DIY Tape-delay problem

Arthur Vermeij

New member
i just bought a reel to reel recorder, because i want to use it for tapedelays.
i am able to get the delay effect with a simple mixer, but since i want to use my mixer for other this as well, i wanted to build something into the reel to reel for the delay effect.
i thought i needed to solder the RIGHT line out to the LEFT and RIGHT aux in and then i would control the amount of feedback with the aux in controls. the right channel would have one repeat and the left channel would have multiple repeats depending on the aux in control.
however, when i tried it, it didn't work.. I can't hear the source signal when i switch the machine to source, and when i switch it to tape i only hear one repeat and it is really quiet..
i think it has something to do with the signal levels, but maybe i'm overlooking much more.

does anyone know what i need to do or has done it him or herself?
thanks,
Arthur
 
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Not sure how you think you're going to get multiple repeats/feedback with a typical tape recorder.
For those things, you need multiple record heads..etc.

A typical tape deck only has one record and one playback head = one repeat.

The most you could do is control the delay time somewhat by adjusting the tape's speed...either via pitch control and/or changing its actual REC/PB speed if it has more than one.

AFA the level...all depends on what the recorder is using relative to your mixer, etc... -10 VS +4...etc...look at the specs and compare.
 
The recorder has 3 heads so it is capable of multiple repeats, with my mixer it works fine but i want to build a permanent mixer into the machine..
 
You can get multiple repeats by feeding the output signal back into the input*...Carefully! Obviously there will be a point where it goes unstable but like any "feedback" e.g. mic/speaker, there will first be a "clangy" quality that is the harbinger of total sonic anarchy.

*A mixer for this is easily built around an NE 5532, better is the LM 4562. If the TR does not use ICs it will likely have a single supple rail. You can use 10k "splitter" resistors or do it "properly" with a cheap chip. NB. Always use local decoupling and take supply + and - wires back to the first supply capacitor. DON'T pinch juice just where you "happen to be"!

Anytime you are fooling with ICs and audio, get Douglas Self's book. Small Signal Audio Design.

Dave.
 
but i want to build a permanent mixer into the machine..
If that's the way you want to go, I guess you need to find the tiny mixer you like and drill some holes in the your tape machine for the knobs. Not sure what you're gaining by doing that because the resale of the tape deck just plummeted, but i'm all for you doing what you want.

Be careful of locations and maybe add some shielding against motor noise. Maybe. Some decks have lots of room inside and others not so much. Don't know your transport nor the mixer you wish to use.

P5
 
Having been a tape recorder technician for many years don't mess up the deck as the correct process can be had in the correct use of the mixer and without making a mess of the deck. Most the time people that have not the technical knowledge to do things like this destroy equipment and never get what they want.

The truth is that all the delays and circulating echo can be done through two channels of the mixed and everything controlled nicely with EQ modification and even cross echo. To get the echo you need to put the machine in record and leave the deck in monitor mode. The amount of delay will be controlled by the speed the deck is at. The recirculation or bounce has to do with the injection level and the pan pot setting. A person who knows how to set up a mixer and tape deck will never even need to heat up a soldering iron.

IF you are destined to wreck a tape deck do so on a Akai or Dokorder as then nothing will be lost.
 
You can't simply solder an output to an input and expect it to work properly. There are plenty of small mixers for around $50 that will do what needs to be done. No sense messing up your deck.
 
This thread is old. But I imagine they guy abandoned the idea.

or at least got a hold of a cassette answering machine and modded that for a fake echoplex.
 
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