SN2 TUNER light blinks

Posted by: mpw on 08 January 2019

Hello
 
 
My turntable is the only source right now and its connected to the TUNER input on the Naim SN2 via a phono stage
After playing about 3 records - the TUNER light sometimes flashes and goes away and i cannot hear the record and then after few seconds the TUNER light comes back ON and i can hear the record play
 
Today i also saw the CD input light flash for a few seconds..
 
I switched off everything
 
I saw the instruction manual and it reads
 
TUNER light flashing - over current
CD light flashing - over heat
 
But i am perplexed as to why this could be happening
 
the body of the SN2 does get warm but is certainly not hot
 
What can i do to trouble shoot ?
 
anyone experienced this before ?
 
 
Thanks
 
mpw
 
Posted on: 08 January 2019 by mpw

volume level is slightly above 10 o clock

Posted on: 08 January 2019 by Richard Dane

Check the turntable setup. You may be putting a lot of LF subsonic rubbish through the system if the compliance is not quite right. Wobbling speaker cones are a good visual warning of something amiss here. Itís one reason why a subsonic filter used to be a common and useful feature. The better the turntable, arm and cartridge match the less this problem occurs, unless from acoustic feedback from the system.

Posted on: 08 January 2019 by mpw

Thanks Richard

That would imply my SN2 is in the clear ??

how do i check the compliance between the cart and the tonearm ?

The jewellers scale shows 1.85 gms which is Ok for the MP30 cart - needle pressure.

My turntable is an old kenwood Trio 4100 and the cart is a Nagaoka MP30

The music sounds good to me though when it plays

But i havent seen the speaker cones so i will see then next time i play.

My phono stage is a Lehmann Audio and it has some DiP switches for "corner frequency"

I do not understand what that is

is this a subsonic filter ?

I can sort out my turntable setup but i am worried about my SN2

 

 

Posted on: 09 January 2019 by Richard Dane

Crikey, an MP30 in a Trio KD-4100!  That's a lot of cartridge for that turntable.  

Compliance match can best be checked by using an appropriate test disc, such as the HFNRR test disc.

Yes, according to the manual, when Lehmann refer to "corner frequency" they are referring to the low frequency cut off.  With no switches activated it's a very low 7Hz.  In your case I would apply some subsonic filtering.  I would recommend reading the manual for your Lehmann stage to learn more about this.

Ideally though you would probably be best off looking to upgrade the turntable.  I know the KD-4100 deck reasonably well.  It's fairly typical of many late '70s early '80s low to mid market decks.  They're fine up to a point, but even a basic Rega P1 is fundamentally so much better, particularly the tonearm, which is very weak on the 4100,and possibly hasn't improved with age and use.

Posted on: 09 January 2019 by mpw

Yeah - i know what you are saying 

Its like having the best software in an outdated hardware...to put it mildly..

I got the MP30 - pre loved one ( from someone i know  ) at a very very nice price ( less than USD 150 )

I plan to use that on a Rega RB330 arm on my under progress Lenco L75 - hope to finish by March 2019 - depending on the time i am able to spare from work.

I looked at the DiP switches under the  Lehmann phono and they were set to low corner freq of 7 Hz and have last night moved them to a higher corner freq of 47 hz but this morning i am traveling out of city for work and will return after a few days.

The cost of the subsonic filter will be more than what i paid for the Trio 4100.

but even for the Lenco L75 - are there any recommendations on which one ?

I see KABUSA and DB Acoustics ( USD 179 Vs USD 22 ) 

I would prefer to avoid too many electronics in my chain - ideally.

The Trio 4100 is purely to get by - so i dont starve of music.

The MP30 weighs 8.5 gm - do you think a lighter cart like MP110 ( wt 6.5 gm ) will be better for the Trio tonearm ?

Maybe a good idea to get by without the Trio 4100 as well and just stick to my small ifi nano DSD DAC anf play whaever music i have thru my laptop

I am frightened of risking the SN2.

regards

 

 

 

 

 

Posted on: 09 January 2019 by Richard Dane

No need for an additional subsonic filter.  The Lehmann has provision via the dip switches (corner frequency).  From what i can see the cut off can be set prior to or post gain stage, so plenty of flexibility there. 

Try with a fairly steep LF cut off and see how it goes.

Posted on: 12 January 2019 by mpw

So, i just wanted to update the readers..

 

On the Lehmann phono i made the adjustments on the DiP switches on the underside of the phono

 

The phono seems to have responded positively to this tickling and thus far..

 

I ran the turntable from the CD input on the SN2 and then reverted back to the TUNER input with TT connected to it.

 

All is well..

 

The Green eyes dont blink and i am happy

Total play time was about 5 hours...

Just for kicks - i took my Naim nait 5i-2 out of hibernation ( last 6 months ) and am giving it a spin.

I kept the little brother ON for about an hour i thought the circuits could breathe electricity for some time before i ask the speakers to pull current from the amplifier.

Thank you Richard !