digicom (packetradio for the C64). Back in the day a friend of mine worked with it, and I had Amicom at the Amiga :)

[@Um...Yep.]

32:06 Wow! It sounds rad! Thank you very much for sharing this tubular SID stereosucculence.

[@daghtus]

Popeye is my favorite game on C64. Thumbs up from Slovakia.

[@danield.7359]

I'm blown away by the sound quality.

[@auro1999]

thanks !

[@aphexteknol]

Great to see the Evo64 finally running. Love this sort of insanely over-the-top mods and upgrades in a C64 board. And glad I was able to help out even a tiny bit. :)

[@retrobitstv]

Thanks again for your help with this project Mitchell!

[@lucasrem]

Help, why they needed help ? What are you running on these CMOS emulators, Sound ? Creative ?

[@leesmithsworkshop]

Absolutely amazing board they have made and a great video to show it off.

[@retrobitstv]

It really is a beautiful thing!

[@UNSCPILOT]

As someone with a Vacume tube Amp attached to my PC for headphones, this is a fun idea, mixing and matching different eras of tech can have some fascinating results

[@auro1999]

it was a fun experiment ! and when I made it work, and called wife to listen, she said. WOWOWOWOWOW

[@paulstubbs7678]

Not sure what you did with your audio, but as soon as you started it it really stood out here. "Hello other KZbin channels, this is how to do C64 audio"

[@retrobitstv]

No effects were applied to the audio, it was recorded directly from the Evo64! The only thing I did was choose SID music that really demonstrated the capabilities of the stereo 8580s and the NuTube64 :)

[@lucasrem]

SID needs to be on emulation, not simulating it. so apps you run on it, see it as a native system. Why you use the audio chips on them ???

[@BearMeat4Dinner]

Dude this made me cry. Sounds great 👍👍👍

[@exidy-yt]

Dude....I am so friggin jealous of you right now. What an amazing piece of kit, and that transparent case displaying it and the VFTs in that amplifier module is just....(chef's kiss) c'est magnifique! Thank the company for providing it to you and thank you for sharing this glory with us!

[@auro1999]

C64 with tubes and Jfets.

[@jouniko]

23:34 Those translucent keycaps look coool. I like the old keys too, but not in a transparent case.

[@ChristopherNelson2k]

So full of wow, I'm watching this for a second time!

[@G.Yam74]

Man that sounds really clean....

[@MartinGalway]

DROOL 🤩 that sounded great!

[@computer_toucher]

"Vacuum Tubes" and "Audiophile" always go hand-in-hand, strangely enough. Gimme that sweet, distorted signal that /should/ be incompatible with getting the purest representation of an audio signal. Class D amps outperform any tube but we can't have that. Some even believe the /network cable/ has something to do with the quality of a digital bitstream. You can't fight stupid. Tube are cool though. If run within spec (for music amps) or blasted to hell (for instruments lol). They glow, and look awesome. And this board looks super nice. Also since they say "to add warmth and character to your SID music" which also clicks good with the SID being an analogue chip too. I get that :)

[@pauldeane8369]

Great review! That's one sexy C64 mobo! I've refrained from any of the remake boards in favour of the originals, but this just might be the one I splurge on. Thanks!

[@nyccollin]

⁠​⁠2 mins in and already liking it much more than 8-bit guy’s review.

[@retrobitstv]

I don't feel like he gave the audio subsystem a full and proper workout. For those who are interested, check out some of the FLAC recordings I made with the stereo Evo64+NuTube64 here: retrobits.tv/Evo64_SID_Demo.zip

[@petergillott3005]

That board would look so nice in a Plexilaser case with LED's fitted.

[@retrobitstv]

That would definitely show it off better. The 64C case isn't really clear at all and has a lot of features that obstruct the view.

[@HelloKittyFanMan]

Oh wow, and then there really is the old-style, traditionally shaped tube setup that wasn't just a mock-up for an interesting thumbnail! I had no idea that there would be such a difference in audio quality from something that's just 8 bits worth of technology, as well as people with overengineered ears and preferences that they'd be this much "-phile" about it!

[@c64os]

I just noticed (time index: 21:37) that the joystick ports have nice through-hole for internal access to the joystick lines. This is very nice. I wish Ulltimate64 had these, because I want to internally mount a MicroMys adapter putting the PS/2 port for mouse in the side of the case, closer to the front than control port 1. And leave control port 1 open for a joystick to be connected at the same time. That'd be easy with this board!

[@MD_il_microcanale]

fantastic! this is proven proof that the Commodore 64 never dies!

[@lucasrem]

Why you need them, running what on them ? Amiga i repair for creative people, never needed a C64 ! Why he called it COOL, how mad nedry they are !

