Hey People
Hope your all well!
Thanks for all the great info, learned a lot here over the last few years. First post so any assistance greatly appreciated! Hope its in the best thread?
Repairing/Upgrading amps in my ADAM S2.5A powered studio monitors. Still sounding amazing and mostly working well, feeling they have lost some definition over their 15 years of good use. Would really appreciate some advice so apologies about the many (sometimes lacking in knowledge) questions below!
One speaker repeatedly clicks when tuning off, the other clicks once. Could the be the C5468 Transistors (found some very close replacements, only difference in specs is Pd of 500mw vs 625mw on originals, is that an issue?
On inspection one of the power supply storage caps felt loose, desoldered and better but probably the snap-in on the actual cap is loose. Hot glued in place until I can find some good replacements, haven't tested yet.
There are 2 installed and 4 spaces, would there be any point replacing the 2 10,000uf 50v's with 4 suitable caps, or best stick to the 2? some 380LX103M050J052 from Mouser will fit nicely (381 too wide).
Will do all caps on all boards (smaller caps on power board done).
What else to upgrade or replace with new on the amp board?
Any point doing resistors after 15 years? The big green ones are marked 0R10 5W 5%, .1 ohm yeah? Maybe some Mundorf MOX replacements?
Do transistors degrade much over time? Have some On Semi 5200/1943 in stock, should be ok to match pairs on both speakers.
MJE 340 and MJE 15030, well out of my knowledge spectrum as to worth of replacing/upgrading these..
Crossover/EQ/Protection Board. NE5532, a bunch of there there, replace with fresh 5532's (if so best brand?).
Flim caps, all the Whima and Visays I have are branded and nothing on these guys so maybe worth upgrading?
Flim resistors to SUSUMU RS? Put some in a Resonance circuit of a very nicely build synth (Vermona) and did improve stability and creamy sound quality.
Also feeling it would be good experience to do a few parts at a time to learn more about what difference I get from each upgrade. Either that or just get it done and get back to writing music!
Thanks for reading 🙂
Cheers
Hugo
Hope your all well!
Thanks for all the great info, learned a lot here over the last few years. First post so any assistance greatly appreciated! Hope its in the best thread?
Repairing/Upgrading amps in my ADAM S2.5A powered studio monitors. Still sounding amazing and mostly working well, feeling they have lost some definition over their 15 years of good use. Would really appreciate some advice so apologies about the many (sometimes lacking in knowledge) questions below!
One speaker repeatedly clicks when tuning off, the other clicks once. Could the be the C5468 Transistors (found some very close replacements, only difference in specs is Pd of 500mw vs 625mw on originals, is that an issue?
On inspection one of the power supply storage caps felt loose, desoldered and better but probably the snap-in on the actual cap is loose. Hot glued in place until I can find some good replacements, haven't tested yet.
There are 2 installed and 4 spaces, would there be any point replacing the 2 10,000uf 50v's with 4 suitable caps, or best stick to the 2? some 380LX103M050J052 from Mouser will fit nicely (381 too wide).
Will do all caps on all boards (smaller caps on power board done).
What else to upgrade or replace with new on the amp board?
Any point doing resistors after 15 years? The big green ones are marked 0R10 5W 5%, .1 ohm yeah? Maybe some Mundorf MOX replacements?
Do transistors degrade much over time? Have some On Semi 5200/1943 in stock, should be ok to match pairs on both speakers.
MJE 340 and MJE 15030, well out of my knowledge spectrum as to worth of replacing/upgrading these..
Crossover/EQ/Protection Board. NE5532, a bunch of there there, replace with fresh 5532's (if so best brand?).
Flim caps, all the Whima and Visays I have are branded and nothing on these guys so maybe worth upgrading?
Flim resistors to SUSUMU RS? Put some in a Resonance circuit of a very nicely build synth (Vermona) and did improve stability and creamy sound quality.
Also feeling it would be good experience to do a few parts at a time to learn more about what difference I get from each upgrade. Either that or just get it done and get back to writing music!
