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Vintage Tape (Audio), Cassette, Wire and Magnetic Disc Recorders and Players Open-reel tape recorders, cassette recorders, 8-track players etc.

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Old 23rd Mar 2018, 11:14 am   #1
Glyn1884
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Default 1/2 or 1/4 track?

Hello to all on this forum i should have found it earlier, I need some advice from seasoned users of reel to reel machines.
I have a varied likes of music and have a nice turntable amp and speaker setup, but I am venturing into reel to reel and wanted to ask which system is best 1/2 or 1/4.

I have been given a great deal of pre-recorded tapes from the sixties/seventies but I seem to read that there can be some bleed from the other track come through so if I buy the 1/2 track and record straight from a tuner or internet will they just sound like it or will they have a nice warm sound.

I have a chance to purchase one of two great machines both Revox one is the A77 which is the 1/4 and the other is a B77 1/2 so what do you think because any advice will be very welcome.
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Old 23rd Mar 2018, 12:01 pm   #2
Phil G4SPZ
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Default Re: 1/2 or 1/4 track?

Hi Glyn. A half-track stereo machine uses the full width of the tape for a recording. Thus you can't turn the tape over and record on the other side. This obviously uses more tape per recorded hour, but the quality is likely to be better. I have a half-track A77 which sounds excellent.

Quarter-track machines can be excellent too. The recorded track is only half the width of a half-track, but a semi-pro machine should be capable of perfectly good performance.

A Revox tape recorder in good condition should replay what has been recorded faithfully and without altering the sound in any discernable way. If you're looking for some sort of 'warm' sound then you may be disappointed!
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Old 23rd Mar 2018, 12:01 pm   #3
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Default Re: 1/2 or 1/4 track?

Unless you plan to do editing, or plan to record your own music making, to my mind there's little point in using half track stereo. Tape is very expensive. If you use half track, you only get to use the tape in one direction as the full width is used. Plus, the half track units usually come from Broadcasting or semi pro environments and have seen a lot of use. In addition, these decks usually run at 7.5 or 15 ips, so you get even less tape time.

There are some excellent quarter track units whose sound can almost match the half tracks. For making compilation/mix tapes for home playback they should be more than adequate. I have a Sony TC755A (1/4 track, 3.75 and 7.5 ips) in my main system and a TC766-2 (1/2 track, 7.5 and 15 ips) which I hardly use for the reasons mentioned earlier. Never had any track bleed problems personally. Like the Revoxes they are 3 head, 3 motor transports.

The A77 is older so make sure the Rifa caps and pots have been changed as a minimum to avoid trouble. Both are nice machines and easy to service.

edit - post crossed with Phil. Great minds think alike ;-)
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Old 23rd Mar 2018, 12:14 pm   #4
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Default Re: 1/2 or 1/4 track?

My main experience of quarter track machines was the Philips EL3548 (I think) it was a three speed four track machine and sounded superb, that was largely due to the improvement in frequency response, the Philips would record with the same quality at 3 3/4 ips as many did at 7 1/2 ips.

I had no problems with print through if replayed and the same machine but you could get it on others on which the alignment must have differed slightly.

I bought the machine new in about 1960 and it was the best around. We sold them and others so I was able to compare them. Every time a new model came out, which was quite frequently in those days, I would look up the spec for the HF response and Philips were leading all the way in the domestic market.

There was one for sale not to far from me a couple of weeks ago but I was outbid, I would like another one but what would I do with it after I had played all the tapes that I had recorded on my new one?

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Old 23rd Mar 2018, 12:27 pm   #5
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Default Re: 1/2 or 1/4 track?

Peter: Good though those Philipses are, the decks mentioned above are semi pro stereo units and a quantum leap away in terms of sound, wow/flutter, specs, etc. We're not really comparing like with like.

PS. I am sure I have a manual for that Philips unit if you'd like a scan!
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Old 23rd Mar 2018, 12:54 pm   #6
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Default Re: 1/2 or 1/4 track?

