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DIY Stompboxes => Building your own stompbox => Topic started by: thomas2 on September 18, 2004, 08:34:49 AM

Title: DIY tape echo thingie..
Post by: thomas2 on September 18, 2004, 08:34:49 AM
OK! i've already built the mechanical part. now i gotta figure out how to make the record head record the input signal to tape and how to amplify the signal from playback heads.. any suggestions where i could maybe find such information? thanks.
Title: DIY tape echo thingie..
Post by: Ansil on September 18, 2004, 12:27:42 PM
question???  why hnot canibalize a real tape recorder. its so easy. or did you just want the experience.

personally if you want a good taper saturation. get a little walkman that has a tape player and rip out its amplifier section you can;t beat the simpliicity and the loudness of it.

it has like a transistor or jfet preamp you just cut off the playback head and solder new wires there and from the preamp you go into its lm386 [type chip] and it pumps out your signal
Title: DIY tape echo thingie..
Post by: thomas2 on September 18, 2004, 12:44:00 PM
yeah.. i'm doing this just for fun. i've already got the record and playback heads + motor from some old tape recorders that were broken. i was thinking of making some sort of 386 based amp to it (386 is my favourite chip anyway).. i just don't understand how the recording works.. do i just feed the input signal amplified to the record head?  :lol:
Title: DIY tape echo thingie..
Post by: thomas2 on September 19, 2004, 03:03:48 AM
anyone?
Title: DIY tape echo thingie..
Post by: thomas2 on September 19, 2004, 09:43:17 AM
i'm pretty sure someone knows how the recording head works! that's the only thing i don't get..
Title: .
Post by: petemoore on September 19, 2004, 10:15:08 AM
Well it probably has impedance.
 Matching this equation would probably be easier if the impedance part was known?
  Sorry Thomas Im obviously [I hope[ just guessing.
 The technology for this is so automated [I guess again] that there's little DIY going on around?
 IIUC the head is a precise electromagnet [?] and electro waves are exposed to the magnetic tape leaving a magnetic wave pattern on it...
 try to Look up tape head replacement data sheets?
Title: DIY tape echo thingie..
Post by: Ansil on September 19, 2004, 03:05:39 PM
you could always look how they did it in the past and go from there.  i didnt' want to look too much into it thats why i just used a already built unit.  [keep in mind that i did do a lot of searching for a particular tape recorder as i had had one when i was a child that i kept till i was an adult and did all sorts of recording with it and loved the tape saturation that it gave.]
Title: DIY tape echo thingie..
Post by: Johnny Guitar on September 19, 2004, 03:16:23 PM
You probably already know this but all tape recorders have a bias oscillator which is mixed in with the signal to the record head. I want to say this is around 40-50kHz but I don't remember at all. You need that bias osc to get a good quality signal on the tape. You may also need to filter it out (or otherwise demodulate it) from the recorded tape.

I have a buch of old reel to reels, cassette decks, and Walkman tape players/recorders which I've thought about canibalizing. I wouldn't really know how to start and it seems like a lot of work.

J
Title: DIY tape echo thingie..
Post by: thomas2 on September 19, 2004, 06:27:47 PM
yeah.. i've heard about that. sounds diffcult/impossible to make with my skills.. and without any schematics. thanks anyway..
Title: DIY tape echo thingie..
Post by: Thomas P. on September 20, 2004, 02:59:01 AM
I found this thread rather intersting so I've searched on my own and found this:

echoplex2 (http://www1.korksoft.com/~schem/veffects/echoplexep2.pdf)
echoplex3a (http://www1.korksoft.com/~schem/veffects/ep3b.pdf)
echoplex3b (http://www1.korksoft.com/~schem/veffects/ep3a.pdf)

All schematics are from http://www.schematicheaven.com

And here's a guy who build one from this schematics (the site is in german, maybe you could google the url and translate it):
http://www.jogis-roehrenbude.de/Leserbriefe/Lorenz-Bandecho/Bandecho.htm

I hope this will help you...
Title: DIY tape echo thingie..
Post by: thomas2 on September 20, 2004, 03:22:57 AM
thanks, but i don't wanna start messing around with tubes and high voltages.. only the simplest solid state one will do.. i have schematics for one other (much simpler) tube tape echo from some old 60's finnish magazine, but i'd like it solid state.
Title: DIY tape echo thingie..
Post by: Johnny Guitar on September 22, 2004, 12:00:44 AM
I've actually been thinking about this for a couple of days now and thought up a couple of other points:

1) you can avoid (I think) the problem I mentioned involving the bias oscillator merely by taking *all* the electronics with the play head from one tape deck and transplanting all of it onto the deck with the erase and record head and electronics.

2) If I were to do this I'd look at using old 8 Track players since they use a continuous loop in a self contained cartridge. They also use 1/4" tape. If some small manufacturer were smart (???) enough to try and introduce a replacement for the Echoplex or Space Echo, I think they would well suited by using 8 Track tape technology and outfiting the record and play electronics with either full track mono or two track (half track) stereo heads. But you could already put a standard 1/4 trck electronics into an 8 track transport. It would sound as good as a 1/4" stero tape deck (good!) and would not be *that hard* to do.

J
Title: DIY tape echo thingie..
Post by: LinuxMan on September 22, 2004, 02:46:04 AM
Quote from: Johnny Guitar
2) If I were to do this I'd look at using old 8 Track players since they use a continuous loop in a self contained cartridge. They also use 1/4" tape. If some small manufacturer were smart (???) enough to try and introduce a replacement for the Echoplex or Space Echo, I think they would well suited by using 8 Track tape technology and outfiting the record and play electronics with either full track mono or two track (half track) stereo heads. But you could already put a standard 1/4 trck electronics into an 8 track transport. It would sound as good as a 1/4" stero tape deck (good!) and would not be *that hard* to do.
Heh, you can have an Echoplex replacement right here (http://www.fulltone.com/tte.asp). If you have 999$
that is. ;) He does his own tapes and there's even a video showing how.

Cheers
LM
Title: DIY tape echo thingie..
Post by: Johnny Guitar on September 22, 2004, 08:50:12 PM
Quote from: LinuxMan
Heh, you can have an Echoplex replacement right here (http://www.fulltone.com/tte.asp). If you have 999$
that is. ;) He does his own tapes and there's even a video showing how.

Cheers
LM

Yep!

A *bit* more than I'd want to pay but I'm sure it's a great machine.

Next idea: find those old cassette loops for the older style phone machines!

J