2. amps-preamps
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Help...hum issue with new preamp

Hi goners, I have just switched preamps from an Aesthetix calypso sig to a Supratek Cabernet and I am now getting a  decent hum from the balanced connections from my Atma-Sphere monos to the Supratek where as I did not get it at all with the Aesthetix. Now I had an old set of single end cables that I used with the Supratek to troubleshoot and the hum was gone. The only thing I can think of is that since the Supratek is not truly balanced it must be causing an issue, as we know the Aesthetix is truly balanced. In any event I want to keep my xlr connections because of length. No I have not contacted Mick from Supratek yet as I'm hoping this can be resolved easily. .Any help would be appreciated. Thanks so much. 
barfbag
15 responses Add your response
czarivey
5,658 posts
 
most-likely you'll have to use unbalanced cables.
in balanced ground is isolated from signal path in unbalanced ground is negative and not isolated. hum transfer is quite possible. your long xlr connectors are irrelevant and only would work between two fully balanced components. all of your balanced benefits are unfortunately gone. 
jea48
4,258 posts
 

No I have not contacted Mick from Supratek yet as I'm hoping this can be resolved easily. .Any help would be appreciated. Thanks so much.

You should contact Atma-Sphere and ask them what you can do to solve the problem.

Maybe Ralph, the owner of Atma-Sphere, will see this thread and respond.


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http://www.rane.com/note110.html

lalitk's avatar
lalitk
5,053 posts
 
@jea48,  Thank you for sharing the article. 
barfbag OP
24 posts
 
Yes thank you.
atmasphere's avatar
atmasphere
11,567 posts
 
Maybe Ralph, the owner of Atma-Sphere, will see this thread and respond.
Indeed I did.

I'm pretty sure all that is happening here is that the Supratek has no internal connection on its XLR (since its a single-ended preamp) between pin 1 and pin 3. As a result, pin 3 is picking up noise and the amps are amplifying it.

A jumper installed between pin 1 and 3 on the XLR inside the preamp should sort it out.
jea48
4,258 posts
 

atmasphere,

Couldn't he do the same thing at the end of the two XLR cable connectors that plugs into the preamp? Solder a jumper wire from pin 1 to pin 3 of the female connector.

I doubt he would want to void the warranty on the preamp if he did it inside the unit.

Or could he just take and old RCA interconnect cable and demo the inside pin of the plug on one end. Cut off the cable and bare the return ground wire and connect it a metal screw on the chassis. Then plug the RCA plug of the cable into any output RCA jack on the back of the preamp?

Jim  

barfbag OP
24 posts
 
Thanks Ralph& Jim, I'll check it out.

jayrossi13's avatar
jayrossi13
182 posts
 
@barfbag How do you like the Cabernet as compared to the Calypso?
jafant
18,774 posts
 

OP-


what did not you not like about the Aesthetix?

barfbag OP
24 posts
 
Hello Jay, well first I originally had a standard calypso which I liked in an old system, then moved on to a different setup with a Supratek Chardonney which I loved but no remote and no xlr so I found a Calypso signature thinking this would take me off the merry go round but what a disappointment from the Supratek. So of course I found a Cabernet dual 3,days later and bought it, and viola, I got my  holographic 3d expansive soundstage back, funny I could tell from the first vocal track. To me Supratek performs magic in the midrange,  So in MYsystem both Suprateks trounced the Aesthetix. I won't ever part with this one. Cheers.
jayrossi13's avatar
jayrossi13
182 posts
 
Thank you, I appreciate the feedback. I'm currently having a new Cabernet Dual built with 300B tubes. 

I'm definitely looking forward to hearing it in my system. 
barfbag OP
24 posts
 
Hi Jay, wow that's great you should be very pleased. Tell me about the rest of your setup, I'm always curious. Thanks.
atmasphere's avatar
atmasphere
11,567 posts
 
Couldn't he do the same thing at the end of the two XLR cable connectors that plugs into the preamp? Solder a jumper wire from pin 1 to pin 3 of the female connector.
Yes, he could. I doubt the preamp is in warranty FWIW; if it is I would consider having the manufacturer fix the oversight, as that's what it is.
barfbag OP
24 posts
 
Thanks guys, no warranty but I'm handy so I'll do the surgery, I hope it's just that. 
thaluza's avatar
thaluza
278 posts
 
Did you take a look at the insides? When my Supratek Cortese was shipped to me it arrived with a loose wire to the phono stage. When I sold it, the buyer received it with a loose part in the power supply. Both issues were fixed easily. It was a great sounding preamp. I had an Aesthetix Janus before owning the Supratek, and I much preferred the Supratek.
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