Need Help, Want to build a 3head tape machine!

[peps1]

Hey guys, really need some help, Want to build a very simple 3head tape machine. I can get away with it being really limited function as its going to be part of a echo unit akin to the 60's tape echos by Wem.
http://www.youtube.com/watch?v=FtL0efmtFSk

Want to see Just how small I could get this down to by using c90 Compact Cassette rather then tape loops with a simple wipe-record-play head configuration.

Iv got no problem modulating the sound once its into the unit......Trouble is, Iv never built anything using tape heads, so as they are a unknown quantity I could do with some help if anyone has advice, plans or schematics that could help.

[Mark R]

There is this here

http://www.schimmel.talktalk.net/tape/index.htm

where the guy has built something similar, looks like a big job!

Let us know how you get on.

cheers Mark

[Steve_P]

Well, if you're building your own deck, you need to machine up every piece. I'm sure that Colin could do it, but most of us it's a no-no. The same applies here for reel to reel and cassette. Actually, with a cassette, you haven't got room for the three heads.

You need to erase, record and play back music. The erase is easy, just pass a strong alternating current through an erase head. As far as recording goes, you need to bias the signal before recording it. Playback is simple enough.

Back in the day, most home constructors used an existing deck. The process of recording and playing back on a tape is explained here...

http://hyperphysics.phy-astr.gsu.edu/hba.../tape.html

Good luck!

Cheers,

Steve P.

[peps1]

Thanks Steve P., really good info!

Machining is not a huge deal issue, got a few friends with big tools and metal working shops.

From the looks of it I can use a off the shelf unit striped down walkman for the Driving the tape, Erase head and record head (as it will be biased).......so just need add a 3rd head for the Playback!!!

Now time to find out how to add a 3rd head and.......its look like it works the same as a guitar pick up!?

[Mark Hennessy]

3 head cassette decks were very popular back in the day, but they were expensive - I couldn't afford one when I was a student and cassette was still the predominant way to record. I've since bought a couple from eBay for approximately one hundredth of the original price, so that's nice

Anyway, these use a "Siamese" recording and playback head that fits into the centre opening of the cassette shell. The erase head fits into the left, and the pinch roller into the right.

It might be possible to find one of these, but the trouble is, the record and playback heads are only separated by a few millimetres - so I don't know if you'd get the echo effect you're after - even at 1 7/8 IPS.

Incidentally, some really posh 3-head machines had dual capstans as well, meaning the erase head had to be really tiny to make it fit. This might enable you to separate out the record and replay heads a bit more?

So, if you see a broken high-end 3-head cassette deck offered for spares and repairs, it might be worth biting

And don't underestimate the challenges of making good record/replay circuitry of any sort of quality. I'd re-use as much as possible from an existing unit, and I'm talking as someone who has made a *lot* of audio stuff over the years...

Hope this helps,

Mark

[Steve_P]

For echo, you will need to take the tape out of the cassette to separate the heads enough to do this. So the cassette will have to have the tape come out and go back in and between this form a loop. Think of a video recorder.

The erase and record head on one side of the loop, the playback head on another.

You can then use the whole tape and vary the speed to get the echo you want.

Cheers,

Steve P.

[tiv48]

you could use apermenent magnet instead of the erase head making room for another playback head
better to use a 3 head reel to real but it still wont sound like a wem copy cat
rob t

[peps1]

Thanks guys, some really handy information....and LOTS of reading to do!

[Paula A]

What a shame I lost it in the move. I had a Sharp auto-reverse walkman with a 4 track head.

Interesting project, but an odd thing to want to do. I recently gave away a Melos tape echo unit because it needed a new mini 8 track type tape cartridge and they cost more than a working 70's Copycat.

I saw this and had a quick look on the music forums for gear for sale... and came across a Teac professional tape echo machine on offer sort of working for £5 plus postage. I remember using them back in the day when a used cocycat was £5 and the Teac was still current and over £200 .. just shows.. people want the Copycat because of it's sound (all that hiss and fixed delay times.. never liked them) and will pay more for one than for a decent digital rackmount..

A micro casette dictation machine and a cheap walkman will provide most of the bits you need, then just cobble it together.. Most tape loop machines didn't use an erase head, just a fixed magnet.

[Eddystonepete]

Hi Peps, you could start with an 8 track deck. That would give you 2 playback pre amps to start with. Extra heads could be got from a R to R machine, and if it was a transistor one, the rec/bias/erase could be used without much alteration. You would have to have the tape exiting the cartridge though. Another idea, jingle cart machines are now old hat, although I havn,t seen many around for years. They usually had separate rec and play amps, plus erase, all you need!. Loved the rock and roll though. What guitar is that?.
Peter