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#1 |
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diyAudio Member
Join Date: Dec 2005
Location: Singapore
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I have been using the Denon DL-103R with the Denon AU-300LC and the AA 2006 Phono
Recently I decided to try the Cinemag CMQEE-3440A as step up based on good feedback on audioasylum. However, after wiring it up as per cinemag's documentation, all I get is very distorted and scratchy sound, and I still can't figure out why. Appreciate any suggestions from anyone to help me troubleshoot. I already checked the wiring many times, I also tried using only one primary, without success. thanks!
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#2 |
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diyAudio Member
Join Date: Oct 2004
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It's hard to say. But have you made sure it's properly grounded?
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#3 |
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diyAudio Member
Join Date: Dec 2005
Location: Singapore
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I tried grounding both primary and secondary, only the primary. I tried revering one primary, I get very low sound level but the sound seems un-distorted. With both primaries in the same direction (as per the instructions), sound level is OK but distorted.
The instructions are here I'm really scratching my head on this one, I thought this should be relatively simple to do... |
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#4 |
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diyAudio Moderator
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If you haven't already, use an ohmmeter and get a sanity check on the windings. Mistakes on the manufacturer end have been known to happen...
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If there's a sucker born every minute, where do the rest of them come from? |
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#5 |
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diyAudio Moderator
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BTW, maybe some of the analog and transformer experts can weigh in here, but that connection scheme shown at the Cinemag page linked to by pengboon seems very suboptimal, wasting wire and throwing away potential common-mode rejection advantages. Or am I missing something? How well balanced are those primaries?
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If there's a sucker born every minute, where do the rest of them come from? |
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#6 |
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diyAudio Member
Join Date: Dec 2005
Location: Singapore
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I have, the primaries are about 26 ohms, with the centre tap somewhere in between the 2 ends. The secondaries are 3.9k. Anything else I should check?
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#7 |
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diyAudio Moderator
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OK, for fun, ignore one primary completely. Connect your cartridge across the other, ignoring the CT for the moment. What happens?
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If there's a sucker born every minute, where do the rest of them come from? |
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#8 |
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diyAudio Member
Join Date: Dec 2005
Location: Singapore
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Hi SY, same result, scratchy, distorted sound.
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#9 |
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diyAudio Moderator
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OK, now do this same thing with the other primary.
When you were measuring resistances, did you check that all coils were isolated from one another and all isolated from shield and core? edit: How do you have the secondary hooked up to the phono stage? Which input, what loading, yadda, yadda?
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If there's a sucker born every minute, where do the rest of them come from? |
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#10 |
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diyAudio Member
Join Date: Dec 2005
Location: Singapore
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Same result with the other primary.
I chekced between coils, the resistance were in terms of Mohms, then slowly decreasing to kohms... is this normal? I have the secondary (VIO) into the phono's input and white/grey/black into the phono's input ground. I tried connecting phono ground with primary ground and not, both yielded the same negative result. The loading of the input should be 50kohms, I tried a 30k in // to make the reflected loading 14R to match the cart, but same result still. The thing is, my Denon SUT (AU-300LC) works fine, so I think my TT/cart is fine, and the phono is fine. Something is wrong with the way I am hooking up or with the SUTs themselves... |
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