[@mosquitobight]

I remember reading Compute! magazine. Before magazines came packaged with a disk, there was actually free software in the back pages in the form of a text listing of machine language code which you had to type into your computer byte by byte and save to floppy disk. I only had the time and patience to type in a couple of those. I wonder how many other people bothered.

[@petercortens6019]

Gorgeous! I know what my mancave is missing now, thanks!

[@lucasrem]

the soldering or the load music ? mad here ! Who needs crap simulation ? Russing what on it ???

[@cinocefalo284]

People often forgets that SID and POKEY are Musical instruments (synths) Better amp, better sound. Not replaceable with emulators

[@andrewdupuis1151]

c64 my fav computer of all time

[@Midcon77]

TY so much for this! Lots to consider for my C64 build!

[@retrobitstv]

You're welcome! Lots of options to choose from for sure these days!

[@synthoelectro]

I spy on the shelf in the back, a Tandy Color Computer II, but for now, we'll watch this awesome video.

[@temporarilyoffline]

You had me at vacuum tubes!

[@retrobitstv]

Even though I grew up in the era of the transistor, I am still fascinated by older tech and this was too cool not to review :)

[@paulcattrone3196]

Time to rebuild my mod file collection!

[@Zhixalom]

Simply over-the-top brilliant! - I am however wondering why a dual VIC-II chip option, with the capability to switch between NTSC and PAL on-the-fly, wasn't added. - And my old retro-heart is also screaming out in silence (and likely in vain) for a C128 equivalent.

[@C64EVO]

Having dual VICII chips on the board may be considered for a future board revision.

[@mgas1237]

That was super fun :) I don't really use the half dozen C64's I already have so it may be hard to justify an Evo, bit I think I may 'need' one...

[@CybAtSteam]

I really wish someone would make a transparent breadbin case. I just can't get myself to switching to the flat 64c case.

[@Ryoga-Oneesan]

are you keeping up with the commodore...? coz' the commodore keeping up with you.... 🎵🎶 .... old, but not obselete .... 😊😊❤️

[@pvc988]

I like those miniature ZIF sockets.

[@RacerX-]

That is quite awesome. I have been digging my ICS64S and this will be a great addition.

[@lucasrem]

What you run on them, creative apps ???

[@lochinvar00465]

I have a C128D and love it but this is definitely on my wishlist. Beautiful build! I wold love to see this running on my desk.

[@Kw1161]

Beautiful circuit board and setup, but I thought they were going recreate the first Univac computer hooked up to a C64 clone…😅. Great Video, have a Happy New Year 🎉!

[@retrobitstv]

Thanks, you too!

[@colinsmith6480]

just wow !

[@simonl7784]

That Nutube chip is 'the star of the show' on this board and looks all wonky.. Considering the value of this luxury item and the enthusiast market it's aiming for, I would have expected a higher level of attention during assembly. Also, the audio hookup with the screw terminals seems out of place. I'm sure they can do better. Thanks for this great video retrobits. Cheers!

[@C64EVO]

Matt is working with a hand-assembled EVO prototype. The final production boards will be assembled professionally as part of the manufacturing process.

[@coyote_den]

Oh yeah. I can for sure hear a difference with the NuTube preamp, even via YT. Might not be so much that it uses tubes as much as the EQ it applies, but being that it's the SID preamp you will get its tone in your capture. I mean, guitarists use tube amps all the time and you can hear it in recordings, right? Like a guitar amp (and unlike audiophile tube amps) using tubes to preamp the SID might actually be doing something. A semiconductor amp is going to clip on a really hot signal from the SID, whereas tubes roll off when they saturate and produce warmer harmonics. You design those amps to have some distortion when the gain is turned up because that is the sound you want.

[@retrobitstv]

Fair point. If you play back the capture on good hardware you should hopefully get a sense of what it sounds like compared to a stock 64. I'm sure lots of people are watching YT on their phones as well though. I still need to try adjusting the pots on the NuTube to fiddle with the harmonics and see/hear what's possible there.

[@KRAFTWERK2K6]

Yup, the soft clipping and distortion from a analog amp that uses Tubes in the signal path (either for amplification itself or just as a audio-buffer pass-through) will always beat a solid-state amplifier. Because of the way the sound is transformed into electrons in the tubes and then caught up inside in a amplified form. That transition is what does the magic to the audio signal.

[@erwindewit4073]

Wow, I AM an audiophile, but wow, after shipping to Europe, this could easily run over 1000 euros for the Nutube (going to research that, never heard of it before). It looks very well made. You still need a case, keyboard, chips and cartridge as well. Bit rich for me, but I'm very happy to see that something like this exists. And I'd SO MUCH like to hear what a dual SID sounds like (Commando f.i.) through the valves... I also wonder why 4 are used 😀 It would be a reason to finally fix and recap my NAD amp though...