Thanks for reading 🙂
Cheers
Hugo
If u don't know what u doing,don't do anything.Learn,read,write then try it.Then again:Learn,read write! 😀
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Some skills 🙂
Thanks Basi 🙂
Yes I’ve been researching, experimenting, collecting, reading and listening for a number of years. I repair Macs and phones to logic board chip replacement level plus some audio gear, so I have some competence. Still always much more to learn!
Some opinions of those who have been doing the above and more for a much longer time would be greatly valued. We all need to receive the odd shorter path from time to time.
Cheers
Hugo
Thanks Basi 🙂
Yes I’ve been researching, experimenting, collecting, reading and listening for a number of years. I repair Macs and phones to logic board chip replacement level plus some audio gear, so I have some competence. Still always much more to learn!
Some opinions of those who have been doing the above and more for a much longer time would be greatly valued. We all need to receive the odd shorter path from time to time.
Cheers
Hugo
Why on earth would you replace transistors or opamps with "fresh" ones - they don't degrade over time.
Semiconductors can fail suddenly, usually through overload, over-voltage or thermal cycling. Or they can last decades without the slightest problem. It might be worth stocking up on suitable replacements for any parts thay could become hard to find in the future though.
As for replacing resistors after 15 years?? No no no, completely pointless. (Unless they are carbon composition or burnt out!)
Electrolytic caps are the _only_ component that you'd expect to age. (well, switches and pots can too)
Checking solder joints for cracking is worth it (vibration and stress over time can cause this, especially in a subwoofer)
Any large components not tied/glued down can fatigue their leads too, you've noticed this.
Semiconductors can fail suddenly, usually through overload, over-voltage or thermal cycling. Or they can last decades without the slightest problem. It might be worth stocking up on suitable replacements for any parts thay could become hard to find in the future though.
As for replacing resistors after 15 years?? No no no, completely pointless. (Unless they are carbon composition or burnt out!)
Electrolytic caps are the _only_ component that you'd expect to age. (well, switches and pots can too)
Checking solder joints for cracking is worth it (vibration and stress over time can cause this, especially in a subwoofer)
Any large components not tied/glued down can fatigue their leads too, you've noticed this.
Ok thanks for info, appreciated.
Replaced all small caps on power supply, definitely better transients, more definition compared to other monitor. Will continue with the recaping!
Just the standby section thats clicking when switching off, interestingly developed a it of a pop when tuning on now, will check for dry joints on the control board. Just not using standby switch for now and all good.
So MilanAudio, how good did it feel? and did you think it sounded better because of how good it felt?
Replaced all small caps on power supply, definitely better transients, more definition compared to other monitor. Will continue with the recaping!
Just the standby section thats clicking when switching off, interestingly developed a it of a pop when tuning on now, will check for dry joints on the control board. Just not using standby switch for now and all good.
So MilanAudio, how good did it feel? and did you think it sounded better because of how good it felt?
Note that cap replacement applies to electrolytic caps, the ones with a plus or minus near one terminal. Alternately some old ones have a red end for plus. Mark the board for polarity with a sharpie before replacing, if they go in backwards they boil. Another variety of electrolytic cap has "NP" after the voltage, meaning non-polar. Found in speaker crossovers often. Replace with film if the new ones will fit.
film caps are forever except some brands sold 1964-67 like scr. Ceramic caps also unless the foil is showing through the case. potentiometers, switches, and plugs/sockets that can oxidize are other trouble points after a half dozen years.
I use some transistors daily made in 1970. Overheating overvoltage or overcurrent kills transistors. Properly rated ones for the application may never fail. Exception certain white plastic transistor found in 70's Japanese organs.
Zener diodes & regulator IC's containing such have a non-zero failure rate even within ratings. But not as doomed to failure as rubber sealed slime bottle electrolytic caps.
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Thanks mate
This is the first board I've worked on that doesn't mark polarity, taken good photos before removing anything 🙂
All info noted and appreciated!
Cheers
Hugo