Few Questions About Components

Soundork

Super Member
Hello,

I am in the middle of creating a parts list for several receivers from the late 70's. My questions are:

1. If I were to replace some of the electrolytic capacitors with non-electrolytic types, what type of the latter is best suited for this application? I hear film of some sort...Is there a brand/line that you have successfully used?

2. If I were to replace the ceramic capacitors, what type should I be replacing with? Same as in question one: Is there a brand/line that you have successfully used?

3. If I were to replace the resistors, what type would be the best to use?

Keep in mind that since the receivers are from the late 70's, these should be through-hole components.

Thanks in advance.

Soundork.
 
A few thoughts -

Get a schematic.

Don't touch anything in the RF section unless it is broken.

Confine replacements to signal path.

Films may be too large to physically fit PCB space and electrolytics the only option.
 
Your questions are so huge that it would take pages to answer fully and correctly, with all points of view supported. And all of this has been addressed and answered on AK many times.

I think you should do a lot of searching & reading on AK and look up how others have dealt with the various component replacements required in the models of gear you propose to restore.
 
Your questions are so huge that it would take pages to answer fully and correctly, with all points of view supported. And all of this has been addressed and answered on AK many times.

I think you should do a lot of searching & reading on AK and look up how others have dealt with the various component replacements required in the models of gear you propose to restore.
Thank you for your reply, John.

Going along with your logic pattern, I propose that we just stop posting, because everything has been said already.
 
A lot of people replace smaller electrolytics - say, 4.7 uF and lower - with WIMA film caps. These caps are known to be very stable over long periods and are non-polar, so orientation doesn’t matter. Depending on how tightly the board is packed, they may occasionally be too large. Also, there may rarely be times when they are not the best substitute. That’s where studying model specific threads, as Hyperion suggested, can steer you in the right direction.
 
A lot of people replace smaller electrolytics - say, 4.7 uF and lower - with WIMA film caps. These caps are known to be very stable over long periods and are non-polar, so orientation doesn’t matter. Depending on how tightly the board is packed, they may occasionally be too large. Also, there may rarely be times when they are not the best substitute. That’s where studying model specific threads, as Hyperion suggested, can steer you in the right direction.
Thank you for your reply, Steven.

Actually, I am starting with an experiment: I have two identical receivers, both Harman Kardon 330C. Both of them in original condition, one has a bad transistor in the phono stage. My goal is to do "upgrades" in increments and evaluate if there are improvements to the music material if any.

I plan on replacing all, including the malfunctioning transistors in the phono stage and evaluate the performance against the untouched one. If seeing improvement, do the same to the preamp and power amp stages.

Next step is to replace electrolytic capacitors and quantify the improvements (if any). Next replace the ceramics and evaluate and finally the resistors...then I would like to apply the knowledge gained to the rest of my broken gear...
smile.gif


I am just curious and I guess have too much time on my hands...
smile.gif


P.S. Last, but not least...My curiosity is driven only by the idea of seeing how much change new components with tighter tolerances would make and which change would have the most (if any) effect on sound reproduction. I am skeptical, but I have been wrong many times.
 
That sounds like an interesting experiment. The closest I have seen on AK is a lengthy thread by member patfont where he tried many kinds of electrolytics in the same unit and did detailed listening tests to see the differences. I learned a lot from that thread. Good luck with your quest!
 
Actually, I am starting with an experiment: I have two identical receivers, both Harman Kardon 330C. Both of them in original condition, one has a bad transistor in the phono stage. My goal is to do "upgrades" in increments and evaluate if there are improvements to the music material if any.

Great plan! Much will depend on your differential evaluation methodology. It deserves at least as much thought as your replacement regimen in order to produce meaningful conclusions.
 
Thank you for your reply, John.

Going along with your logic pattern, I propose that we just stop posting, because everything has been said already.
It doesn't read to me anything like that. It looks like a polite suggestion to educate yourself in order that you gain some understanding of what's involved with what you are trying to do rather than expecting others to pick up your slack.
 
there's a cap hierarchy - upgrading by going up the list. ecap std to audio-grade ecap,
film: polyester/mylar to polypropylene or polystyrene. then Teflon for your test.
choice is dictated by cost, lead spacing (does it fit through the existing hole), height
under other components/shields/cover/etc,

some caps do not require replacement - they don't degrade. BUT replacing ceramics
with c0gs, polyester films with polyprops, polyprops with Teflon is your test.

earlier post says signal path - good advice.

over 15years old? recap power supply. add bypasses, upgrading specs
(ESR, operating temp, and usually what most forget - rated hours).

then if you're going to be really good. read the schematics and change
polar caps to non-polars where there's a possibility of signal polarity,
increase the replacement cap working voltage when it appears the
original caps are close to rail voltages but only where this is true.

changing all caps to 1% is not useful - time and money much better spent
elsewhere (like measuring transistors for noise, Hfe, matching, or
for opamps, compensation, PS bypassing, etc)

research frequency response for caps. a 1% change may result in raising or lowering by 0.01 hz.
certainly won't affect bypassing, zobels, and in certain circuits for compensation
and in many cases feedback. in fact if you change a 5uf with a 15uf cap (300%)
you may not hear it, nor be able to measure it unless you have lab instrumentation.

don't change all the resistors for type (MF for CF or CC) until the end,
but before then pull and measure each and every one. replace with identical
before upgrading. this preserves the sonic signatures. Japanese designs
tend to one type over others and still have a mx - this is part of their voicing
that they strive for - the Marantz sound, etc. for example, changing to MFs
lowered the noise floor on a Hafler DH101, better caps widened the sound stage,
each change may or may not work.

compare both units, at the component level, making sure they are identical
with NO parts substitution (by design or by last guy hacking inside), upgrades
or running changes, or by guys who previously decided to test the sound but
gave up and sold you the incomplete unit.

then reflow everything. this eliminates any connection problems due to power
and heat cycling. also ensures reliability. like re-torqueing head bolts.

learn to use a scope, signal gen, etc. proceed to spectrum/distortion analyzers.

mark the PCB for cap orientation, if in doubt or to be thorough, compare board
layout to parts list to schematics - all must be identical.

replace one component at a time: take before picture, pull part, measure old part,
grab new part from labelled bag, measure part, solder part in, take after picture.
do not do newbie flipper by unsoldering 200-300 parts then try to remember
which goes where, and not understanding where a section might have been bad.

if you get into a problem, have someone else look at the pictures, you will never
see the issue - if you did as you were replacing then you might not have had a
problem - this is not a criticism of your skills, nor impugning your IQ/reputation
but a reflection of why the very best organizations separate out the builders
from the QA. they see things differently and will catch issues faster. as a
former member of the computing/programming community it's a guarantee
the coder does not the problems.

however, you may have very special skills and this might just be the vehicle
that brings it out. do return the gift by completely documenting your journey
by not describing it as "replaced everything and sounds wonderful".

and don't slam folks for their input, however smart you may think you
are. that person may have fixed the very receiver that you will be having
problems with (you test a component live, probes slip, kills unit, spend
100 hours isolating down to section, find out components are NLA) and
that person will place you on an ignore list. he may also be a geezer
and has fixed hundreds of units over the last 5 decades and you are
starting your first. and he knows exactly how to re-engineer that NLA part.

thank everyone, you get better advice when you're nice. (poem)

next up, research the AK giants here, how they tackle a problem, how they
fix them, how they upgrade, how they replace entire sections, and mostly
importantly how they improve the device.

I once spent about a year researching a rare amp that I bought, I exhausted
the English URLs, then went to the German sites, and then the Japanese
sites, and had to use the then primitive translation tools. nowadays it's
easier than chugging a small beer.

lastly, if you do all this, post your journey.

good luck
 
Great pointers, Bob; saved to disk. Love the one about being blind to one's own mistakes. See the small fail/epic flail in the (Roman-numbered) video series about "fixing" a 2265B on DrCassette's YouTube channel from a few years back (search videos for 2265B).
 
Thank you for your reply, Steven.

Actually, I am starting with an experiment: I have two identical receivers, both Harman Kardon 330C. Both of them in original condition, one has a bad transistor in the phono stage. My goal is to do "upgrades" in increments and evaluate if there are improvements to the music material if any.

