This will probably be buried but my mom had this keyboard when I was growing up. Seeing this really brought me back. Keep up the good work, both of your channels are amazing!
The sound of that keyboard is stellar. Just, what else can scream "welcome to the 80's" quite like that heavily synthesized audio? It's the sound of video games from the late 80's and 90's and it encapsulates the childhood of so many people and grants a feeling of anemoia for those who missed out on such media because they were born too late to grow up with it. Such a cool bit of kit and I'm glad you were able to get everything working again. It makes some great sounds for when you really want to embrace that synthwave genre.
If I'm using an old keyboard, I'm not really looking for "realistic" sounds. There's usually sort of an uncanny valley effect on these kinds of keyboards. A clearly synthetic voice is more appealing to me than a somewhat realistic voice that isn't quite realistic enough to pass off as a real instrument. If I wanted a good piano sound, for example, I'd just use a real piano. I like old keyboards specifically because they sound synthetic.
Each keyboard reflects the sub culture behind it. Remember, it is a commercial product designed to make money for its creator. As a musicologist I like this sort of thing.
I have no clue about electronics nor do I play piano/keyboard however between you and Markusfuller's channel I love watching these Teardown/Repair videos! Thank you, I appreciate what you do.
Does not matter how much you know, what matters is if you are willing to try things and learn. That is the basics for all repairs and design of everything that has ever been made. Just remember some websites such as archive.org, servicemanuals.net, or manualslib.com and spend some time on trying to find manuals. If you have to download anything other than a PDF, or give them any information (unless you are buying something) go elsewhere as they are a scamming site, and there are many.
Here's a brief look into the synthesis engine that the HT-700 uses. The HT-700 uses a synth method called "Spectrum Dynamics" or SD for short. SD works by using two digital oscillators where one is used as the main body of the sound and the other as overtones. The overtone and body oscillator have their own DCA that allows their volume to fade in and out independantly of each other. Both are then mixed together and sent to the analog filter section which has its own DCA as well. Then it's outputted to amp and thats it. The biggest issue with SD, or rather Casio's implementation, was that the Oscillator DCA's were nonprogrammable and thus you ironically had no control over the very thing the SD was special for. All you could do was choose waveforms and that was it. Hope you all found this tid bit interesting.
I think you can program the oscillators on the HT-6000, and change the envelope curves on both waveforms. Or at least it has a lot more preset waveforms to choose from than the HT-700.
Well I own many synthesizers and some keyboards ,this casio ht-700 is actually a digital synthesizer with analogue filter which in ht-6000 you can explore more.This pro synth-keyboard from casio were not went good on sales, cause casio had already the famous cz line which was the most advanced for sound synthesis..casio perhaps wanted to bring something between the cz and other keyboards but there was not so good of quality ..but the engine circuit inside can produce timbres that are good for some kind of music especially instrumental..
@@diggydude5229 having owned a 3000 and still have a 700 they are both very versatile, real synths, once cheap, the 6000 is as far as I have read massively more versatile with I believe double the oscillators and basically everything else ! I want one ha ha
I got this keyboard for Christmas 1987. I still have it. It’s still in great shape and I’m pretty sure I even still have the manual for it in my big box full of manuals in the garage. I haven’t touched it in quite a few years but you have made me want to dig it out and dust it off and your channel(s) has made me realize that it deserves a home in my retro game room. Thanks!
Andy Doane Good one, that made me laugh There’s another rumor going about that 8 Bit Guy did all the keyboard work for Michael Jackson because he saw so much potential in a 11 year old’s heart in the early 1980s, and that talented kid grew up to be a keyboard repair guy. Cool story intended to be a joke, but i don’t see adding a punchline anytime soon, because there was no punchline. Sike!
AndeGott546 Productions my GUESS is that a combination of The 8-Bit Guy, a bag of weed and Sonic The Hedgehog made it. Have you checked out his other channel, "8-Bit Keys"?
Hey David! I'd love to see you take on other older electronic drum machines, keytars, and other unique ones. I loooooove old electronics and love how you break down features and how they're made. I think one of my favorite types of videos you do are restorations, there's something so.. Calming about it! Thank you for the great content!
You did an astonishing job of restoring this keyboard, you proved that even a cracked or rusty motherboard can be still used by desolder and wiring stuff directly to eachother. I am amezed that once you extended those screw holes by drilling that you did not end up drilling trough the other side of the plastic.
I heard simular sounds in a novation synth we had at my old job in a music store. The mistake they made was to call these noises things like piano and E piano when they are clearly not.
This was my first keyboard that I got back in the late '80s, and I still have it. For a consumer-focused synth, it has a surprising amount of flexibility. I actually ended up making my own sounds quite often. It is built quite cheaply, but mine has held up pretty well considering it's over 30 years old. The speakers occasionally come loose, and the power adapter has suffered years of abuse and had to be replaced eventually. There are also two keys whose hinges have broken, and now they are held in place with tape. I haven't taken it apart again to look at them, but I assume that the hinges are simply just bending plastic that eventually broke through. Even after I got a Boss DS-330 and eventually software synths, I still continued to use the HT-700 as a MIDI controller until a couple of years ago. In spite of the tiny keys and fixed velocity, it served that purpose well. I mostly do step programming, so it wasn't really an issue. I plan to hold onto this synth indefinitely. It may not be amazing compared to the other synths I've acquired since then (both hardware and software), but its hybrid nature creates sounds that I haven't encountered anywhere else.