[@greenaum]

The Nutubes have a rep for being a bit crappy. Korg couldn't fund their own tube factory, so they got someone to slightly adapt the VFD displays that lots of AV equipment uses. Since VFDs have a vacuum and electrodes, by re-purposing what's there, you get a basic, weird, triode. Some people love them, maybe for the novelty, maybe they like the sound it produces, they were invented for use in Korg's keyboards to give a different sound. That "tube sound" in a tiny space, although synths have not usually been plugged into tube amps, they're more a guitar thing. It's a novelty, and an expensive one. Audiophiles are the people it's designed to syphon money from, and why not? Stops them buying special bits of rock to put near their turntables. Literal bits of rock. Audiophile rock. Enhances the stero field and makes individual instruments sound clearer. But it's a polished rock. Stops them using solid silver mains cables, neglecting the 99,000 miles of aluminium cable between their house and the power station. They are silly people who may be suffering from obsessive-compulsive disorder. Or maybe just having too much money. 4 triodes are used, maybe it's a Class B, and is stereo. Maybe the commonly available tube they chose doesn't make a suitable amp with just one. One day I'll make a Class D amp with triode outputs, and sell if for a ton of money to idiots.

[@erwindewit4073]

@@greenaum Wow, that shows great disdain towards the NuTube and the audiophile community at the same time. You must feel quite superior I guess. Perhaps the most silly person is the grumpy old man complaining (but never trying anything really). Who perhaps doesn't have 'too much money'. But it shows disdain to the creator too. So please keep your vile to yourself and keep things positive here.

[@greenaum]

@@erwindewit4073 I don't lack for life experiences, but I've missed out on silver mains cables and magic stereo-field enhancing turntable rocks. You're right, I couldn't afford them, but what's important is that I wouldn't buy them if I could. Though I've been experimenting recently and have found the most amazing beans. They actually smooth those awful steps between the bits of a CD player! Other people would use a filter of course, but my beans cost $10,000 so they must be good. To you, $11,000 to make them sound even better. I'm afraid I am superior to complete idiots who piss away tons of money on nothing. Seriously, who would be fucking stupid enough to buy a ROCK to improve their stereo? EVERYBODY is superior to "audiophiles". They're the second-worst kind of phile. Maybe you know that, secretly, and that's why you make pissy defensive comments on KZbin. Also I think you meant "bile". Or else "vile comments". Never mind, put on some classical music and see if you can count the instruments.

[@erwindewit4073]

@@greenaum haha, you just sound like a sad grumpy grandpa.. Raging against the world.

[@erwindewit4073]

@@greenaum Oh, thanks. English is not my primary language, didn’t know it was ‘bile’. I love language though.. Oh, and the only people with rocks like that that I ever met were the more new age types. If they believe in them, good for them. But the anger inside you isn’t healthy though. Perhaps you should talk to someone about that. In stead of raging against the world. Why do you care so much if anyone spends their money on things YOU don’t believe in? Still, as a scientist, if you don’t REALLY try, you really know nothing. Maybe, just maybe, all those people aren’t stupid after all… None the less, anger is clearly eating you alive, so do yourself a favour..

[@Xoferif]

Not seen that style of ZIF socket before. Neat!

[@arcanescroll]

That caught my eye as well, I might pick some up for one of my 128's. Having a ZIF 128 would be fun and "normal" ZIF sockets are too wide. Looks like they are available from a few places.

[@auro1999]

ARIES low profile.

[@lucasrem]

ZIF you can do on any chip, remove it, any chip you can ! Why you need that ?????

[@lucasrem]

@@arcanescroll any socket can you replace by Ziff solutions ! Why you need that ?????

[@arcanescroll]

@@lucasrem I'm not quite sure what you are asking. If you are asking why I would want ZIF sockets on a motherboard, it makes testing IC's much easier and safer. Constantly prying 40 year old IC's out of sockets isn't exactly the best thing for them.

[@nycdogs]

It takes me back... back in time...

[@deagt3388]

Worth every penny! ;-)

[@auro1999]

thanks

[@C64EVO]

@deagt3388 Sincerely appreciate the sentiment!

[@blackterminal]

Would like to see more vacuum tubes on retro computers. I have some vacuum tube radio's thanks to my Father and the way they glow is so cool.

[@skeggjoldgunnr3167]

I just bored a HUGE hole into the top of my Commodore 64 breadbin. There's a dual-beam tetrode FU32 vacuum tube headphone & powered speakers pre-amp sticking out the top of my C64!

[@tonyfremont]

Most people under 25 couldn't begin to read that beautifully written letter. It may as well be encrypted. Scares the hell out of me.

[@ChrisD4335]

Younger people are capable of reading grandpa, your just scared because the world has left you behind.

