Hi, hope your all well and clever!!
I have a Cyrus 3 amp, but its ill!!, it blows the main fuse at the back of the case, the torroidal trandformer is unserviceable, so i wanted to use it for DC battery use only, bit like haveing a Cyrus PSX PSU forever??- i dunno... but thats the plan.
I have removed the transformer and rectfier diodes but one channel "sinks" the whole 12v from my regulated lab type supply, its beyond the fuse part in to the surface mount area (but not necessarly confined to the surface mount components as there are some descrieet ones to ) also the amp dosent blink on to say "HI" this comes from another regulated supply (so i have 3 supplys in total) .....does any one have a circuit diagram for a cyrus 3 amp??
OR... the input daughter PCB is linked to the main mother board by a 24 way ribbion cable, can this be salvaged as it has a very nice phono stage on it.
Its to nice to throw away so any info greatfully received.
thanks you lot
Johnny555
ps wot no spell checker!
I have a Cyrus 3 amp, but its ill!!, it blows the main fuse at the back of the case, the torroidal trandformer is unserviceable, so i wanted to use it for DC battery use only, bit like haveing a Cyrus PSX PSU forever??- i dunno... but thats the plan.
I have removed the transformer and rectfier diodes but one channel "sinks" the whole 12v from my regulated lab type supply, its beyond the fuse part in to the surface mount area (but not necessarly confined to the surface mount components as there are some descrieet ones to ) also the amp dosent blink on to say "HI" this comes from another regulated supply (so i have 3 supplys in total) .....does any one have a circuit diagram for a cyrus 3 amp??
OR... the input daughter PCB is linked to the main mother board by a 24 way ribbion cable, can this be salvaged as it has a very nice phono stage on it.
Its to nice to throw away so any info greatfully received.
thanks you lot
Johnny555
ps wot no spell checker!
Hi johnny555,
Contact Cyrus. You are closer to them than I am. They are very friendly but I don't know about the schematic thing.
Your current draw is either a shorted rectifier, or output stage. They normally will shut down and blow a fuse on the board.
How the devil did you kill the main power transformer??? I've never seen that done! I have my doubts that it is blown (they normally open, not short).
You are correct. The Cyrus III is a nice amp. I'd fully repair it if I were you. Because of it's smt construction, consider sending it to Cyrus for service. If you want to check the easy stuff, test the diodes.
My own experience on these is that non-Cyrus techs often ruin the board while changing something as simple as outputs or rectifiers. It's double sided with plated through holes.
-Chris
Contact Cyrus. You are closer to them than I am. They are very friendly but I don't know about the schematic thing.
Your current draw is either a shorted rectifier, or output stage. They normally will shut down and blow a fuse on the board.
How the devil did you kill the main power transformer??? I've never seen that done! I have my doubts that it is blown (they normally open, not short).
You are correct. The Cyrus III is a nice amp. I'd fully repair it if I were you. Because of it's smt construction, consider sending it to Cyrus for service. If you want to check the easy stuff, test the diodes.
My own experience on these is that non-Cyrus techs often ruin the board while changing something as simple as outputs or rectifiers. It's double sided with plated through holes.
-Chris
that cyrus amp!
Dear Gents, thank you both for your replys, if only it were the rectfier, that yould be easy!!, the fuses were blowing in the back, i observed the tranny was sparking when the fuse blew, i removed the tranny, tested it on a megger, it flashed over, got a second opinion, it was breaking down, i wanted to make it a DC amp (ie batts, ) so i removed the rectfiers (a couple of which were not conducting) and put DC directly to the big input caps (those nice black ones, 4.700 uf),after carefull connection of both channels and the other i/p for the micro processor?? any how thats the state is in, a bit beyond cyrus to economicly fix (ie its more that the psu and its in the SMT part of the PCB, so thats the state of play gents
johnny555
Dear Gents, thank you both for your replys, if only it were the rectfier, that yould be easy!!, the fuses were blowing in the back, i observed the tranny was sparking when the fuse blew, i removed the tranny, tested it on a megger, it flashed over, got a second opinion, it was breaking down, i wanted to make it a DC amp (ie batts, ) so i removed the rectfiers (a couple of which were not conducting) and put DC directly to the big input caps (those nice black ones, 4.700 uf),after carefull connection of both channels and the other i/p for the micro processor?? any how thats the state is in, a bit beyond cyrus to economicly fix (ie its more that the psu and its in the SMT part of the PCB, so thats the state of play gents
johnny555
Hi johnny555,
If it were smt parts, you would have traces going POOF! right before your eyes. There are a pair of fuses in line to the the rest of the world, so maybe a cap is shorted?
