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INTRODUCING THE T-1500 MK2 300B SET STEREO INTEGRATED AMPLIFIER
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.
The T-1500 MK2 has the following features:
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10 watts per channel of pure Class A, high power output. The T-1500 MK2 is a SET (Single-Ended
Triode) power 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 90V swing voltage, with very low distortion (about 0.3%). It is this drive
delivered to the T-1500 MK2’s 300B power tubes that allows for a higher output (10 watts) and
lower distortion than what can often be expected from standard 300B circuits.
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The T-1500 MK2 uses the excellent and popular 6SL7 and 6SN7 tubes for its preamplifier and
driver sections. There are many brands, both new and old, of these tubes, and the T-1500 MK2 is
a “tube-roller’s dream”, as a result of its ability to use all the available brands of these tubes.
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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
lower 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 use a very big
nickel core, so as not to be magnetically saturated at a high current of level of 100mA.
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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.
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Auto-bias of the power tubes, with current meters for 300B monitoring. Auto-bias provides bias
stability for the life of the power tubes. The associated current meter for each 300B indicates the
status of tube, providing a clear indication of the tubes status. In conjunction with the auto-bias
feature, the T-1500 MK2 can utilize any brand of 300B. The T-1500 MK2 can also use tubes such as
the 300B XLS, though it will not drive those tubes to their full capability.
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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- 1500MK2 has a relatively high “damping factor', very low distortion, and a
higher S/N ratio, without losing the signature single ended natural sound quality.
