Question about Audio Players & Recorders

1 Answer

NHT SA-3 Ben- Please explain how to do the checking you mentioned. I have (if I can find them) schematics for the SA-3. Let me know how to do the testing you mentioned. I have a multimeter to check V/A/ohns. Do I need something to check resistance (ESR?) as well? Thanks. Jeff

Posted by on

  • Anonymous Jan 04, 2009

    The schematic is helpful. I have the 5 page schematic somewhere and am trying to track it down. Those are the correct transistors. You have to take the transistors out to test them? I was hoping I could just test them on the board as it will be a pain to pull everything out. Is it possible to do a board test, and if okay check other things before I start pulling things apart? As Mentioned I already replaced the two paired 10K and 6800uf electrolytics that had leaked all over. I cleaned up the board as well.

    Thank you for your well thought out input.




1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.

    Brigadier General:

    An expert that has over 10,000 points.

  • Master
  • 6,966 Answers

Appreciate the direct "Ask Me". With reference to your post here;

Voltage checks are done with the power on whereas resistance/continuity check are performed with the power off and preferably the component out of circuit. The VOM would do.

You posted that the fuses have not blown and therefore you are assuming that the output transistors are not defective. Pls confirm this by performing a check on the base to collector to emitter of the output transistors. This page would illustrate how to check a transistor using a VOM. The output transistor once removed from the circuit (pls mark which goes to where), laying flat with the pins/feet pointing towards you would be base, collector and emitter. Although the real outputs if 2SA1302/2SC3281 would be larger.
NHT SA-3 - c05c37f.jpg
Most NHT sub amps are standard design amplifiers. To my knowledge, NHT amps (but not all) uses a unique design to supply power to the output transistors. The fuses does not tie directly to the output transistors from the +/- of the power supply. Instead the fuse goes to several power MOSFETS (IRF640) that regulate/control/monitor the current/voltage supplied to the output transistors. If any of the IRF640 is blown, the output would have no voltage even if the fuses are good.

To be more specific and to confirm the above, would appreciate if you could post/share the schematic diagram.

May I also inform you that there are posts made by other members of the community (our co-experts, I am aware that you have provided solutions yourself in some other posts) that would be of additional help. ginko has posted the method/manner by which you could test the transistors and other components, while bunnydawg addressed the fuse not blowing. welcomejee has posted with an amp schematics of an NHT Subtwoi.There were however and I would expect more posts that are too general/generic to be of any real use to you. I would leave it to your discretion to filter through the flood of information.

As a site policy, once you rejected a solution or give it a "Thanks for Trying", that particular post/expert would no longer be viewable. For your benefit, may I suggest that you copy and paste the "workable solutions" to a document that you would have a record of previous or no longer viewable postings.

Posted on Jan 04, 2009

  • Louie  Role
    Louie Role Jan 04, 2009

    Testing them while still on the board would not be conclusive. You would also be testing the other components connected to the 3 pins.

    Why not try this first. Power it up, Set the VOM to 100VDC or thereabouts, test the voltage across each of the capacitors that you have replaced with respect to ground. One would be +, the other would be -. Do the same to the 2 fuses. Again, one would be +, the other would be - with respect to the ground. Do the same to the collector/center leg of the transistors, similarly one would be +, the other would be - with respect to the ground.

    pls post back results.



1 Suggested Answer


6ya staff

  • 2 Answers


Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

NHT sa-2 amplifier won't go into standby mode after 10 Minutes of no signal

Does the NHT sa-2 have it's own pre-amp? Because I'm wondering if the power off only works when it's own pre-amp is used? So when your receiver is connected it's shut off.

You could try something connected to it's own pre-amp (if it has one) and see if it goes off when there's no signal from that.

Jan 30, 2015 | Audio Players & Recorders

2 Answers

Ben travel 126 km in 21/2 hours. how many kilometers did ben travel iafter 3 hours

126km/21.5hr = 5.86km/hr This is how far he travels each hour.

