Reel-to-Reel Tape Recorder Puzzlement

I picked up an old Akai 4000Db reel-to-reel tape recorder the other day. I’ve got some old tapes that were recorded at 3 3/4 ips that I wanted to listen to. Trouble is, I can’t find a way to change the speed on the deck. It runs at 7 1/2 ips. There is a rocker switch marked “EQUALIZER” with “7 1/2” above it and “3 3/4” below, but changing its position doesn’t alter the speed of the tape. Since “equalizer” would seem to be a sound function I’m not surprised. I have searched every exposed surface of this machine and cannot find a switch to change the speed. I guess its a one speed (7 1/2 ips) recorder. So what is that “EQUALIZER” switch with the two ips speeds for?

It looks like there’s some sort of sleeve you need to remove to get the slower speed:

http://www.oaktreeent.com/Akai_Reel_Tape_Deck_Capstain_Speed_Sleeve_Replacement.htm

I’ve no idea what the ‘EQUALIZER’ switch does, but it’s probably explained in the 4000Db Manual.

You da’ man, Squink! There’s a knurled nut that holds a metal sleeve on a spinning shaft that the tape passes over as it exits the head assembly. Unscrewing it, allowed me to remove a metal sleeve that does, indeed, change the speed to 3 3/4. It’s somewhat inexplicable, to me anyway, but it works! Thanks for the quick answer. I’m now listening to my teenage self play drums in my first band. Boy did I suck.

In the old days, we had to swap out capstans to change speed.
revealing my ancientness :frowning:

Bah! In my day we had to instruct the Portuguese man-servant to crank the Victrola a little slower!

Now that I think on it, I’d bet that equalizer switch is to emphasize the high frequencies when you record (play?) at the lower tape speed.

That switch is nothing to do with controlling the speed.

It changes the bandwidth of the head amplifiers.

Its not quite the same as equalisation, although it has a similar effect in some ways.

Basically,when you run reel to reel tape, you have a choice, have a wider bandwidth and you get more high frequency hiss, but you also get much better dynamic range.

If you are recording music at high levels you don’t hear the tape hiss anyway.

ie The drive and punch of the music (compare a low bitrate MP3 file to a high bitrate one and the picture is similar in terms of dynamic range)

If you run at a lower speed this is more noticeable, and its why recording studios operate at up 32 in per sec.

The Akai400Db has Dolby noise reduction and was quite rare, most folk had the 400oD or the DS.

Changing this model from one speed to another means taking some part off it.

http://slbender.exactpages.com/akai4.html

Folk seem to think that MPS3 files or CDs give the best quality sound, what they don’t realise is that an awful lot of stuff was originally mastered on analog tape, which still performs extremely well.

I have stuff from the 1960’s that sounds almost live, all the early Elive stuff was recorded this way, and when you get the collectors versions of the CDs, such as the ‘Sun Recordings’ box set, you can hear the tape hiss, but the music still sounds fresh as it was made, you almost feel like you are in the recording studio.

Yep, that’s the deck I bought. One picture caption there explains the little post above the headcover is where you out the capstan sleeve for safekeeping after you remove it to make the speed change.

Thanks for posting this link!

In the *really *old days, we just told the guy to “bang the drum slowly.”