Help, I need a combined head for ReVox B215!

Lee White

Member
2008-03-15 3:00 am
Revox Head

There is a person who bought out Nortronics, the OEM manufacturer of Reel to Reel recorders. He has a head match, perhaps not OEM but superior to OEM.
Have you relaped your heads yet. If not you may want to do this first; and then purchase a new set.
In addition you need to find someone who knows how to bias the recorder for maximum tape saturation. Most biasing is designed for MOL or maximum operating level, generally plus 6 db or 516 nwbr, with a controlled frequency response of 50 to 11.5 KHZ at -1db. This is done by increasing the bias voltage at 11.5KHZ, ref. 100KHZ at 7.5 inches per second and monitoring the play back head to where the meter goes past the 6 db range and overbiases dropping to 5 db using a signal generator and a volt meter. 3 db doubles the voltage, so 6 db would be a reference of 4 volts out. So doing this little trick, your machine will work 1 db hot. For 15 inches per second, your machine more than likely would need instead of 100 KHZ, a doubling of the bias. Just remember that bias effects frequency response, more bias less distortion however; and thats why Revox/Studder uses the theory of MOL, maximum operating level.
Please keep in mind this is to cause roll off at that set frequency, allowing for maximum out put. After all a good 4 volts out makes nuiances in digital rather wimpish; and the analogue attack and decay constants of analog are about 100 times faster in real time.
Hope, I have been of help. If you need the name of the Nortronics new named supplier, please e-mail me in kind.
Finally, keep in mind the laws of Physics, frequency response above the music spectrum is dangerous and adds alot of noise to your recording. Remember 1st harmonic 4.4 KHZ, 2nd Harmonic 8.8 KHZ and third harmonic 12.6KHZ - all the sound you would ever need; and only 3% of the 3rd harmonic is required.
Compare this to digital 4.4 medium, intermodulating with the 44.4 KHZ pilot frequency with a controlled bandwith of 10KHZ; and the fact that digital is a beat frequency/psycho accoustic fraud meaning that you hear the harmonics in reverse order, like hearing the bullet flying by before you hear the blasting cap leaves little wonder why bass can be heard predominately with digital. The threshold presence to distortion leavel of digial to me is pathetic - and digital audiophiles do not even hear the reference threshold, which makes the actual usuable db range of digital to about 10 dbs as compared to your revox at 60 dbs, not to mention equilization speed, 60 microseconds of digitals best compared to 5 microseconds of a high end 7.5 inch per second reel to reel.
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Dimitar13

Member
2007-11-29 3:21 am
combined head for cassette deck ReVox B215

Thank you for the replies. I have heard for instance that the combined head of cassette decks Sony TC-K71 and Sony TC-K81 is identical to that of ReVox B215. So bought old Sony TC-K71 from ebay and will be replacing the worn-out headset with its own. Have somebody done something similar ? Are there any tricky moments? For instance I saw that the ReVox headset is inside a casing which is different that the Sony headset casing. So for now the only tricky moment which I see is to get the old headset from its casing and put the new one there.

Dimitar
 

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