rupert neve "tape effect"

[nhaudio]

any idea on how to do it diy?

cheers nick

from www.rupertneve.com
"Two-channel ?True Tape? Emulation. An actual tape drive circuit is used to drive a tiny magnetic circuit and fed to a replay loop and actual replay preamp. ?Record? and ?Replay? levels are counter-ganged to keep overall gain approximately constant that only varies, as a tape would, with saturation level. The frequency response is tailored to that of an actual tape recorder. The result is a remarkable simulation of true tape sound, providing the nostalgic rounding and compression that offsets the harshness of poor digital recorders. Use with care! The dynamic range of a tape recorder was a lot less than that of the high resolution Portico Line circuit in which it is nesting!"

 

[NewYorkDave]

Ummmm... How about this? Take an old tape machine and re-orient the record and playback heads to face one another. Adjust the gap and record/playback EQs to yield the desired result. :wink:

This is, after all, the same concept on which those car stereo cassette adaptors work. I'm sure Rupert's product adds useful refinements but I wouldn't be shocked if this basic premise is at the heart of it.

 

[NewYorkDave]

Yes, you could interpose some sort of material between the heads that has a B-H curve similar to tape; that could make the simulation more realistic. You could even use a little transformer. The concept is ripe with possibilities for experimentation, and a great way to play around with "junk" parts that might be laying around. And it would be more fun if the aim was to come up with a usable effect and not so much to exactly reverse-engineer what Rupert is doing.

 

[tk@halmi]

I have experimented with tape heads facing each other because we noticed the "punchiness" added on by the CD-to-tape converter gadget. This was back in the early 90s when CD players in cars were uncommon so we used a SONY walkman running into the tape player through that converter.
It sounds great in a car, but when you try it, even in today's project studio, the lack of bass and HF roll-off becomes obvious.
Does anyone know of a source of tapeheads that have decent bandwidth, but does not cost a year's salary?

 

[SSLtech]

[quote author="tk@halmi"]Does anyone know of a source of tapeheads that have decent bandwidth, but does not cost a year's salary?[/quote]
If the gap wear is unimportant (it might be significant, it might not) then old tape heads from a multitrack would be a thought.

Think about it... if a 24-tk machine wears out the bottom three tracks, then 21 tracks still work. there is even a theory that I've heard that says that a tape head sounds best shortly before it wears out, though I've never taken the time to research it and it might well be audiofoolery... none the less, if you want a head cheap that probably has more that 16 perfectly good working channels on it, I probably have a couple of Studer 24-track 2" heads (record and playback) that I can lay claim to...

Just ask John French of anyone else who re-laps and replaces heads... they'll probably be able to give you a dozen!

Keith

 

[Samuel Groner]

www.groupdiy.com/index.php?topic=6892

Samuel

 

[Learner]

[quote author="SSLtech"]

Just ask John French of anyone else who re-laps and replaces heads... they'll probably be able to give you a dozen!

Keith[/quote]

For free!???? :shock: :shock: :shock:

Where Can I find Mr. John French? I would be interested to play with a coupled big heads, may be placing a 4 band crossover at the input in 4 tracks segments with variable input gain for each segment.

I don't understand how that would be different to transformer coupling, since isn't tape saturation about the response of the tape to a very high input level instead of a hot input to a magnetic coupling device???

 

[SSLtech]

John French is the most respected re-lapper of heads in the USA. (JRF)

Please be respectful and don't pester the man unless you're offering to pay shipping etc... but other than that, what's to lose? -As long as he's not inundated with people asking for free stuff you might be lucky! -As for me, I have some old Studer A800 24-tK heads here... :twisted:

Keith

 

[Learner]

[quote author="SSLtech"]
Please be respectful and don't pester the man unless you're offering to pay shipping etc... but other than that, what's to lose? -As long as he's not inundated with people asking for free stuff you might be lucky!
Keith[/quote]

Wasn't really going to ask just suprised he might give them away that's all, I pay for what I take and I don't expect freebies from no one.

