I also need a service manual...
Hi.
I also require a service manual or schematic for a Hill DX700.
This is a 2-channel PA amplifier manufactured by ECR, London in the 1980's.
It is rated at 625w + 625w.
The output transistors are originally Motorola DX1000. I cannot find any data on these. Can anyone help ?
In mine, some have been substituted by 2N3773 and MJ15003.
Are these good substitutes ?
Thanks
Andy
Hi.
I also require a service manual or schematic for a Hill DX700.
This is a 2-channel PA amplifier manufactured by ECR, London in the 1980's.
It is rated at 625w + 625w.
The output transistors are originally Motorola DX1000. I cannot find any data on these. Can anyone help ?
In mine, some have been substituted by 2N3773 and MJ15003.
Are these good substitutes ?
Thanks
Andy
GOD !!!!
is this a terrible amplifier or what????
i wonder if anyone can spent a moment and a couple of words to explain me how it works ....
i also wonder about the transformer and how much can effect speed and bandwidth ....
compaire to this my AB+B amps should be really hi end devices ha ha ha ha
thanks !!!!
is this a terrible amplifier or what????
i wonder if anyone can spent a moment and a couple of words to explain me how it works ....
i also wonder about the transformer and how much can effect speed and bandwidth ....
compaire to this my AB+B amps should be really hi end devices ha ha ha ha
thanks !!!!
Re: GOD !!!!
It's a 1970's low-fi amp topology. It doesn't require anything high voltage or high current except the outputs. Stuff like this is fun to play with, but not for anything serious.
The transformer is used as a phase plitter - driving the two stacked outputs out of phase. These things are quite limited in open-loop bandwidth (on both high and low end), and not exactly the most temperature stable. Probbaly a lot of crossover distortion on this one - it doesn't even have Vbe temp comp. Even the old PNP Ge units with this topoology used to use thermistor or diode bias. Using fixed resistors is asking for either distortion or thermal runaway (take your pick).
sakis said:
It's a 1970's low-fi amp topology. It doesn't require anything high voltage or high current except the outputs. Stuff like this is fun to play with, but not for anything serious.
The transformer is used as a phase plitter - driving the two stacked outputs out of phase. These things are quite limited in open-loop bandwidth (on both high and low end), and not exactly the most temperature stable. Probbaly a lot of crossover distortion on this one - it doesn't even have Vbe temp comp. Even the old PNP Ge units with this topoology used to use thermistor or diode bias. Using fixed resistors is asking for either distortion or thermal runaway (take your pick).
I have not compared the schematic with my amp.
However, on another thread on the net, it states thermister stabilization which makes sense. maybe the variable R in the output stage is a thermister.
Certainly, I think mine has one !
The amp is for PA not Hifi use. Check Google for Hill Audio DX700
Andy
However, on another thread on the net, it states thermister stabilization which makes sense. maybe the variable R in the output stage is a thermister.
Certainly, I think mine has one !
The amp is for PA not Hifi use. Check Google for Hill Audio DX700
Andy
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