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Dark Voice 339 - Page 129

post #1921 of 2241

I am looking for some tech help as my 332C died last week and I have no luck finding a local tech with experience on tube equipment. I live in Pattaya Thailand so there is not a lot of alternatives here for repair techs but if you need a bar you're in the right place. The left channel on the amp stopped outputting any sound. The right channel still does have output. I own several sets of tubes so I tried changing tubes, but no luck. It is most likely a resistor in the circuit. I own a meter but my level of competence with this is not world class. My main problem is that I don't know how to discharge the capacitors to prevent killing myself. I really want to live through this experience.

 

My understanding is that you cannot measure the fault in the circuit without lifting the resistors? Any advice from those more technically inclined would be greatly appreciated. I realize this is the 339 thread and my amp is a 332C but this thread is very active and the 332 thread is long dead. I know this is like a shot in the dark but any help would be greatly appreciated. I tried to contact La Figaro but I cannot even get an email response from them. Help!!

post #1922 of 2241

Update: shortly after I wrote my plea for help I received an email from Liu Yi who I believe is the owner of La Figaro. He said it is one of the large yellow 25w resistors that has died. He certainly has the experience so I believe him. He is going to send me the resistor. Now all I have to do is figure out how to change it without killing myself. I still need advice on how to discharge the caps before I can go changing resistors. Any advice would be welcome.

 

I haven't used a soldering iron in years but I think I can deal with that. I used to be pretty handy with an iron long ago. 

post #1923 of 2241
Quote:
Originally Posted by Chodi View Post

Update: shortly after I wrote my plea for help I received an email from Liu Yi who I believe is the owner of La Figaro. He said it is one of the large yellow 25w resistors that has died. He certainly has the experience so I believe him. He is going to send me the resistor. Now all I have to do is figure out how to change it without killing myself. I still need advice on how to discharge the caps before I can go changing resistors. Any advice would be welcome.

 

I haven't used a soldering iron in years but I think I can deal with that. I used to be pretty handy with an iron long ago. 


Exactly what I told you in the PM ;-)

I hope someone can help you out and explain the "how to". I took mine to a tube amp shop.

Good luck!

post #1924 of 2241

Never find a tube amp shop in this town. I will have to change it myself. If I can safely discharge the caps then the rest is easy. The inside of the amp is all point to point and there is a lot of space between components so it's really simple if I can safely discharge the voltage first. 

post #1925 of 2241

am so glad i never ever had problems to be repaired with my darkvoice ksc75smile.gif

 

i hope ur problem can be solved quickly and SAFELYfrown.gif
 


Edited by hifimanrookie - 7/22/13 at 5:38am
post #1926 of 2241
Quote:
Originally Posted by Chodi View Post

Never find a tube amp shop in this town. I will have to change it myself. If I can safely discharge the caps then the rest is easy. The inside of the amp is all point to point and there is a lot of space between components so it's really simple if I can safely discharge the voltage first. 

You can use for this purpose 25 Watt/250V bulb, I was using it successfully to simulate the load of voltage inverter or switching power supply also to discharge the capacitors. Next method is to use bleeder resistor 1k - 10k wire wound resistor 5 to 10 watts could be enough, short circuit pole + & - of cap until the DC drops to safe min.

post #1927 of 2241

I am really going to show my ignorance here. Do I need to discharge every cap in the circuit individually or is there a way to discharge the entire circuit? The bleeder resistor approach would suggest that they must be done individually? The light bulb approach suggests that there would be a point where you could do this for the entire circuit at once?

 

Since this resistor is huge metal package can I just desolder and replace it without touching myself to any charge? I don't have to stick my fingers in there.

post #1928 of 2241

Thank God for youtube. I found this video which explains how to discharge a tube amp;

 

http://www.youtube.com/watch?v=sw9KnSFy3Fs

 

According to that video; if you bring the amp up to normal operating temperature then turn off the amp with the tubes in place, the tubes will discharge the amp by themselves. The video shows how you can easily verify this with a meter. Great video! It also shows how you can do this with a cold amp using a 10K resistor. 

post #1929 of 2241

Don't touch nothing unless you completely sure that any cap in your amp is discharged.
The amp should discharge the caps when is turned off for a while but in your case no!
one of resistor in power supply is faulty, the resistors are in series, each resistors contains capacitors all together, this creates a PS filter so when the circuit is interrupted (by faulty resistor) one fully charged capacitors will be in this state for a very long period!
I would have used a bulb with the isolated leads connected to the plinth then short the pole( - & +) of capacitors individually to be sure.
Check with multimeter is any DC left then u can start to fix your amp.