[@tonyfremont]

@@ChrisD4335 I don't know where you are, or how old you are, but most US schools haven't been teaching cursive writing for over a decade.

[@asgerms]

It is actually cheaper than I would have thought.

[@KRAFTWERK2K6]

6 Voice Stereo is really how the SID should have always been, if Commodore only had allowed it to happen and not cutting costs. At least NOW we can truly experience it. If only the 8580 wasn't so quiet on the Sample parts. At least in SID Emulation you can add Sample volume boost. Does this feature exist for the hardware SID modding as well?

[@C64EVO]

There are independent gain adjustments for each SID’s output, so you can compensate for any output level differences

[@auro1999]

yes, there are trimmers, BOTH for the transistorized output (1 turn) and for the nutube/triode outputs (25 turns !!). Plenty to make the balance right.

[@KRAFTWERK2K6]

@@C64EVO @Auro Awesome!! :D good to know.

[@erikmolnar6585]

The sound quality has gotten pretty good on youtube. Might not be as good as being there in person, but I believe everyone has that understanding. That being said, I wish you would have included the real audio. I know you had to overdub that audio or I am hugely impressed! Aside from that, does it load Ultima any faster??? Joking

[@retrobitstv]

The SID audio that was demonstrated toward the end of the video was all recorded directly from the Evo64 using either aStartech USB3 capture device or a digital camera with a 1/8" cable that steps down the line level for the mic input.

[@erikmolnar6585]

@@retrobitstv Wow, most certainly heard a difference from what I remember. It's fascinating to see these new builds and interest in the childhood computer I am my friends and family owned.

[@needfortweed8734]

This is such a cool thing. If I had upwards of $1000 to spend, I would get the Evo64, the nutube64 and so forth. But this left me with another itch to scratch; what other things than Korg synths and Ibanez tubescreamers uses the nutube? I must find out. I NEED to find out!

[@CubicleNate]

I do love my vintage technology and the Commodore 64 but I don't think this is for me. I do, however, think this is an amazing project and I hope it's tremendously successful!

[@LynxCarpathica]

Funny. I've been working on an All in one ROM switcher for the C64, just like this, with a 2Mbit EEPROM chip I harversted from a dead motherboard. I'll definietly finish it, as it is definietly very useful

[@lucasrem]

We make new boards now, needed ? running what on them, Audio pro levels ?

[@MrMarianoamigo]

this is madnes!

[@incumbentvinyl9291]

Very impressive.

[@jameslewis2635]

I think I would be tempted to go for the triode 64, but only with a custom case as otherwise you would be drilling holes in the old casings and you would need to add a cage around the valves anyway to avoid them being touched accidentally and possible electric shocks/burns.

[@C64EVO]

We're working with some case manufacturers to come up with a design to showcase the Triode64. Please stay close to project to follow progress...

[@jooch_exe]

Nice video and product. As an audio engineer tubes can be interesting for making music, reproduction however is another thing. When i listen to SID music i usually do emulation and increase the sample rate to 96khz. A lot of people have crap hardware and then the harsh sounds of a SID chip can be fatiguing, this is when people resort to tube setups. A bad thing to do in my opinion, just buy better audio gear.

[@HamsterSnr]

Nice presentation, and very nice board, I am tempted. Where to source those sockets, and where to buy the case, and keycaps ?

[@retrobitstv]

The sockets are ARIES low profile and are available at the usual places like digikey and mouser. The case is from icomp.de and the keycaps are from an Indiegogo campaign but will be available from cbmstuff.com once all backers receive their shipments.

[@michaelsasse8427]

Call me old fashioned, but I like the look of the brown keys. Those blue key caps look a little cheap looking (even if they are not).

[@bozimmerman]

The SID addressing stuff is interesting. Back in the day, the common address choice was $de00, to match the original Stereo SID documentation, as well as the SID Symphony cart from CMD. Some people, however, chose to go with $d700 to keep their cartridge port clear. So, my question: where does $d420 and $d500 come from? Is there some software or hardware that pushed those choices that I just haven't run into?

[@retrobitstv]

Pretty much all the stereo .sid files and demos from PAL regions seem to use $d420 but I am not aware of the reason for this unfortunately. edit: that address also seems to be used by Cynthcart as well.