Once you find this out you multiply by 3 hours because you want to know how many kilometers he traveled in 3 hours not each hour. 3 * 5.86= 35.16 km.
Ben traveled 35.16 Kilometers after 3 hours.

Jun 09, 2011 | Sharp EL-2630P Calculator

2 Answers

Hi, i just recently joined Fixya, and would like to know, How/when do you start earning?

Hi, actually everything is mentioned in the "FaqExp" section [click HERE], I am also one of FixYa's expert like you, so I don't think it's necessary to explain everything to you. I would suggest you to contact FixYa CM (Community Manager), she'll explain you everything. Here's her email address "". For your information, let me suggest you something, when I checked your solutions, there are few solutions which cannot be considered solution, for example, you've posted "Google it bro..", "Google the schematics...It most likely will be there." etc.. It's very important for us to help them with the download links if the askers need it instead of telling them to simply google... I don't mean anything, but it's for the betterment of FixYa and for us experts. Good Luck.
Let me know if you need further help.

Regards, Nonontech

Apr 21, 2011 | Computers & Internet

1 Answer

Bosche cooktop nht 725 a uc 1999 need conversion kit to go from natural gas to propane, hate to toss a good stove top need model kit order numbers

I spoke with Bosch customer service who said there is no natural to LP gas conversion kit available for the NHT 725.

Oct 05, 2010 | Bosch 30 in.NGP746UC / NGP742UC Gas...

1 Answer

I have a NHT SA-2 Amplifier 1996 model year. Once unit warms up I get load poping noises from the subwoofer. Please advise what may be causing this to happen.

sounds like speaker is clipping (overdriving) put a meter onthe disconnected speaker and see what the resistance is,4 ohms ,8 ohms ,if the meter wont stay in one place (numbers changing constantly) you have a burnt or damaged coil in your sub, if that is not the problem change your RCA's cables to make sure it not a bad wire including speaker wires! GOOD LUCK

