I want to add the following:
I measured the buzz with an app on my iphone held within a few inches of the speakers.
I can hear the buzz from my listening position which is about 12 feet away from the speakers. |
Roxy - it’s been so long since I took the int to CODA, I can’t remember the specifics of what was discussed. I do remember that: 1) no noise was heard on their dedicated circuit, 2) they said that it was very unusual for one of their products to elicit the buzz I told them I was hearing.
Stringreen - can you be more specific about “inverting plugs”? The noise is constant, no matter what other electrical devices are on or off anywhere in both my current and previous homes.
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To imhififan: thanks for the explanation. I didn’t think this was an issue, but thought it worth asking the question. I was really surprised by how well the tube integrated drove my speakers......and it was almost a brand new unit with minimal burn in time. If coda can’t fix my issue, I may switch to a tube integrated.
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Thanks for all the suggestions. I was busy today walking the dog then doing some interior painting. I will dig into this tomorrow and give you some feedback.
I agree, given that I have the same problem in a second house, it seems unlikely to be the electrical system at my new home. OK, all for now.
Thanks again. |
Did want to share some additional info:
I originally started with balanced interconnects (had a Sony HAPZ-1ES at the time), and the buzz was present. As far as I can determine, the buzz has been with me since I got the integrated. I switched to single ended cables as they sounded better with my Sony. Before I try to find the “right” cables for the Lumin T2 (which I just purchased) I thought I would try again to solve the buzz problem.
Someone a long time ago recommended shorting plugs in the empty inputs. Can anyone point me to some shorting plugs I can try?
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Just tried the experiment; unplugged everything from the amp except speakers, ran OEM power cord directly into wall. As expected, the buzz still exists. It exists no matter which input is selected (Aux 1, Aux 2, etc) or what volume I have it set at. In fact, there is no change in volume of buzz, no matter what I do. As I soon as I turn the bias “off”, there is no further sound through the speakers.
So, does this in fact mean a noisy AC line? I would not suspect the equipment since I know that the amp was dead quiet when plugged into the AC at one audio store and the manufacturer. But, to be fair, this was about 4 or 5 years ago (I’ve been living with the buzz that long).
FWIW.....someone asked who did the modification to increase amount of Class A power......it was the manufacturer at the time of purchase.
Is it still worth trying grounding plugs?
Any other thoughts?
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Jea48: I will try ground cheater tomorrow. Mute button does not change anything either. |
Ground cheater installed. No effect. Buzz still exists.
To Jea48: definitely the buzz, not a hum.
Should I now order and try input shorting plugs? If so, can someone send me a link for viable ones that are inexpensive? Will I need them for both RCA and balanced inputs?
Thanks again to all - this IS very frustrating. I so like the overall sound of my system, but this has been a persistent problem that I would really like to get solved. |
Thanks imhififan. Given that you have a dead quiet amp, and mine has been “noisy” in two separate homes, I have to think that despite it being quiet at manufacturer and audio store, something is likely amiss with the amp itself. I will try your experiment, and then contact CODA for repair.
Just out of curiosity, did you have CODA bump up the amount of Class A watts? |
So, here’s a weird one. The input shorting plugs arrived today, so I installed them (for the heck of it). Not only did it not impact the buzz at all, but.......it prevented the amp from generating any sound until I removed them all! Now I know for a fact that I’ve had more than one input connected at one time (I only have one currently), so I don’t get it.
Can anyone explain this issue? Is it at all related to what might be wrong with the unit? |
Ordered grounding plugs for RCA and XLR inputs. Should arrive in a few days. Will try this experiment as well as the one with the breaker and report back early next week. I’m expecting that none of these will solve the issue and that I’ll need to send the amp back to CODA. I hope to be pleasantly surprised. |
OK oldhvymec: did the following:
unhooked right speaker - buzz on left speaker
unhooked left speaker - buzz on right speaker
unhooked red leads to speaker - quiet!
reattached red leads to speaker, unhooked black leads - quiet!
What does this mean??
Had to look up what a variac was......don’t have access to one. |
To cakyol: I tried your suggestion of plugging the amp and streamer directly into the wall (no power conditioner). It made no difference, the buzz was still there. I also tried just the amp alone into a regular outlet (no streamer); the buzz remained. I vaguely remember that I purchased the power conditioner in the hopes that it would eliminate the buzz, and even though it didn’t, it had a positive effect on the sonic quality of my system.
So where, in your opinion, does this leave me? |
To oldhvymec: my speakers only have one pair of binding posts, not two, thus I could not try your suggestion.
I have multiple built in appliances in my house and thus could not unplug everything as you suggest. A previous suggestion was to turn off all the breakers except for the one to the stereo. Will this work as well as what you suggested? |
To oldhvymec:
“You know what is strange, when you had a complete system swap a few years back it was even noiser. How does that play into it?”
I suspect, but do not know for certain, that my previous house did have an AC noise issue. So that when I tried the second system in the house, it too was noisy.
Yes, I put up with the buzz for a long time. I had a lot of other things going on in my life, but now, with COVID, I have more time to dig into issues that have been put on hold for a while.
Will be calling CODA tomorrow morning.
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UPDATE: I had the chance to borrow a new Prima Luna EL 300 integrated tube amp this morning. The amp was dead quiet! Clearly, I have a problem with my integrated amp. I will call CODA and inquire about repair.
QUESTION: The Prima Luna had both 4 & 8 Ohm speaker inputs; I used the 4 ohm inputs as that is what my Dynaudio Focus 380’s are rated at. The CODA only has one set of speaker inputs. Is there any chance at all that there is a mis-match between the CODA and the speakers due to impedance difference? |
UPDATE: have spoken with CODA. They have heard of the buzz issue before (has something to do with the jumpers on the circuit boards). They said that pre-2015 units had about a 25% chance of buzz. The owner gave me instructions to bypass and test the jumpers. Unfortunately, despite my hopes, the buzz remains after having tried the suggestions offered.
I will be sending the amp back to CODA. |
Yes, using single ended cables. No, did not try isolation transformer. It is clearly an amp issue which I will get fixed. |