This was my first keyboard. Loved it at the time. Interestingly, I really liked the data entry knob *because* it had a hard stop. Easier to "feel" without having to look at the display. Each to their own :-)
Simply the best retro site I have ever seen. clear and easy to follow. Some of those old boards were so much fun. I owned a Casio Mt800, PT80 and a Poly 800. All the best and thanks
I have zero interest in keyboards and yet I very much enjoy this channel and have watched all videos because they are well made and very relaxing. Thank you 8-bit guy.
At 9:32, you should have held down a chord as you had fingered mode on or selected chord mode and held down 1,2,3 keys to the right of the root note. Also this keyboard had a built chorus unit to fatten up the sound, this was lost as the recordings sounded mono. The Data entry control pot was much quicker than just having up down keys, and was a luxury at the time :-) Sounded bright and interesting in it's day, a cheap multi timberal midi keyboard with a analogue filter with resonance although very limited + Song recording + chord + bass + drum programming.
I had one of these for a while and the knob was brilliant once you got up to speed. Its funny how the early synths were all beautifully controlled with knobs and all that went out the window in the 80's with baffling key combination UI's that took over. I did quickly learn to hate this keyboard overall. Its sounds are weak. You can really give them a sonic shot in the arm with effects but its hardly worth it really.
This model has an analog pot for the data entry wheel. I guess rotary encoders were too expensive at the time. I have two HT-700s. One is fairly minty and has a crisp sound. The other one has a mushy sound, which makes me think the caps need to be replaced. If I remember correctly, the little PCB with the MIDI jacks on it needs to be rebuilt on that one too. I also have the non-programmable version, the HZ-800, and the full-sized programmable HT-6000, which was the top of the Spectrum Dynamic line and was supposed to be a professional model, but the build quality was more like a typical Casio toy model. The HT-6000 sounds much more professional than its mid-sized siblings. The HT-700 sounds cartoonish in comparison.
The NEC D23C256 is a 32kByte mask ROM. Those other OKI 6294 Chips are 8KByte of static RAM each, no ROMs. And yes that D78C10 is in fact the CPU. From all I can see that "MIDI Controller Chip" is just another static RAM, but a very fast one, like the cache chips for old 80486 boards. Edit: The OKI 6294 are not static RAMs but percussion generators. Very misleading numbering. The small "MIDI controller chip" is a static RAM but not a fast one, just a small one.
The schematic refers to the 6294's as "percussion generator 1/2". The pin assignments are completely different to an SRAM :-) EDIT: Also the speed grade of the actual SRAM is 150ns. The trailing zero is usually left off. In '87, if you could even get an 8KB SRAM in 15ns grade, it would cost a fortune! No way the bean counters would go for that. If you don't need the performance, don't pay for it :D
That's weird anything with 62x4 is usually static RAM. Yeah 1987 is a bit too early for cheap fast RAM. However back then there were "fancy" 300 mil 150ns SRAMs around in order to "safe space". But I have seen weirder things like an ITT4017 (in Delta-Lab delays) that is actually 16kx1 DRAM and not a HEF4017 counter... Could you please provide a link to that CASIO schematic?
Thanks. Those OKIs are weirdos and very misleading numbering. They only use one chip select signal the write signal and the 8 data bits. They also got the CLK signal that tell that they have some counter like stuff in it. Apparently they got 4 channels each and only the MIX out is used. The DAC converters or at least some PWM DAC thing seems also to be inside them.
The OKI MSM629x series usually relates to sound chips of one sort or another. The 6295, for example, was used in a lot of early arcade machines for general purpose 4-bit ADPCM sample playback. I can't find a datasheet on the 6294 but from the information we now have available, I can guess it works a little bit like the 6295 but has a mask ROM for the waveforms rather than arbitrary ones being loaded by the host CPU. Cheapest possible way to make something that did the job well enough, I suppose!
I have one of these keyboards that I nabbed for $5 from a local yard sale. Its not the be-all and end all, but a few things that were overlooked in the video were the asdr envelope, the filter/resonance, and envelope controlling the filter. There's also chorus which is nice. Although you have limited access to your sound modifiers, you can get around this a little bit by setting your jog dial to something you want to control such as the cutoff for the filter , or decay...and sweep the dial- This is really nice for pads, arpeggios, etc. The jog wheel is a little bit steppy, but for so cheap, its permissible imo.
1:30 The OKI chips are definitely some sort of ROM chip or something for sample storage. They were a very popular manufacturer of PCM sampler chips for arcade games (usually used with FM chips by Yamaha) so that's the only logical conclusion.
Also, after watching more of the video, I'm starting to think that that the NEC chip you brought up earlier is a wavetable sythesizer chip similar to the HuC6280 in NEC/Hudson Softs PC Engine system. Many of the synthesized instruments have the same weird, harsh sound that the HuC has.
That multitrack sounded a lot like one of the songs for the game Raptor: Call of the Shadows, one of my favorite top-down fighter plane shooter games. Really fun to listen to!
That's actually the way every English speaker in the world used to pronounce that sound. Why on earth would they write it WHeel if it was pronounced weel? Language changes, and most young English speakers today do not pronounce the h sound anymore.
Omg! I have a hardware store and I wish my clients tried to find the screws they need by themselves. They are always like: "too short.... too long.... too thick.... not the right type etc......" and I am so boreeeeddd.. I wish I had David as a client he could have as many screws he want for free!
I love the organ sounds on the MT-70. The jazz organ makes a fairly convincing Hammond B3 substitute. Got her hooked up to a Korg G4 rotating speaker simulator right now, but haven't done much with it yet.
I absolutely love you videos! The way you show every step is extremely helpful; I do stuff like this too from time to time and I have never heard of de-soldering braid until watching your channel. Needless to say, I'll be buying some!
