Topic: help, left channel busted

[kia]

tulong po mga kabayan,

meron po akong tube amp "yaqin mc 10t" , d po gumana ang left channel, tina try ko na e swap ang connection on right speaker to the left channel of the amp ayaw pa rin. all tubes are glowing, pinalitan kona rin lahat ng tubes, ayaw parin.


salamat.

[rochie]

tulong po mga kabayan,

meron po akong tube amp "yaqin mc 10t" , d po gumana ang left channel, tina try ko na e swap ang connection on right speaker to the left channel of the amp ayaw pa rin. all tubes are glowing, pinalitan kona rin lahat ng tubes, ayaw parin.


salamat.

kung wala po kayong alam sa electronics better na dalhin nyo na lang sa qualified technician to check.it can be as simple as wires from amp to the binding post/rca input to amp got disconnected or some components inside failed. yung potentiometer/volume control pwede din na yun ang sira.

pa check mo na lang po sa qualified at reputable technician.

[tony]

merong fuse yan sa OPT B+ check mo kung nag open sya...

[kia]

salamat po sa mga sagot. na try ko na po mag tanong pagawa kya lng npaka mahal po $70/ hour minimum 3hrs po pa check, pag d nkita papatak po per hour on top.

sir tony ano po color ng fuse na tinutukoy nyo? try ko nlang po gawin. bka po kc ma charge ako ng mahal pa sa amplifier.

kinabitan ko kc ng sub bka yun ang dahilan, bali nka kabit po sa high input ng sub tapos nkakabit ang kabilang dulo sa 2 channel ng amp. gumana po ng about 3 months bago bumasted.

[JojoD818]

iirc, there is no fuse in the 10L's secondary.

does the busted channel's power tubes have any measurable bias?

[kia]

iirc, there is no fuse in the 10L's secondary.

does the busted channel's power tubes have any measurable bias?

yun po every el34 tube may butas pra bias, dun po ako nag aadjust  bali nka lagay po sa 375 mv.

[JojoD818]

yun po every el34 tube may butas pra bias, dun po ako nag aadjust  bali nka lagay po sa 375 mv.

so yun busted channel at yun working channel pareho may bias ang power tubes? if yes, then your tubes are receiving their power supply.

do you know how to read a schematic? you may also want to check the frontend for power.

last thing to do is if you can swap the output transformer wirings, wag naman sana pero pwedeng output transformer but it's still too early to say.

[kia]

so yun busted channel at yun working channel pareho may bias ang power tubes? if yes, then your tubes are receiving their power supply.

do you know how to read a schematic? you may also want to check the frontend for power.

last thing to do is if you can swap the output transformer wirings, wag naman sana pero pwedeng output transformer but it's still too early to say.

meron po. lahat ng 4 power tubes may bias adjustment. d po ako marunong mag basa ng schematic. ang pinag taka ko po ay may power lahat ng tubes pati yung 4 na buffer tubes. yung pagka glow lahat ng tubes ay parehas lng nung d pa bumasted kya lng wla tunog yung left channel.

[JojoD818]

oh wait, tube amps contains high voltages so the usual disclaimer applies and if you donot know what you are doing it may seriously injure you or worst case can cause death.

now with that out of the way, you may want to post some pics of your amp so we can point things out.

[JojoD818]

meron po. lahat ng 4 power tubes may bias adjustment. d po ako marunong mag basa ng schematic. ang pinag taka ko po ay may power lahat ng tubes pati yung 4 na buffer tubes. yung pagka glow lahat ng tubes ay parehas lng nung d pa bumasted kya lng wla tunog yung left channel.

pag lahat ng tubo may sindi that means may heater voltage silang lahat but that doesn't mean may power supply (B+) na sila. bukod ang heater sa plate supply requirements ng tubes.

[kia]

pag lahat ng tubo may sindi that means may heater voltage silang lahat but that doesn't mean may power supply (B+) na sila. bukod ang heater sa plate supply requirements ng tubes.

na check ko po yung bias ngayon lng, yung 2 sa right may reading, pero yung 2 sa left parehas 0 ang reading. ti na try ko e pihit and bias d ko po ma adjust 0 tlaga.

