Help with CT-3 - humming through TFM-55

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brit01
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Help with CT-3 - humming through TFM-55

Post by brit01 » Tue Aug 05, 2008 3:08 pm

Hi,

Just purchased a CT-3 and TFM-55 via ebay. Well I tested it out in a local known shop as the seller was a good friend of the owner. It's a small country.

Everything sounded fine in the shop through a pair of Paradigms. We tried with various music genre.

Now at home I'm getting some interference creating a humming sound from the Pre. I tried disconnecting the pre and using another source, and everything perfect. When I have the volume of the pre at zero and turn up the gain on the power I can hear the humming/buzzing.

Now I'm immediately thinking it's my cheap interconnect cables without shielding. Of course in the shop he had good cables.

I'm off down to the local shop now to buy a new shielded pair praying that this will be the solution and it's not something internal.

Any advice?

Cheers
TFM-55, CT-3, Klipsch F-1, Rotel RCD 930AX

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Re: Help with CT-3 - humming through TFM-55

Post by BillD » Tue Aug 05, 2008 4:37 pm

Sounds like a grounding issue to me - especially if it sounded fine in the store.
It should sound like it isn't there!
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Re: Help with CT-3 - humming through TFM-55

Post by brit01 » Tue Aug 05, 2008 5:36 pm

Bought a new interconnect cable and it appears to have eradicated 95% of the hum! :D
I'll buy another for the cd-pre connection tomorrow.

A big relief.

Now I'm going through my collection and beginning to experience the Carver sound. Hearing new things and realizing how the music peaks especially with rock music. Just on low volume it jumps from 5 watts to 60/70 watts with some music as shown on the front needles.

Now I can visually see the peaks and understand the clipping much more.

Cheers guys
TFM-55, CT-3, Klipsch F-1, Rotel RCD 930AX

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Re: Help with CT-3 - humming through TFM-55

Post by brit01 » Wed Aug 06, 2008 9:46 am

Although 90% of the hissing has been eradicated there is still a faint hum from the speakers when I turn the gain on the tfm-55 to maximum with source signal at zero.

Is this normal due to power of the amp?

Cheers
TFM-55, CT-3, Klipsch F-1, Rotel RCD 930AX

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Re: Help with CT-3 - humming through TFM-55

Post by TNRabbit » Wed Aug 06, 2008 9:54 am

If it's humming, you should TEACH IT THE WORDS.... :lol: :lol:
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Re: Help with CT-3 - humming through TFM-55

Post by brit01 » Wed Aug 06, 2008 9:57 am

:-({|=

Jaja Lol.
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Re: Help with CT-3 - humming through TFM-55

Post by OBI56 » Wed Aug 06, 2008 10:30 am

brit01 wrote:Although 90% of the hissing has been eradicated there is still a faint hum from the speakers when I turn the gain on the tfm-55 to maximum with source signal at zero.

Is this normal due to power of the amp?

Cheers
The amp should be dead silent. IVe had that kind of problem before that was caused by the speaker wires picking up some residual AC hum from the electrical wiring and feed ing it back through the amplifier.

Make sure that you are not running the speaker wires bundled with the speaker wires or parallel within 6" to 12" of each other. In fact, make sure that your IC cables are not running in close proximity to the AC wiring either. You mentionned that you had iffy AC power, so that would be my first suspect as to why you are having this issue. One last thing you can try is to put the amplifier and pre-amp on separate electrical circuits if possible.

Keep us posted
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Re: Help with CT-3 - humming through TFM-55

Post by brit01 » Wed Aug 06, 2008 10:36 am

I have some cheap Jenson gauge 18 speaker cable 8-[

Yes some bundling going on behind the equipment. Also shady wiring in the whole house :roll:

As I mentioned the new interconnect cable between pre and power improved it a lot. New shielded speaker cable maybe??

Not much choice here. There was some Jamo 14 gauge cable which was fairly well covered on offer in my local.

What do you think about the speaker cable?

Cheers
TFM-55, CT-3, Klipsch F-1, Rotel RCD 930AX

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Re: Help with CT-3 - humming through TFM-55

Post by OBI56 » Wed Aug 06, 2008 11:04 am

brit01 wrote:I have some cheap Jenson gauge 18 speaker cable 8-[

Yes some bundling going on behind the equipment. Also shady wiring in the whole house :roll:

As I mentioned the new interconnect cable between pre and power improved it a lot. New shielded speaker cable maybe??

