This is perhaps one of the most peculiar magnetic delays ever mass-produced; instead of relying on a traditional tape transport, the heads are resting on a spinning magnetic disc, somewhat similar to an old-style computer floppy. It is, to my knowledge, the only device of its kind.
The EM-200’s magnetic disc.
EM-200 Magnetic Disc with heads in place
I own both a Univox and a Melos unit. Both units have extremely low wow & flutter and a very crisp, bright delay signal. The tone quality is very different from tape-type delays, which makes this unit precious and unique. The inputs distort really nicely, and the unit is very reliable. For this reason, the Echo-Tech was my main stage delay for many months, back in Canada when I was playing live a lot. On the negative side, whevener I send the unit into self-oscillation (which can happen very quickly), it always winds up oscillating on a really high-pitched, ear-piercing note, not pleasant at all… I’ve hit that note a couple of times during concerts, and could feel the whole audience cringing!
The condition of the disc is critical to the sound quality of the EM-200. The disc that came with my Univox was in great condition, so the delays are clear and not noisy. Unfortunately, I can’t say the same about the disc my Melos came equipped with; it has many dents and scratches, which makes one of the heads very noisy to use (think of the sound of a worn-out, scratched vinyl record; if you enlarge the picture above, you can clearly see the damage). I do have a replacement, brand new disc, but unfortunately it’s in Canada, and I’m in Tokyo… Next time I visit I’ll grab it and bring it back, unless I can find a replacement here, or fix my disc with the instructions in the next section.
One interesting feature of the EM-200 is the “two-knob” speed control, which is also unique to this unit. One knob is a 6-position selector, for rough speed adjustment, while the other one allows for minute speed variations. With the fine-tuning knob, I’m able to get flanging tones very easily and reliably, without messing up my main delay tempo. Really cool.
Other points of interest are: an overload LED indicator and a mix knob for the two heads. You can go from head A only, 50/50 at 12, to head B only. This was also very fun to tweak live.
Technical Info / Service Notes
The disks used by the EM-200 are becoming very hard to find. Fortunately, they seem to last a long time, so chances are if you buy an EM-200 you won’t have to change the disk, but be aware that they may be scratched. One way to check is to plug the output of the unit in an amp, put the ‘echo balance’ knob at 10, the ‘echo repeat’ knob at 0, crank up the volume of the amp and listen to both heads using the ‘head mixing’ knob. If you hear strong popcorn-type sounds, you know the disc is damaged…
I’ve written a short article about the disk on the tape media page, which you can access here.
Replacement disks for the EM-200
I recently opened up my Melos EM-200 to check out the condition of the disk, and to see if perhaps I’d be able to flip the disc upside down and use the other side. I was very surprised when I found out that, actually, there are two discs sandwiched together. So the picture above doesn’t show two replacement discs, but actually one pair, both of which need to be put together in the machine. I don’t exactly why this is so (perhaps one layer isn’t thick enough to support the head’s weight), all I know is it doesn’t seem to be possible to flip one, or both of the disks, in order to get a ‘clean’ surface. One reason why I can’t do it is that the tiny mounting screws positioned all around the disc are recessed, their head flush with the metal rim, and only 1 of the discs, on 1 side, has the necessary recessed holes to accept the screws.
In this picture, I’ve taken the disc ‘sandwich’ out of the unit, and separated them
Notice how both of them are damaged.
I was fortunate enough to be given digital copies of documentation for the EM-200 , which I now make available for everyone to share. One document that was given to me was an Email transcript from an engineer that used to service these units. He describes a procedure to refurbish old disks and remove dings and scratches. I haven’t tried it yet; when I do I’ll post the results here.
“The life of the disk really depends on the speed of rotation, so a very fast delay wears the fastest and a slow delay makes it last longer. As long as the heads aren’t scratched up, the disks should last a couple of years, depending again on speed and rotation time. If they are scratched, use a #6000 grit mylar lapping tape and polish out the scratches. One of the principles for the design of the machine was ease of replacement of the media and no need for alignment of the heads. That’s about all I can remember about it – sorry! We didn’t get a lot of them back for servicing.”
Here’s a copy of the owner’s manual, schematics and disk replacement instructions.
