Sutherland Phono Block

Sutherland Phono Block

Phono preamplifiers

Sutherland Phono Block
Sutherland Phono Block
Sutherland Phono Block
Sutherland Phono Block
Sutherland Phono Block
Sutherland Phono Block
Sutherland Phono Block
DISCONTINUED
AVAILABILITYN/A
Introduction
The PhonoBlock is the phono preamp I designed for my home system. Its design was a self indulgence. I built it to please me. There was no consideration to accommodate any market influences. That mind-set gave me the absolute freedom to build an uncompromised and, in my opinion, the best phono preamp.
Ron Sutherland

POWER SUPPLY:
Much of the PhonoBlock’s effortless musicality can be attributed to power supply capability. The power supply is not ‘sized’ for the gain stage’s load. On the contrary, gain stage power requirements place an insignificant load on the power supply’s capacity. The power available to the amplifier section is a bedrock solid foundation. Precisely defined by fixed current regulators, shunt voltage regulators right at the load and over 100,000 microfarads (per mono chassis) for energy storage. It takes nearly 20 seconds for this huge reservoir to fill up when AC power is applied. For a design guided by simplicity, the PhonoBlock’s power supply may, at first, appear plenty complicated. Admittedly, it is both simple AND complex. It is a long chain of individually simple elements. Each element has a function of either filtering or regulation (also doing a filtering function). Each element inserts a level of isolation. The accumulated isolation is unprecedented.

The chain looks like this
- AC power entry connector
- AC fuses
- First torroidal transformer
- Dual pi ferrite bead / film capacitor filter
- Second torroidal transformer
From here, there are two parallel power paths. One for the first gain stage and another one for the final gain stage. EACH of the two separate paths has these elements.
- Slow recovery, discrete diode, full-wave bridge rectifier
- Initial filter capacitors
- Constant current regulator
- First RC pi filter
- Second RC pi filter
- Shielded ribbon cable between shielded compartments
- Cross over from the right compartment to the left compartment
- Third RC pi filter
- Forth RC pi filter
- Fifth RC pi filter
- Constant voltage shunt regulator
- Electrolytic and film capacitor bypass at the active devices

You can clearly see that each element adds ‘distance’ from the incoming AC power source. This is also apparent when you look at the physical layout of components. Each element adds a physical distance from the AC power connector. All listed items before the ribbon cable are in the right shielded enclosure. They are in linear order from back to front. The ribbon cable goes from right to left, taking power to the front of the audio board. Power filtering elements then go in linear order from front to back on the audio board. Finally, you will see the electrolytic and film capacitors very closely clustered right at the chips they are powering. Simple, logical, straightforward, reliable AND effective.

Specifications

Cartridge Loading
- 50 Ohms
- 100 Ohms
- 200 Ohms
- 475 Ohms
- 1k Ohms
- 10k Ohms
- 47k Ohms
- blank card, can be configured for 1 to 47k Ohms plus capacitance

Gain settings
- 45 dB
- 50 dB
- 55 dB
- 60 dB
blank card, can be configured for 40 to 70 dB

SIZE:
- 17” wide, 17” deep, 3.25” high

WEIGHT:
- Net 21 lbs each
- Shipping 26 lbs each

POWER REQUIREMENTS:
- 110 – 120 VAC, 10 watts, each or 220 – 240 VAC, 10 watts, each