Topic: Surplus amps

[rascal101]

Puwede ka magpa service sa Pier dun sa Little Chatty's. Sabihin mo sa technician na lahat ng parts mangagaling sa iyo. This way puwede kang bumili ng original parts. Medyo matagal nga lang itong process na ito dahil hindi gagalaw iyung tech hanggang hindi mo nabibili iyung parts. Kung mangagaling naman sa kanya most probably galing iyung parts sa isang vintage na amp din. Siyempre kapag luma, most probably konti na lang itatagal.

[hattori_hanzo]

Sir, ask our fellow PDVD sir 2ny, he can advise you more...

[scofield]

rascal101,

meron pa kayang mga original parts ang sansui?

[rascal101]

Baka dun sa Pier meron. Hindi ako sure sa Quiapo.

Base sa description mo, ang problema mo lang yata ay mga knobs/pots. If so, marami kang makukunan nito. Puwede rin linisin mo mga ito baka maayos mo. Dun naman sa isang channel baka mataas na biasing. Si 2ny magaling dito, nandito rin sa thread na ito iyung mga guidelines niya tungkol sa mga pots and biasing adjust. Iba kasi linya ko.

[scofield]

oi salamat sir!  i will try to contact 2ny

[ATJr.]

 

Kung mangagaling naman sa kanya most probably galing iyung parts sa isang vintage na amp din. Siyempre kapag luma, most probably konti na lang itatagal.

hey rascal, you may find it odd, but i also do repairs/upgrade for pc psu, and my favorite source of parts are the sidewalks of raon! i am more confident buying them than from say, deeco

and parts coming from vintage amps are no issue imho, specially power transistors, small signal ones are easy, they can be replaced at will.

ss devices unlike tubes does not suffer from emission depletion over time, they are either good or they are bad, seldom in between.

[ATJr.]

Mga sir's,

When I use ba a 100V stepdowns instead of 110V will it change my Yamaha A/V amp temperature? besides from modifying the AMP itself, how can I lower the heat being produced by the amp? 

Your comments and suggestion is highly appreciated!!!

Thanks...

it is doubtfull that temps will be lower when using 100volt stepdowns, temperature is a function of idle current setting, so setting idle currents to a lower value will definitely decrease temps.

[ATJr.]

Hello,

san ba pwede mag pa service ng mga vintage na amp?

meron kase akong nahukay sa bodega ng tito ko na integrated stereo amp (sansui A-5). nilinisan ko, gumagana naman, yun nga lng pag pinipihit ko kahit na anong knob nagkakaroon ng maingay na sound, tsaka pansin ko kahit na zero ang volume may lumlabas pa rin na sound from the left chanel..

meron ba kayong kilala na marunong gumawa? natatakot kase ko pagawa sa ib kase baka karnehin an parts, sayang naman.

you can open the hood, then apply contact cleaners on the switches, volume and tone control pots, this should fis the problem, no need to send the unit to a shop fopr repairs. you can diy it. be carefull though not to dislodge anything or apply preassure on any parts unnescessarily.

[hattori_hanzo]

it is doubtfull that temps will be lower when using 100volt stepdowns, temperature is a function of idle current setting, so setting idle currents to a lower value will definitely decrease temps.

Thanks sir 2ny....

Sir, another question, is there another way of lowering the amp's temperature? sir efficient ba yung pag lower ng voltage supply (particularly 100V stepdown) will it be felt? wala kasi akong instrument to test this, except an external digital thermometer....

[ATJr.]

changing your transformer to 100volt is no guarantee that temps will go down, it could be that voltage in your place is high, say 230volts and above, so temps are still high. or you may have a 110volt meralco power yet the voltage is 200 and below, then your amp may have decreased temp.

aside from idle current adjustment, you can also install small fans blowing into the heatsink to manage the temps to comfortable levels if you do not want to adjust pots.

[rascal101]

 

hey rascal, you may find it odd, but i also do repairs/upgrade for pc psu, and my favorite source of parts are the sidewalks of raon! i am more confident buying them than from say, deeco

and parts coming from vintage amps are no issue imho, specially power transistors, small signal ones are easy, they can be replaced at will.

ss devices unlike tubes does not suffer from emission depletion over time, they are either good or they are bad, seldom in between.

I'm afraid I will not take this chance at Raon unless I don't have a choice.  Too many customer failure analysis in the past. 

The only parts I buy from Deeco are small signal transistors and diodes. The rest, free samples     from component suppliers or from my pocket - I buy from RS components, Farnell or from China (I ask some people to buy for me).