Owner’s Manual. Click to download
Melos / Univox EM-200 Schematics
Specifications
| Manufacturer | Melos Electric Co., Ltd. (Japan) |
| Date | Late 70s / early 80s |
| List price | |
| Transport type | Magnetic disc |
| Motor speed | Variable, 6-speed selector + fine-tune knob |
| Playback heads | 2 |
| Head selection | Mix knob |
| Delay time | Short/mid range |
| Inputs | 4 |
| Outputs | High, Low |
| Wet output only | Yes, mix knob goes 100% wet |
| Pinch roller | |
| Tone control | None |
| Remote Control | Echo on/off footswitch jack |
| Operating Voltage | |
| Related models | Univox Echo-Tech, and other rebrands. |
Gallery
Thank you! Your page is great, full of help and ideas. I have an JBX Disk-Echo. It looks exactly like your Melos echo, except it says JBX instead of Melos. The problem with my machine is that an old echo feedback cant be turned off. It immediately starts to feedback when I turn the power on. If you have any ideas what I can do, please tell me.
/Ralf
Ralf,
There could be many causes to your problem: perhaps the ‘feedback’ pot is dirty or shorted (try spraying it with contact cleaner and wiggling it for a while), or perhaps there’s a problem with the erase head on the unit.
If you know a little bit of electronics, I would start tracing from the ‘feedback’ knob, follow the wires and see where they bring me on the circuit; then, look around for faulty parts…
I have the Univox version of this groovy echo machine, it looks identical to the photo you posted.
Alas, mine is making a “tik – tik – tik” sound from some sort of problem – scratch or otherwise – of the disc material.
Do you know where I can purchase replacement disc material??
I love the unit, still! I bought mine back in the late 1970s, used it a lot, but I could never use it for anything serious since that noise has always been there ever since I bought it.
I’m so glad I found you article on this thing!! If you can help me locate replace disc material I’d be very grateful! Kind regards, John
John,
If the ticking sound varies speed as you turn the speed knob, it’s definitely a scratched disc. Unfortunately, I don’t have a reliable source of replacement discs. I’ve seen them on auction sites a couple of times, so you could be lucky but it might take a while before others pop up.
Some people have reported good results using an modified 5 1/4 floppy disc, but I’ve personally never tried it. It could be worth a try if you’re desperate. Let me know if you attempt it!
Hello, very nice page. 🙂
I´ve been looking for a disk echo for some time how would u discribe the sound compaired to an analog delay pedal? And in how many ms is the longest delay time on one of these units?
Best reg ES
Hello, first thanks for this helpfull site with lots of info about tape echo,s, really great!! i visitid your site years since i,m interestid in tape echo,s!! very helpful and detailed information,Thank You!!
I also own such tape disc echo ,the echollete ecs4(same disk echo,they were sold under different brands) my disk had some serious tears so had to be replaced.
For replacement of the disc i tried 5 1/4 floppy discs ,i burnt the holes for the screws with a solder iron,that works great,you git clean and neat holes in a second with a point tip on youre solder iron!
The 5 1/4 disc works yes,but there is a difference with the Original disc, you get a more lofi sound and the character what this disc echo is normaly produce is gone,it doesnt sound so living anymore as it were with the Original disc,this is probaly because floppy discs or made for data and not for sound i think,but whatever,it works yes.
I wanted to have my echollete ecs4 back in a Original sounding state ,so i bought a second hand Ampex 456 Grand Master 2 inch Studio Mastering Audio Tape from ebay for 25 dollar ,i cut 3 pieces about 14 cm and joined them with splicing tape ,i burnt the holes with solder iron with the Original disc layering on it ,put it on the disk and screw it tight and flat,than with a scissor i removed the tape not used around the disk.
The result was amazing!! I didnt believe my ears!! The character like it soundid before with the Original disk was back!! and i didnt hear the splicing points were the tape was joined( you have to join them exactly ofcourse) for me i think this is the best solution to git this disk echo back to life ,it sounds wonderfull,just like before!!
Maybe there or owners of this type disk echo how find this info usefull ,it works great for me ,so i wanted to share my experiences on this site wich hase been very helpfull for me since i got interestid in tape echo,s.!!
Greet from the Netherlands!!!!
Thanks for much for sharing your experience! This information is extremely useful for myself and I’m sure visitors to this page. As you know, finding replacement original discs is almost impossible nowadays, so your solution will allow many units to be brought back to life, that’s fantastic!
Just got the Univox em 200 and the heads have wore a ring around the disk. Are the heads supposed to drag on the disk??
Mine are making contact with the disk, and there is a visible ring where they’ve passed, yes. The design is much like any magnetic tape format, the heads have to be in contact for it to work.