[JojoD818]

na check ko po yung bias ngayon lng, yung 2 sa right may reading, pero yung 2 sa left parehas 0 ang reading. ti na try ko e pihit and bias d ko po ma adjust 0 tlaga.

that means hindi po nag conduct ang power tubes ninyo.

digital voltmeter po ba yan gamit ninyo?

paki alis po ang dalawang EL34 ng left channel at measure ninyo yun voltage sa pin #3 ng power tubes, dapat po meron at least 400+ volts.

ingat lang sir ha at medyo delikado baka madikit po kayo.

[kia]

that means hindi po nag conduct ang power tubes ninyo.

digital voltmeter po ba yan gamit ninyo?

paki alis po ang dalawang EL34 ng left channel at measure ninyo yun voltage sa pin #3 ng power tubes, dapat po meron at least 400+ volts.

ingat lang sir ha at medyo delikado baka madikit po kayo.

sir nka on po ba ang amp during testing? yung red pin ang ilagay ko sa #3 saang butas ko ilagay ang itim?


don't worry sir nka rubber gloves ako paniguro ba. lol.

[JojoD818]

sir nka on po ba ang amp during testing? yung red pin ang ilagay ko sa #3 saang butas ko ilagay ang itim?

yes sir, pero with the amp OFF, alisin niyo po yun output tubes ng left channel, then yun red sa pin #3 (bale counter-clockwise po and bilang starting from the tube notch) at yun black po sa body ground ng chassis. don't forget to set your voltmeter to highest DC range.

then pwede niyo na po power ON yun amp and read the measurement.

[kia]

19 lng young rating sir sa 2 tubes.

[JojoD818]

19 lng young rating sir sa 2 tubes.

19V lang sir sa pin #3?

[JojoD818]

it seems that either power is not being delivered to your left channel or there's something wrong with your output transformer.

swapping the left output transformer with the right output transformer and trying it out if it will work will seal the faith of the left output transformer.

but don't worry, there could still be other things causing the problem.

[kia]

sir kung transformer ang problema mahirap ba palitan yun? considering that i'm a noob?

[JojoD818]

sir kung transformer ang problema mahirap ba palitan yun? considering that i'm a noob?

actually, being a noob is already enough reason for me to stop you from poking around with your amp that has more than 400V inside. yun mga tests na pinagawa ko sa iyo ay para malaman kung alin ang may sira, kung ikaw din magpapalit pwede din naman pero being a noob it will cause so much questions and confusion, and again, the danger involved.

it seems that your amp may require more than just a newbie so it is better to have it checked by someone qualified to do work on it. mahirap na sir baka makuryente ka pa, the next steps require you to remove the top cover eh.

[kia]

salamat sa concern sir, don't make this wrong sir jojo pero na cha challenge ako nito after my exams kakalikutin ko to, i hope d ka mag sawa sa kaka answer pag nagtanong ako sayo. matagal na ako nagsusubaybay dito, ngayon lng talaga ako nag register, pero alam ko na malalim ang kaalaman mo pagdating sa audio systems specially sa field ng tube amps plagi na ako nkakita ng mga post mo dito.

salamat ulit sir.

[JojoD818]

I see, not to tolerate your enthusiasm but it's true that what does not kill you makes you stronger but then again, curiosity killed the cat so kaunting review din sa electrical. Basta gumawa ka ng may kasama sa bahay, preferably with experience in cpr and have a phone by your side ready to call 911 just in case.

Madami dito maalam na handang tumulong sa iyo sir. Nagkataon lang may ilan 10L na din ako nagawa na hindi naman nalalayo sa 10T, iba lang ang tubo sa frontend niyan.

Anyway, first things first, aral ka muna at good luck sa exam mo.

Cheers

[tony]

there is a yaqin amplifier users support group in facebook, you may want to check it out also..https://www.facebook.com/groups/yaqinaudio/?fref=ts