A Lyrical Tale of the Beauty and the Beast
Thivan Labs artfully combines a very distinctive and minimalist, highly functional and bold Bauhaus aesthetic with an unmistakable sonic identity … one that, with disarming honesty, infuses the “system equation” with a rich and lyrical narrative … a sonic narrative that is beguilingly poetic in cadence, such that the more you listen, the more lyrical the musical journey becomes !
THIVAN LABS 813SE LEOPARD
SINGLE-ENDED TRIODE TUBE AMPLIFIERS
THIVAN LABS LEOPARD 813 SE Mk2
Thivan Labs Leopard 813 SE Mk2
813 Integrated Amplifier
Output power : 2x45W
Class of operation : SE (class A)
Tube complement :
2x 813, 1x 12AU7, 1x 6SN7, 2x 6V6
Inputs : 2x RCA , 1x XLR
Remote : Yes
Outputs : 4,6,8,16 ohm
Input sensitivity :
Frequency bandwidth : 15Hz-38KHz (-3dB)
Input impedance : 100K
Power consumption : 560VA
Size : 450×500x340mm
Weight : 64kg (141 lbs)
Hardwired Point-to-Point Circuit
$ 8,700/ DD-P $ 6,990
As is the case with all Thivan Labs amplifiers, the Leopard 813 SE Mk2 Integrated's power source is carefully designed with 5 filter levels including large-sized chokes and oil caps. The power supply for the Power and Driver stages is separated to provide absolute stability and stillness for the amplifier.
Thivan’s power transformer is specifically manufactured to suit the Driver and Power stages. This solution has maximized the powerful and smooth sound quality of the 813 tube, and has also resulted in better sound spectrum control, especially when it comes to bass response.
Thivan’s OPT transformers are all substantially up-rated, and as such, they are very large and heavy. Again here, as with the Power Supply circuit, the aim is to ensure delivery of this tube's power output capacity of 45w across the entire 20Hz – 20 kHz frequency range.
The components used are de facto of high quality and are guaranteed by Thivan Labs to ensure stable and reliable operation. The Thivan Labs gear Build and Construction Solidity falls into the "extreme" type arena, and this beast of a piece is no exception weighing in at 64kg ... 141 lbs !!
Two 6V6 tubes serve as grid current drivers, and a 12AU7 (ECC82) and 6SN7 share input duties. The balanced inputs are connected to internal unbalancing transformers.
... about the tubes ...
... "to roll or not to roll" ...
More about the 813 Tube
The 813, first designed by RCA and introduced in 1938, is a general-purpose transmitting beam power pentode tube. It has thoriated-tungsten filaments and a maximum plate dissipation of 125 watts.
It is a very linear tube in triode connection with the same amplification factor of ~8x as the infamous Russian Ulyanov GM70, and a reduced internal resistance so with the same 10Kohm output transformer it is possible to get a better damping factor.
In a direct comparison with the 845, the 813 (FU-13) and the GM70 have the same tonal qualities, but these tubes have the great advantage of a higher voltage gain to allow for a simpler driver stage. In triode mode, the 813 tube's low output impedance (near to 1ohm) will deliver enough power [ ~ 25w - 45W, depending on the circuit ] to drive any kind of loudspeaker, including 3 way full range, low efficiency types, and electrostatics.
The 813 and the GM70 with graphite plates are goods good but, if available, one should use the "copper plate" GM70 and "metal plate" 813 (FU-13 Shuguang).