Anyways, some experiments are based on my previous experiences in the office. So I no longer have to tweak around. Some small experiments I use Simetrix. 

[scofield]

Sir,

ok na ung amp ko. pinalitan ng potentiometer yata? balance na, tapos kahit zero ang volume level wala na talagang sound na lumalabas sa kahit anong channel.

thanks

[hattori_hanzo]

Sir 2ny,

THANK YOU FOR YOUR ADVICE!!!

Effective nga ang gumamit ng 100V stepdown instead of 110V, my DSP-2000 is now cooler than ever...
I match it with the amps specification. 200W at 100V. got the transformer at Raon for Php. 550 branded as Matchbox with lifetime service warranty...

Salamat ulit Sir 2ny for the advice on "how to cool your surplus amps!"...

[scofield]

gusto ko lang i-share..kaninang umaga napasarap ang pakikinig ko, naphit ko sa 12 o'clock ang volume knob, at nagulat ako nag iba tunog ng speaker ko, parang sasabog...sumobra sa high tapos nawala ang base, basta kakaiba..pero pag 10-11 o'clock setting ok naman cya.

ganun b talaga kalakas ang 25 watts per channel? gamit ko sansui a-5. kase sa avr ko 45watts per channel pero d ko na-experience yun kahit -15db volume level. e sabi na nga nila na yung avr na gamit ko high current yun...or dahil wala akong sub na kinabit dun sa sansui set up ko kaya nag kaganun at bookshelf lang yung mga speaker ko? tama ba?

ano ba kelangan ko i-check para malaman ko kung may na damage sa mga speaker ko? o pano ba malalaman kung sira na yung speaker?

nakalagay nga pala sa manual ng speaker ko:
Recommended Power Amplifier Range:  10 - 100 watts 

[ATJr.]

what you experienced is your amp clipping! power supplu ripple is coming thru minimising bass, your tweeters are the forst to suffer from this! just back off and you should be ok.

you will know if your speaker got damaged when the tweeters do not sound the way it did before!

do not worry about speaker wattage so much, it does not mean anything much to me.
it will always be the amp that will run out of steam before your speaker does , as what you have experienced.

[m0b1u5]

sirs,
 my Kenwood L-03a is dying...  .  initially, the there were distortions with the right channel and sometimes no sound was coming out.  only the left channel is working but after about four or five songs, no music can be heard from both channels.  can you point me to a very good repair shop for this amp?  will the shops in pier be a good place to have it repaired?  or someone here in PDVD can do the job?

thank you very much.

[rascal101]

sirs,
 my Kenwood L-03a is dying...  .  initially, the there were distortions with the right channel and sometimes no sound was coming out.  only the left channel is working but after about four or five songs, no music can be heard from both channels.  can you point me to a very good repair shop for this amp?  will the shops in pier be a good place to have it repaired?  or someone here in PDVD can do the job?

thank you very much.

You can have it repaired at the Pier at Little Chatty's. I had my NEC A-700 repaired there. Took about a week.

[scofield]

2ny,

so yun pala ang clipping, ibig sabihin ba di kaya ng amp yung speakers ko at medium to high level?

thanks

[gob]

hi question lang po ulit, is there a surplus phono stage available in pier? anong brand available?

[ATJr.]

2ny,

so yun pala ang clipping, ibig sabihin ba di kaya ng amp yung speakers ko at medium to high level?

thanks

yes, clipping is a function of the amp's power supply vis a vis the input signal, if input signal is such that the amp can no longer supply power, then clipping occurs.

the amps will clipp first before the speakers reach their limits!

[m0b1u5]

Puwede ka magpa service sa Pier dun sa Little Chatty's. Sabihin mo sa technician na lahat ng parts mangagaling sa iyo. This way puwede kang bumili ng original parts. Medyo matagal nga lang itong process na ito dahil hindi gagalaw iyung tech hanggang hindi mo nabibili iyung parts. Kung mangagaling naman sa kanya most probably galing iyung parts sa isang vintage na amp din. Siyempre kapag luma, most probably konti na lang itatagal.

sir di ba risky ito.  baka kasi kapag sinabi sa kin kung anong parts ang kailangna palitan eh dagdagan... 
where did you source your parts sir and how much was the charge when you have it repaired?

thanks.

