[Vintage-Audio] Re Revox Models

[WBob]

Fred you are right. There are four "kinds" of 1/4 inch decks. all but one is 
incompatable with the others.

First there is the one track or mono deck. I have two of these where there is 
one fat track across the tape. Both of mine are Ampex ATR 700s. Since the head 
block is interchangable on this deck, I am offering a mono head block on ebay as 
I type.

The second is two track or half track where there are two tracks symmetrical 
across the tape with a wide gap between. This is common for mastering decks and 
for broadcast applications. The tape is only played in one direction and is 
normally stored in a "tails out" configuration and rewound before playing. A lit 
of prerecorded music tapes are available in this format. When played on a mono 
deck the stereo sound is mixed between the channels and you lose about 3 dB in 
loudness due to the less tape under the head gaps. If you play 4 track stereo 
(see below) on a mono machine it will be a mess.

Four track stereo is really two tracks at a time to record/play stereo using 
channels 1 and 3 for left and right in the forward direction and 4 and 2 in the 
reverse direction. The deck may come with heads with two small channels on 1 and 
3 track positions and you need to reverse the reels to play the reverse 
direction forward. or it may have two sets of heads, one set up for 1 and 3 and 
the other set on 4 and 2 or it may have a set of four channel heads as in a four 
channel deck (see below) and switch two channels of electronics.

Now comes the real tape deck for 1/4 inch, the 4 channel 4 track deck. It has 4 
complete erase, record, play heads and 4 channels of electronics. You can select 
tracks 1 and 4 and get a fairly good play of a two track recording and if you 
start with an erased tape, you can get a fairly good recording of two track. For 
Mono you just listen to all four channels and record on all four channels on an 
erased tape. For four track stereo you choose tracks 1 and 3 sand swap reels to 
get the reverse tracks. It does everything. These decks were originally used for 
quad, but now are very poipular for these reasons. Some very fine 4 channel 
decks were made including the Teac 2340,3340,44,40-4,22-4, Akai 1730 and more, 
Sony something I have somewhere.

WBob

Fred Olsen wrote:

> Duane Fischer, W8DBF wrote:
> 
>> do not know how true this is, that the two track deck had two vu 
>> meters and the
>> four track had four VU meters.   
> 
> etc.
> 
>> Hence, I think we are confusing tracks here. Correct me here, but are 
>> there not
>> stereo two track machines for quarter inch tape that are one direction 
>> and use
>> 1/8 inch per track?
> 
> etc.
> 
> Duane, this discussion has been mixing "four track" with "quarter-track" 
> and "two track" with "half-track".  Speaking about stereo machines using 
> quarter inch tape, a half-track machine uses (somewhat less than) an 
> eighth inch per track, or channel, and runs in one direction.  A 
> quarter-track machine uses (somewhat less than) a sixteenth inch per 
> track, or channel, made up of tracks one and three in the forward 
> direction and two and four in the reverse.  And except for the R/P head 
> it's the same with either manual reverse (flop the reels) or auto 
> reverse.  A quarter-track stereo machine still has only two channels.
> (All of that subject to errors of recall; anyone please correct me if 
> required.)
> 
> There were some "quad" decks which had four channels and four meters and 
> used a quarter-track transport in one direction only.  Thank goodness 
> quad died its well-deserved death.
> 
> With half inch and one inch decks you're getting into the realm of pro 
> gear and there are several variations, but most run in only one direction.
> 
> Fred