Unicord/univox Ec-100 Tape Echo No Wet Sound

[methodofcontrol]

i'm looking for a schematic, or perhaps someone had a similar problem and can tell me what you went through to fix it.
dry signal passes, but i can't get the echo. motor works. any suggestions?

[Enzo]

Either it cannot read from the tape, or it is not recording.

Hold something with an AC field near the playback head to see if it picks it up. A soldering GUN, a head demagnetizer, a small transformer - all emit a field. In fact, the old tape ought to have old material or noise on it.

It is just a tape recorder after all, so is there a large oscillation on the erase head? SHould be on the record head as well. I would guess 50kHz to 100kHz at substantial level. We call that bias. No bias oscillator, no record.

So first, think of it as a reverb not working. is it the drive end or the pickup end?

And send me an email with Unicord EC-100 schematic as the subject line.

tmenzo at msn dot com

[methodofcontrol]

the playback head is definately picking up. i held an ipod earbud up to it and the music from the ipod played through the guitar amp the ec100 was hooked up to.
i also found that if removed the plastic guard that guides the tapes in, i was able to hold the tape at a certain angle w/ a certain amount of pressure and it sounded the like the unit was functioning properly for a moment. i'm looking into trying to adjust the position of the record head, it seems there is one screw that uses a spring as a spacer, whereas the other screws on the heads are using regular fixed spacers.

[Odd I/O]

the playback head is definately picking up. i held an ipod earbud up to it and the music from the ipod played through the guitar amp the ec100 was hooked up to.
i also found that if removed the plastic guard that guides the tapes in, i was able to hold the tape at a certain angle w/ a certain amount of pressure and it sounded the like the unit was functioning properly for a moment. i'm looking into trying to adjust the position of the record head, it seems there is one screw that uses a spring as a spacer, whereas the other screws on the heads are using regular fixed spacers.

You may want to make sure that the pinch roller is up to spec before going through all the trouble with aligning the head. The pinch roller can look decent and still be out-of-round or worn at a circular angle. A bad pinch roller can prevent the machine from recording or playing back even though it looks like the tape is going along business-as-usual.
----Just a thought

[Brad1]

What tape are you using? Do you have an old original Apollon, or are you using a new (not made anymore, but sometimes can be found) Dictaphone?

It sounds like you may have gotten a Dictaphone, since you mentioned trimming. The Dictaphones must be trimmed just right for them to work properly, or they won't let the shell seat properly to contact the heads. If you look at the cartridge from the open end, top up, that right-most tab must be worked down flush. You don't have to do anything to the top or bottom part sticking out, though.

It's also possible that there is something else wrong in the circuitry that is preventing the signal from making it from the record head to the playback head. Could even be something relatively simple like a bad "Echo Balance" pot, or loose wires, or something.

I have two 80s and a 100. I had $30 invested in them when I got them, so I figured they were worth trying to fix up. I had to repair all of them, and then I finally found some tapes. I originally only had one worn out Apollon, but it was good enough to work with. I've adjusted the two 80s so they have different speed ranges. One is set much longer. It can get really ugly at the slowest delay, but they are fun to mess with to get the EVH "Eruption" dive-bomb.

They also put out a pleasingly ugly grungy boost when you plug a guitar into the low input, and crank the unit's volume....on some amps. The one I have set for faster is great for rockabilly slapback.

http://www.univox.org/

Check out the above link, and click on "Schematics".

Brad1

[methodofcontrol]

in regards to the pinch roller: seems like it's working fine. the tape moves along like it should. also, when i held the tap at a certain angle w/ a certain pressure and the unit functioned...for that 10 seconds or whatever the tape recorded. and afterwards while i was tinkering around, about every minute or so i would hear that 10 seconds of recording play back through the amp.
in regards to the balance pot and potential loose wires: i've wiggled all of the wires to check for signs of a bad connection, i also resoldered all of the pots and cleaned them and measured them. all pots are working accordingly. as for the wires...i didn't find any problems on either of the boards when all coponants and wires were wiggled.
i'm not sure f i have an apollen or dictaphone tape. i borrowed it from a friend who has the univox version of this unit w/ a similar problem. the idea being...i'll get mine working, and then i'll know how to fix his. (hopefully) i looked at the cartridge from the open end, top up...and i see no tab on the right. i'm not sure what you're talking about. i can post a picture of my cartridge later today if that would help you figure out the origins of it.
thanks for everyone's help!

[Enzo]

Oh. Is this the one with the rectaqngular cartridge that plugs in the rear? There are a couple pressure pads in the cart that push the tape out against teh heads? Those foam pads break down so there is now no pressure holding tape/head contact?

[methodofcontrol]

i had that thought. i'm going to take the cartridge apart and check it out. although, it looks like it's alright. i mean, the foam under the tape at the play head window is the same as the foam at the record head window. and we know that the play head is making contact fine.
any suggestions as to what i can use to replace that foam? i've used a piece ofa sponge on old casettes back in the day, but i'm not sure if this application is a little more critical.

[Odd I/O]

certain types of weatherstripping material for door frames or windows might work. ---Or possibly a clipping of the soft foam that is used to make canned beverage insulators (known as "koozies" here in South Texas).

[methodofcontrol]

i think i fixed it. i fattened up the pads behind the tape to get the tape closer to the heads and i just played around w/ the unit for about an hour w/ no issues. thanks for the help guys!
just in case there is a decent head adjustment i can do, please let me know. i ended up not touching the heads at all, but i fear there may be too much padding behind the tape now, so if the heads can budge a little and i can remove some of the padding..that might be the best way to go.
thanks again.

[Enzo]

Oh I don't think the tape and padding will shove the heads anywhere.