Dec 15, 2008 | Now Hear This SA-2 Amplifier

1 Answer

A premium problem

Beni maraming salamat saiyo,sa binibigay mo na link medyo,nahuhuli naako meron nang nakakuha ng Best solution.Magtatagalog nalang ako saiyo Ben,nakakahiya saiyo.Hindi kuna aaksayahin itong pagkakataon nato na hihingi ako ng tawad saiyo, "sorry talaga" tungkol doon sa pagkopya ng solution mo,"Cold solder"akala ko noon ok lang,dahil nakita ko sa iba na komopya din,sa solution ko .Dati noong una kung mga solution talagang tinatyp ko mabagal akong magtayp dahil hindi ako sanay sa pagtatatyp at saka sa computer .Kaya lagi akong nahuhuli,hindi ko rin alam ang pagamit ng mga links .Kaya noong nakita ko ang solution mo,akmang-akma sa problema,kalimitan kasi sa electronics epektibo ang cold solder talaga. Maganda ang pagkasulat mo,kaya kina copy paste ko at lagi kung ginagamit ko sa una sa "free solution", hindi ko ginagamit sa "premium solution",iniwasan ko na magkasabay tayo,kaya lagi ako nakakuha ng FIXYA rating free solution. Sa kalaunan akala ko okey lang ginagamit kuna sa "Premium solution" pati,ang iniwasan kung mangyayari na magkakasabay tayo nangyari talaga. Kaya seguro nagagalit ka sa akin,pinopuna muna ang solution ko sa "Misubishi TV tungkol sa sagot ko na "DM" board ,binulgar mo sa lahat saan ko kinokopya yon at tungkul sa kotse din na ginu-googles ko kinuha ang sagot at totoo yon ang lahat nayan,pagtinatamad ako at nagmamadali ako,baka mahuhuli ang sagot ko.
Ang tingin ko seguro nanyayari ito dahil hindi ako nagrespond saiyo sa 'lounge'. Kaya hindi naako pumapasok sa lounge dahil lagi akong pinupuna nila,noon pa. Nagumpisa ito noong nakakuha ako ng FIXYA sa premium solution sa sagot ko sa kotse,tingnan mo ito dito nag-umpisa ang lahat;
Unang nagalit at nagkomento si ,robotek,tapos nagpa follow up si ekse,sinundan ni abrsvcs,at ibang pang expert na bilib na bilib kay ekse at robotek.Parang nag feel insecure sila pagnakafixya ka o best solution lang.Nakita muna cguro yon ginawa ni robotek sinulat niya ito
Mula nito hindi naako pumassok sa lounge,nakakainis lang minabuting kunalang na huwag pansinin. Lagi ang komento nag googles copy paste,hindi daw ako technician. Maraming top expert nag googles din,si maiksi ,ginko nakasabay ko to sila,tinago ko lang sa premium.Si maiksi lang parang allergic sa akin.Madalas kaming magkasabay,mahilig siya sa maiksi sagot ,parang one liner lang,kaya insecure siya ,baka malaman na siya mahilig mag "place holder",pagwalang makakasabay,saka banatan niya maraming sagot at ang kustomer hindi nag repost kuha na niya. Lagi siyang sumisigaw ng place holder,totoo pala ang kasabihan "kung sinong nagsisili,siya ang hangan". Seguro kung hindi ako technician hindi ako makapasok dito disgrasya lang, ito ang dahilan ; Naghahanap ako ng free download schematic diagram.Nagkataon iyon nagpapagaling ako sa operasyon ko sa gall blader.Seaman ako 3RD marine engineer,alam muna pag ang marino nasa lupa ubos talaga lalo na sa kalagayan ko nagkakasakit.May electronics shop ako sa Imus cavite isa at dalawa dito rin sa cebu .Sa pagka ngayon inabalahan ko ay "satellite unlimited" walang load-load,kuha ko diyan sa tondo 5,500 tapos ibinta ko dito sa cebu 25 to 20 thousand,sa bohol ,leyte at saka mindanao.Ang gusto ko sa fixya updated sa repair at makakuha ako ng idea.Sory talaga Ben at saka kay Marked ok lang yong koment mo...
Ikaw Ben tagasaan ka ?Saan ka dati nagtratrabaho..ito number ko 09068050462. Sory pala doon sa lounge bastos kasi yong taong yan si keamo,kabagobago lang niya,kung umasta parang sino.Galit siya sa pinoy tinira din niya si Namizka doon sa car aircon . Hinintay kulang magkamali siya at saka si abrsvs nayan.Etxt muna lang yong number mo...

Oct 01, 2008 | Watches

1 Answer

J'ai instaler des freins intégra 93-94 pas de abs les calipers plaquette neuf master neuf hydrovac ben correct pis le proportining valve intégra pis la les break colle je slake les seingneux pis...

You need to bleed the brakes every time you change the brake pads. In order to do this correctly, you need 1 more person with you to press on the brake pedal while you bleed the system, getting rid of the air in the lines is a top priority after a change. And yes, it's a DOT-3 brake fluid.

Aug 21, 2008 | Honda Civic Cars & Trucks

1 Answer

Technics sax-710 receiver Nht sb-1 speaker developed a buzzing sound when playing, Kids may have over drove speakers(not sure) Replaced with nht supezeros now both speakers sound very staticy like off...

The speakers have buzzing sound because of damaged cones.
Over driving speakers, especially with heavy low frequencies, can tear the voice coil away from the cone.
Once damaged, only replacement will help

Apr 24, 2008 | Audio Players & Recorders

Not finding what you are looking for?
Audio Players & Recorders Logo

Related Topics:

446 people viewed this question

Ask a Question

Usually answered in minutes!

Top Audio Players & Recorders Experts


Level 3 Expert

5699 Answers

The Knight
The Knight

Level 3 Expert

76177 Answers


Level 3 Expert

85216 Answers

Are you an Audio Player and Recorder Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides