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Hoffman Amps Forum image Author Topic: Bare Bones Tube Echoplex?  (Read 10544 times)

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Offline jerryjg

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Bare Bones Tube Echoplex?
« on: June 07, 2009, 06:45:50 pm »
Okay, first of all, let me pre-qualify this by stateing I couldn't carry any of you guys jockstraps. I am one of the guys here not at all electronically proficient. Now, Something very stupid just came into my head- and that is the possibility of useing this old Tube recorder, which actually works very well, to make it into some close approximation of a tube tape echo device.
Like a tube echoplex.
You would need some type of control for the actual effect besides the FF/stop/ RW/ FW controls like  a direct in box and/or some type of preamp or control unit?
Also, in case its necessary, I do have another tube tape machine of this type to run  the both together. Maybe some kind  Anologue  delay unit  direct into this tape recorder to act as the control unit?
I am asking this cause a real vintage exchoplex now costs almost a grand. Also, they arent tube , they are solid state.
If I'm way out in left field, I aplogise, and won't ever try this type of grandiose thing again. Thanks.;


[/img]
« Last Edit: June 07, 2009, 06:55:23 pm by jerryjg »

Offline thermion

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Re: Bare Bones Tube Echoplex?
« Reply #1 on: June 08, 2009, 11:50:01 am »
the tape needs to be looped and a real plex needs a way to change the distance between the record and playback head.  i think it could be done if you study some plex schematics and get a feel for what's going on, then try to emulate with what you have in front of you. you may need to figure a way to get more control over the motor speed.
guaranteed if you see this through you'll have at least partially overcome your electronics deficiencies. good luck!

Offline tubesornothing

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Re: Bare Bones Tube Echoplex?
« Reply #2 on: June 08, 2009, 12:37:35 pm »
You can change the time between recording and playback heads by adjusting the tape speed.  You will probably need to grab a schematic for the unit and cannibalize it somewhat.  See if you can find one and post it - it look like a fun project.  Continuous loop would be good but not required as long as you have a long enough tape.

You'll need to check the head arrangement hopefully is erase head, record head then playback. If not, then you'll have to remount them. I wounder if that unit actually had erase heads...





Offline PRR

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Re: Bare Bones Tube Echoplex?
« Reply #3 on: June 09, 2009, 01:24:27 am »
> head arrangement hopefully is erase head, record head then playback. ... I wonder if that unit actually had erase heads...

Probably; but it surely has a combined record/play head, and one single amplifier switched between the two functions.

> I do have another tube tape machine of this type

I've never seen ONE of that model, you got TWO?

And you know it is good: it says "professional" next to the 2-cent RCA jack.

It says "Armour Institute" inside.

OK, lucky bastid. Side by side. Full reel on left spindle left machine. Empty (dummy) reel on takeup spindle left machine. Takeup reel on takeup spindle right machine.

Thread tape from far left, over left heads, NOT through pinch roller, guide through dummy reel. Now to right machine, over heads, through the pinch, and take-up.

Left machine in REC. Right machine in PLAY.

I bet there is no tape-break sensor; if it knows the tape is mis-threaded, you have to gimmick the safety features. And you should shove a stick in the dummy reel; it will work spinning or stationary, but stationary is better.

Is that reely a steel reel?

It may be 15ips, or 7.5ips. (I bet the capstan comes off and the innard is half-size.) At 15ips you get just about 1 second delay between side-by-side machines, a short riff. At 7.5ips and 30 feet between heads you get 48 seconds (I have done this live on stage before an audience), a whole verse.

Just like that, you get one repeat and you better be done before the reel runs out.

Take a mike stand, jam a 1/4" rod, slide a 3" reel on it, adjust same height as the decks. You may need more guides on the decks, be clever (but non-magnetic). Cut the desired length/time of tape, splice the ends (the best Scotch Tape is excellent), thread around the path, move the mike stand to carry the loop. Jam all spinning spindles. Now you can play forever (well, the tape can last longer than the drugs).