[@tetsujin_144]

Well the SID itself only actually uses 32 registers (29 actually) but on the C64 the SID gets the whole address range of D400 - D7FF - an entire kilobyte of I/O address space for fewer than 32 registers... On the C64 the first SID is accessible anywhere in that range, so D400 is the same as D420, D500, D760, whatever... So basically the first SID gets way more address space than it needs, so it's kind of a logical place to put a second one without impacting any other functionality. The way the address decoding works is the hardware matches a certain number of bits on the address bus to determine whether the bus activity should be directed to the SID (the highest 4 bits must be 0xD and then the next two lower bits must be 01) and the SID only looks at the bottom 5 bits. A stereo SID mod would monitor one additional bit, either bit 5 (for D420) or bit 8 (for D500) to determine which of the two SIDs to use. Each choice has its own logical merits I guess: D420 puts the two SIDs one after another (over and over again) in RAM, while D500 would put each SID on a different memory page (D4xx for SID 1, D5xx for SID 2, D6xx for SID 1 again...) On the C128 they changed that, the SID is only accessible from D400-D41C, and D500 is actually used for the MMU (which could be a good argument for using D420 for a second SID) I have also heard that there is some software that assumes the SID registers will be accessible over that whole range of memory, and so it'll just keep incrementing the address it uses as it plays sound. In this case D500 might make more sense for the second SID because, if the code only increments the low byte of the address, it'll just keep accessing one of the SIDs, and wrap around when the count overflows (D4FC -> SID 1, D4FF overflows into D400, which is still SID 1) Using D500 may therefore be better for such code that's optimized for a stock C64. D420 could be better for code that accesses both SIDs, since you could access both SIDs on the same memory page. (This is beneficial for certain addressing modes and programming patterns on the 6502)

[@eightsprites]

@@tetsujin_144 Thanks! I never knew how that worked. Now I do. 😊

[@KRAFTWERK2K6]

The optional Tube Amplifier modules are really something. I'm glad to see the Korg NuTubes being used outside of Korg's own products. And the blueish glow really suits the C64 a lot. Unless you prefer the warmer amber glow of the regular Triodes. I wonder if there will be another module that allows you to use inexpensive OpAmps, like the LM4562NA for example. That would be a great solution for those who don't need Tubes. I think i'll look at that project some more. Was thinking about putting together an all new Custom C64 without new old stock parts, except the ones you have on a part donor. So this one here really seems like what i've been looking for.

[@auro1999]

Yes, I can do it, but I would prefer not using op-amps, but JFETs instead. The new board will NOT have the screw terminals, but a nice header connector. One can stack them up, and have more than one output. Like nutube and triode simultaneously.

[@KRAFTWERK2K6]

@@auro1999 I really love this modular and changeable aspect of the audio output. JFETs would require heatsinks, don't they?

[@auro1999]

Not necessarily. The current nutube64 has 8 Jfets in class A. 4 to generate constant current and 4 for adapting the input and output inpedence to the nutube64 . Gain of the nutube is very low. It is mostly a “sound processor” adding even harmonics (positive or negative). The gain is given by the jfets. The current on them is around 7-8 mA each. So at 24V they do not get warm. You could even bring up the board to 40V, if you were choosing jfets with less IDss. By carefully matching them, you can make a preamplifier without feedback, which is what you want to avoid. The OPA works all on feedback, which creates delay - retardation - as the sound propagates back and gets superimposed with “newer” sound. You truly want to avoid feedback. Anyway, trust depletion jfets for sound. Their dispersion is parabolic which is more “linear” than the exponential of transistors. Schematic can be quite simple if devices are good.

[@auro1999]

@@KRAFTWERK2K6 not necessarily

[@KRAFTWERK2K6]

@@auro1999 Ah! So it's basically a tube buffer like most inexpensive headphone tube amps that use Transistors or OpAmps for the actual amplification and just pass the audio through the tubes for saturation and "warming up". Yeah that already does something noticeably to the sound. Especially with the proper audio-grade tubes. Yeah, it's important to have matching pairs of tubes since you want them both to take roughly the same voltage with not a lot of difference. Thanks for clearing this up :)

[@jeffscheeler2532]

The stereo effect works fine on my Samsung galaxy tablet.

[@tiemanowo]

4:27 Those sockets are very interesting. I've never saw anything like this before.

[@auro1999]

ARIES low profile. Both Nickel and Gold plated available. No 32 pins available, unfortunately. Good zifs are NOT CHEAP.

[@DerIchBinDa]

@@auro1999 Thanks for the info! May use them in other retro projects to make switching chips easier.

[@HelloKittyFanMan]

Hmm, I'd like to see those ROM jumpers replaced by little switches on the outside of the case.

[@C64EVO]

That's absolutely doable. We already have a pin breakout module that will easily enable a variety of switch types to be used to control the system ROM & Cartridge image states. We're also working on an automated soft-ROM switcher that will intercept hot-key-press sequences to enable the state changes. Take a look at the Keyman64 project to get an idea of what this could ultimately become.

[@rc-fannl7364]

Next up, replace the cassette player with vinyl records to load programs and a sterling engine to generate the needed electric power. Seriously, this is a pretty cool mod.

[@donaldhoot7741]

Usagi move over! Tube C64!? Cool!