I got a HT700 a few years ago (picking it up is it's own story) and i love it. I use it for my side-project and already did the synth-pan flute sound in "Escape" with it.
Other than the CZ101/ 1000, the CZ series were aimed at the pro market (even though the 101/ 1000 used the same sound engine). The CZ 3000/ 5000 and CZ-1 are very substantially made with metal chassis, pitch and mod wheels, expanded memory and in the case of the CZ-1, have a velocity sensitive keyboard with aftertouch. They're excellent synths and still very usable today.
Glad to see the synth was easy to repair. It has quite a distinct sound across all instruments - the Typhoon one reminds me of Giana Sisters and the Level 1 music!
YES! You're the first person I've seen mention that. When I first played the sound that is the first thing that came to mind. I had actually meant to mention that in the video and I forgot.
Do you think it would be possible for you to make a video on retro game OST composition? What are the specifics compared to composing songs for anything else?
oh thats not what I mean, the hardware side of things, I was thinking about the composition, what makes the tunes 8-bitty so to speak, the chord progressions etc
There's a channel called 8-bit Music Theory which has videos about how music was composed for old games. It might have the kind of videos you're looking for.
yep, thats EXACTLY what I was looking for! Thanks :) I actually found it just earlier today through suggestions! Makes me wonder if the youtubes neural network suggestion algorithm made the suggestion based on my comment here, who knows all the things it takes into account!
This is definetly one of the older keyboards that we don't expect to have realistic sounds, we're finding some special sounds out of it instead what can't be shown on regular pcm keyboards. Some higher end versions of the SD synthesizers are of course has more features
Curious why you didn't just try to scrape back the solder mask on the crack area and just run new small patch wires or even small solid wire to bridge the traces at the crack? Seems that would have been easier than completely desoldering the wires off the speaker..etc? Would have only required a smaller bit of hot glue over the repair for insulation and less wire across the board.
That's what I was thinking. Scrape the coating off, patch the wires at the cracks and reinforce the cracked area with epoxy. I would have built up the base of those broken plastic studs too. But this works just fine, just a difference of opinion on repairing it. I really like the song.
But for the work he did in desoldering etc...it would have been just as quick and looked more professional if he had just repaired the two broken traces at the crack. Would have been less work and looked much better than a large length of white wire hot glued to the back of the main PCB. I'm really not trying to be critical and was just more curious than anything. Additionally the keyboard states it is in stereo, but the video doesn't have any samples to show if that is really true.
The HT has a stereo chorus effect. The actual voice output is mono, but is made (pseudo) stereo if the chorus is used. It also has left and right line outs, and outputs in "stereo" with the chorus in use. Otherwise without the chorus, both left and right outputs share the same signal.
Gotta say you're an amazing engineer. I watch your explanations of how you fix the keyboards and kinda half-understand what's going on (still better than I've understood anything like that before :D). It's amazing what you're able to do with something that many people would just write-off as "doesn't work anymore". I've always liked these sorta synthetic instruments where you can still kinda tell what instrument they're "supposed to" sound like, but they don't quite make it and end up with their own colour and character instead. As opposed to something like general midi where the instruments do often make it most of the way but just end up sounding limited or simplistic.
The reason this happens is that much of the pieces are recorded separately, so when I connect all of the bits together in the final edit there end up being more "so" words than it originally sounded like. However, I can often run into the same problem using the word "next" or "now." it's a constant struggle.
So, once I noticed this I couldn't stop hearing them. So. I counted 38 in total. So-so. I think David's content and production quality is great, *so* i'm not complaining.
I had this keykoard back in the early 90s, it rocked!!!... it's mainly feature for me was the kinda sequencer it has, it allowed me to make complete cover of various songs like "Big In Japan", "The Year of the Cat", "I Love to Hate You" and others... I could program drums, bass and strings very close to the original songs... I mean, at 13 years old I made karaoke samples in my room... 30 years ago!!! Man, I miss that keyboard...
Why would you expect it to be realistic? I think most people who play these old home keyboards now are doing it because of the way they do sound, not because they're looking for a realistic piano sound.
Believe it or not.. I get a lot of people asking me which retro keyboard they should get so they can learn to play piano...and I usually tell them to avoid retro keyboards from the 80s because they usually don't have a good piano and rarely even a sustain pedal.
Yeah, I found that too. fixing old keyboards can be surprisingly easy. I have a 1998 Yamaha PSR-79 keyboard that I got around that time, and through my own bad judgement it ended up with battery corrosion, and about 1/3 of the keys stopped working. When I checked inside, the damage wasn't too severe, but I did notice how the keys themselves were basically just a dumb switch matrix attached to a ribbon cable. Sure enough, a continuity check on the ribbon cable with a multimeter showed that two of the wires were broken. So... I got some lengths of wire about the same size as the ribbon cable, and soldered it between the two ends of the broken wires... And that fixed it. Nothing complicated. Anyone with a very basic understanding of how to solder and use a multimeter and a bit of logic could have checked it, worked out what was wrong, and fixed it. It CAN be that simple in some cases...
it's good to see these once in a while. I don't even like music (I usually skip the multi-track sample you do) I come for you (david) would pretty much watch all your channels
I always like your videos. But did you realized that you used the word "so" too many times... Without wanting to belittle the way you speak, you could improve on it. big thumbs up for you....
JB-Weld FTW! It's great stuff ...metal filled epoxy, dries at room temp, reasonably long work time, and it can be sanded and drilled once dry. I used to use it all the time in robotics projects in college. I even know a guy that fixed a crack in the engine of his WWI biplane with the stuff. It was a stop-gap solution, but he managed to fly it home! It should definitely be your go-to for any broken plastic.
