New Tape Delay Day (photo links updated - 2018)

[culturejam]

I'd love to own a real tape delay (the potential maintenance woes kind of worry me though).

It seems to be mostly replacing the tape and keeping the heads clean/demagnetized. This little Univox is surprisingly simplistic.

[peAk]

the two pieces of vintage equipment that I still can't believe I sold were my RE-201 and my Prophet 5 

Hang on to that tape delay, they are the coolest.

[raulduke]

the two pieces of vintage equipment that I still can't believe I sold were my RE-201 and my Prophet 5 

Hang on to that tape delay, they are the coolest.

You let a Space Echo go. Noooo 

God I would love one of those. Here's to hoping Catalinbread do some kind of epic recreation at some point (their Belle Epoch is amazing). The new boss digital unit just does not do it for me.

[culturejam]

Saw a similar EC-100 on ebay for cheap ($110) and bought it. 

This one was listed as "passes signal but no echo", and that indeed was the case when I got it. I cracked it open, and it is very similar to the EC-80, mechanically speaking. I noticed two issues right away: 1) the motor spindle had no pulley/guide for the belt that drives the capstan flywheel. The belt was just haphazardly moving up and down on the spindle as it spun. 2) one of the ground wires on the playback head was no longer soldered to the pin. I resoldered the ground wire, but this did not restore functionality (no echo).

So I went out to some local thrift shops and found a small crappy tape player. I removed the play/record head (it is combined on small and cheap decks), and also several other odds and ends that might be useful (pulley wheels, pinch roller, belts, etc). Turns out one of the pulleys was a perfect fit for the EC-100's motor spindle, so that problem was solved.

I removed the old record head from the EC-100 and replaced it with the play/record head from the tape player. Much to my shock, this transplant actually worked.     So now the EC-100 works and sounds similar to the EC-80 (same weak/drop-out repeats), so my original theory that the tape cartridge was the problem seems to have been correct. The motor noise leaks into the audio (changes pitch with speed), which is odd. But I've read some descriptions that say this is common to all EC-100s. It's probably a feature for drone/noise guys.  Another plus for ambient/noise rock dudes is that the Echo Repeats knob is also a push-pull switch that disables the record head, effectively turning the unit into a looper.

I also replaced the 50K motor speed pot with a 500K to allow for a bit longer delay times (about 350ms now, as opposed to maybe 250ms with the stock pot).

The arrow points to the head that was replaced. I left the wires long in case it didn't work, and I'll likely go back and shorten it up before putting it back in the head cab.

[peAk]

Saw a similar EC-100 on ebay for cheap ($110) and bought it. 

This one was listed as "passes signal but no echo", and that indeed was the case when I got it. I cracked it open, and it is very similar to the EC-80, mechanically speaking. I noticed two issues right away: 1) the motor spindle had no pulley/guide for the belt that drives the capstan flywheel. The belt was just haphazardly moving up and down on the spindle as it spun. 2) one of the ground wires on the playback head was no longer soldered to the pin. I resoldered the ground wire, but this did not restore functionality (no echo).

So I went out to some local thrift shops and found a small crappy tape player. I removed the play/record head (it is combined on small and cheap decks), and also several other odds and ends that might be useful (pulley wheels, pinch roller, belts, etc). Turns out one of the pulleys was a perfect fit for the EC-100's motor spindle, so that problem was solved.

I removed the old record head from the EC-100 and replaced it with the play/record head from the tape player. Much to my shock, this transplant actually worked.     So now the EC-100 works and sounds similar to the EC-80 (same weak/drop-out repeats), so my original theory that the tape cartridge was the problem seems to have been correct. The motor noise leaks into the audio (changes pitch with speed), which is odd. But I've read some descriptions that say this is common to all EC-100s. It's probably a feature for drone/noise guys.  Another plus for ambient/noise rock dudes is that the Echo Repeats knob is also a push-pull switch that disables the record head, effectively turning the unit into a looper.

I also replaced the 50K motor speed pot with a 500K to allow for a bit longer delay times (about 350ms now, as opposed to maybe 250ms with the stock pot).

The arrow points to the head that was replaced. I left the wires long in case it didn't work, and I'll likely go back and shorten it up before putting it back in the head cab.

Unreal, congrats man!

[selfdestroyer]

The front panel and knobs looks awesome on that ebay find. Must resist getting another tape delay but you are making it hard to avoid.

Cody

[culturejam]

The front panel and knobs looks awesome on that ebay find. Must resist getting another tape delay but you are making it hard to avoid.

