Buzzing sound from amp

[alexk0il]

Just got a new Marantz PM6007. It makes humming/buzzing noise from the inside, I can hear it at 30-40cm distance. No statics on the speakers.

AI tells me it's absolutely normal for torroids. Is it?

[Barry]

If there is no humming/buzzing noise heard through the speakers, then it is mechanical rather than electrical.

In general toroidal transformers are virtually silent as regards mechanical noise compared with non-toroidal designs, If they do hum/buzz then that can be due to magnetostriction effects; possibly because of the choice of an electrically under-rated transformer.

It might also be due to the central transformer fixing becoming slightly loose. Try having a go at tightening it up.

[Macca]

Not normal for it to buzz. Maybe a faint noise only audible if you put your ear against the amp is acceptable, a buzz you can hear from a distance isn't.

I don't know how many amps I have owned but it's dozens and not one of them buzzed.

It's new, so send it back while you can. It's not acceptable.

[Pigmy Pony]

Just got a new Marantz PM6007. It makes humming/buzzing noise from the inside, I can hear it at 30-40cm distance. No statics on the speakers.

AI tells me it's absolutely normal for torroids. Is it?

I wouldn't agree with AI that it's absolutely normal, but it is quite common. My amp has always done it, definitely mechanical, never loud, sometimes almost silent. I suspect the mains supply might have something to do with it, but tbh it's never bothered me and I don't notice it unless I'm close to it.

If it bothers you, you could get it changed for another as it's new. If the new one does it, then you know it's normal. If it doesn't, happy days :)

[alexk0il]

Thanks everyone for confirming that's not normal. Turned out it only makes buzzing noise when connected to a dyi-ish power rail that is triggered by auto-sensing 12v audio trigger.

I guess no auto-sensing for this setup now, I will have to learn to press the on button on RC to manually turn it on. 😂

[Puffin]

I will have to learn to press the on button on RC to manually turn it on. ��

Just think of it as part of your daily exercise routine :lol:

[Pigmy Pony]

Just think of it as part of your daily exercise routine :lol:

Just make sure you build up to it gradually, and don't forget some stretching exercises first :)

[alexk0il]

Nah, no exercising for me... Returning this magnificent piece of a lab equipment. No match to my recapped Hitachi SR-604 that gave up to being 47 year old. Can't stand the modern sound, however polite and tuned it is. I need harmonics, and rumble. Cellos and violins need to have body, trumpets must have edginess that doesn't come at a cost of singer's saliva being spat into my ears.

Will try PM7200 instead. Finger's crossed.

[Macca]

What speakers do you have?

[alexk0il]

Klipsch RP-150M + BK XXLS400-DF. I know, I know, it will benefit from a RP-250C center, but it still sounded quite good with the old amp. Even my teenage son says he misses the old sound.

[Macca]

Your Hitachi would cost about a grand in today's money so perhaps a budget Marantz isn't a fair comparison. Just doesn't have the beans.

Personally I'd go Denon rather than Marantz. Marantz budget models have always been a bit weedy.

[Macca]

You might consider getting one of these amplifiers

https://www.amazon.co.uk/AIYIMA-A20-Amplifier-Adjustment-Integrated/dp/B0FMR7SLP4/ref=asc_df_B0FMR7SLP4?tag=bingshoppinga-21&linkCode=df0&hvadid=79852239237583&hvnetw=o&hvqmt=e&hvbmt=be&hvdev=c&hvlocint=&hvlocphy=41725&hvtargid=pla-4583451701928620&psc=1&msclkid=0fe960d64cac1127bb2209f154a475d6

It has a high pass filter so you can set it so very low frequencies only go to your subwoofer. This will reduce distortion in your speakers and give increased headroom - in theory, better sound quality, especially when you crank it up a bit. Will do 120 watts into 4 ohm so about twice the power of your Hitachi and almost three times the Marantz.

[alexk0il]

My Hitachi would be around $2000, about £1500 today. Plus I recapped it using better quality capacitors, so I;d raise the bar to £2000K at least.

As for the modern class D-class, I tested and quickly returned the Sabaj A30A, same reasons as Marantz PM2007. Though I must admit, Pm2007 handles highs more gracefully than the exaugurated crispy gritty sound of A30A. I am actually entertaining an idea of getting a good old school vintage amp with good pre-amp and just run it into an Ayima ot Fosi amp.

Anyway, I got a few recommendations to try Marantz PM7200 for it's rich sound, if anything it should be less accurate than PM6007. Might even try to recap it if all goes well.

[Lawrence001]

I assume being Klipsch your speakers are efficient. I would try a class A amp with them if you can find something within your budget. Might be a Chinese clone type amp they sound quite nice.

[alexk0il]

The PM7200 I'm waiting to receive from ebay has dual A ans A/B mode.