I'm glad you don't love the HT-700 as much as I do, or the 2nd hand value would skyrocket! This is a beautiful, programmable, 80's Casio with a resonant analog filter! Thanks for down-playing it!
Another interesting and entertaining video. Lovely sounds from this keyboard, it has a certain 16 bit video game sound to it. I will keep my eyes peeled for one!
What made the Roland D-50 so great and groundbreaking was it used PCM samples for the attack/decay and synth for decay/release. So the sound started sounding real, but didn't have to end after the sample is finished.
Great video on a great little synth. I have had mine sine I was about 14 years old and it still works. Used it mainly with the Apple IIgs for midi work for the last few decades. Was originally purchased at Odd Lots in the mid to late 80s for 79 dollars as a birthday present. It was given as a replacement to the CZ series I originally bought but came with broken keys.
Got exact same keyboard. Found it in a dumpster a decade ago. It had a broken power plug, and required minimal repair. It serves me to this day. Menus are quirky and hard to manipulate with the dial, but the sounds are good. Effects are very decent. The biggest problems for me is the lack of velocity sensitive keys. I often feed a newer keyboard though the MIDI port and use HT-700 as a tone generator to acquire velocity. Unfortunately there's almost no multitimbral functionality and no General Midi compliance, so it cannot be used as a retro gaming sound module.
This will probably be buried but my mom had this keyboard when I was growing up. Seeing this really brought me back. Keep up the good work, both of your channels are amazing!
I absolutely love how this keyboards sounds! It hits the spot right between realistic and synthetic.
The sound of that keyboard is stellar. Just, what else can scream "welcome to the 80's" quite like that heavily synthesized audio? It's the sound of video games from the late 80's and 90's and it encapsulates the childhood of so many people and grants a feeling of anemoia for those who missed out on such media because they were born too late to grow up with it. Such a cool bit of kit and I'm glad you were able to get everything working again. It makes some great sounds for when you really want to embrace that synthwave genre.
If I'm using an old keyboard, I'm not really looking for "realistic" sounds. There's usually sort of an uncanny valley effect on these kinds of keyboards. A clearly synthetic voice is more appealing to me than a somewhat realistic voice that isn't quite realistic enough to pass off as a real instrument. If I wanted a good piano sound, for example, I'd just use a real piano. I like old keyboards specifically because they sound synthetic.
Exactly! I wish more people got that.
Exactly, I was thinking the same thing when I saw the video.
Even classical music sounds better with proper synthetic sounds.
Each keyboard reflects the sub culture behind it. Remember, it is a commercial product designed to make money for its creator. As a musicologist I like this sort of thing.
Besides... You can never replicate sounds like a saxaphone.
I've yet to hear a synth one that sounded real.
8-Bit Keys, the most criminally-underrated channel on TH-cam.
lol
Strelnikov_ YES
Not anymore
I have no clue about electronics nor do I play piano/keyboard however between you and Markusfuller's channel I love watching these Teardown/Repair videos! Thank you, I appreciate what you do.
love me some marcusfuller
Bo88y Beretta is
Does not matter how much you know, what matters is if you are willing to try things and learn. That is the basics for all repairs and design of everything that has ever been made. Just remember some websites such as archive.org, servicemanuals.net, or manualslib.com and spend some time on trying to find manuals. If you have to download anything other than a PDF, or give them any information (unless you are buying something) go elsewhere as they are a scamming site, and there are many.
Here's a brief look into the synthesis engine that the HT-700 uses. The HT-700 uses a synth method called "Spectrum Dynamics" or SD for short.
SD works by using two digital oscillators where one is used as the main body of the sound and the other as overtones. The overtone and body oscillator have their own DCA that allows their volume to fade in and out independantly of each other.
Both are then mixed together and sent to the analog filter section which has its own DCA as well. Then it's outputted to amp and thats it.
The biggest issue with SD, or rather Casio's implementation, was that the Oscillator DCA's were nonprogrammable and thus you ironically had no control over the very thing the SD was special for. All you could do was choose waveforms and that was it.
Hope you all found this tid bit interesting.
I think you can program the oscillators on the HT-6000, and change the envelope curves on both waveforms. Or at least it has a lot more preset waveforms to choose from than the HT-700.
So its west Coast synthesis method mixed with east Coast. Interesting for sure
Well I own many synthesizers and some keyboards ,this casio ht-700 is actually a digital synthesizer with analogue filter which in ht-6000 you can explore more.This pro synth-keyboard from casio were not went good on sales, cause casio had already the famous cz line which was the most advanced for sound synthesis..casio perhaps wanted to bring something between the cz and other keyboards but there was not so good of quality ..but the engine circuit inside can produce timbres that are good for some kind of music especially instrumental..
That sounds suspiciously similar to Casio's "vowel-consonant" synthesis.
@@diggydude5229 having owned a 3000 and still have a 700 they are both very versatile, real synths, once cheap, the 6000 is as far as I have read massively more versatile with I believe double the oscillators and basically everything else ! I want one ha ha
I got this keyboard for Christmas 1987. I still have it. It’s still in great shape and I’m pretty sure I even still have the manual for it in my big box full of manuals in the garage. I haven’t touched it in quite a few years but you have made me want to dig it out and dust it off and your channel(s) has made me realize that it deserves a home in my retro game room. Thanks!
You make interesting videos, keep doing your thing, I enjoy watching them! :)
My oh my, the Typhoon sound though! The 80's just blew through my headphones and into the cosmos beyond. Thanks, Casio and 8-bit guy!