More interested in if anyone is willing to make the effort and do some experiments on how a coupled head would work/sounds vs playing off tape, and shed some light in the magic tape business where there is only talk but NO REAL useful data?

 

[SSLtech]

[quote author="Learner"]Wasn't really going to ask just suprised he might give them away that's all, I pay for what I take and I don't expect freebies from no one.[/quote]
Iss' cool!

:thumb:

Yeah, most of the old heads hit the trash, from what I hear.

Other tape head lappers would also probably toss their old dead heads also...

Keith

 

[Learner]

Back to the subject, anyone know what is the difference between a coupled record head(without biasing) with a playback head vs a transformer??

What exactly is the artifect produce by the tape when recording a very large signal?? The oxide on the tape gets aligned when applied a voltage, as the voltage(amplitude) increase more oxide gets aligned until it reachs a point where most of the oxide on the tape gets aligned. If we inject a max voltage the head can handle, it would be logical that the oxide on the section of the tape will be fully aligned. How does the tape then distort the signal or create harmonic distortion??

Could it be the preamp on the recorder distorting???

Anyone willing to do some tests and put this voodoo to rest???

 

[BYacey]

If you put a piece of tape or other magnetic material between the heads you effectively close the magnetic circuit and the level will drop. I think it is best to leave it open. Some effects may possibly be had by varying the distance and alignment between the two head gaps.

 

[SSLtech]

I'd have thought you'd want something with some reluctance between the two, so that things like the bias would have an effect. If there's no need for bias to pass signal, then that immediately gives the lie to the idea of 'tape simulation' to my way of thinking...

Keith

 

[nhaudio]

sorry for the very pragmactical questions, but, when it concerns electronic, I'm still kind of a "speak slowly" type of guy. :shock:
so here's the path I have come with following the threads:

is this correct?
people are talking about the bias setting, which is, if I'm correct, correlated with the tape/tape head allignment. is this true? if yes does my cheapo chinese walkman have this control?
what would control the tape effect level? as suggested the bias level? or the record level? or both?(or does the bias would affect the type of effect and the record level the amount of effect?)
does the eq need to be pre or post the record head? or both?
What guts of my chinese walkman should I keep? (being just for testing.)(lets say that it has a playback and a record head)
Due to my lack of knowledge of electronic fundamentals, I don't understand very well how a transformer can be compared to a record head? is it something to do with magnetism? Something to do with amplifying the signal?
is a record head just a playback head but with inverted wires?

sorry for all the questions, but i'm really curious:idea: I would like tor try to protoptype this kind of effect.

cheers,

Nicolas

 

[SSLtech]

Record head and repro head are reversed int he drawing. If there's any magnetic hysteresis (as there is with tape) you'll need a bias source, amplifier, gain level and mixer. You'll need pre and de-emphasis according to speed. Tape also has a wavelength-to-gap rolloff at the hf, and a wavelength-to-poleshoe size rolloff ath the lf.

Head saturation with HF bias and HF audio at high levels is a factor with some heads...

Anything else?

Keith

 

[Learner]

[quote author="BYacey"] Some effects may possibly be had by varying the distance and alignment between the two head gaps.[/quote]

It might be easier to control the input level to the record head than varying the distance between the rec and the playhead coupling.

 

[Learner]

[quote author="nhaudio"]people are talking about the bias setting, which is, if I'm correct, correlated with the tape/tape head allignment. is this true?...........
what would control the tape effect level? as suggested the bias level? or the record level? or both?(or does the bias would affect the type of effect and the record level the amount of effect?)

Nicolas[/quote]

High fidelity tape recording requires a high frequency biasing signal to be applied to the tape head along with the signal to "stir" the magnetization of the tape and make sure each part of the signal has the same magnetic starting conditions for recording. This is because magnetic tapes are very sensitive to their previous magnetic history, a property called hysteresis.

You can find further reading HERE