High-end playback boardfor allRevox B77
1.177.259-21 new development
We were able to improve a lot here.
The original playback board only had two trimmers for channel levels. Neither the levels can be adjusted independently of the selected speed, nor the treble. Here, too, we said to ourselves; if something new, then right! It was clear from the start that we wanted to set the level and treble separately for each speed. It was perfectly clear to us that this would involve an enormous amount of extra work! In addition, we wanted to make the circuit board universal for all versions of the B77.
the technique
Jumper
Dizziness
3 jumpers are set twice for the respective equalization of the playback board. The jumpers cannot be set arbitrarily, there are always groups of 3. Equalization can only be set correctly if there are 3 jumpers in a row! The jumper setting is described in detail in the manual. This is the only way the new playback circuit board fits all Revox B77 (SLS, LS, Std, HS NAB and HS IEC).
input capacitance
The input capacitance can be set via one jumper per channel in three positionsfrom 220 pF as shown in the picture, over 320 pF (jumper left) to 780 pF (jumper right).This means that the input capacitance is sufficiently accurate and independent of the set equalization. Just fits ......
The biggest change, improvement!
Eight trimmers
8 trimmers instead of 2 trimmers ensure a much more precise adjustment. Simply copying the existing circuit board 1 to 1 is not our thing! Here you can set the levels independently of the speed. That makes 4 trimmers. In addition, the heights can be adjusted independently with 4 additional trimmers.
The fact that the levels are set independently of the selected speed alone is an advantage that should not be underestimated. You no longer have to compromise when setting playback levels. You don't have to choose one speed and take the second speed for granted.
In addition, you can now also set the heights for both speeds independently. All of this makes the calibration of the Revox B77 much more accurate than ever before!
Original
adjustment
You will receive precise installation and adjustment instructions for installation and adjustment. We adjust and adjust according to the specifications of Studer and Revox B77 and PR99. For the adjustment you need the right tool, some experience and reference bands for the two speeds!
we are happy to take overfromrevox-online does the comparison for you
Many other optimizations
which we at revox-online don't want to do without!
Waiver of electrolytic capacitors
As always, we are happy to do without electrolytic capacitors in the signal. Electrolytic capacitors are sluggish and like to swallow the smallest, finest facets of the music scene that make up the music. waiver! And then more electrolytic capacitors than the original? Yes, the many optimizations and larger capacities lead to the majority of electrolytic capacitors!
voltage buffering
The voltage is buffered and blocked individually for each amplifier stage and each channel. In addition, the collector resistance of the first stage was split and buffered again. The additional effort is enormous!
The separate buffering of the individual amplifier stages leads to better resolution.
All amplifiers have their own voltage source. The power does not have to come from the power supply unit far away via additional strands, conductor tracks and various soldering points and is immediately available.
Bypass capacitors
Although we only use high-quality Panasonic e-caps, all e-caps have the obligatory bypass capacitors. The bypasses are mandatory for us!
Half the operating voltage
Instead of a voltage divider to 1/2 UB for the complete circuit, we now have 6 voltage dividers for each stage and the channels separately. This measure also increases the number of electrolytic capacitors by a further 5 pieces plus the bypasses.
The separate voltage dividers increase the spatial resolution, the channel separation becomes larger, better!
speed evaluation
S-Speed
So that the settings can be made to match the respective speed, the S-speed signal of the playback board must be fed to the pin provided (PIN 18)! A wire bridge (included in the scope of delivery) must be plugged in for this purpose.
connector
The S-Speed signal is routed from connector J10 pin 7 of the audio interconnection board to tab P32.
Playback circuit board from revox-online
We have used all technical possibilities to pass the audio signal through in the best possible way and without distortion. Even if the band is the biggest limitation, the electronics don't have to degrade the signal! With 8 trimmers, playback can be adjusted much more precisely!
if you want the best!
brand new playback board
1.177.259-21
for all Revox B77 can be found in our shop
Thomas Schröder
Schottjer Straße 30
26529 Upgant-Schott
Germany
Schottjer Straße 30
26529 Upgant-Schott
Germany
49 4934 - 80 44 39
info@revox-online.de