Low level hum/buzz driving me CraZy!

[CJinSC]

Originally Posted by CJinSC

Thanks Ivan. How do you think the AMR cd77 would compare to this Ayon cd3-sx I'm demoing? Do you still sell the AMR players? <_UIBarButtonItemAppearanceStorage: 0x1aa719c0>

No hum from just amps on.
Next I'm assuming I unplug power cord & interconnects from preamp & then reconnect preamp to amps (with no CD player connected to preamp) turn on preamp & amps & listen for hum? If no hum with preamp in the circuit, then do same procedure with CD player?

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[CJinSC]

Hum is coming from the preamp, though at a much lower level than before after removing & reconnecting all power, interconnect, and speaker cables (bi-wired). I can deal with the hum at this level but will probably call CJ about the preamp tomorrow. Did notice some loose cables on bass modules of speakers. Guess those low frequencies loosen spades over time. Maybe I should go back to a clock radio, as I tend to be a "set it & forget it" guy😱

Thanks All!

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[Masterlu]

Originally Posted by CJinSC

Thanks Ivan. How do you think the AMR cd77 would compare to this Ayon cd3-sx I'm demoing? Do you still sell the AMR players?

[Coppy]

Your goal is to determine what components, upstream from the amps, are causing the ground loop hum. It will have nothing to do with the speaker cables, this is a power disfunction issue. If there's no hum with the amps on and nothing on the inputs, plug in the preamp and turn it on. if there's hum, put a cheater plug on the preamp. Then on to the CD player. In my case with a similar setup, i use cheater plugs on the mono blocks and an FM tuner... cures all hum.

Good luck with the headache. You will find the solution.

Bob

[CJinSC]

Originally Posted by Coppy

Your goal is to determine what components, upstream from the amps, are causing the ground loop hum. It will have nothing to do with the speaker cables, this is a power disfunction issue. If there's no hum with the amps on and nothing on the inputs, plug in the preamp and turn it on. if there's hum, put a cheater plug on the preamp. Then on to the CD player. In my case with a similar setup, i use cheater plugs on the mono blocks and an FM tuner... cures all hum. Good luck with the headache. You will find the solution. Bob

This morning the hum level is back up to the previous annoying levels. CJ told me to get some cheater plugs and try one first on the GAT to see if this eliminates the hum. If not, put another one on one monoblock, see if this kills hum. If not, will need another cheater plug on the CD player. Long term I need to get an electrician to wire a dedicated 15-20 amp circuit for the stereo.

On to the hardware store tomorrow. Thanks Bob! Are you still enjoying the LP 140's or have you been tempted to move up to the ART's with good demo prices popping up periodically?

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[Coppy]

Hey CJinSC,

Still loving the LP140s. Every now and then I haul out the Premier 350 to see if somehow all that power sounds better. Always go back to the LP140s, those monos are just terrific sounding. As to the ART monos, I now live in Sarasota, Florida where the warmth of all those tubes is less desirable, so not tempted. The sound would be a tiny bit better but have all the power I need now. A dedicated line is a good thing but it is not likely to cure your issue. Pardon this technical description but the issue is the difference in ground potential between the individual component chassis. All circuits lead to ground inside, but there is no central ground so they all lead to the chassis. (not the casework as that could lead to trouble from human contact) When you connect then together with ICs theres a voltage difference and current flows between them. A ground loop. "Lifting the grounds" with a cheater plug cuts off the differential but arguably adds an element of electrocution risk if something were to short to the chassis, especially in tube equipment with high plate voltages, so be cautious with small children, pets and yourself. That said, the ground has always been lifted on my monos with no ill effect thus far. Seems to me a cheater on the GAT would be far less risky than on the big power amps... so there's that. I may give that a try also. Have a good trip to the store.. the plugs are cheap enough.

Bob

[CJinSC]

Bob, my GAT & LP 140's make a great combo with the Verity Amadis. I don't need more volume either, but Jeff at CJ was telling that the ART's output transformers are superior to the LP 140's & would certainly provide tighter bass and better speaker control as the primary benefits if I upgraded. Although, my bass response seems perfectly acceptable now. I guess I'm still curious how much deeper/wider that soundstage would get with ARTs.

I'm enjoying a "hotter than 40 hells" summer in SC as well. Maybe more tubes isn't the answer😓

Regards,

John

.ohgizmo.com

[4RE]

Some good advice and suggestions are given.
Still groundloops or current drifts can be complicated matter, sometimes all it needs to fully cure is a simple cheater plug to discover, other times it can be a dreadful and ongoing thing to get the buzz found.

The usual procedure is by way of elimination. other trick is to ask oneself : when did the problem occur first in time? most times something has changed and then a buzz occurs.

And sometimes the source of the problem can be very unlikely, but still is.
As an example I have the weird phenomenon that after changing out XLR interconnect between Cd player and preamp WITHOUT putting the CD player OFF in the first place, there occurs a very strange high frequency distortion afterwards.. When the CD player is put off and sequently turned to on, it resets internally and is totally quiet again situation normal.

But finding this out was only after exchanging all tubes one by one and busting many braincells. Sometimes a restart is all it takes on a digital source...

The much anticipated multiple audio AC groups and even separated fuses is in principle asking for groundloops. I Don't say it always does, but the chance on groundloops is higher.
In any case ALWAYS use one phase on the AC incoming, then divide into groups.
Have two 20 Amp groups myself, but if I could do it over again, would use one single 20 Amp group now. YMMV as they say, every situation can ask for a somewhat different plan.

[Coppy]

Originally Posted by CJinSC

Bob, my GAT & LP 140's make a great combo with the Verity Amadis. I don't need more volume either, but Jeff at CJ was telling that the ART's output transformers are superior to the LP 140's & would certainly provide tighter bass and better speaker control as the primary benefits if I upgraded. Although, my bass response seems perfectly acceptable now. I guess I'm still curious how much deeper/wider that soundstage would get with ARTs.

I'm enjoying a "hotter than 40 hells" summer in SC as well. Maybe more tubes isn't the answer😓

Regards,

John

.ohgizmo.com

Hey John,

Jeff is certainly correct. There is a difference. The upgrade gets you two major benefits; a wider FRQ response profile, mainly due to those big output transformers, and a bunch more power which represents itself in rather an ease producing music, as with all big amps. The effortless power thing is most noticeable. How much all that is worth to you is a matter of personal judgement.

So, "you pays your money and you makes your choice."

Keep us posted...

Bob

[CJinSC]

Originally Posted by Coppy

Hey John, Jeff is certainly correct. There is a difference. The upgrade gets you two major benefits; a wider FRQ response profile, mainly due to those big output transformers, and a bunch more power which represents itself in rather an ease producing music, as with all big amps. The effortless power thing is most noticeable. How much all that is worth to you is a matter of personal judgement. So, "you pays your money and you makes your choice." Keep us posted... Bob

Well since stocks are correcting maybe I'll INVEST in some CJ ARTs instead !

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