Bipolar transistor Phono Stage
The BPS is an ultra-compact, battery powered phono stage, using transistor technology maintaining the traditional Nagra quality.
The BPS works with either moving magnet (MM) or moving coil (MC) cartridges using custom wound transformers, as in the PL-P preamplifier and VPS phono stage.
Electronic design concept
The BPS electronics consume so little power that they are driven from a single 9-volt battery giving an autonomy of about 100 hours. Assembled on a single motherboard, the electronics use discrete military-specification components. The amplification is provided by individually selected and matched bipolar transistors. The capacitors in the signal path are of audiophile quality and the precision resistors are MELF (Metal Electrode Leadless Face).
The MC input transformers are designed and wound, in-house, by Nagra, benefitting from our unique know-how in this domain coming from the highly demanding field of microphone inputs on professional recorders. The case is made of top quality aluminium which is in turn brushed to give the finish to match all other products in the range in the usual Nagra style.
Adaptive loading circuits
Taken from the concept of the VPS, the BPS also uses adaptive loading circuits built onto small additional boards, that can be inserted. ŒæSix of these circuits are delivered with the unit, allowing the input impedance of the BPS to be altered to match virtually any phono cartridge.
Its very compact size reduces the cartridge cable length to a minimum, thus reducing the risk of interference through this very sensitive link.
|Frequency response:||Œæ||20 Hz (+1dB) at 30 kHz (0dB) RIAA conform|
|Harmonic distortion:||Œæ||< 0,15%|
|Signal-to-noise ratio:||Œæ||> 77 dB (ASA A)|
|Channel separation:||Œæ||Typically 60 dB|
|Input circuit load:||Œæ||47 k‘© without load module installed|
|Loading modules:||Œæ||6 modules supplied (100, 150, 220, 330, 470 ‘© and 1k‘©)|
|Transformer gain:||Œæ||(MC input) Ratio 1:3.54 (+11 dB)|
|RIAA stage gain:||Œæ||53 dB|
|Total gain:||Œæ||64 dB, switchable to 49 dB with internal jumpers|
|Output level:||Œæ||2 V|
|Correction norm:||Œæ||RIAA 1953|
|Power consumption:||Œæ||70 mW|
|Power supply:||Œæ||1 battery 9 V type 6LR61 (PP3)|
|Estimated battery life:||Œæ||Approx. 100 hours|
|Input connections:||Œæ||RCA-Cinch (gold-plated)|
|Output connections:||Œæ||RCA-Cinch (gold-plated)|
|Weight:||Œæ||480 g (16.9 oz)|
|Dimensions:||Œæ||(L x D x H) 110 x 27 x 160 mm (4Œ_ x 9äóÁí_Œ«16 x 6Œ_ inches)|