i fixed an Orion HCCA 250 last night with a digital reference heat sync and a 1'st generation board?? at least according to the amp guts pictures. neither of the channels were inverted so i know it needs a bridging module to run mono but i'm wondering if this was released this way or if it was a pieced together unit?
it all appears original but it's hard to say. it has the 4 large sideways 3300uf 50v caps in the center and the 2 smaller sideways 3300uf 16v caps near the power entry.
i changed the 4 large caps to 4700uf and replaced a leaking smaller electrolytic cap and parts that were corroded around it and a blown out resistor from the +/- regulated voltage curcuit.
it seems to play fine now. what should the rail voltage be and where is the best place to measure it from?
for such an old amp the soldering on the bottom of the board looks fresh and new! i've seen much newer ams with horrible soldering that was dried up and corroded. these amps were very nicely built!!!
it all appears original but it's hard to say. it has the 4 large sideways 3300uf 50v caps in the center and the 2 smaller sideways 3300uf 16v caps near the power entry.
i changed the 4 large caps to 4700uf and replaced a leaking smaller electrolytic cap and parts that were corroded around it and a blown out resistor from the +/- regulated voltage curcuit.
it seems to play fine now. what should the rail voltage be and where is the best place to measure it from?
for such an old amp the soldering on the bottom of the board looks fresh and new! i've seen much newer ams with horrible soldering that was dried up and corroded. these amps were very nicely built!!!
The second generations amps had a different drill pattern for the heatsink. If the holes matched up perfectly and there weren't any out of place (under transistors), the sink is likely original.
I don't know the rail voltage but it would be best to measure it from the secondary center-tap to the emitter resistors (end not connected to the output transistors).
If you can post good quality photos of the section of the board with the opto-couplers, it may be possible to determine how the regulator works and from that, determine the rail voltage (assuming that it's regulated).
I don't know the rail voltage but it would be best to measure it from the secondary center-tap to the emitter resistors (end not connected to the output transistors).
If you can post good quality photos of the section of the board with the opto-couplers, it may be possible to determine how the regulator works and from that, determine the rail voltage (assuming that it's regulated).
back in the days if you sent orion your amp along with $100 they would place the board in a new heatsink.
i remember this because the sales guy told me $50, then when i went to do it, he charged me $100...so i didnt do it.
those 1st generation amps had gobs and gobs of extra solder applied to some of the traces underneath... i think this was the only generation that was truly mil-spec as advertised.
i remember this because the sales guy told me $50, then when i went to do it, he charged me $100...so i didnt do it.
those 1st generation amps had gobs and gobs of extra solder applied to some of the traces underneath... i think this was the only generation that was truly mil-spec as advertised.
ECM said:
i'm getting 25v rails measured from the secondary center tap to the emitter resistors with 13.8 volts input.
what is your power supply input voltage?
i replaced the 4 big caps with 4700uf 35 volt nichicons. i guess i'm ok with 25 volt rails? it sounds very strong and clean!
by the way it is definately a series 1 in a digital reference case. strange ha!
I'll check for other mounting holes on the sync but from what i can see everything lines up as normal.
If they use the same power supply scheme as the digital reference series, then all you have to do is replace the zener diode in the regulator circuit with another one rated maybe one volt higher.
I have three 225 HCCA amps and they don't all measure 22V, that's just average. One is closer to 21V.
I would say that 25V rails are good enough, especially if it works and sounds the way it should.
I get 26.6V rails on the 250 with anything between 10-16 volts, no load on the amp.
I have three 225 HCCA amps and they don't all measure 22V, that's just average. One is closer to 21V.
I would say that 25V rails are good enough, especially if it works and sounds the way it should.
I get 26.6V rails on the 250 with anything between 10-16 volts, no load on the amp.
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