I plan on replacing all, including the malfunctioning transistors in the phono stage and evaluate the performance against the untouched one. If seeing improvement, do the same to the preamp and power amp stages.

Next step is to replace electrolytic capacitors and quantify the improvements (if any). Next replace the ceramics and evaluate and finally the resistors...then I would like to apply the knowledge gained to the rest of my broken gear...
smile.gif


I am just curious and I guess have too much time on my hands...
smile.gif


P.S. Last, but not least...My curiosity is driven only by the idea of seeing how much change new components with tighter tolerances would make and which change would have the most (if any) effect on sound reproduction. I am skeptical, but I have been wrong many times.
Its not just new components with tighter tolerances, but replacing old fashioned parts, like paper dielectric caps with modern polypropylene caps. I wouldn't touch the ceramics because they are probably part of the tuner circuitry and just straightening them up physically, can detune the RF stages. Be careful here.
 
That sounds like an interesting experiment. The closest I have seen on AK is a lengthy thread by member patfont where he tried many kinds of electrolytics in the same unit and did detailed listening tests to see the differences. I learned a lot from that thread. Good luck with your quest!
Thank you for your reply, Steven.

I have learned a lot from pathfont's post too. One of the goals of my exercise is to test an observation of his on my own. I am a skeptic, but still have an open mind. Originally I dismissed his claim about significant change in sound upon replacement the wire leading to the filtering capacitors, but am willing to give it a try.
 
It doesn't read to me anything like that. It looks like a polite suggestion to educate yourself in order that you gain some understanding of what's involved with what you are trying to do rather than expecting others to pick up your slack.
Thank you for pointing out what I may have misread, absolon. To my defense, I hinted that have done research on my own in my post. It is easy to misinterpret a thought when the person is not in front of you.

I will send John a message as it looks like I read it wrong.
 
Last edited:
there's a cap hierarchy - upgrading by going up the list. ecap std to audio-grade ecap,
film: polyester/mylar to polypropylene or polystyrene. then Teflon for your test.
choice is dictated by cost, lead spacing (does it fit through the existing hole), height
under other components/shields/cover/etc,

some caps do not require replacement - they don't degrade. BUT replacing ceramics
with c0gs, polyester films with polyprops, polyprops with Teflon is your test.

earlier post says signal path - good advice.

over 15years old? recap power supply. add bypasses, upgrading specs
(ESR, operating temp, and usually what most forget - rated hours).

then if you're going to be really good. read the schematics and change
polar caps to non-polars where there's a possibility of signal polarity,
increase the replacement cap working voltage when it appears the
original caps are close to rail voltages but only where this is true.

changing all caps to 1% is not useful - time and money much better spent
elsewhere (like measuring transistors for noise, Hfe, matching, or
for opamps, compensation, PS bypassing, etc)

research frequency response for caps. a 1% change may result in raising or lowering by 0.01 hz.
certainly won't affect bypassing, zobels, and in certain circuits for compensation
and in many cases feedback. in fact if you change a 5uf with a 15uf cap (300%)
you may not hear it, nor be able to measure it unless you have lab instrumentation.

don't change all the resistors for type (MF for CF or CC) until the end,
but before then pull and measure each and every one. replace with identical
before upgrading. this preserves the sonic signatures. Japanese designs
tend to one type over others and still have a mx - this is part of their voicing
that they strive for - the Marantz sound, etc. for example, changing to MFs
lowered the noise floor on a Hafler DH101, better caps widened the sound stage,
each change may or may not work.

compare both units, at the component level, making sure they are identical
with NO parts substitution (by design or by last guy hacking inside), upgrades
or running changes, or by guys who previously decided to test the sound but
gave up and sold you the incomplete unit.

then reflow everything. this eliminates any connection problems due to power
and heat cycling. also ensures reliability. like re-torqueing head bolts.

learn to use a scope, signal gen, etc. proceed to spectrum/distortion analyzers.

mark the PCB for cap orientation, if in doubt or to be thorough, compare board
layout to parts list to schematics - all must be identical.

replace one component at a time: take before picture, pull part, measure old part,
grab new part from labelled bag, measure part, solder part in, take after picture.
do not do newbie flipper by unsoldering 200-300 parts then try to remember
which goes where, and not understanding where a section might have been bad.