[@C64EVO]

Updated May 6th 2023: Latest testing video of the near production-ready Triode64 module kzbin.info/www/bejne/bajYh4GcgKmMjtk

[@LuciRosseTV]

THIS IS FANTASTIC! my question is... How do you program sounds and patches? is it easy to sequence? is there proper software to push the limits of this?

[@retrobitstv]

There are a number of popular sequencers available but I have never used any of them. I think MSSIAH cart with MIDI interface is a popular one. You know who to ask? Lukhash has been putting out all kinds of amazing SID music recently. I wonder what he uses.

[@LuciRosseTV]

@@retrobitstv yes, I've been following him, great sound! I think he uses Cynthcart, is it different from Mssiah? I have a couple of c64

[@thomasleeuwen124]

Would it be possible to record a few songs and make them available as FLAC encoded files somewhere (f.e. mega, dropbox, ...)? Would really like to hear some common sids/games/demomusic and compare with my recordings that way to see how much more detail the nutube provides.

[@retrobitstv]

Sure, I can do that! Each SID channel's gain/distortion/harmonics are adjustable to personal preference and not all songs will sound as good with just one setting or any particular set of speakers, etc. Hopefully you will still be able to get an idea of what it sounds like, but I can't promise anything! Any songs in particular you would like to hear? I recommend stereo SIDs designed for a PAL machine as that's the configuration I'm currently running. Mono SIDs just don't have the depth and fullness of sound the NuTube is capable of producing.

[@retrobitstv]

Here are some recordings I just made in FLAC format. I was using my PC's on-board Realtek sound so it may not be the best recording quality though. Again I want to reiterate that the tubes can be tuned to your preference and this is just one possible setting. retrobits.tv/Evo64_SID_Demo.zip

[@thomasleeuwen124]

@@retrobitstv Thanks so much. The Cane-Phobos example song shows the nuances of the NuTube64 quite well. Certain gentle harmonics can be heard in mid-frequency. And the bass is so much more umph-y ... The 6581R4AR is the only one that can go so low IMO, but only at the cost of making the complete song sound muffled. Not like with the NuTube64. Oh man, it's going to cost me a bit to get one to Europe. How much do kidneys go for these days? :)

[@greenaum]

I don't think the joystick connectors need standoffs or screws, you can just remove the original ones and leave it. Looks like the DE9 connectors they're using are intended for serial ports, which usually have the screw holes to match screws on the cable, you screw the cable into the socket for a secure fit on a cable that might be very long and heavy. VGA ports have the same screws, for a contemporary... more or less... example. Just to stop the plug coming loose. The standoffs are only there to hold a serial cable tight, they don't attach the socket itself to the board, that's just done through soldering the pins, and possibly a supporting pin or two if it's present. You can just get rid. You could even Dremel off the metal on the sides. Hopefully the production version, you mention is changed, uses proper joystick connectors instead of serial port ones.

[@johnandrews2167]

Love this! I have a 128D. Is there anything in the works for one of those? I'd love to do some work like this. Especially since it was my very first computer and it still works! Though it seems to have a video color problem lately. But an updated board for it would be so sweet!

[@retrobitstv]

There are reproduction C128 boards (check out the C128 Neo) but I'm not aware of any that are such a dramatic overhaul of the original design as the Evo64.

[@tenminutetokyo2643]

That is freaking nuts but at 3:15 you can jam in a TRS-1 2450 for even better heat reduction.

[@retrobitstv]

There's a new version that uses an ultra low noise switching regulator, some details of which can be found on the Lemon64 thread here: www.lemon64.com/forum/viewtopic.php?t=79194&start=120

[@sheep1ewe]

I like it, maybe not something i would buy personaly right now, but i deffinitly think there is a market for it and it's not that much money in the HiFi circles anyway compared to other equipment that figures there.

[@HelloKittyFanMan]

Oh my gosh, at first I was like, "I don't see any tubes on this!" So is what you're saying that even though VFDs are fairly old, using small iterations of them as audio tubes is a brand-new way to go somewhat old-school with tubes -- sort of a hybrid of old and new?

[@C64EVO]

I think that's a good way to describe the goal. A whimsical mix of old and new, that (hopefully) pleases a desire for retro-authenticity, while improving on the incidental and secondary layers of the architecture, which will provide a better user experience and ensure a much longer product lifecycle (or easier said, having more fun with old stuff!)

[@bobsbarnworkshop]

I've been watching many of your videos and your voice sounds so familiar! I got it! Joe Mantegna

[@cartman414]

Nice. I've been curious about what a fixed SID would be like given how the original was kind of rushed.

