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It is currently 10 Dec 2019, 20:46

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PostPosted: 05 Jun 2019, 06:58 
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Joined: 19 Oct 2018, 15:30
Posts: 132
Location: Montréal, Québec
mwhouston wrote:
Gab wrote:
Very nice build ! Must be very enjoyable to listen to something as silent as it seems to be. I wish my 4S preamp was as silent as this !


Try moving the earth wire. On one build I put the earth on the RCAs to stop the hum. In another I moved the earth to the pot and not the RCAs. By the earth I mean the negative of the HT.

If you have the mains earth connected to the HT negative try removing it if not try connecting it. And do that in combination with the above two connections. Generally don’t have two earth connections by that I mean don’t connect to the RCAs and the pot. Or if you haven’t try both. All this varies from one built to the next and there never seems to be a set way.


Thanks for your advices. I’ll try this tomorrow when i’ll receive my new rectifier. I have no idea how, but I broke the envelope of the one I had... I find ground loops to be very tricky to solve. I’ve been struggling with this problem for several months, but I haven’t been able to bring the noise to an acceptable level. I have built the power supply at least 4 times according to the original design with very little success. The best results I’ve had were with a chinese filter board instead of the original psu. Most of the noise I get is 120hz. I’ll keep on trying !

Back to your thread. I’m getting off topic with my noise problems, but really appreciate your inputs ! Thanks !


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PostPosted: 20 Jun 2019, 19:57 
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Joined: 06 Jun 2008, 18:23
Posts: 5151
Location: Australia
Astounded by how well “LeManja” worked I figured why not add a HP driver section to one of the best sounding and most expensive tube preamps I have built. This in no way effects the performance of the preamp and extends its use to a HP amp also. Listened for about 8 hours yesterday all afternoon and into the night and are extremely impressed. Cheap and easy to do and just adds extended functionality to the preamp.
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Projects: "Precision" - 300W Class AB Holton power amp | "retro2308" - chip based headphone amp | ”Calibre 834” - tube phono MM preamp |


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PostPosted: 15 Aug 2019, 06:29 
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Joined: 04 Nov 2013, 21:18
Posts: 92
Location: Florida
These are beautiful... on the last amp, is that CAT5 wire?

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PostPosted: 15 Aug 2019, 06:38 
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Joined: 06 Jun 2008, 18:23
Posts: 5151
Location: Australia
vixr wrote:
These are beautiful... on the last amp, is that CAT5 wire?

That one is Cat5. Solid core copper. Most of it twisted pair. Thanks for the nice comments.

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Projects: "Precision" - 300W Class AB Holton power amp | "retro2308" - chip based headphone amp | ”Calibre 834” - tube phono MM preamp |


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PostPosted: 16 Aug 2019, 18:08 
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Joined: 06 Jun 2008, 18:23
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Location: Australia
Just added another input to make four; Pi server and DAC, TT, new Sony 4K player and audio ripper and Oppo 95. I also have a aptX HD blue tooth receiver but happy to swap out one other input for the few times I will use it.

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Projects: "Precision" - 300W Class AB Holton power amp | "retro2308" - chip based headphone amp | ”Calibre 834” - tube phono MM preamp |


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