If you un-tack one wire on the erase head, the tape-loop is not erased on every pass, and prior sounds will come around again, but weak because the REC head has some erase effect.

For re-re-re-peat, take the PLAY output and +mix+ it back to the REC deck. This will apparently need an external mixer. I guess the $49 2-in Bee-ringer toy is plenty good for this.

You ask: why skip one pinch-roller? The two machines don't run the same speed. The tape either breaks or spills. One tape, any number of heads, but only one pinch.

Gah. I'm going to smell like tape-dust for a week.

Offline jerryjg

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Re: Bare Bones Tube Echoplex?
« Reply #4 on: June 09, 2009, 11:47:51 am »
> head arrangement hopefully is erase head, record head then playback. ... I wonder if that unit actually had erase heads...

Probably; but it surely has a combined record/play head, and one single amplifier switched between the two functions.

> I do have another tube tape machine of this type

I've never seen ONE of that model, you got TWO?

And you know it is good: it says "professional" next to the 2-cent RCA jack.

It says "Armour Institute" inside.

OK, lucky bastid. Side by side. Full reel on left spindle left machine. Empty (dummy) reel on takeup spindle left machine. Takeup reel on takeup spindle right machine.

Thread tape from far left, over left heads, NOT through pinch roller, guide through dummy reel. Now to right machine, over heads, through the pinch, and take-up.

Left machine in REC. Right machine in PLAY.

I bet there is no tape-break sensor; if it knows the tape is mis-threaded, you have to gimmick the safety features. And you should shove a stick in the dummy reel; it will work spinning or stationary, but stationary is better.

Is that reely a steel reel?

It may be 15ips, or 7.5ips. (I bet the capstan comes off and the innard is half-size.) At 15ips you get just about 1 second delay between side-by-side machines, a short riff. At 7.5ips and 30 feet between heads you get 48 seconds (I have done this live on stage before an audience), a whole verse.

Just like that, you get one repeat and you better be done before the reel runs out.

Take a mike stand, jam a 1/4" rod, slide a 3" reel on it, adjust same height as the decks. You may need more guides on the decks, be clever (but non-magnetic). Cut the desired length/time of tape, splice the ends (the best Scotch Tape is excellent), thread around the path, move the mike stand to carry the loop. Jam all spinning spindles. Now you can play forever (well, the tape can last longer than the drugs).

If you un-tack one wire on the erase head, the tape-loop is not erased on every pass, and prior sounds will come around again, but weak because the REC head has some erase effect.

For re-re-re-peat, take the PLAY output and +mix+ it back to the REC deck. This will apparently need an external mixer. I guess the $49 2-in Bee-ringer toy is plenty good for this.

You ask: why skip one pinch-roller? The two machines don't run the same speed. The tape either breaks or spills. One tape, any number of heads, but only one pinch.

Gah. I'm going to smell like tape-dust for a week.

  Wow, thats pretty amazeing!  Thanks.   I've decided this might be just a little easier lol;
http://guitars.musiciansfriend.com/product/Danelectro-DE1-DanEcho-Guitar-Pedal?sku=151855&src=3WFRWXX&ZYXSEM=0&CAWELAID=26018608

Offline thermion

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Re: Bare Bones Tube Echoplex?
« Reply #5 on: June 09, 2009, 02:32:28 pm »
Quote
I've decided this might be just a little easier lol
Yeah lol alright...PRR dumps his brain for you and you say "TOO HARD!"
Maybe in the future he won't waste his time with such excellent insight and just refer you straight to MF.
Tell your electronics deficiencies I said hello...

Offline jerryjg

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Re: Bare Bones Tube Echoplex?
« Reply #6 on: June 09, 2009, 05:27:09 pm »
Quote
I've decided this might be just a little easier lol
Yeah lol alright...PRR dumps his brain for you and you say "TOO HARD!"
Maybe in the future he won't waste his time with such excellent insight and just refer you straight to MF.
Tell your electronics deficiencies I said hello...
I see waht you mean, and I apologise. I didnt mean to diminish his efforts. I read it with great interest. I might try it if I actually thought i was capable of it. Anyway, point well taken and I stand down.

