Erik Signature 70
70 in the model designation stands for the directly heated triode GM70, an audio tube that has very good sound qualities combined with high power.
The circuit bears Erik Anderssons signature from his previous designs, but now with the implementation of interstage coupling transformers from Lundahl Transformers in Sweden. Long time has been spent on evaluating components, layout, wiring and working points for the Tubes. The circuit solution of the amplifier is completely without external feedback and it is completely point to point built in the signal part.
The power supply is passively regulated, a choice we made after listening tests with different solutions. It turned out that the passive regulation was the best for reproducing both the dynamics and micro details.
The magic that often is a hallmark of single-ended class-A is fully present along with the power that the powerful GM70 tubes provide.
The amplifier has been tested against speakers that are recognized as difficult in terms of load and it has proven to meet various challenges with praise.
In parallel with the development of the new circuit, a chassis was designed that has more width than depth to facilitate furnishing.
Of course, the basic layout from Erik Anderssons previous designs was retained with a division into two planes where the power supply is shielded and placed above the signal part.
At Knispel Audio, we believe that a High-End product must be a feast for the eyes, not only for the die-hard audiophile, but also for family members and visiting non-audiophiles. That´s why we put a lot of work into the aesthetics. For example, it can be mentioned that visible screws were not allowed, either on the amplifier or on the remote control.
Before the final design was determined, more than 20 sketches were presented for comments. After some final adjustments, we are proud to say that the amplifier really deserves to be seen in a beautiful living room.
The uncompromising approach to appearance and quality has led to time-consuming manufacturing where many chassis details are made in house.
An example is the 1.5 mm thick brass sheet metal that covers the top of the amplifier to hide screws and to create a frame for the tubes.
The sheet metal is laser cut and polished, both on the top side and around the tube openings, to a mirror-like surface before chrome plating.