[@lochinvar00465]

I remember replacing the RAM on my first C64C. Replaced the 64K chips with 256K chips but didn't connect the bank switching before I sold it when I bought the C128D. The bank switching would have been done with the cassette port and I hadn't worked out how to still be able to use the cassette port for the cassette.

[@borayurt66]

What are those super sleek ZIF sockets called? I love them! It is a great solution to make a totally ZIF'ed C64 without having to mod a lot of bits to make the sockets fit like with regular ZIFs.

[@auro1999]

ARIES low profile. Look mouser/digikey. They exist with nicker or gold plated contacts (latter hard to find). They do NOT have 32 pins, unfortunately.

[@borayurt66]

@@auro1999 Thank you! Will check out now.

[@StariusPrime]

Is there a waiting list anywhere for this board?

[@retrobitstv]

The production board isn't finalized yet so I would say check out the Lemon64 forum or Facebook group to stay up-to-date on product development and release. It should be out in the next couple of months from what I understand.

[@tetsujin_144]

It's taken some time but I've gradually gotten used to the idea that stuff like this is a bit expensive. Cool stuff, though, would love to hear the difference sometime...

[@retrobitstv]

I was surprised that even with my little desktop speakers the difference in sound was drastic as I flipped back and forth between outputs. It really does have to be heard in-person to be believed.

[@JoedeLange]

Take my money already!

[@auro1999]

almost ready. be prepared

[@rager1969]

Using DIP switches on the mobo is a horrible way to choose ROMS/carts. It's cool that it's built=in, just not a good implementation;

[@John_Koenig]

dip switches are soldered on female headers. The board has soldered male headers. You can remove the dip switches and connect a remote control through a ribbon connector.

[@tetsujin_144]

Something like a programmable soft-switch or a menu to select the ROM would be more convenient, but using switches to toggle address lines on a ROM chip keeps it reasonably close to how the original machine operated (as in, this is how a ROM switcher would have operated back in the 1980s if you added one to the machine)

[@retrobitstv]

It's mentioned in the Evo64's documentation that you can use a product called Keyman64 to allow for keyboard-based selection of the ROMs/carts - henning-liebenau.de/keyman64/ I think it would also be fun to put about a dozen external toggle switches on the case that can select all the various SID and ROM settings. But not this case.

[@neophytealpha]

Wonder if the Evo will work with the 6526 replacement that is out there. or the 6510 replacement.

[@C64EVO]

Yep - works with all known CPU & CIA clones (MLC64, Montotech 6502 to 6510 converter, J-CIA, J-CPU, etc., etc.)

[@neophytealpha]

@@C64EVO Cool

[@androskris]

Very interesting, niche product. I can think of worse things to spend money on and the value can only go up right? My only concern is the original chips (Sid, VIC, CIA) as there is not a question of if but when they will decide to fail. Hopefully the Kawari replacement comes out whenever the chip shortage ends.

[@retrobitstv]

I have a couple of replica SIDs I want to try out next and see how they sound compared to the real deal. With the Kawari available now and CIAs in the works, it looks like we'll be able to keep these old things running forever :)

[@Renville80]

One thing I would have done differently is to add some tape on top of the one SMT capacitor under the one bracket to minimize the chance of the bracket shorting against the capacitor since there is often measurable resistance from the case on an electrolytic capacitor to its terminals. Edit: I do see that tape was added later on.

[@retrobitstv]

Great point and I did go back later and cover two of the large caps with tape because I was worried about any possible short to ground since the bracket absolutely does make contact there!

[@auro1999]

Yes, kapton tape which does not melt with time and patience

[@Explore531]

im looking forward watching your shows now on im also very big fan on the Commodore 64, I was once too had commodore 64 but it was Commodore 128D, I have also Subscribe too your channel and im looking for getting new commodore 64 that will uses sdcard slot on the side and usb on the side also I would love replay all those classic games that I once had really miss old games for the commodore, Im glad found your videos for fun

[@retrobitstv]

Welcome to the channel! A few good options for mass storage on a real C64 are the sd2iec and 1541 Ultimate II+, both of which I have reviewed in past episodes. There are, of course, many other solutions available. And of course modern recreations like The C64, MiSTer FPGA, etc. It all depends on your particular needs.

[@Renville80]

Wonder if this includes the version 2 Kernal? It has a bug in the screen editor that causes the 64 to crash. First, the cursor needs to be a color that has bit 2 set (the default light blue for example). Next, go down to the bottom of the screen and type at least 80 characters to cause the screen to scroll in two new lines. Last, backspace to cause the cursor to cross back to the previous line. If the version 3 Kernal is present, nothing happens. If it is the buggy version 2, it will immediately try to load from tape, and holding the C= key will cause the screen to flicker between upper and lower case. If you don’t have a tape player hooked up, only way to get out is a power cycle.

[@C64EVO]

Production EVO boards are unlikely to ship with ROMs due to copyrighting issues. This means that anyone is free to write any ROM images they want to their own EEPROM

[@philcarter9738]

How about a little bit of heat shrink on the keyboard bracket foot, through could look quite neat 🙂

[@rutabagasteu]

I noticed the lack of modern connectors on the back of the unit. Any hard drive ?

[@C64EVO]

No hard drive, but definitely offers all the standards, like cartridge port, user port, composite and S-video, as well as stereo audio, IEC/Serial for disk drives & printers.

[@rutabagasteu]

@@C64EVO thanks !

[@paulvanderlaak700]

In combination with an 1541 u2 cartridge you have full usb storage support

[@2000freefuel]

Kapton Tape should be more durable, can you drill out the standoffs for heat set brass inserts?

[@mirabilis]

A bit sad that you cannot customize the filter capacitors (47pF for 6581 and 22nF for 8580) to use polystyrene caps instead, for example.

[@stickyfox]

I need someone to prove to me that NuTubes are not just colon separators from 1960s VFD clock parts, that someone found a shipping container of and decided to sling as a modern-day audiophile part to make a whole crapload of money off of people who don't know better. Why not use an AX7 like everything else in the world? They're available everywhere. Or a FET?

[@HifiCentret]

I've never understood the fetish of a few tubes in the audio path - most of the times they're just another component in the path and not really needed as the circuitry is actually a better driver than the tubes themselves. Don't get me wrong I'm a fan of tubes too but they have to make sense. F.ex. a full tube amplifier (pre and/or power or integrated amp). Beside the C64 is from a very non tube era - not even for nostalgic reasons as today. So a good quality modern chip or transistor circuitry in the 64 and hook it up to a modern integrated full tube amplifier and hear the angels sing. The evo64 board is nice though. Have for a while thought of making my own "brand new" C64. The hard part is to decide which board to go with. Each board their pros and cons.

[@C64EVO]

There is a fair amount of noise within the standard C64 itself, which EVO is eliminating. Starting form the power sources, through rectification, through audio signal generation and propagation, etc. So, EVO's preamp module is fed with a clean, smooth and consistently stable audio signal, which wouldn't be possible on a standard system. Of course you could add a filter stage to the output of a standard system, in front of the preamp / amp stage, but the results wouldn't be quite as clean. With regard to the tube preamp modules, they were clearly developed to cater to a niche audience that wants a completely unique audio experience. They're definitely not a requirement for people that might be interested in experimenting some of the other facets of the EVO.

[@HifiCentret]

@@C64EVO I totally agree it makes sense to adress the noise in the system. My gripe or so to say is only on the tubes. I have one machine with a long board. Can't remember if it's 250425 but the odity is that the CPU is 8500 and SID 6581 - can't remember I've seen such combo anywhere in the internet. Anyway that machine has way lower noise than any of my other with short board. The worst of them is the one with the last revision short board. Composite outputs show the same story. Really good on the long board and worst on the newest short board. Can't decide whether or not just to leave them intact. Incidentally I believe the one with the newest board is identical to the one I got as a kid (outer appearence) but can't tell which revision board I had back then - only that I didn't remember output to be that bad (even on RF) or can be my quality reference hasd changed with time 😂. For a while I've thought about making a new 64 with as much new components as possible and so the other machine won't get much use. Difficult to make a decision which board. If only available in the US that adds a hefty shipping and tax "fine" on top.

[@YoreHistory]

How does this compare to the C64 Reloaded ?

[@auro1999]

I have the mk2. I have an ICS64,. I have ultimate (2 of them)... hence I made mine. They are all good products.

[@YoreHistory]

@@auro1999 Ya same have the MK2 and Ultimate+/Elite but was curious on the Evo which seems to be closer to MK2?

[@C64EVO]

In short, EVO64 has some notable improvements in the audio and video output stages, beyond what the Reloaded MKII has done.

[@YoreHistory]

@@C64EVO Ah great thanks Darrell, great to know! Sounds like I need to add it to my collection then!

[@auro1999]

@@YoreHistory Yore: if I were happy with the other products, I would have not made mine... I have other things to do in life.

[@charliesybert2683]

If I wanted to build a sixty clone what revisions should I get and what chips do I need to buy separately

[@biggiejohn3360]

interesting to see so many C64 board remakes when C64's never suffered from cap leakage or battery damage.

[@auro1999]

we should switch to tantalum. All the 10,22, 47,100uF could go tantalum. The big ones would still remain Al-electrolytic - for size. Decision is strictly about costs.

[@C64EVO]

The reason there are so many remakes of the C64 is that it's such a beloved machine, with a big history and lots of nostalgia connected to it. Plus it's a very accessible platform with some great documentation and a vibrant user community supporting it.