I have indeed noticed that on other amps and if possible always decided to go back to original. This amp according to some is different in design which actually makes this not so, I'm just saying what I read and heard, I'm not stating who is right or wrong. There was a lot wrong with the amp (not only the outputs so just replacing with the original ones wouldn't have fixed it, and again, the cheapest (not fake ones on ebay) I found were 23€ a piece meaning a total of almost 200€ just for the outputs...
I was poking around with a wooden stick and precisely when I hit the 2SK109 I had a little peak, since then it seems stable, I've checked the solder joints but they are clean and not touching, could it be that the transistor itself is failing at some point ?
I was poking around with a wooden stick and precisely when I hit the 2SK109 I had a little peak, since then it seems stable, I've checked the solder joints but they are clean and not touching, could it be that the transistor itself is failing at some point ?
Why didn't you start with some not so expensive transistors to get it working and later on there is allways the possebility to upgrade
Very rare but not impossible.By poking around everything in the neighbourhood vibrates a little, it take not much for a bad contact to misbehave.
Mona
Attachments
I had some BD911/912 in my stock, I started with those but another member of the forum advised me to go straight for the single pair of outputs so i GOT THOSE 2sa5200/2sc1943, they weren't very expensive and at that time the amp seemed to be working ok.
I've tried poking again, a little more on the components surrounding them and nothing happens, got stable and close to no dc offset and clean sine wave on both channels.
I don't like the fact that all the sudden its working without actually changing anything...
I've tried poking again, a little more on the components surrounding them and nothing happens, got stable and close to no dc offset and clean sine wave on both channels.
I don't like the fact that all the sudden its working without actually changing anything...
Are you really sure there are no cracks between the pads of the transistor and the tracks? There already have me get this kind of attention and I assure you that it was almost not visible, I find the track on quite fragile Marantz especially when he had had welded and heated several times ...
In posts before we have explained what is a mechanical failure in transistor
Die inside is welded that means that every time a transistor warms up things inside expand ...This circle of expansion from cold to hot might took place thousands of times in the life of a semi ,this can make the weld loose that is why you measure a semi with a DVM and seems ok and fails under voltage or load
Remember that carbon resistors might suffer from similar issues depending on the manufacturer , age and fatigue.
A carbon resistor is a piece of carbon that has a specific resistance and has 2 cups on each side to accommodate the leads while the all thing holds together just on a little pressure and the external coating
These might fail too ...
Capacitors might suffer from similar issues but statistically this far more rear ...
Kind regards
Sakis
Die inside is welded that means that every time a transistor warms up things inside expand ...This circle of expansion from cold to hot might took place thousands of times in the life of a semi ,this can make the weld loose that is why you measure a semi with a DVM and seems ok and fails under voltage or load
Remember that carbon resistors might suffer from similar issues depending on the manufacturer , age and fatigue.
A carbon resistor is a piece of carbon that has a specific resistance and has 2 cups on each side to accommodate the leads while the all thing holds together just on a little pressure and the external coating
These might fail too ...
Capacitors might suffer from similar issues but statistically this far more rear ...
Kind regards
Sakis
NAD amplifier took 8 hours to find why output was latching to +rail presenting some 3-4V offset in the output clicking the protection relay unable to adjust
one fu****king resistor carbon type
what pisses me off is that i have fixed that only once more in the past like 7 or 8 years ago but i didn't remember ....
one fu****king resistor carbon type
what pisses me off is that i have fixed that only once more in the past like 7 or 8 years ago but i didn't remember ....
At this point i wild like to offer you a Joke though its real 1000%
In the year 1999 i was the head tech of a firm producing electronics amplifiers and dimmers
Nice things simple technology and just a bit of innovation.
I had under me 40 ppl working for the production . It was the will of the boss to clear out some people that wasn't effective enough and get new ones that had what it takes .
So beyond my tech duty i had to interview the new guys ...
One day i had a 10.00 appointment with a person that responded to the classified that we have posted
The guy was there 10.00 sharp exactly on the time scheduled.
i was supposed to be there 9.00 went there late , found 25 emails in my PC while few of them extremely urgent , some production mistake that means that 40 guys yesterday was doing mistakes , and a few lines on hold on my telephone ...
So first i thanked the guy for being extremely sharp at 10.00 exactly as scheduled, and offered him a cup of coffee for 15 minutes in the cafeteria of the company ( we had also that function ) in order to quickly clean up the mess in front of me and then take his interview . here is the conversation that followed :
---Please have a cup of coffee in the cafeteria i will need about 15 minutes to clean up the mess in front of me and then i will gladly take your interview .
---That's OK i don't drink coffee...
---You don't drink coffee ?
--- Noap ....
---That will mean that you also don't smoke ?
---Yeap ....
---Then that will also mean that you listen to Greek Music not international ?
---( Guy very confused ) yes ....
---Please Go ...you are not fit for this job ....
The guy got away in a way sad and confused he probably thought that the criteria that was rejected was either wrong or god knows what .....
40 days after that fellow of the cloth working in a company that did also electronics production but mostly for marine application called me since we knew each other worked together in the past and so on .
He said
Is this story true ? you actually did rejected this guy under the specific criteria and conditions ?
I said yes ...why ? what do you care
We have this guy working for us
So what do you think ?
you was 100% right ...a very fine guy nice and polite good enough to push the button 1000 times a day but if the tech next him has a hart attack he will only find out by the end of the shift ...
I can explain this a bit farther ...speed of processing is required in this job ...memory is required in this job English with understanding is required in this job ( the international music thingy )
Point of the real joke is that if the failure is not written permanently in your brain then you are not fit for this job ...Later on age will take away much of it but as a starting point everything has to be in your brain ....
