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Rogue Perseus noisiness- DIY fixed! (mostly)

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Posted on April 19, 2017 at 12:50:20
MWE
Audiophile

Posts: 2196
Location: Burlington, NC
Joined: June 8, 2000
The Perseus I bought about nine years ago, in spite of otherwise sounding very nice, has always had a noise problem. Essentially a high-pitched hum/low-pitched buzz- 60 Hz harmonics, I assumed, at a constant level, not VC-dependent. Had just lived with it lo these many years but was getting frustrated. Wasn't convinced that the factory was going to be helpful, and thus decided to take a whack at it myself. So I removed the top, removed the toroidal transformer retaining nut, and propped the transformer up on a plastic foam block so that it was raised up about three inches from its usual position at the bottom of the case. Voila'! Noise reduced about 80%.

However, I didn't want to use it like that, as I could no longer put the top cover back on. So I replaced the transformer back to its usual spot but tried rotating it about 90 degrees, the wires fortunately being long enough. Now had noise reduction of about 70%, and I can live with that. Would love to hear any insights on this from anyone in the know.

Mark in NC
Mark in NC
"The thought that life could be better is woven indelibly into our hearts and our brains" -Paul Simon

 

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Why did you assume the factory would not be helpful??, posted on April 19, 2017 at 18:38:39
JoshT
Audiophile

Posts: 6622
Location: Eastern Massachusetts
Joined: July 4, 2000
By all accounts Rogue has about the best customer service there is and in all those years you never reached out to them?
___
"If you are the owner of a new stereophonic system, this record will play with even more brilliant true-to-life fidelity. In short, you can purchase this record with no fear of its becoming obsolete in the future."

 

Well, two reasons, really..., posted on April 19, 2017 at 19:02:57
MWE
Audiophile

Posts: 2196
Location: Burlington, NC
Joined: June 8, 2000
First, based on other people's experiences with the same problem as read on various audio forums over past years. Second, when I called them to report my initial findings to ask them how to get the same results with the transformer back in original position, they couldn't really offer any help. It was just through happenstance that I tried rotating it. The problem had been lower priority for me after having fixed my C-J PF-R not too long ago, thereby allowing me to use it, but that repair (an intermittent problem that the C-J service dept. was unable to diagnose) motivated me to take a whack at the Rogue problem.

Mark in NC
Mark in NC
"The thought that life could be better is woven indelibly into our hearts and our brains" -Paul Simon

 

RE: Rogue Perseus noisiness- DIY fixed! (mostly), posted on April 19, 2017 at 20:23:21
6bq5
Audiophile

Posts: 4363
Location: SF Bay
Joined: August 16, 2001
Transformers are very interesting components within the structure of a tube amp.
beyond the assembly and finish of the transformer, the orientation IS important. Glad that you found a solution- it makes sense that it worked out that way.
Happy Listening

 

RE: Rogue Perseus noisiness- DIY fixed! (mostly), posted on April 20, 2017 at 11:51:03
Ugly
Audiophile

Posts: 2912
Location: Des Moines, WA
Joined: August 22, 2006
If you prefer not isloating the analog circuitry from the xfrmr by separation distance, perhaps some magnetic shielding could offer you even more immunity to the noise. Something like some mumetal might help divert that noise energy to someplace less consequential to the audio.

 

RE: Shielding w/ mu-metal..., posted on April 20, 2017 at 17:23:22
MWE
Audiophile

Posts: 2196
Location: Burlington, NC
Joined: June 8, 2000
I had given a bit of thought to that, as there's still some room left, I believe, to reduce the noise level further. Not having had any experience with mu-metal, are there any tips/techniques for using it effectively?

Mark in NC
Mark in NC
"The thought that life could be better is woven indelibly into our hearts and our brains" -Paul Simon

 

RE: Shielding w/ mu-metal..., posted on April 20, 2017 at 20:24:39
Ugly
Audiophile

Posts: 2912
Location: Des Moines, WA
Joined: August 22, 2006
I've never owned any. As I understand it it will be most effective for certain bands of B field.

If that isn't working try an E field shield such as some copper.

Rules of thumb for shields: 1. the more you can completely enclose the noise source by continuous shielding the better. 2. Thicker is better 3. with the e field shield, try floating, earthing, etc.

 

Will try this. Ought to be interesting. nt., posted on April 20, 2017 at 20:55:10
MWE
Audiophile

Posts: 2196
Location: Burlington, NC
Joined: June 8, 2000
nt.
Mark in NC
"The thought that life could be better is woven indelibly into our hearts and our brains" -Paul Simon

 

Speaking of Conrad Johnson Service Dept., posted on April 21, 2017 at 04:55:18
From my experience, using Conrad Johnson's service department, was a total disaster. They replaced one resistor on a 17LS pre-amp, charge $420.00.
5 Week turnaround time.

Never again will I purchase a CJ product.

 

RE: Speaking of Conrad Johnson Service Dept., posted on April 21, 2017 at 06:59:41
AbeCollins
Audiophile

Posts: 46196
Location: USA
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Contributor
  Since:
February 2, 2002

It was a specially tuned audiophile grade resistor that was highly praised in various magazine reviews. ;-)



 

Ouch!! nt., posted on April 21, 2017 at 07:21:19
MWE
Audiophile

Posts: 2196
Location: Burlington, NC
Joined: June 8, 2000
nt.
Mark in NC
"The thought that life could be better is woven indelibly into our hearts and our brains" -Paul Simon

 

Use a thin hard rubber pad.. Raise it maybe 1/8 to 1/4"??, posted on April 21, 2017 at 11:42:18
I would think you can raise it a little without hitting the top?

 

RE: Use a thin hard rubber pad.. Raise it maybe 1/8 to 1/4"??, posted on April 21, 2017 at 12:13:06
MWE
Audiophile

Posts: 2196
Location: Burlington, NC
Joined: June 8, 2000
Tried that, but it didn't work. Only way to get significantly reduced noise was to raise it several inches, or rotate it in its usual spot, leads fortunately permitting. As it stands, it's not dead quiet but very tolerable, much better than before. Also, radiating from large Maggies, the noise that's left is somewhat "diffused" so is less noticeable. Thanks for the suggestion, though. It was just really gratifying solving this problem on my own.

Mark in NC
Mark in NC
"The thought that life could be better is woven indelibly into our hearts and our brains" -Paul Simon

 

A strip of metal (copper or mu metal) separating the transformer from the rest of interior., posted on April 21, 2017 at 20:32:54
Even a strip as tall as depth of chassis, wrapped around transformer. and grounded.
The little hole for the wires will not be a problem.

 

RE: Rogue Perseus noisiness- DIY fixed! (mostly), posted on April 23, 2017 at 07:11:52
duck decoy
Audiophile

Posts: 233
Location: NC
Joined: August 20, 2014
I had a hum from my Rogue Sphinx and fixed it by placing an "Ebtech Hum X" between it and my PLC. It was about $60 from Amazon years ago; I don't know what they cost now.

 

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