hello all- i have an aragon 4004mk2 that suffered a spike when the negative power supply rail on my preamp failed. 1 channel popped a fuse and i found a couple of driver transistors shorted and a shorted current regulating diode.
it looks like i need a schematic to proceed further.
if anyone out there can help, i would be most appreciative.
regards, leapingknome
it looks like i need a schematic to proceed further.
if anyone out there can help, i would be most appreciative.
regards, leapingknome
I only very briefly examined the schematic, but I did note an interesting design decision. The inclusion of 680pF capacitors C2 and C12 seems odd, as they are located inside the error correction loop and will shunt high-frequency currents to outside the loop. The input stage error amplifier will attempt to correct for the lost loop current, decreasing high-frequency feedback and, I should think, increasing high-frequency distortion. I would think that Cdom caps., C3 and C13, should be sufficient for stability, unless they are undersized. Perhaps, the designer felt it simply sounded better this way. 🙂
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Sorry to revive an old thread but I have a 4004 MK I that has a hum in both channels but only when connected to ANY preamp via the RCA inputs. If the amp is powered on and connected to speakers and not connected to a preamp or source, no hum. If the amp is then connected to ANY preamp including a 100% dc ipod nano touch as a source, both channels have a clearly audible hum. Sounds like 60 hz. I have tried 3 different preamps all with the same result.
Any ideas? The amp still plays and sounds great, just hums with a pre or source connected. Also the toroids do have an audible buzz when powered on. i have tried a DC blocker with no results. This amp ran fine in a friends rig for years with no hum from the speakers even though the toroids have always had a low buzz. Now in my rig it hums. Both channels.
Any ideas? The amp still plays and sounds great, just hums with a pre or source connected. Also the toroids do have an audible buzz when powered on. i have tried a DC blocker with no results. This amp ran fine in a friends rig for years with no hum from the speakers even though the toroids have always had a low buzz. Now in my rig it hums. Both channels.
Hi,
I have an Aragon 8002 with an intermittent problem. Once in a while it starts making a crackling noise on its left channel that goes away as soon as I power cycle it. Any hints on what could be going ?
Anyone has a schematics for the ARAGON 8002 so I can ask my technician to look at the problem ?
Thanks a lot,
Andre
I have an Aragon 8002 with an intermittent problem. Once in a while it starts making a crackling noise on its left channel that goes away as soon as I power cycle it. Any hints on what could be going ?
Anyone has a schematics for the ARAGON 8002 so I can ask my technician to look at the problem ?
Thanks a lot,
Andre
Hi, i know you write for 5 years ago, but i hope you cam help me, when i have a Aragon 4004 mk2 with cracking sound, did solose the problem on you Aragon 8002, an did you please tell med what i s wrong? Best regards from Henrik, Denmark.