It must be outputs and / or drivers. Battereis can dump silly amounts of current, so ...... Use a current limited supply to test. 1/2 A is enough.
You need a 7 VAC winding and about +- 33 VDC for the amplifier section. The 7 V winding will generate about 8.2 VDC for the uP power supply.
I have repaired some that were "struck by technician" with a damaged PCB. That is considerably harder than what you have there. How much is a transformer? Never priced one.
-Chris
If it were smt parts, you would have traces going POOF! right before your eyes. There are a pair of fuses in line to the the rest of the world, so maybe a cap is shorted?
It must be outputs and / or drivers. Battereis can dump silly amounts of current, so ...... Use a current limited supply to test. 1/2 A is enough.
You need a 7 VAC winding and about +- 33 VDC for the amplifier section. The 7 V winding will generate about 8.2 VDC for the uP power supply.
I have repaired some that were "struck by technician" with a damaged PCB. That is considerably harder than what you have there. How much is a transformer? Never priced one.
-Chris
Hi,
http://cgi.ebay.co.uk/Mission-Power...oryZ4665QQssPageNameZWD1VQQrdZ1QQcmdZViewItem
Not sure which Cyrus amp' this transformer is for!
http://cgi.ebay.co.uk/Mission-Power...oryZ4665QQssPageNameZWD1VQQrdZ1QQcmdZViewItem
Not sure which Cyrus amp' this transformer is for!
Hi Johnny555,
Just thought i'd say that transformer is not from a cyrus I or II (only have one center tapped secondary), probably from a newer cyrus amp, cyrus 5 or another product. Cyrus sell service manuals for there products (well for earlier products they seem to, think a Cyrus I manual was £15-20 when i asked). You said one channel sinks the 12volts from your PSU, i take it the other channel seems ok? can you test it? if it works you've got a reference point to check the other channel against, or maybe it won't work properly with too low voltage powering it?
I also take it your powering it with a dual rail power supply. As anatech said, use a current limiting power supply to test it, don't want to damaged other components. If it is sinking lots of current worth checking the output transistors for shorts, or power it off a current limiting supply and see if there's voltage on the output terminals, or output point on the circuit board if it has protection.
The daughter board can probably be salvaged (presuming it works) you would need to trace the signal and power supply signals (on the main board where it plugs into), work out which wires on the connector do what, probably +/-15volt for Opamps (can you see what the chips are on it? search on google? the cyrus schematic would make life really easy
)
My choice would be to fix it up if there's not too damaged, with a cheapish transformer if possible (servicing would probably be quite expensive), got to love cyrus equipment! (pretty indestructable as well, as my Cyrus One with partly rusted through components proved when i tried it out.....)
Hope that's some help! (only my second post or so, just a determined DIYer now wanting to help others....)
Just thought i'd say that transformer is not from a cyrus I or II (only have one center tapped secondary), probably from a newer cyrus amp, cyrus 5 or another product. Cyrus sell service manuals for there products (well for earlier products they seem to, think a Cyrus I manual was £15-20 when i asked). You said one channel sinks the 12volts from your PSU, i take it the other channel seems ok? can you test it? if it works you've got a reference point to check the other channel against, or maybe it won't work properly with too low voltage powering it?
I also take it your powering it with a dual rail power supply. As anatech said, use a current limiting power supply to test it, don't want to damaged other components. If it is sinking lots of current worth checking the output transistors for shorts, or power it off a current limiting supply and see if there's voltage on the output terminals, or output point on the circuit board if it has protection.
The daughter board can probably be salvaged (presuming it works) you would need to trace the signal and power supply signals (on the main board where it plugs into), work out which wires on the connector do what, probably +/-15volt for Opamps (can you see what the chips are on it? search on google? the cyrus schematic would make life really easy
)My choice would be to fix it up if there's not too damaged, with a cheapish transformer if possible (servicing would probably be quite expensive), got to love cyrus equipment! (pretty indestructable as well, as my Cyrus One with partly rusted through components proved when i tried it out.....)
Hope that's some help! (only my second post or so, just a determined DIYer now wanting to help others....)
In this case this thread could be of interest:
http://www.diyaudio.com/forums/soli...hematics-later-models-wanted.html#post1998327
http://www.diyaudio.com/forums/soli...hematics-later-models-wanted.html#post1998327
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