You do need to think what you actually want a R2R machine for. They are expensive to buy, fiddly to use, bulky and require a lot of maintenance. Tape stock is expensive, bulky and prone to deterioration. They don't have a 'warm sound' unless there's something wrong with them. If you want to play around with analogue recording, you would be better off with a good quality domestic cassette deck. These can equal the quality of R2R at 3.75ips with good quality pseudochrome or metal cassettes - in fact the really good ones can equal most R2Rs at 7.5ips.
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Old 23rd Mar 2018, 1:12 pm   #7
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Default Re: 1/2 or 1/4 track?

Hi
Going back to the OP it appears he has a number of old tapes to listen to. In that case, he needs to ascertain whether these are 2 or 4 track recordings.
If you play a 4-track tape on a 2-track machine then you get the recording on the other side playing back backwards at the same level as the one you want to listen to. Perhaps that's what you mean by 'bleed'? If you're not sure, then a 4-track is the one to go for as you can play 2-track recordings on this. Also you need to know the speed of recording - 3.75 ips is the most common, then 7.5. Both Revoxes have only two speeds so check they are standard machines - some were high speed or, rarely, low speed versions.
I have A77 and B77 machines and both are great performers, but do take heed of Ben's advice on the RIFAs if you want to avoid a room full of acrid smoke! If you aren't able to do this yourself it's a nice easy job for someone with a soldering iron.
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Old 23rd Mar 2018, 1:52 pm   #8
Glyn1884
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Default Re: 1/2 or 1/4 track?

Thank you for all the replies. What I read about 1/4 track will teach me to stay off American forums after all they have enough trouble.

I really should have stated that the tapes I have are all 4 track and mostly are 7 1/2" speed but a few are 3 3/4".

You have helped me make my mind up and I have chosen the B77, it's a great looking machine in excellent condition and has been serviced recently. I really wanted to hear the tapes I have now from classic to pop and in between.

Once again many thanks and I will be on here regularly.
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Old 23rd Mar 2018, 4:00 pm   #9
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Default Re: 1/2 or 1/4 track?

If you already have pre-recorded 4-track tapes, then you will need a 4-track (or 1/4 track) machine in order to listen to them. The same machine can also be used for listening to pre-recorded 2-track tapes -- or converting them to 4-track!
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Old 23rd Mar 2018, 10:47 pm   #10
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Default Re: 1/2 or 1/4 track?

The essential difference in performance between half and quarter track is the theoretical loss of 3dB signal to noise ratio caused by the halved track width. There is also a slight risk of LF crosstalk between tracks running in opposite directions, as heads respond to LF signals beyond the width of the head track. In practice, this is seldom annoying, although dropouts caused by coating defects or edge damage are more so.

The major practical difference between half and quarter track pre-recorded tapes is that most of the half tracks were copied in real time or double speed at worst, whilst quarter track were duplicated at anything up to 32x speed. High speed copying is a capricious process at the best of times, and many mass market American tapes sound dreadful. Small concerns, such as Barclay Crocker, provided a higher quality product, using better tape stock. low copying speeds and Dolby B processing.
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Old 23rd Mar 2018, 11:04 pm   #11
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Default Re: 1/2 or 1/4 track?

Quote:
Originally Posted by Glyn1884 View Post
I really should have stated that the tapes I have are all 4 track and mostly are 7 1/2" speed but a few are 3 3/4".

You have helped me make my mind up and I have chosen the B77,.


In your first post you said that the B77 was half track. That won't play your 4 track (aka 1/4 track) tapes correctly.
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Old 23rd Mar 2018, 11:50 pm   #12
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Default Re: 1/2 or 1/4 track?

I've run a quarter-track Revox A77 for about 40 years.

I've never had any problems with bleed-through between tracks. I don't believe everything I read on the internet. Some people get hung-up on theoretical differences and lose any sense of scale so they are unaware of how significant differences are in real use. It's the difference between armchair sportsmen and those who go out and actually DO it.

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Old 24th Mar 2018, 2:20 am   #13
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Default Re: 1/2 or 1/4 track?

If you've just been out and bought a 2-track tape recorder, and then all your mates go out and buy 4-track ones for hardly any more money, then you're going to tell yourself anything to justify your purchase as the better machine, and not be jealous of their ability to turn over the reels at the end and use the other side of the tape.

@Ben -- Good spot! How did I miss that?
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Old 24th Mar 2018, 3:07 am   #14
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Default Re: 1/2 or 1/4 track?

