PHILLO Amplifiers are custom hand built amplifiers using all point to point wiring. This amplifier is in new condition with about 8 hours of burn-in time.
Visually the PA25 amplifier emulates a 1950's classic look. The design concept for this amplifier was to have an appreciable amount of power in a small package that delivers quality high fidelity sound. The internal point-to-point wiring is easily accessible for servicing with an open flat chassis design.
Coasting along with a pair of 6L6GC output tubes, driven by the line output of an audio control pre-amplifier the PA25 is designed to provide up to 25 watts of power. When used with a medium or high efficiency speaker system the PA25 provides plenty of volume well below amplifier saturation. Using popular economical 6L6GC output tubes keeps tube replacement cost to a minimum.
The amplifier is intended to be driven with 1 volt of audio (standard DBV) from a suitable pre-amplifier line output. There is enough headroom at this input level to accommodate higher bass levels from pre-amplifier tone control settings and loud music passages without distortion. There are no volume or tone controls on the PA25 itself.
The circuit is a common push-pull output using a pair of 6L6GC power tubes driven by a 12AU7. The phase inverter is a split triode using half of the 12AU7. The phase inverter is biased using a voltage divider circuit between the input stage plate and the inverter cathode biasing the inverter exactly in the center of linear operation. Using a split triode eliminates the need for balanced 12AU7 tube sections such as when a dual triode inverter is used. All grounds are wired together to insure a good ground return instead of just relying on the chassis ground connections.
Except for a few component leads, most of the wire used in the PA25 is Teflon insulated. Teflon insulation resists melting when heated for soldering and stands up longer over time.
Components in the PA25 come from several sources. The power and output transformers are manufactured in Chicago. The engraved chassis plate is made in New Hampshire.
25 watts @ 8 ohms @ 1 KHZ
reference = 1KHZ @ 0DB
+1db -2db 30HZ to 70,000HZ
80db below 25 watts output
AT 1 WATT
.15% @ 1KHZ
AT 10 WATTS
.25% @ 1KHZ
AT 25 WATTS
(2DB BELOW CLIP)
.5% @ 1KHZ
10 inches wide by 6 inches deep
US SALES ONLY
FREE SHIPPING OFFERED ONLY WITHIN THE US 48 CONTIGUOUS STATES
Alaska or Hawaii contact for shipping cost
Shipment must be by Federal Express insured. (free in US as stated above)
One year warranty includes parts and labor
Amplifier must be returned to PHILLO Amplifiers for warranty work
More information including schematic at the web site