Audio Research VT-100




This VT100 came into the store with 1 dead channel.    Many of these AR amplifiers have been unsuccessfully repaired by previous attempts elsewhere.


Audio Research has always been difficult because the company prefers to see all units go back to the factory's repair department.     Nevertheless, we have a friendly and cooperative  relationship with AR, and they will sell parts to us albeit expensive at times.


The VT-100 is a hybrid design utilizing transistors as a constant current source.    Sometimes when the tube goes, it takes out the transistors.     Replacing the transistors are difficult due to the industrial engineering design of the amplifier.   It has to be completely disassembled.   The transistors are common but the identification codes are rubbed off and replaced with AR's in-house color codes.   


After we replaced the transistors, the tubes were replaced with a specific narrow range requirement which meant not every tube will work for this amplifier.   You need to know the specific bias range of the tube.


We replaced the defective parts, re-biased the amplifier, followed by a 48 hour stability test.


Subsequent bench test met factory specification.    The problem the repair job took us 6x longer than quoted, nevertheless we charge by a per job rather than a per hour basis.    We lose money on the job but customer satisfaction is No. 1 and we always keep our promises.


We are proud of the work which we have done. 





 Contact us:             416-523-6655 

Store visit by appointment only, do not show up without an appointment