About the transformer: On 'one side' the wires go as follows: White, Yellow, Brown, Orange, Red, Grey, Black. Why anyone would need to do that is mostly beyond me (anyone actually got a 32 ohm speaker?!), but there's no reason it wouldn't work. Unfortunately I threw out the amp and didn't write down the number and now I am trying to use the transformer to build an audio amplifier. just GROUND the negative speaker terminal (you might have to tap into where the black wire from the OPT grounds inside the chassis) and hook the positive speaker terminal to the 16 ohm tap. you COULD use a 32 ohm speaker on the HF89. Now, the way the transformer is wired, the same transformer could work either way.
On the HF89, the feedback was taken from the 4 ohm (green) and 16 ohm (orange) taps, through a rather complex network. Here's the wiring from that one:įrom comparing the HF89 to HF87 schematics, here's the only way I could see that the transformer could be wired in an HF89: They used 1:1 to 1:3 turns ratio and classical push pull power amplifier in the output stage.If there's five wires on the secondary side with those colors, I don't think it's an HF-89 transformer. Interstage coupling transformers used to be popular in vacuum tube based designs. This requires both low resistance windings and very low leakage inductance. Therefore, a line output transformer should have low output impedance which remains low at high frequencies. Typically, audio transformer is driven by an amplifier and loaded by several thousand pF cable capacitance and high input impedance of line receiver. Hence, the transformer is used in step-up configuration so that amplifier sees an impedance of 600 W in order to achieve good noise performance. Due to this, it is very difficult to achieve good noise performance in an amplifier. Moving coil phonographs are very low impedance devices (~3 W ). They also transform the impedance as microphone input transformers and have high CMRRs. Line input transformers are generally driven by balanced line and drives an unbalanced line.
0 kommentar(er)
