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Cart recorder head - dumb question

not if you expect any kind of decent performance

record head gaps are generally 6-10 X as wide as playback gaps

plus the inductance is lower, to allow use of bias frequency

you CAN go the other way, use a record head for PB, but HF response will drop drastically
 
Actually, there are (were) heads designed for dual use, recording and playback, although I don't remember a cart manufacturer ever using them. They were fairly popular on moderately priced home reel to reel recorders. Sony, Miranda (house branded as Lafayette) and others used the technique.
As regards all the cart machine play heads I've ever run across, Gary G is correct.
A major problem was/is the record head windings must withstand bias current as well as record current,which requires some compromises in manufactire; which compromises aren't necessarily compatible with good audio performance.
As an aside, Akai built and marketed a line of reel recorders which used a seperate bias head (They were called "CrossField" machines). Mechanically, they were nightmares... but when they were properly aligned, the performance was excellent.
 
Thank you both.
When I made the question I had in mind the standard 2 head k7 tape recorder :)

My intention is to use of of my 6 ITC Deltas as a companion for the record amplifier wich is connected to a ITC triple decker at the moment.
I have the manual, now I have to find a recording head (ebay?), 3 connectors and wire to make the harness.

Pedro
 
littlejohn said:
Actually, there are (were) heads designed for dual use, recording and playback, although I don't remember a cart manufacturer ever using them. They were fairly popular on moderately priced home reel to reel recorders. Sony, Miranda (house branded as Lafayette) and others used the technique.
As regards all the cart machine play heads I've ever run across, Gary G is correct.
A major problem was/is the record head windings must withstand bias current as well as record current,which requires some compromises in manufactire; which compromises aren't necessarily compatible with good audio performance.
As an aside, Akai built and marketed a line of reel recorders which used a seperate bias head (They were called "CrossField" machines). Mechanically, they were nightmares... but when they were properly aligned, the performance was excellent.
Click to expand...

I have one of the Akai reel to reels. They put the recording "bias" head on the opposite side of the tape, slightly upstream from the recording/playback head.
The advantage was that since the audio was impressed in the "declining field" of the bias, it was not subject to the partial erasure during recording that happens when when the audio and bias frequency are in the same head. The result was that the high frequency response was equal to what you would get normally at the next higher speed. Recordings at 3 3/4 easily went to 19 khz or so on average quality tape.
They used back tension to maintain tape-to-head contact, and there are times when I sure do wish there were felt pads to do the job. :-\
Once I wished I had a professional quality machine instead of the consumer version, an X-165D.
On the other hand, the consumer version had a much simpler mechanical control system instead of solenoids for functions.
As all drive on the consumer version is off a single motor, it is easy to have any tape transport mechanical variations telegraph through into the motor speed and end up as flutter in the recording or playback. It has been some work to keep it clean-running all these years.

I remember reading that dual purpose head decks actually got better frequency response as the head wore out and the gap became more and more shallow, until eventually the depth was gone and the gap began to get wider as wear continued. The the response fell off VERY quickly afterward.
 
Dunno as i quite agree with that analysis of frequency response. I believe you'll find response (assuming the thing is aligned properly) is pretty much a functuion of gap width and tape speed. I'm discounting frionge effect here.
 
littlejohn said:
Dunno as i quite agree with that analysis of frequency response. I believe you'll find response (assuming the thing is aligned properly) is pretty much a functuion of gap width and tape speed. I'm discounting frionge effect here.
Click to expand...

That info about the partial erasure during recording resulting in decreased response was straight out of the Akai literature.
My assessment and experience was that the response is equal to "one speed higher".

I can't 'member where I read about how freq response changes as the gap wears down, but I know I didn't make it up.
It's another one of those things that seemed important enough to file in my "permanent mental file".
 
Eventually it would degrade response. This because of the way the pole pieces are shaped. Looking down from the top, the gap would be at the apex of a V. Wear it enough, and the metal at the bottom of the V will be gone and you are running the tape against the legs. So yeh, at that point the gap would widen causing a loss of response. You're s'pposed to replace them before you see daylight through them though :):)
 
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