Tape contact with the head is far less critical for playback than record. To record, teh tape head actually has to affect the physical makeup of the oxide on the tape surfacce. It aligns the particles magnetically. SO the record head needs very good clean tape contact.

Generally to align the heads on something like this, adjust it up and down while listening to what is on the tape - the wet setting - and tweak it for max treble.

[Brad1]

I still suspect you may have a Dictaphone tape that needs the cartridge trimmed. The old Apollon tapes were all white, with a paper label on top. The Dictaphone tapes (the ones I have anyway) are white on the bottom, with a see-through gray top. If it is a Dictaphone, and it hasn't been trimmed, it will do exactly as you indicated.

Where the tape opening is, the entire front edge sticks out a bit...look at it from the top, and you'll see what I mean. Now, look at it top up, peering at the tape. From left to right, you have the roller, the record pad, and the playback pad. They are seperated by the plastic "posts".

To the immediate right of the playback pad, the part of the plastic that is sticking out needs to be trimmed for a Dictaphone tape to work properly in a Univox EC- machine. You only need to cut, file...whatever the vertical tab flush to the body of the rest of the cartridge...flush to the immediate right. You don't need to cut down any part of the top or bottom plastic at that point. JUST the rightmost vertical part that's the same thickness of the top and bottom that is part of the protruding tape access windows.

What happens it that "tab" contacts something in the machine, and pushes the tape away from the heads on the right side. THAT'S the playback head. Why you can hear it when you push the tape in is because you are forcing it in close enough to actually pick up, but you are also applying undue pressure on the mechanical part that is contacting. Why it works when you put more padding behind it is because now you have pushed the tape outward far enough to reach.

Of course, if it IS seated properly, and there IS a chance that it is, and the pads ARE worn, that may be a solution. But if it's because it's a Dictaphone tape, and it hasn't been trimmed, then it's not a very good solution. The tape cartridge needs to be seated properly in the slot.
Pushing the tape out farther than it was designed will cause undue wear from having to slide against the plastic on either side of the head. That added friction could also put more strain on the machine's transport, if it's tight enough that it drags. It could start stretching the tape, and eventually break it.

Are there no markings to identify the tape? The Apollon is all white, and has (or used to have) a paper label on top. The Dictaphones are white bottom, gray see-thru top, and have "Dictaphone 90 Sec." on the rear edge.

Before you call what you did a permanent solution, I would seriously research the thing to find out if all you need to do is trim the cartridge. Trimming that part will not hurt it for it's original use.

i just stuck a small piece of printer paper that I cut, sized to go inside the cartridge's rightmost part, under the part going to be trimmed...and taped it in place to protect the tape. I took my wire cutters and started snipping it down, then I took a file to file down what was left. All three work perfectly on all machines.

This is a well-known problem with a well-known solution in the Univox world, since you can't get the original Apollon tapes, and people started using Dictaphones.

If it IS just worn pads, and not a Dictaphone tape, I suspect the tape is probably at least as worn as the pads, and sooner or later, you're going to have to have find a Dictaphone tape or two on Ebay, like I did. It will be good to be aware of this. They don't make the Dictaphone tapes anymore, either, but they are still out there, easier to find, and probably better than trying to buy an old, worn-out Apollon. I got lucky and ordered three brand-new, sealed-in-the-box ones from a guy. They weren't cheap, but for the little money I had in the three units ($10 each), and the fact that they don't work without the tape...it was worth it to me. He knew what people were using them for, had them in the musical instrument section, and knew he could get what he was charging. Actually, he gave me a better deal for buying three at once.

Brad1

[methodofcontrol]

my tape is white on the bottom and clear grey on top. i don't understand this whole "protruding tab" thing, though. perhaps my friend who lent me the tape already took care of this? i'll have to upload a pic for the experts to check out. expect that this evening. how much are these tapes selling for used? i'm going to need to get a tape for myself sooner or later anyway.

[Brad1]

Method,

It's not exactly a protruding "tab"...it's part of the molded plastic that protrudes a bit at the front of the cartridge. if it IS a Dictaphone, the cartridge would be pretty much a perfect rectangle except for a few things. The left and right sides at the back end are indented to provide a grip to pull it out. then it goes straight to the front (with a very small semi-circle near the middle) where it angles inward on each sideand meets the front. Then it goes parallel to the back about a 1/4", which is where the "protrusion" begins. It protrudes where the roller and the two pads are exposed for tape contact.

The protrusion is molded in all the way around where the tape access is. Run your finger across the front (tape access area) of the tape...it protrudes in the middle as referenced to the extreme right and left. The furthest right part of the protrusion...the vertical white plastic immediately right of the playback pad, needs to be filed down almost flush.
Then you'll have the right side of the cartridge coming in at an angle to the front of the cartridge. Instead of meeting the vertical "protrusion" before it gets to the right pad (the playback), it will simply be flat in that spot, and not push the cartridge out. That vertical part is the same width as the top and the bottom.

My digital camera gave up the ghost, or I'd post a pic. Suffice it to say that if that is a Dictaphone tape (which it sounds like), and it has not been trimmed, then it needs to be to work properly. Just protect the tape while you are doing it.

I don't know how to explain better than this. Maybe there are some better explanations if you Google "Univox tape", "Univox Ec-100 (or 80)", "Dictaphone tape", "Apollon tape"...whatever. Visit that Univox site I linked earlier, and look around in forums. I think you may find an explanation in there.

BTW, the guy I found about 6 months ago wanted $30 each. Since I ordered 3 of them at once, he sold them for $20 each. So, I have $90 and a few hours, wrapped up in three working Univox tape delays. Yep..expensive tape. They originally went for about $10 each from Dictaphone, but since they are no longer made...there ya go. Gotta pay to play, man, if they ain't made no more.

Post your pics, and I'll see if things can be made clearer.

Brad1