Playback cards without Bias Trap
By omitting the high frequency bias circuit, the sound of our upgrade card will be even better. Please check the review from our customer (review tab is located next to description tab). However, cards without Bias Trap can only be used in playback only tape machines, not equiped with sound recording feature.
SEPEA playback amplifier module with output transformer
SEPEA playback amplifier is direct replacement for the original Studer 1.080.986 playback amplifier. It can be used in A80R, A80RC, A81 and B62 machines. Although it is fully compatible, it offers some added features like better audio performance, multi-turn trimmers for accurate adjusting, switching between IEC and NAB playback equalization and easy adapting for high speed (15/30 ips) machines.
Basic amplifier adjustment (level, treble and bass correction and crosstalk compensation) should be done in the same way as at the original amplifier. Refer to the service manual for the specific tape recorder machine for exact adjustment procedure. Switching between IEC and NAB standards. IEC/NAB switch is located in the front of the playback amplifier. Select the required standard accordingly in which standard the tape you are palyed back was recorded. You can switch between standards whenever you want without need to stop playback or switch off the machine.
Adapting for 15/30 ips speed
Equalization curves for different tape speed are not the same. The playback amplifier has to be set accordingly which speeds your tape recorder machine uses. The setting is done by means of the SPEED jumper on the playback amplifier board (see the fig.1). If you use the machine with 7,5 and 15 ips speeds, set the jumper to the left position marked 7,5/15. If you use high speed machine with 15 and 30 ips speeds, set the jumper to the right position marked 15/30. This setting has to be done before inserting the card into the rack. Both channels should have the identical setting.
Using the VU pannel, MONO/STEREO switch or CONNECTION PANEL
The signal path between level control stage and the next driver stage is broken (see the fig.2). This is because mostly the external connection from pin 11 to pin 10 via VU panel, Mono/Stereo switch or Connection panel (1.080.997, 1.080.989, 1.081.939) is used. If you don't use none of these, the internal connection has to be applied. If this is the case, set the jumper marked CONNECTION to the left position (internal connection), otherwise set it to the right possition (external connection). This setting has to be done before inserting the card into the rack. Both channels should have the identical setting.
Attention: Switch off the machine before removing and inserting the amplifier modules.
Fully ballanced playback head input
Balanced transformer line output
Build of up-to-date, modern components
Top quality WIMA polypropylene capacitors
Precision multi-turn cermet trimmers for adjusting
Switchable IEC/NAB equalization
Speed 30/15 or 15/7.5 ips, switchable by jumper
Excellent signal to noise ratio of 65dB (lin)
Extremely low distortion, THD < 0.016%
I modified my Pb cards with no bias trap today. Wow! It’s quite a improvement although I need to realign them to have same output level as before.