Offline thermion

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Re: Bare Bones Tube Echoplex?
« Reply #7 on: June 09, 2009, 09:25:26 pm »
jerry- you CAN do this. stand up! that's the beauty of this forum; it's like a hive-mind. you have access to true-blue folks who can help you with anything you want to do in the world of amps/effects/stirling engines/CNC/owls.. whatever. learn and learn, take advantage of what's here, and learn some more. no disrespect intended.

Offline Shrapnel

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Re: Bare Bones Tube Echoplex?
« Reply #8 on: June 10, 2009, 12:19:00 am »
that's the beauty of this forum; it's like a hive-mind. you have access to true-blue folks who can help you with anything you want to do in the world of amps/effects/stirling engines/CNC/owls..

hehehehe... AND as long as it fits in the proper slot, no one gets their panties in a knot if it isn't  related to a specific amp, guitar or otherwise.  :grin:
-Later!

"All the great speakers were bad speakers at first" - Ralph Waldo Emerson

Offline PRR

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Re: Bare Bones Tube Echoplex?
« Reply #9 on: June 10, 2009, 02:39:22 am »
> jerry- you CAN do this

I did it, long ago, mostly on salary. It was wonderful to be paid to diddle around with wires and tapes. And "long ago" was days when this stuff was still pretty amazing.

Now that we have computers smaller than a room, under a million bucks, and iPods and MP3s and buck/gigabyte storage, it all seems quaint. Razor cuts all over my fingers, splicing tape stuck to my ass, doing limbo under tape-loops strung across the lab and back. And constantly cleaning heads, rubber pinch-rollers, patch cords.....

I love to play with the tech-toys, but looking back, I don't see very much music came of it. The few exceptions, I think the least tech-cost the better... I saw Steve Miller in Dayton Ohio (when he was just starting to book big venues) and he had a live piece with massive echo (I don't think he ever put it to wax). That was probably tape, and probably made somebody like me crazy setting-up and being sure it would work. I'm sure it often didn't. Today it would surely be done with the $79 box (or $79 of guts in a $999 box), better because it would always work.

So if Jerry wants to punk-out, that's probably smart.

I'm still really curious what brand that machine is. No fast-forward.... that's pretty old and crude.

Offline The Radium King

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Re: Bare Bones Tube Echoplex?
« Reply #10 on: June 13, 2009, 10:56:55 am »
univox makes a VERY inexpensive tape echo unit called the ec80. 30-60 bucks on ebay. lo-fi, solid state signal path. i looked into changing the signal path to tube (keeping the mechanicals as is, c/w ss motor drives, etc.). you can search my thread around here someplace. prr advises - possible but tough; in my case the record/erase heads used for ss have a difference impedance than those used for tube. everything would have to be buffered; a plethora of tubes. so sad.

Offline nastyoldtech

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Re: Bare Bones Tube Echoplex?
« Reply #11 on: July 31, 2009, 06:08:11 pm »
univox makes a VERY inexpensive tape echo unit called the ec80. 30-60 bucks on ebay. lo-fi, solid state signal path. i looked into changing the signal path to tube (keeping the mechanicals as is, c/w ss motor drives, etc.). you can search my thread around here someplace. prr advises - possible but tough; in my case the record/erase heads used for ss have a difference impedance than those used for tube. everything would have to be buffered; a plethora of tubes. so sad.

I think I used to have one of those. Is that the one with the little teletype cassette tape in the back?

Offline tubesornothing

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Re: Bare Bones Tube Echoplex?
« Reply #12 on: August 02, 2009, 08:58:26 pm »
Quote
"punk out"    
   
To be intimidated to the point of retreat.


"come on man jump..don't punk out"

"I just punked out 5 guys with bats by showing them my gun"

"building a tape echo from two old tape units is too much - I am going to punk out"

 


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