Allnic/ZL Technologies T-1500 mk2

The T-1500 mk2 stereo amplifier is Allnic Audio’s top of the line 300B SET stereo integrated amplifier model. Like all Allnic Audio products, the T-1500 mk2 has Permalloy (iron and nickel alloy) for its transformer cores. Allnic is grateful to Mr. G.W. Elmen of Western Electric for inventing Permalloy for transformer core use, and in so doing, providing an enormous service to recorded music listeners everywhere.

• 10 watts per channel of pure class A high power output
• Real power drive
• Nickel alloy output transformer
• Self-bias control grid
• Analog power tube current monitoring meters
• Soft-start Circuitry

The T-1500 mk2 has the following features:

• 10 watts per channel of pure class A high power output. The T-1500 MK2 is a single ended, stereo integrated amplifier. Almost all other 300B amplifiers are under, and distortion, driven. This is a result of the use of conventional “Resister-Capacitor” circuits, which give only up to around a 70V swing voltage, with high distortion. This means that an already distorted signal of a lower than optimum swing voltage is directed to the deep biased 300B grid. Allnic’s powerful “Inductor Drive” circuit gives up to a 150V swing voltage, with very low distortion (about 0.3%). It is this drive delivered to the T-1500 MK2 that allows for a higher output (10w) with much less distortion than can be expected from standard 300B circuits.

• Real power drive. The drive tube, 6SN7 is a moderate-mu (about 20) twin triode. We use this to drive the 300B’s via a choke plate inductor. Our choke inductor (100% nickel permalloy PC core) has very low power loss and infinitely high load impedance. This configuration is an ideal drive stage for 300B SET. And as the first tube, a twin triode 6SL7, has a very high-mu (about 70), the T-1500 MK2 has a total gain of +35dB.

• Nickel alloy output transformer. Allnic uses sophisticated ratio mixed nickel permalloy PB cored output transformers. Because of their extremely high initial permeability, it is possible to use fewer turns on the primary winding while retaining very high ‘open circuit inductance”. That means a resulting very wide frequency range and low distortion bass response. This is another reason why the T-1500 MK2 excels over other 300B integrated amplifiers. Allnic also uses a very big nickel core, so as not to be magnetically saturated at a high current level of 100mA.

• Long life and trouble-free operation. Allnic employs a “soft start circuit” to protect the tubes and other parts. It applies the high B+ voltage only after tubes are fully warmed-up.

• Self-bias control grid.

• Analog Power Tube Current Monitors. Allnic uses analog current meters to display the condition of each channel’s power tube. The meters make it exceptionally easy to see the status of each tube at any time and offer a simple, unambiguous indication of each tube’s status compared to conventional LED bias monitors.

• Natural negative feedback. The T-1500 MK2 applies about -6dB of negative feedback. This is a very complimentary amount of negative feedback that differentiates the Allnic 300B single ended amplifier from the standard, which has a very coloured and weak speaker driving force. With this natural feedback, the T-1500 MK2 has a relatively high “damping factor’, very low distortion, and a higher S/N ratio, without losing the signature single ended natural sound quality.

• We use a NEW remote controlled high quality 41 step silver contact attenuator Ver.2 (all resistors non-inductive) instead of a carbon filmed slide potentiometer.

• Beautiful 20KHz square wave response.