Don't worry about the output coupling caps in 332c it will discharge by it self, in less then few min it has own 10K bleeder resistor in parallel.

post #1930 of 2241

I use a lightbulb too and discharge all the capacitors. Check the voltage left with a multimeter and be extremely carefull if it's your first time. No scarf or long necklace, be steady and all will be well L3000.gif

 

Those amps will still be up and running in 50 years!

post #1931 of 2241
Quote:
Originally Posted by WALL-E View Post

Don't touch nothing unless you completely sure that any cap in your amp is discharged.
The amp should discharge the caps when is turned off for a while but in your case no!
one of resistor in power supply is faulty, the resistors are in series, each resistors contains capacitors all together, this creates a PS filter so when the circuit is interrupted (by faulty resistor) one fully charged capacitors will be in this state for a very long period!
I would have used a bulb with the isolated leads connected to the plinth then short the pole( - & +) of capacitors individually to be sure.
Check with multimeter is any DC left then u can start to fix your amp.

Don't worry about the output coupling caps in 332c it will discharge by it self, in less then few min it has own 10K bleeder resistor in parallel.


hey wall-e..i see in ur signature u want to have a hd800 next..for ur info....i bought my 337 from a owner who just had bought a hd800 2 months before and didnt like the pairing at all..thats why it was on sale...but with my he500 it sounded wonderful...but u probbaly know that already having a 339 in ur possesion biggrin.gif

i just wanted to share my experience with a hd800 and the 337...but as u have the 339 and modded on top of that it could be a whole new ballgame...with my 337 its a no go...

post #1932 of 2241
Quote:
Originally Posted by hifimanrookie View Post


hey wall-e..i see in ur signature u want to have a hd800 next..for ur info....i bought my 337 from a owner who just had bought a hd800 2 months before and didnt like the pairing at all..thats why it was on sale...but with my he500 it sounded wonderful...but u probbaly know that already having a 339 in ur possesion biggrin.gif

i just wanted to share my experience with a hd800 and the 337...but as u have the 339 and modded on top of that it could be a whole new ballgame...with my 337 its a no go...

Hi Hifimanrookie the HD800 are for Burson Conductor only, no doubt he 500 with lf339 is the perfect match I can't imagine this might be even better, hmm... maybe with LCD3biggrin.gif

post #1933 of 2241
Quote:
Originally Posted by WALL-E View Post

Hi Hifimanrookie the HD800 are for Burson Conductor only, no doubt he 500 with lf339 is the perfect match I can't imagine this might be even better, hmm... maybe with LCD3:D
Oh okay wink.gif...oopsie..i have to admit i tried my 337 with the lcd 2.2 also and again..it was missin something..thelcd 2.2 sounded much better on a v200... But damn..never ever tried the lcd3 though..i heard it has a completely different siundsignature then the 2.2...lighter on its feet and faster..so it could be a good pairing....so keep me Updated okay when u do have the chance to try that wonderful lcd 3 with ur 339...am curious bout it..

Pity darkvoice/lafigaro never made a stronger amp to drive a he6...as that would be maybe almost perfect i guess. That would be the day!!!

U know whats a pity..on the he500 thread almost no one believes that a 337/339 can be a super pair with the he500... As its a tube amp..and because no one talks bout the 337/339..They all talk about budget high power from SS speakeramps to be the only way...am glad we both know our humble amps can make the he500 sing... wink.gif okay i admit..we both invested in tubes and u also in intensive modding..but its worth it right? tongue.gif
Edited by hifimanrookie - 7/22/13 at 1:43pm
post #1934 of 2241
The 339 was my fav amp for the HE500 till I got my custom 300B tube amp. Incredible sound!
post #1935 of 2241
Quote:
Originally Posted by hifimanrookie View Post


Oh okay wink.gif...oopsie..i have to admit i tried my 337 with the lcd 2.2 also and again..it was missin something..thelcd 2.2 sounded much better on a v200... But damn..never ever tried the lcd3 though..i heard it has a completely different siundsignature then the 2.2...lighter on its feet and faster..so it could be a good pairing....so keep me Updated okay when u do have the chance to try that wonderful lcd 3 with ur 339...am curious bout it..

Pity darkvoice/lafigaro never made a stronger amp to drive a he6...as that would be maybe almost perfect i guess. That would be the day!!!

U know whats a pity..on the he500 thread almost no one believes that a 337/339 can be a super pair with the he500... As its a tube amp..and because no one talks bout the 337/339..They all talk about budget high power from SS speakeramps to be the only way...am glad we both know our humble amps can make the he500 sing... wink.gif okay i admit..we both invested in tubes and u also in intensive modding..but its worth it right? tongue.gif

I agree a little bit with what he500 thread believes talking about power full SS amps as a better suit for the planar magnetic headphones but with few exceptions 337/339, the he500 realy can be driven by those two amp to its best ofering something "special" for what we like the tube amps and what is almost impossible to achieve the same with SS amp. Btw my SS, 4 Watts Burson Conductor which cost more then twice as much as lf339 can't drive the he 500 to its best, I am talking about the power about the dynamic about the bass hit. That why I using it for most of my time as a digital sours I can admit that DAC section of Burson Conductor is better from everything I've heard so far and combination with lf339 is excellent.

 

 

 

out of topic, hmm....maybe not 
private listening session in my home with the guy who built this prototype

Edited by WALL-E - 7/22/13 at 4:37pm
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