A60 Power Amp problem

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antonio66
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A60 Power Amp problem

Unread post by antonio66 » Fri Oct 04, 2019 6:08 pm

Well I've stripped down the system today trying to find the source of crackling in the left hand speaker. I've also had a hum on both speakers which I've put down to the phonostage, so have purchased a 4 shelf to replace a 2 shelf rack which I'm hoping will sort the problem giving a larger distance between phono and power supplies. I've only set up the digital side of things for now and the crackling still exists, even when unplugging the inputs in the power amp so one can assume I have a fault in the power amp. I will dig out an old intergrated tomorrow to confirm, but if it's the fault of the A60 is it just sent back to NVA with an appropriate note?

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savvypaul
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Re: A60 Power Amp problem

Unread post by savvypaul » Fri Oct 04, 2019 6:20 pm

One channel or both?

Intermittent or constant?

Crackling or pulsing?

antonio66
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Re: A60 Power Amp problem

Unread post by antonio66 » Fri Oct 04, 2019 7:28 pm

At the moment one channel Paul. It an crackling sound, constant but louder and softer noises. Hope this helps.

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karatestu
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Re: A60 Power Amp problem

Unread post by karatestu » Fri Oct 04, 2019 7:29 pm

If its a rustling noise then you have a couple of mice nesting in there :grin:
DIY inspired by Richard "The Doc" Dunn RIP

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savvypaul
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Re: A60 Power Amp problem

Unread post by savvypaul » Fri Oct 04, 2019 7:35 pm

antonio66 wrote:
Fri Oct 04, 2019 7:28 pm
At the moment one channel Paul. It an crackling sound, constant but louder and softer noises. Hope this helps.
OK. Swap the speaker leads over at the amplifier outputs - take out the red cables FIRST, re-insert the red cables LAST.

Does the noise change channel or stay in the same channel?

antonio66
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Re: A60 Power Amp problem

Unread post by antonio66 » Sat Oct 05, 2019 6:43 am

Why didn't I think about swopping speaker cables :doh:
Anyway just done that and the crackling has moved to the right hand side speaker, more intermittent. This is with the input cables removed.

antonio66
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Re: A60 Power Amp problem

Unread post by antonio66 » Sat Oct 05, 2019 7:32 am

I have changed the cables back, there is intermittent crackling on the left hand side speaker and also a low level noise when putting your ear next to the speaker. There is no noise coming from the right hand side speaker.

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savvypaul
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Re: A60 Power Amp problem

Unread post by savvypaul » Sat Oct 05, 2019 9:48 am

OK.

In that case it points to a fault on one of the amplifier boards. I will double check with Tomasz that I haven't overlooked anything...then PM you with the next steps.

antonio66
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Re: A60 Power Amp problem

Unread post by antonio66 » Sat Oct 05, 2019 10:33 am

Thanks Paul, I'll be posting my P90 on Monday. Got a Yamaha AS300 in the system now so at least there's music.

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slinger
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Re: A60 Power Amp problem

Unread post by slinger » Sat Oct 05, 2019 1:24 pm

If you give it a "slap" and the crackling stops or gets worse, it's probably a dry joint. :lol: :lol: :lol:

NO!! I AM NOT RECOMMENDING THAT. IT WAS A JOKE. SUCH TESTS SHOULD ONLY BE CARRIED OUT UNDER LABORATORY CONDITIONS AND BY QUALIFIED ELECTRONICS ENGINEERS.
Amps - NVA P50, A30, A40, Stanislav Palo Tube Headphone Amp BB 85
Speakers - Monitor Audio Silver RX2
Cables - NVA LS1+LS3, SSC, Gotham S/PDIF, IBRA Optical
Digital - NAD C516BEE, SONY ST-SDB900 DAB TUNER, TEAC UD-H01 DAC
Analogue - Pro-Ject Debut Carbon Esprit SB, Graham Slee Gram Amp 2 Phono
Cans - Grado SR80, ATH-M50X

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