Tuesday, July 20, 2010

6AS7 SET amplifier

This very special, one of a kind, SET is based on the 6AS7 twin power triode. A two stage amplifier with a 12AX7 driver. Only two valves in the audio circuit and valve rectification. The rectifier valve is a rare JAN CBXL-5R4GY (brown base). The power valve is an English United Electric and driver valve, 12AX7 Australian made AWA.

Valve rectification and a reactor filtered power supply ensure true musicality. Combine this with an internal power filer, vibration isolated power tranni and OPTs. This makes a very quiet and dynamic amplifier.

There is no input capacitor. The critical inter-stage capacitor, joining the driver stage and power stage, is a large and expensive Jensen, pure copper, paper and oil type. Silver wire is use to bring the audio to the driver stage and component-2-component wiring is used throughout. No PCBs exist in this amp!

After much listening I am convinced this is the best amp I have ever built. Not only based on its detailed mid-range and extended highs but its deep and weighty bass. The volume of bass I was not expecting. The sound stage is deep and wide both behind and in front of the speakers. Sibilance is natural and sustain and reverb. extremely well rendered.

A lovely Mirbeu timber base (custom built especially for this amplifier) holds something very different. A blue top plate carries exquisite but bulky componentry. Though only a few watts, with the right speakers this simple amp will delight and surprise you. With a frequency range from 12hZ to 50,000hZ it is easy to understand why this amp sounds so good. And why the bass feels extended and full. I true audiophile SET amp.

Tuesday, July 6, 2010

6SN7 remote driver stage for the Be Bamp

The 6SN7 driver stage has enriched the musical performance of the Be Bamp. The bass weight is excellent, mid-range texture is extended and sound stage depth dimensional . Treble is controlled, detailed and mellow. Cymbals are naturally rendered and sibilance well controlled.

This remote driver stage is an improvement over the 6N1p stage (see other blog entries). Some may prefer the original driver stage to this with its brighter top end and crisp mid-range. The natural musical qualities of SE UL tubes amps is evident with the combination of this 6SN7 driver stage and the KT120 based Be Bamp.

For more technical information about the 6SN7 remote driver stage and Be Bamp see entries below.

6SN7 remote driver stage for the Be Bamp

Having the flexibility to change driver stages allows many different types of valves to use with the Be Bamp KT120 power section. The original 6N1P drivers stage can easily be unplugged and other suitable drivers stages plugged in. The power amp does not have to be turned off but the amp is placed in stand-by.

This stage is based on the 6SN7 twin triode valve. It is an extremely popular valve used by audio craftsman. The valve sits atop and a small metal enclosure. The base is sprayed with an epoxy enamel paint and the finish is hammered copper. Once again Russian military paper, foil and oil inter-stage and low ESR capacitors are used.

There is no hook-up wire or PCBs. used and once more component-2-component wiring is employed. The driver stage is compact and attractive and brings a whole new sound scape to the Be Bamp.