[rascal101]

Sa akin kasi konti lang sira. Pero you can source your parts at RS components (matagal lang delivery  ). For e-caps you can try Eleshop but for high end there is a thread in pinoydvd for Black Gates capacitors. For resistors Alexan, DEECO, etc. For semiconductors Akihabara in Raon or Caloocan (near circle and very near to 711).

[arizton]

hi guys,

i need help on my audio set up, theres a clipping sound whenever i turn the volume up to 10 o'clock pa lang parang may nilulutong pop corn s loob ng speaker, tpos pag pinatay ko @ binuksan ko ulit may pop corn pa din kahet zero na yung volume? im using a trio ka-7300 driving an aurum cantus f6600.

the first time i encounter this prob i immediately turn my amp off, tapos binalik o agad sa pier (little chatty) yung amp para ipatest. when they test it sa pier ok naman hindi nag clip for 3 hours @ 10 o'clock volume!

f6600 is 4ohms & trio ka-7300 is rated 4-16ohms around 85w/channel i guest, im using a 12ga generic wire( if this matter)
guys i need ur help very badly, pls

can anybody tell me where to contact sir jojod, para mapatignan ko po yung amp ko?
than you so much po in advance for ur help!

ariz

[sandawa]

i don't think it's clipping. what you need is re-capping. usually that distortion disappears after awhile. if it's still there even when the amp is already warm, you have likely a bad case of dried capacitors. KA-7300 is a very good vintage amplifier, don't throw it away. have it checked by a good technician. in the '80s the best Kenwood mechanic was in Avesco's main office in Roosevelt. 2ny, jojoD and the other techies here could probably help you, if you want to go DIY.

[arizton]

haay..... sir sandawa thank god ur online! sir i really need all the help i can get, san o pa kaya pwedeng ma contact sila sir 2ny o sir jojod?

at first ang akala ko mali yung pag biwire ko kaya ganon, pero kanina ng may pop corn ulit e tinangal ko na yung biwire ko ganon pa din nandon pa din yung pop corn sound. sir hindi ba nakakasira ng speaker un? (kabibili ko lang po kc non last jan 2 e... )

actually sir sandawa yung ka-7300 lang ang nakita ko sa pier na nasa list ko kaya yun ang kinuha ko e...
matagal-tagal na din ako nagbabasa dito namumulot ng mga mabuting salita.

thanks sir sandawa

ariz

[arizton]

calling sir 2ny & sir jojod818 need help po! ( badly)

[sandawa]

baka mali ang diagnosis ko. kung walang distortion pag switch-on sa Little Chatty, hindi capacitors ang problema. i test mo using another speaker or another wire. o di kaya, tanggalin mo ang wire ng speakers - tapos ikabit mo ulit ng maayos. wag ka munang mag-bi-wire, simple installation lang para makita mo kung talagang sa amp, pwede din na DC leak 'yan.

[ATJr.]

at first ang akala ko mali yung pag biwire ko kaya ganon, pero kanina ng may pop corn ulit e tinangal ko na yung biwire ko ganon pa din nandon pa din yung pop corn sound. sir hindi ba nakakasira ng speaker un? (kabibili ko lang po kc non last jan 2 e... )

popcorn noise is indicative of a noisy small signal transistor, it will test "good" on a tester but replacing it ussually solves the problem, now what puzzles me is why it does not manifest itseld at the pier.

[aHobbit]

I have an amp before bought by my father way back 1983. After certain years of use, a channel also exhibit the problem - pop corn noise. Since it is basically a  straigh forward amp design, I can easily take a careful inspection in the board - and incidentally discovered a terminal of a small transistor is floating from the PCB. I discovered it by putting test speaker in the problematic channel, and pressing gently each PCB component.

After soldering it back, the amp continue to be in use as of today. I am still wondering how such transistor could suddenly float out of the PCB - normal wear and tear?

Also I bought my Pioneer VSX3800 way back 1992. Last year, it also exhibit same problem on one channel. My first guess is the speaker protector, after I sprayed on all pots and switches. Still have no time to check on it now, but may try to do just what I did on the previous amp. However, I might have more difficulty since the model is already the pro logic type, the problem of having too much VLSI chips in the amp makes it extra difficult to diagnose.

The good surplus amps in pier could still be easy to diagnose IMO.

[arizton]

- and incidentally discovered a terminal of a small transistor is floating from the PCB. I discovered it by putting test speaker in the problematic channel, and pressing gently each PCB component.

i doubt i can do this myself but ill try sir ahobbit, tnx.

question sir, what if i cant find the prob myself can u point me to a good amp doctor? 

tnx mga sir appreciate it!