That doesn't sound like a bad keyboard. It has rather unique sounds for the instrumental music.
There's a rumor going around that Michael Jackson's change in appearance was due to the 8-Bit Guy trying to Retrobrite him.
LOL
Andy Doane
Good one, that made me laugh
There’s another rumor going about that 8 Bit Guy did all the keyboard work for Michael Jackson because he saw so much potential in a 11 year old’s heart in the early 1980s, and that talented kid grew up to be a keyboard repair guy. Cool story intended to be a joke, but i don’t see adding a punchline anytime soon, because there was no punchline. Sike!
How do I like this comment more than once?
Tremendous!!!!11
There's also a rumor that Michael Jackson released a new version of his song "Bad": "Dead". "I'm dead, I'm dead, you know it, I'm dead..."
Excellent video as usual David!
Caleb Goodwin how did you made that conclusion? The video just came out.
Got here at like 15 views. It's been out for like 10 hours. Just finished it now.
Caleb Goodwin weird, for me it just came out.
Yeah, TH-cam notifications are always late. I got my notification 10 minutes ago, just while I was watching this.
Look at EpicLper's comment
You owe us no apology for setting your own schedule. Besides, 1-2 a month on a side channel is cranking them out pretty good.
I freaking love it when this man repairs stuff. I'd break something for him just to watch him repair it lol. Not something of his of course, but mine.
That new intro song is just pure love in my ears
I seriously want Rene Didden to post the full track somewhere, I love it!
EpicLPer Was just about to ask if we could get the full version.
I love it too!
Who did it? Anyone know?
AndeGott546 Productions my GUESS is that a combination of The 8-Bit Guy, a bag of weed and Sonic The Hedgehog made it. Have you checked out his other channel, "8-Bit Keys"?
I love these restoration videos
Yep, me too
agreed
Me too
Me tio
Too
I really liked the song you made!! The sounds of this keyboard really remind of the late 80s.
Hey David! I'd love to see you take on other older electronic drum machines, keytars, and other unique ones. I loooooove old electronics and love how you break down features and how they're made. I think one of my favorite types of videos you do are restorations, there's something so.. Calming about it! Thank you for the great content!
I love how Enya is your go to demo song ❤️❤️❤️
Did nobody else notice when he was going over the sounds he left it at synth bass for like 3 sounds?
Justin Noker Yeah, I was wondering if anyone was going to comment on that.
Justin Noker Yup. Was going to comment on it. I'm not sure that's something you can go back and edit in TH-cam without reposting the entire video.
You did an astonishing job of restoring this keyboard, you proved that even a cracked or rusty motherboard can be still used by desolder and wiring stuff directly to eachother.
I am amezed that once you extended those screw holes by drilling that you did not end up drilling trough the other side of the plastic.
The sounds are very agreeable to me even though they are synthetic. The kind of stuff you pay a premium for these days.
rimmersbryggeri my thought exactly
I heard simular sounds in a novation synth we had at my old job in a music store. The mistake they made was to call these noises things like piano and E piano when they are clearly not.
rimmersbryggeri yeah. but that doesn't make them bad sounds
Exactly. I meant if you can get them for cheaper in an older package it's way cooler.
No need to apologize. I think your premium quality content well worths the wait.
Yes! Ace Hardware is my absolute go-to place for things like screws and fasteners. Lots more selection than at Home Depot.
And more welcoming & comfortable atmosphere.
This was my first keyboard that I got back in the late '80s, and I still have it. For a consumer-focused synth, it has a surprising amount of flexibility. I actually ended up making my own sounds quite often.
It is built quite cheaply, but mine has held up pretty well considering it's over 30 years old. The speakers occasionally come loose, and the power adapter has suffered years of abuse and had to be replaced eventually. There are also two keys whose hinges have broken, and now they are held in place with tape. I haven't taken it apart again to look at them, but I assume that the hinges are simply just bending plastic that eventually broke through.
Even after I got a Boss DS-330 and eventually software synths, I still continued to use the HT-700 as a MIDI controller until a couple of years ago. In spite of the tiny keys and fixed velocity, it served that purpose well. I mostly do step programming, so it wasn't really an issue.
I plan to hold onto this synth indefinitely. It may not be amazing compared to the other synths I've acquired since then (both hardware and software), but its hybrid nature creates sounds that I haven't encountered anywhere else.
This was my first keyboard. Loved it at the time. Interestingly, I really liked the data entry knob *because* it had a hard stop. Easier to "feel" without having to look at the display. Each to their own :-)
Simply the best retro site I have ever seen. clear and easy to follow. Some of those old boards were so much fun. I owned a Casio Mt800, PT80 and a Poly 800. All the best and thanks
"but these are pritty rare and i don't have one" WELP YOU KNOW WHAT YOUR MAIL BOX WILL HAVE NOW DON'T YA?!
Man, I love this channel's content. It's two of my favorite things, electronics and music, combined into this eargasmic concoction of perfection!
Happy today, 8-bit keys and techmoan videos.
I can't play piano or know much about keyboards but I love the synth noise and repair tips you give, you're making me a better repair person!
Oh, that backgroundmusic took me back to the eighties!
Truls Osmundsen And the best part is that it's free download for all: soundcloud.com/eox-studios/falling-in-love-with-you :)
Downloaded, put on disk in the car. I also now follow you on soundcloud :)
Thanks for the 8-bit Keys update David. I love the teardowns and the homemade demo songs!
Wow this synthesizer produces great sounds!
I have zero interest in keyboards and yet I very much enjoy this channel and have watched all videos because they are well made and very relaxing. Thank you 8-bit guy.
At 9:32, you should have held down a chord as you had fingered mode on or selected chord mode and held down 1,2,3 keys to the right of the root note. Also this keyboard had a built chorus unit to fatten up the sound, this was lost as the recordings sounded mono. The Data entry control pot was much quicker than just having up down keys, and was a luxury at the time :-) Sounded bright and interesting in it's day, a cheap multi timberal midi keyboard with a analogue filter with resonance although very limited + Song recording + chord + bass + drum programming.
I had one of these for a while and the knob was brilliant once you got up to speed. Its funny how the early synths were all beautifully controlled with knobs and all that went out the window in the 80's with baffling key combination UI's that took over.
I did quickly learn to hate this keyboard overall. Its sounds are weak. You can really give them a sonic shot in the arm with effects but its hardly worth it really.
This model has an analog pot for the data entry wheel. I guess rotary encoders were too expensive at the time.
I have two HT-700s. One is fairly minty and has a crisp sound. The other one has a mushy sound, which makes me think the caps need to be replaced. If I remember correctly, the little PCB with the MIDI jacks on it needs to be rebuilt on that one too.
I also have the non-programmable version, the HZ-800, and the full-sized programmable HT-6000, which was the top of the Spectrum Dynamic line and was supposed to be a professional model, but the build quality was more like a typical Casio toy model. The HT-6000 sounds much more professional than its mid-sized siblings. The HT-700 sounds cartoonish in comparison.
David, you are a darn good musician. Keep doing what you do!
The NEC D23C256 is a 32kByte mask ROM. Those other OKI 6294 Chips are 8KByte of static RAM each, no ROMs. And yes that D78C10 is in fact the CPU. From all I can see that "MIDI Controller Chip" is just another static RAM, but a very fast one, like the cache chips for old 80486 boards. Edit: The OKI 6294 are not static RAMs but percussion generators. Very misleading numbering. The small "MIDI controller chip" is a static RAM but not a fast one, just a small one.
The schematic refers to the 6294's as "percussion generator 1/2". The pin assignments are completely different to an SRAM :-)
EDIT: Also the speed grade of the actual SRAM is 150ns. The trailing zero is usually left off. In '87, if you could even get an 8KB SRAM in 15ns grade, it would cost a fortune! No way the bean counters would go for that. If you don't need the performance, don't pay for it :D
That's weird anything with 62x4 is usually static RAM. Yeah 1987 is a bit too early for cheap fast RAM. However back then there were "fancy" 300 mil 150ns SRAMs around in order to "safe space". But I have seen weirder things like an ITT4017 (in Delta-Lab delays) that is actually 16kx1 DRAM and not a HEF4017 counter... Could you please provide a link to that CASIO schematic?
Sure thing! The PDF is available here:
synthstuff.wordpress.com/2012/01/04/casio-ht-700-mods/
Thanks. Those OKIs are weirdos and very misleading numbering. They only use one chip select signal the write signal and the 8 data bits. They also got the CLK signal that tell that they have some counter like stuff in it. Apparently they got 4 channels each and only the MIX out is used. The DAC converters or at least some PWM DAC thing seems also to be inside them.
The OKI MSM629x series usually relates to sound chips of one sort or another. The 6295, for example, was used in a lot of early arcade machines for general purpose 4-bit ADPCM sample playback. I can't find a datasheet on the 6294 but from the information we now have available, I can guess it works a little bit like the 6295 but has a mask ROM for the waveforms rather than arbitrary ones being loaded by the host CPU. Cheapest possible way to make something that did the job well enough, I suppose!
I have one of these keyboards that I nabbed for $5 from a local yard sale. Its not the be-all and end all, but a few things that were overlooked in the video were the asdr envelope, the filter/resonance, and envelope controlling the filter. There's also chorus which is nice. Although you have limited access to your sound modifiers, you can get around this a little bit by setting your jog dial to something you want to control such as the cutoff for the filter , or decay...and sweep the dial- This is really nice for pads, arpeggios, etc. The jog wheel is a little bit steppy, but for so cheap, its permissible imo.
I love that sound to be honest
I'm a big fan of your channel!! I have the HT-700 and really appreciate the insight into its inner workings! Keep up the great work!
1:30 The OKI chips are definitely some sort of ROM chip or something for sample storage. They were a very popular manufacturer of PCM sampler chips for arcade games (usually used with FM chips by Yamaha) so that's the only logical conclusion.
Also, after watching more of the video, I'm starting to think that that the NEC chip you brought up earlier is a wavetable sythesizer chip similar to the HuC6280 in NEC/Hudson Softs PC Engine system. Many of the synthesized instruments have the same weird, harsh sound that the HuC has.
Did they made the PCM/DAC part of Sega Genesis' soundchip?
That multitrack sounded a lot like one of the songs for the game Raptor: Call of the Shadows, one of my favorite top-down fighter plane shooter games. Really fun to listen to!
2:48 Stewie Griffin pronunciation of "wHHeel!"
*hwheel*
*Much* better spelling. Thanks! :)
That's actually the way every English speaker in the world used to pronounce that sound. Why on earth would they write it WHeel if it was pronounced weel? Language changes, and most young English speakers today do not pronounce the h sound anymore.
Correction, that's how *awesome* English speakers pronounce the "wh" sound! :)
I didn't even notice the first time around
After watching your videos for a while I decided to get a retro synth and I love it. Thanks David!
Omg! I have a hardware store and I wish my clients tried to find the screws they need by themselves. They are always like: "too short.... too long.... too thick.... not the right type etc......" and I am so boreeeeddd.. I wish I had David as a client he could have as many screws he want for free!
