





Continuing our work in the area of fine preamplifiers, Apollo tube preamplifier was design. With the success of the volume control. We combine our TVC and our tube preamp together in a single chassis. Thus making a superb combination, getting the best of both worlds
Owners of solid-state amplifiers were kept in mind during the design phase, zero offset voltage. The transformers maintains a zero offset voltage. The transformers has a physical isolation thus protecting precious amplifiers and speakers from damage. All the outputs of our Apollo preamp are electrically isolated.
Design
Format
What makes our preamp
different from other manufactures is the usage of the output
transformers. Most preamps in the market are either cap-coupled and OTL
design. This may not be the perfect match in terms of impedance
matching. Feedback is often used in this types of preamps to lower the
gain and the output impedance. We however opted to use the transformer
to perfectly match the preamp tube to power amplifier at the same time
lower the gain and the output impedance. Providing the effortless sound
that we are known for.
Extra care was
place in the
power supply. By using a separate unit with tube rectifier and LC
filter reduces power supply noise. The power supply quality is very
critical to bring out the nuances in the music
The Apollo preamp was design in such a way to maintain the strong sonic character of the TVC while providing gain and dynamics drive. Specially attention was paid to prevent the tube stage from changing the wonderful sonic character of the TVC.
However if a more colored sound is required, a simple swap to the 6cg7 tube would add the coloration and body to the preamp
Parts
Selection:
Tube selection is made to
achieve sufficient gain and output power with only one triode. Russian
6n1P is well known as robust and very linear triode. With our high
quality output transformer, we opted for zero feedback design. Thus
maintaining the musical flow of the preamp. Direct heated rectifier
tube 5r4 provides low noise level and soft start without the normal
transient effects. Implementation of other quality parts Mundoft
Capacitors, allen bradley carbon compostion resistors, silver
rca, and internal 7N wire.
Specifications:
Tubes: 4 x 6N1P , 1x 5r4
Specifications
Gain 12dB , other gain requirements are upon request
Output impedance 20 Ohms
Frequency Response 10Hz to 43Khz (-3dB)
Output Noise 0.3mV
Inputs: 1 XLR, 2 RCA pairs
Outputs 1 XLR, 2 RCA pairs