In the year 1999 i was the head tech of a firm producing electronics amplifiers and dimmers
Nice things simple technology and just a bit of innovation.
I had under me 40 ppl working for the production . It was the will of the boss to clear out some people that wasn't effective enough and get new ones that had what it takes .
So beyond my tech duty i had to interview the new guys ...
One day i had a 10.00 appointment with a person that responded to the classified that we have posted
The guy was there 10.00 sharp exactly on the time scheduled.
i was supposed to be there 9.00 went there late , found 25 emails in my PC while few of them extremely urgent , some production mistake that means that 40 guys yesterday was doing mistakes , and a few lines on hold on my telephone ...
So first i thanked the guy for being extremely sharp at 10.00 exactly as scheduled, and offered him a cup of coffee for 15 minutes in the cafeteria of the company ( we had also that function ) in order to quickly clean up the mess in front of me and then take his interview . here is the conversation that followed :
---Please have a cup of coffee in the cafeteria i will need about 15 minutes to clean up the mess in front of me and then i will gladly take your interview .
---That's OK i don't drink coffee...
---You don't drink coffee ?
--- Noap ....
---That will mean that you also don't smoke ?
---Yeap ....
---Then that will also mean that you listen to Greek Music not international ?
---( Guy very confused ) yes ....
---Please Go ...you are not fit for this job ....
The guy got away in a way sad and confused he probably thought that the criteria that was rejected was either wrong or god knows what .....
40 days after that fellow of the cloth working in a company that did also electronics production but mostly for marine application called me since we knew each other worked together in the past and so on .
He said
Is this story true ? you actually did rejected this guy under the specific criteria and conditions ?
I said yes ...why ? what do you care
We have this guy working for us
So what do you think ?
you was 100% right ...a very fine guy nice and polite good enough to push the button 1000 times a day but if the tech next him has a hart attack he will only find out by the end of the shift ...
I can explain this a bit farther ...speed of processing is required in this job ...memory is required in this job English with understanding is required in this job ( the international music thingy )
Point of the real joke is that if the failure is not written permanently in your brain then you are not fit for this job ...Later on age will take away much of it but as a starting point everything has to be in your brain ....
Point taken, only the memory doesn't work in the same way for everyone. Sometines having just a few notes or even pictures (I actually studied photography, before getting into this, so far still more as a passion/hobby) can get a lot of memories back to date. I'm not saying that I will remember everything in detail on every amp, I don't have the experience for that that you have but having some kind of reminder has helped me with a lot of amps. I'm still learning so I am definitely a lot slower in processing information and drawing conclusions.
what I don't get is the smoking part...
what I don't get is the smoking part...
coffee and cigarettes are process accelerators.....
More jokes
At 2004 i took my dive in the PA business...rental is a very demanding job , in Greece far more worst ( most things in gigs take place the last minute )
I meet there one guy already working for the company for a year or so ...
with a boss that was excellent in communication with the customers but had an absolute zero for field experience or technical background
Company was very busy had many many projects to do and my job was to full fill a huge technical gap that was missing from the company
Mike the guy was working there already suffered from this gap and had no solutions for his problems though he was actually struggling through the situation because at least he had the will to ...
I asked Mike do you smoke ? he said No never did ...
Said to him that you will never survive in this job but i see that you have the will to so expect you to start smoking no later than one year from today ....
Rental company today doesn't exist today the boss that was missing the field experience and the tech background eventually ****** it up
Mike is working with me since 2006 and he is the reason that we had to install reinforced ventilation in the lab
4 people work in the lab with me all smokers ...
I am 50 today i smoke far less and cigars no more cigarettes for me some time in the feature i will give up
I own my shop since i was 18 but from time to time i got involved as an employee in a number of companies to gain expirience in other subjects except audio that i ve been doing all my life ...Done telephony , production , lighting , and a few other things but the best of all was the PA thing east electronics except repairs provides also PA services ...small but effective
More jokes
At 2004 i took my dive in the PA business...rental is a very demanding job , in Greece far more worst ( most things in gigs take place the last minute )
I meet there one guy already working for the company for a year or so ...
with a boss that was excellent in communication with the customers but had an absolute zero for field experience or technical background
Company was very busy had many many projects to do and my job was to full fill a huge technical gap that was missing from the company
Mike the guy was working there already suffered from this gap and had no solutions for his problems though he was actually struggling through the situation because at least he had the will to ...
I asked Mike do you smoke ? he said No never did ...
Said to him that you will never survive in this job but i see that you have the will to so expect you to start smoking no later than one year from today ....
Rental company today doesn't exist today the boss that was missing the field experience and the tech background eventually ****** it up
Mike is working with me since 2006 and he is the reason that we had to install reinforced ventilation in the lab
4 people work in the lab with me all smokers ...
I am 50 today i smoke far less and cigars no more cigarettes for me some time in the feature i will give up
I own my shop since i was 18 but from time to time i got involved as an employee in a number of companies to gain expirience in other subjects except audio that i ve been doing all my life ...Done telephony , production , lighting , and a few other things but the best of all was the PA thing east electronics except repairs provides also PA services ...small but effective
I do get my doses of coffe but no matter how much cigarettes may be process accelerators I don't feel the need to start now and don't intend to. This is a completely different debate and I don't now if it has its place here. I guess everyone has his way of doing things, some definitely more efficient than others. As I said before I'm open and very thankful for all advice and knowledge and sure finished a lot of projects thanks to people like you here on this forum but the rest are personal preferences that (I believe so) don't change the quality of your work.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.