Τάσος Παραστατίδης guess you could say u are getting _screwed_
Giggity!
your example of how-to doing small repairs is valuable and inspiring. thanks!
you should cover one of casio's early 80s vowel consonant keyboards, the mt-65 is essential
I love the organ sounds on the MT-70. The jazz organ makes a fairly convincing Hammond B3 substitute. Got her hooked up to a Korg G4 rotating speaker simulator right now, but haven't done much with it yet.
I absolutely love you videos! The way you show every step is extremely helpful; I do stuff like this too from time to time and I have never heard of de-soldering braid until watching your channel. Needless to say, I'll be buying some!
8-bit keys makes my inner high school ebm goth kid smile.
That outro tune is just magnificent. See you next time, David!
David, did you keep polarizing the speaker? If not, will be played in the counter-phase to another speaker.
Yes, I double checked the polarity was the same as it was before. I just didn't mention it in the video.
8-Bit Keys Can you do a review and repair of the Casio CTK-150, if you have one?
I got a HT700 a few years ago (picking it up is it's own story) and i love it. I use it for my side-project and already did the synth-pan flute sound in "Escape" with it.
I'd like to see a casio cz series keyboard on the channel. They were aimed at amateur musicians and their sound is wonderful.
Other than the CZ101/ 1000, the CZ series were aimed at the pro market (even though the 101/ 1000 used the same sound engine). The CZ 3000/ 5000 and CZ-1 are very substantially made with metal chassis, pitch and mod wheels, expanded memory and in the case of the CZ-1, have a velocity sensitive keyboard with aftertouch. They're excellent synths and still very usable today.
I have a CZ-1000 and have featured it at least 3 times so far.
Terrance Petsas - Nice profile picture.
That is true however I think he ment by a review(a video like this).
Good job you are my favorite channel.
Glad to see the synth was easy to repair. It has quite a distinct sound across all instruments - the Typhoon one reminds me of Giana Sisters and the Level 1 music!
YES! You're the first person I've seen mention that. When I first played the sound that is the first thing that came to mind. I had actually meant to mention that in the video and I forgot.
That synth bass ? (at 7:48.. i think you forgot to change the preset name) with some little reverb would sound fantastic.
I was about to point it out
It was Synth Bells
Coming for retro tech. Staying for the AWESOME music. I love the tracks you're usually playing
Do you think it would be possible for you to make a video on retro game OST composition? What are the specifics compared to composing songs for anything else?
I think there is an 8-bit guy episode about that. Something like how old school music worked.
oh thats not what I mean, the hardware side of things, I was thinking about the composition, what makes the tunes 8-bitty so to speak, the chord progressions etc
I guess if you play music with square or triangle wave, it'll sound pretty 8-bitty.
There's a channel called 8-bit Music Theory which has videos about how music was composed for old games. It might have the kind of videos you're looking for.
yep, thats EXACTLY what I was looking for! Thanks :) I actually found it just earlier today through suggestions! Makes me wonder if the youtubes neural network suggestion algorithm made the suggestion based on my comment here, who knows all the things it takes into account!
Love whenever there are repairs on this channel. Although, this must be the most time consuming type of video.
i love my ht 700
This is definetly one of the older keyboards that we don't expect to have realistic sounds, we're finding some special sounds out of it instead what can't be shown on regular pcm keyboards. Some higher end versions of the SD synthesizers are of course has more features
Curious why you didn't just try to scrape back the solder mask on the crack area and just run new small patch wires or even small solid wire to bridge the traces at the crack? Seems that would have been easier than completely desoldering the wires off the speaker..etc? Would have only required a smaller bit of hot glue over the repair for insulation and less wire across the board.
That's what I was thinking. Scrape the coating off, patch the wires at the cracks and reinforce the cracked area with epoxy. I would have built up the base of those broken plastic studs too. But this works just fine, just a difference of opinion on repairing it. I really like the song.
Jesse Hardesty well, yeah, but the solder joints were already there on the board, so he might as well use them.
But for the work he did in desoldering etc...it would have been just as quick and looked more professional if he had just repaired the two broken traces at the crack. Would have been less work and looked much better than a large length of white wire hot glued to the back of the main PCB. I'm really not trying to be critical and was just more curious than anything. Additionally the keyboard states it is in stereo, but the video doesn't have any samples to show if that is really true.
I thought about it, but wasn't sure it would be as reliable, plus it would have taken longer.
The HT has a stereo chorus effect. The actual voice output is mono, but is made (pseudo) stereo if the chorus is used. It also has left and right line outs, and outputs in "stereo" with the chorus in use. Otherwise without the chorus, both left and right outputs share the same signal.
Gotta say you're an amazing engineer. I watch your explanations of how you fix the keyboards and kinda half-understand what's going on (still better than I've understood anything like that before :D).
It's amazing what you're able to do with something that many people would just write-off as "doesn't work anymore".
I've always liked these sorta synthetic instruments where you can still kinda tell what instrument they're "supposed to" sound like, but they don't quite make it and end up with their own colour and character instead. As opposed to something like general midi where the instruments do often make it most of the way but just end up sounding limited or simplistic.
The end reminds me Dschinghis Khan - Moskau
Always enjoy watching your videos David, reminds me of my childhood, with all the "old" tech
Great video, as usual. You seem to have been infected by the "so" language tic in this one, count the number of sentences you start with "so" :P
The reason this happens is that much of the pieces are recorded separately, so when I connect all of the bits together in the final edit there end up being more "so" words than it originally sounded like. However, I can often run into the same problem using the word "next" or "now." it's a constant struggle.