Not much choice here. There was some Jamo 14 gauge cable which was fairly well covered on offer in my local.

What do you think about the speaker cable?

Cheers
First thing is to unbundle the speaker wires from the rest of your wires to see if that helps with the hum problem. The next thng is to get bigger gauge wire for your speakers to improve the sound.

I have no experience with Jamo speaker cable (I didn't even know they made speaker wire!) but at 14 gauge is is bound to be an improvement over what you have now. As for sheilded speaker wiring, that is sort of a last resort or something you might want to try if you still have persistent hum problems.
Why let facts or common sense get in the way of your opinions.

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Re: Help with CT-3 - humming through TFM-55

Post by TNRabbit » Wed Aug 06, 2008 11:05 am

brit01 wrote:I have some cheap Jenson gauge 18 speaker cable 8-[

Yes some bundling going on behind the equipment. Also shady wiring in the whole house :roll:

As I mentioned the new interconnect cable between pre and power improved it a lot. New shielded speaker cable maybe??

Not much choice here. There was some Jamo 14 gauge cable which was fairly well covered on offer in my local.

What do you think about the speaker cable?

Cheers
You need to straighten out all the wiring first. Run all power cords together away from the IC/Speaker cables. If they MUST cross, do so at 90 degree angles vice parallel.
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From FrankieD's lips to your ears: Sunfire - a quiet box of endless power.

Sunfire TG-IV/400~7 Amp
Carver SD/A-360 CDP
Benchmark DAC-1
Sony SACD/DVD-A
Active bi-amp: Ashly XR-1001 & 2 Rane PEQ-15s
Main: HotRodded AL-IIIs
Sub: Klipsch RT-12d
Center: Sunfire CRS-3c
Surround: Sunfire CRS-3 (x 2)

OconeeOrange wrote:"Gary likes to play it 'loud' as do I. His system begs you turn it up until you die"

RIP WIlliam B. Dibble, 1948-2012. I'll miss you my friend.

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Re: Help with CT-3 - humming through TFM-55

Post by engtaz » Wed Aug 06, 2008 11:22 am

Great post TNRabbit. Some cables can't shield away noise as well as others and power cords are a good source of noise.
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Re: Help with CT-3 - humming through TFM-55

Post by brit01 » Wed Aug 06, 2008 11:34 am

Great guys.

I'll play around with the positioning, mains cables etc and try out some new speaker cables also, can't do any harm at 1.20 dollars a meter for the Jamo 14 gauge.

:D
TFM-55, CT-3, Klipsch F-1, Rotel RCD 930AX

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Re: Help with CT-3 - humming through TFM-55

Post by brit01 » Wed Aug 06, 2008 12:11 pm

I re-routed all cables and equipment well away from each other, used different power sources and the hum appears when I power up the pre CT-3. Now the interconnect cable I changed yesterday improved this hum significantly but it's still there mainly emanating from the tweeter.

What now? Back to the grounding problem? Or dirty contacts?
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Re: Help with CT-3 - humming through TFM-55

Post by TNRabbit » Wed Aug 06, 2008 12:21 pm

When you have only the amp connected, is the hum there? (preamp completely disconnected)

...or does it appear after you connect the preamp? Does the preamp have a headphone jack you can check for hum independently of the amp?

Isolate if it's coming from the amp or preamp, then let's go from there. I know you said when you power up the preamp you hear it, but let's ascertain for sure you have no issues with the amp itself. Then we'll move to the next test.
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From FrankieD's lips to your ears: Sunfire - a quiet box of endless power.

Sunfire TG-IV/400~7 Amp
Carver SD/A-360 CDP
Benchmark DAC-1
Sony SACD/DVD-A
Active bi-amp: Ashly XR-1001 & 2 Rane PEQ-15s
Main: HotRodded AL-IIIs
Sub: Klipsch RT-12d
Center: Sunfire CRS-3c
Surround: Sunfire CRS-3 (x 2)

OconeeOrange wrote:"Gary likes to play it 'loud' as do I. His system begs you turn it up until you die"

RIP WIlliam B. Dibble, 1948-2012. I'll miss you my friend.

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brit01
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Re: Help with CT-3 - humming through TFM-55

Post by brit01 » Wed Aug 06, 2008 12:26 pm

ah yes.

half and half.

With the pre totally disconnected from the power I still get a faint hiss, then when I connect the interconnect from the pre it amplifies it a little.

#-o
TFM-55, CT-3, Klipsch F-1, Rotel RCD 930AX

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