if you get into a problem, have someone else look at the pictures, you will never
see the issue - if you did as you were replacing then you might not have had a
problem - this is not a criticism of your skills, nor impugning your IQ/reputation
but a reflection of why the very best organizations separate out the builders
from the QA. they see things differently and will catch issues faster. as a
former member of the computing/programming community it's a guarantee
the coder does not the problems.

however, you may have very special skills and this might just be the vehicle
that brings it out. do return the gift by completely documenting your journey
by not describing it as "replaced everything and sounds wonderful".

and don't slam folks for their input, however smart you may think you
are. that person may have fixed the very receiver that you will be having
problems with (you test a component live, probes slip, kills unit, spend
100 hours isolating down to section, find out components are NLA) and
that person will place you on an ignore list. he may also be a geezer
and has fixed hundreds of units over the last 5 decades and you are
starting your first. and he knows exactly how to re-engineer that NLA part.

thank everyone, you get better advice when you're nice. (poem)

next up, research the AK giants here, how they tackle a problem, how they
fix them, how they upgrade, how they replace entire sections, and mostly
importantly how they improve the device.

I once spent about a year researching a rare amp that I bought, I exhausted
the English URLs, then went to the German sites, and then the Japanese
sites, and had to use the then primitive translation tools. nowadays it's
easier than chugging a small beer.

lastly, if you do all this, post your journey.

good luck
Hi Bob,

Your post is classic and it deserves to be a sticky. Thank you for spending the time to reply to my questions.

Best

Soundork
 
Great plan! Much will depend on your differential evaluation methodology. It deserves at least as much thought as your replacement regimen in order to produce meaningful conclusions.
Thank you for your reply, awilla6

I might need help with that one as I admit that haven't spent more than five seconds on the subject. My original idea was just to make small, incremental changes in one of the receivers and then listen to both side by side, but I guess that might not be the most scientific approach. I am open to suggestions.
 
Its not just new components with tighter tolerances, but replacing old fashioned parts, like paper dielectric caps with modern polypropylene caps. I wouldn't touch the ceramics because they are probably part of the tuner circuitry and just straightening them up physically, can detune the RF stages. Be careful here.
Thank you for your reply, triode17.

There are no plans at this time to do any work in the receiver section beyond changing the electrolytic capacitors that is. I do have the skills and the knowledge how to align such tho.
 
1. 1uf or lower, anything higher may not fit(maybe 1.5 or 2.2, it starts getting expensive as you go up). Wima seems to be the go to since Panasonic left the business (they are easy to spot if you're selling).
2. Don't touch, unless they are cracked, burned, etc.
3. Don't touch, unless they cracked, burned, etc. There is no best, there is appropriate for the job (which some people get wrong).
4. You forgot Tantalum caps, I'm in the change with new tantalum in a low voltage circuit (pre, tuner, phono, etc). They say they get noisy, explode, whatever after 40 years. If they last 40 years they're great.
 
Last edited:
There was an option in order to create a poll, can I turn thread into such? Here is what I am thinking:

I got an idea. We could do this a community experiment, sponsored by...me. We could decide what parts go into the receiver and when. We will pick the best parts available from the reputable suppliers. We decide how it gets tested and when. Everyone will be welcome to stop by and monitor the process in real time.

I think I got a third of the job done by selecting the solid state devices. I spent probably more than 100hrs looking at spreadsheets in order to find devices that match or exceed the parameters of the original components. I will share the results if everyone supports this initiative.

Now, in order to limit the traffic...Here are my credentials:

I can read schematics and know what the purpose of every component is, I think. I could also perform circuit analysis, have troubleshooting skills and equipment necessary to perform such tasks. I also know how to use the test equipment I own. I can create simulation circuits, assemble component models from datasheets if necessary. I also dont mind a little oversight.

Now if there is an interest in the above, let me know (the poll idea isnt bad either...:)
 
Its not just new components with tighter tolerances, but replacing old fashioned parts, like paper dielectric caps with modern polypropylene caps. I wouldn't touch the ceramics because they are probably part of the tuner circuitry and just straightening them up physically, can detune the RF stages. Be careful here.

That's good to know! Thanks
 
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