If you are willing to do the leg work of fixing up a non-working unit, these Univoxes are outlandishly cheap. They also aren't the greatest sounding tape delays, but it's more about the challenge of repairing/modding for me than it is anything else. I do believe that modern pedal makers have succeeding in capturing with digital tools most of what makes a tape delay sound the way it does. At this point, you're in it for either the nostalgia or the fun/challenge. 

BTW, I'm trying to figure out a way to hack together a DIY tape delay. My research thus far has concluded one thing with a high degree of confidence: there's not going to be an easy/repeatable process to follow. I suspect that is why there isn't already a 10-year-old tape delay project out there. Each build will be a custom project. So it's not really something I expect to  be formalized into a typical DIY project writeup. But I'll share whatever it is that I find. The challenges are legion.   

[jubal81]

Really neat stuff, CJ.
I think you're right, though, about a DIY option not being practical - too much mechanical engineering with motors, etc. Although, since you pointed out the schematic and some of its weaknesses, I think it would be interesting to redesign a better circuit that could be popped into one of these Univoxes - kind of like the "replace your Rat guts" initiative. I have no idea how common these units are, though.
Adding a remote footswitch would be pretty cool, too.

EDIT: Just looked on Bay and Reverb and there were very few and they're very pricey. Oh Well. Maybe if I can snag a really good deal I'll soup one up one day just for the challenge.

[culturejam]

I think you're right, though, about a DIY option not being practical - too much mechanical engineering with motors, etc.

There are a couple of distinct physical challenges. Anyone sufficiently motivated could figure it all out, however. I'm going to take a stab at it, just for the experience.

Although, since you pointed out the schematic and some of its weaknesses, I think it would be interesting to redesign a better circuit that could be popped into one of these Univoxes - kind of like the "replace your Rat guts" initiative. I have no idea how common these units are, though.

Wow, I didn't even think of that. Yes, that's a really good idea. An improved preamp and mixing circuit would go a long way. You could even add a PT2399 in there for multi-tap. 

Adding a remote footswitch would be pretty cool, too.

Both the EC-80 and EC-100 have footswitch jacks built in already. The 80 has it on the back, the 100 is on the front.

EDIT: Just looked on Bay and Reverb and there were very few and they're very pricey. Oh Well. Maybe if I can snag a really good deal I'll soup one up one day just for the challenge.

Just keeping looking. The working units are usually $275 - $350. It's the busted ones you want to look for.

[peAk]

What year was that built? It looks super clean.

[culturejam]

I can't find any hard evidence on when these things were made. The best I can tell, the were made from about 1975 to about 1982-3.

I checked and don't see any codes on the pots.

Edit: the EC-80's motor is dated as being made in May of 1975. The EC-100's motor has no date on it.

[gordo]

I had a few of these and around the time that Van Halen was using them they were a dime a dozen.  This was right on the cusp of the MXR analog pedal coming out and honestly, for me, it wasn't until the digitals started to appear that anyone could touch the Univox, Echoplex, et al.  I had a Maestro SirEcho that was a cheezy version of the EP but I bought a reel of 1/4" recording tape and some splice tape and could refurb my own carts to my hearts content.  Listen to any of the Blackmore era Deep Purple and the first Rainbow album to get a taste of the tape goodness.

Just don't go brain dead like I did and get rid of it...

[lincolnic]

Pretty jealous of your tape finds, CJ! Please do keep us posted on what you come up with for these guys.

[culturejam]

Anyway, I finally got a damn PlayTape cartridge in today (off ebay) to verify that there's nothing wrong with the actual units, and that it's the other cartridge I had that was the issue. So the PlayTape is essentially exactly like the Apollon/Dictaphone cartridges that came stock with the Univox, with one small difference: there is a groove in one side of the Apollon that mates with a notch in the cartridge housing on the Univox. The PlayTapes do not have this groove, so they won't fit the housing. I read that other folks have modified the PlayTape cartridges to make them work but sanding down a groove to make it match the housing. I think this is stupid. Why modify multiple cartridges when you can just modify the one housing? I carefully cut the tiny notch out and smoothed it down flush. The PlayTape now fits and works just fine. It's a little tight, but it definitely works.

Tape delay, baby! The EC-100 is now working in full. The only issue is the motor noise/whine I mentioned previously. I've heard some people report this is normal for these units, but I may try a different playback head just to see if it makes a difference. Still, the repeats are pretty nice. A little hissy, but the modulation is nice. There is some "wow" in all speeds, and on the longer delay times there is also some "flutter" most of the time. The randomness is pretty cool.

Now to mod the EC-80 to take the PlayTape cartridges...and also to learn how to repack these cartridges myself.






Playtape vs Apollon/Dictaphone cartridge:

[Leevibe]

More jealous than before