So don't worry ;)
So, once I noticed this I couldn't stop hearing them. So. I counted 38 in total. So-so. I think David's content and production quality is great, *so* i'm not complaining.
xjj99 at least he doesn't say "as you can see" 100 times
I had this keykoard back in the early 90s, it rocked!!!... it's mainly feature for me was the kinda sequencer it has, it allowed me to make complete cover of various songs like "Big In Japan", "The Year of the Cat", "I Love to Hate You" and others... I could program drums, bass and strings very close to the original songs...
I mean, at 13 years old I made karaoke samples in my room... 30 years ago!!! Man, I miss that keyboard...
@7:00 enya
nice
Niklas Wallin No Holly for Miss Quinn. I was thinking the same.
"Watermark" (1988)... Not justified due to the sound...!
I love the new intro theme. It sounds a lot better in this episode than it did in the next episode.
"The electric piano sound doesn't sound that great". I strongly disagree!
From a recreation standpoint, it really isn't that good. Same with the piano, but there are some niche musicians that can use it.
Why would you expect it to be realistic? I think most people who play these old home keyboards now are doing it because of the way they do sound, not because they're looking for a realistic piano sound.
Correct. It isn't a great sounding piano though, but a great sounding sound nonetheless :P
Believe it or not.. I get a lot of people asking me which retro keyboard they should get so they can learn to play piano...and I usually tell them to avoid retro keyboards from the 80s because they usually don't have a good piano and rarely even a sustain pedal.
This thing is a dream keyboard for chiptune composers. Just put it through some chorus and verb...
Yeah, I found that too. fixing old keyboards can be surprisingly easy. I have a 1998 Yamaha PSR-79 keyboard that I got around that time, and through my own bad judgement it ended up with battery corrosion, and about 1/3 of the keys stopped working.
When I checked inside, the damage wasn't too severe, but I did notice how the keys themselves were basically just a dumb switch matrix attached to a ribbon cable.
Sure enough, a continuity check on the ribbon cable with a multimeter showed that two of the wires were broken.
So... I got some lengths of wire about the same size as the ribbon cable, and soldered it between the two ends of the broken wires...
And that fixed it. Nothing complicated. Anyone with a very basic understanding of how to solder and use a multimeter and a bit of logic could have checked it, worked out what was wrong, and fixed it.
It CAN be that simple in some cases...
We are number one but it's performed by David Murray
it's good to see these once in a while. I don't even like music (I usually skip the multi-track sample you do) I come for you (david) would pretty much watch all your channels
I like this thing. But I don't like the new Intro track :(
Love watching you fix these types of things!
I always like your videos. But did you realized that you used the word "so" too many times...
Without wanting to belittle the way you speak, you could improve on it. big thumbs up for you....
So, what exactly are you saying? Did you find this video "so so"?
JB-Weld FTW!
It's great stuff ...metal filled epoxy, dries at room temp, reasonably long work time, and it can be sanded and drilled once dry. I used to use it all the time in robotics projects in college. I even know a guy that fixed a crack in the engine of his WWI biplane with the stuff. It was a stop-gap solution, but he managed to fly it home! It should definitely be your go-to for any broken plastic.
I had one of this in 90's, had a lot of fun with it and used it in a rock band that I played.
I'm glad you don't love the HT-700 as much as I do, or the 2nd hand value would skyrocket! This is a beautiful, programmable, 80's Casio with a resonant analog filter! Thanks for down-playing it!
I do love the SD sound. I had the HT3000 but sold it when I got the Hohner version of the HT6000.
It’s off-white and has ring modulation. So cool.
Awesome fix. Its always really fulfilling, being able to revive old equipment. 🐱💻
Owner of an HT3000 here! This will come in handy if I need to repair it.
Wow that piece needs an extended version right away. It's so groovy! I can't stop listening.
Another interesting and entertaining video. Lovely sounds from this keyboard, it has a certain 16 bit video game sound to it. I will keep my eyes peeled for one!
Man i love watching these restoration videos
Love the new intro!!!!! Oh and a huge fan!
Great episode! I really like this kind of sound, as I grew up in the eighties.
I have this one in my collection! Enjoyed this one 😉
The repair and reviewi videos are my all time favorite videos keep it up 8-bit keys
Been waiting on this for a while. Great video!
What made the Roland D-50 so great and groundbreaking was it used PCM samples for the attack/decay and synth for decay/release. So the sound started sounding real, but didn't have to end after the sample is finished.
Excellent video as always, thank you for making these!
The multi-trac music is really good. Thanks
The more and more I watch this channel, the more curious I am about what an old true professional keyboard sounds like.
Zanibar Reyener listen to a song from that era. professional musicians use professional gear
Great video! So glad there's no hate in the comment section!
That typhoon sound is totally 80s! I love it!!!
Excellent tune! Reminds me of Depeche Mode when Vince Clark was still in charge. You capture that 1981 vibe completely. Thanks!
Great video on a great little synth. I have had mine sine I was about 14 years old and it still works. Used it mainly with the Apple IIgs for midi work for the last few decades. Was originally purchased at Odd Lots in the mid to late 80s for 79 dollars as a birthday present. It was given as a replacement to the CZ series I originally bought but came with broken keys.
Got exact same keyboard. Found it in a dumpster a decade ago. It had a broken power plug, and required minimal repair. It serves me to this day. Menus are quirky and hard to manipulate with the dial, but the sounds are good. Effects are very decent. The biggest problems for me is the lack of velocity sensitive keys. I often feed a newer keyboard though the MIDI port and use HT-700 as a tone generator to acquire velocity. Unfortunately there's almost no multitimbral functionality and no General Midi compliance, so it cannot be used as a retro gaming sound module.