It may be irrelevant, but I think it worth mentioning that both the British and European models had different pre- and de-emphasis characteristics (CCIR) from the American and Japanese (NAB) machines. But in the 1960s, American and Japanese ones were rare, though the latter came to dominate the market in the 1970s.
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Old 24th Mar 2018, 4:36 pm   #15
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Default Re: 1/2 or 1/4 track?

Quote:
Originally Posted by ben View Post
Peter: Good though those Philipses are, the decks mentioned above are semi pro stereo units and a quantum leap away in terms of sound, wow/flutter, specs, etc. We're not really comparing like with like.

PS. I am sure I have a manual for that Philips unit if you'd like a scan!
I appreciate that Ben but my money didn't stretch that far, of all the domestic recorders available that one sounded the best in terms of HF response and wow and flutter although probably present I didn't notice.

When cassette tapes arrived I did the same analysis and bought a quite moderately priced Japanese machine, I think it was a JVC and that gave 16 kcs at 1 7/8 ips, remarkable in those days seeing that some of the popular ones only gave 5 khz!

Peter
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Old 24th Mar 2018, 5:26 pm   #16
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Default Re: 1/2 or 1/4 track?

Hi
Don't forget the A77 has switchable IEC and NAB EQ unless it's the Dolby version.
More importantly as Ben says I worry you may have misunderstood my previous post - to listen to 1/4 track recordings you need a quarter track machine - the A77 in your first post. Although you don't regret buying a Revox, I think you'd prefer it to do the job you want it to do!
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Old 24th Mar 2018, 10:08 pm   #17
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Default Re: 1/2 or 1/4 track?

Hi, here's some information about the difference between two (1/2) and four (1/4) track formats and the (in)compatibility between the two.

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Old 27th Mar 2018, 12:02 am   #18
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Default Re: 1/2 or 1/4 track?

The moral of this thread is that one reel-to-reel tape recorder is never enough.
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Old 27th Mar 2018, 3:49 pm   #19
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Default Re: 1/2 or 1/4 track?

This is very true. Since re-discovering this now virtually obsolete technology a couple of years ago, and pursuing it as a hobby ever since along with retro hifi, I have somehow managed to acquire 8 machines: I have 3 Revox A77's, a UHER 4400 and 4200, an EMI L4, and an AKAI X1V and AKAI XV !

Regarding 1/2 track or 1/4 track: The 3 Revox A77's that I have cover the most popular tape formats and speeds. The first one is a normal speed 2 track, the second one is a high speed 2 track, and the third is a normal speed 4 track. I converted the third machine to 4 track myself, by replacing the heads and changing the bias oscillator. The conversion was easy and after it was complete I carried out the usual frequency response and audio tests and all seemed fine. In fact I could not really tell the difference between 2 and 4 track, all good.

However, after seeing this post, I thought I'd carry out some further comparisons between the 2 track and 4 track machines. One mistake that I made was that during the conversion I had used brand new recording tape, and only recorded on 'one side' for the purpose of setting up the machine. Consequently there were no recordings on the 'other side', and therefore no cross talk or bleed through to be heard. So I retested recording using tape recorded on, on both sides. Bleed through could be heard, and lots of it. It turns out that I didn't have the erase head aligned properly, which I have now corrected. However there is still some bleed through that can be heard, mainly low level bass frequencies. I've tried adjusting the position of the erase head to optimize erasing, but I can still hear some bleed through. May be this is just a 'feature' of the machine, or the 4-track format. Any ideas on how I can reduce it to a minimum? I'm not too bothered because I only really use this machine for playback of 4 track tapes made on different machines, and can't really hear any bleed through with these tapes.

In summary I'd say if you are serious about making the highest quality recordings then only a 2-track machine will suffice. A 4-track is better for playing pre-recorded tapes and uses less tape, but can suffer from bleed through.
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Old 27th Mar 2018, 5:34 pm   #20
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Default Re: 1/2 or 1/4 track?

edit - I should have said 4-track gives double the recording time, using the same length of tape. Also I would imagine that most commercial pre-recorded tapes were available in 4-track format. There are some on e-bay that I am considering purchasing to see just how good analogue really was
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