396 nwb/m too hot for your R2R deck ?

tony ky ma

Industry Expert
Aug 21, 2010
630
5
930
Whitby Ontario Canada
Old time master tape recorded at 185 nwb/m because tape's out put was limited at that level in their time, today we used highest out put tape 499/GP9 for master in 396 nwb/m recording and the copies use RMG SM900, also in 396 nwb/m, if your machine is set for 250 nwb/m will be too hot to play with, and if your machine can be adjusted repro level then use our test tone to set to 0 db of machine's vu meter, around 4 db down from 250 nwb/m setting, then you can have the most advantage of high out put recording (dynamic range s/n ratio etc.) still we can copy in 250 nwb/m for some one who can't set repro level, but for those have pro deck should try the taste of high out put recording
happy new year to all of you
tony ma
 

bblue

Well-Known Member
Apr 26, 2011
360
3
388
San Diego, CA
Old time master tape recorded at 185 nwb/m because tape's out put was limited at that level in their time, today we used highest out put tape 499/GP9 for master in 396 nwb/m recording and the copies use RMG SM900, also in 396 nwb/m, if your machine is set for 250 nwb/m will be too hot to play with, and if your machine can be adjusted repro level then use our test tone to set to 0 db of machine's vu meter, around 4 db down from 250 nwb/m setting, then you can have the most advantage of high out put recording (dynamic range s/n ratio etc.) still we can copy in 250 nwb/m for some one who can't set repro level, but for those have pro deck should try the taste of high out put recording
happy new year to all of you
tony ma
On the PR99's, B77's and presumably others, to avoid severe clipping in the very first repro stage (right after the head) by very high output tapes, you must adjust the feedback resistor. There are no other controls that affect that stage. I used the valued described in the manual for a full track head and it seems to be pretty close.

--Bill
 

tony ky ma

Industry Expert
Aug 21, 2010
630
5
930
Whitby Ontario Canada
Bill
I don't think that is a good idea to change the first stage gain, just adjust the repro level control will be good enough ( not the out put level control ), our tape has a test tone in 30 S of 1 K that you can use it for set to 0UV or other 250nwb/m test tape in 4db down of setting, when you listen Tape Project's tape back, you can turn it back again, my PR99 only in NAB so I had add a CCIR resistors by a selector switch for Tape Project's tape. but rare to use it now, hard to turn back after a better one
tony ma
 

bblue

Well-Known Member
Apr 26, 2011
360
3
388
San Diego, CA
Bill
I don't think that is a good idea to change the first stage gain, just adjust the repro level control will be good enough ( not the out put level control ), our tape has a test tone in 30 S of 1 K that you can use it for set to 0UV or other 250nwb/m test tape in 4db down of setting, when you listen Tape Project's tape back, you can turn it back again, my PR99 only in NAB so I had add a CCIR resistors by a selector switch for Tape Project's tape. but rare to use it now, hard to turn back after a better one
tony ma
If you can't change the gain of the stage that is clipping, adjusting levels after that stage is not going to help. Revox adjusts the gain/feedback to allow for the much higher output of a full track head (or even a 1/2 track over a 1/4 track). Unfortunately, that isn't sufficient when you play current high output tapes. The output from that stage is a soft edged square wave (but doesn't sound like it -- almost tubish). So reducing the gain there is the only solution.

--Bill
 

bblue

Well-Known Member
Apr 26, 2011
360
3
388
San Diego, CA
Actrally I have not play the PR99 with our high out tape yet for A810 reduce the repro level is good enough
tony ma
Yeah, it seems pretty robust.

Have you ever looked into a higher quality replacement for the NE5532 opamp that is heavily used through these machines?

--Bill
 

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