MX112 capacitor replacement

[saabracer23]

I’m going through the two audio boards in a MX110 preamp. There are two tantalum caps on each board, schematic saying they are 10uF 50v, but looks like they might actually be 10uF 20v? Can I use electrolytics in this part of the circuit without issue? I know they should be low ESR and low current leakage and it’s dependent on where in the circuit they go. I have Elna Silmic II or Panasonic FC in that value. Thoughts? They are C306 and C308 on the schematic.




Dan

 

[clinic-audio]

Hello Dan

Can I use electrolytics in this part of the circuit without issue? No


Can you explain in details why you wish to replace them if they are good ?

 

[w5hro]

I’m going through the two audio boards in a MX110 preamp. There are two tantalum caps on each board, schematic saying they are 10uF 50v, but looks like they might actually be 10uF 20v? Can I use electrolytics in this part of the circuit without issue? I know they should be low ESR and low current leakage and it’s dependent on where in the circuit they go. I have Elna Silmic II or Panasonic FC in that value. Thoughts? They are C306 and C308 on the schematic.

View attachment 1078244
View attachment 1078246

Dan

Yes, you can use electrolytics there, it won’t hurt and I would use 50V caps and not 20V. Tantalums usually don’t go bad unless the 20V rating was too low in the original design. There might have been a service bulletin where they went to 50V caps. It never hurts to bump up the voltage rating anyway to be safe.
.

 

[saabracer23]

Hello Dan

Can I use electrolytics in this part of the circuit without issue? No


Can you explain in details why you wish to replace them if they are good ?

I just know it’s highly suggested to replace tantalums when rebuilding Kenwood integrateds and such. Usual reasons I’ve seen are that they catastrophically fail and that it’s wise practice to remove them when you can.

What are your thoughts on why they won’t work? Good learning time!

Dan

 

[saabracer23]

Yes, you can use electrolytics there, it won’t hurt and I would use 50V caps and not 20V. Tantalums usually don’t go bad unless the 20V rating was too low in the original design. There might have been a service bulletin where they went to 50V caps. It never hurts to bump up the voltage rating anyway to be safe.
.

Thank you, thoughts on the Elna vs the Panasonic?

Dan

 

[w5hro]

If it's a choice I'd use the Elna's and not Panasonic. Panasonic is known for publishing Audiophool type specs for people who don't know any better. They like to make stuff up out of thin air like terms and definitions.I think Elan does the same thing, but are the lesser of the two evils.
.

 

[dshoaf]

Ok, someone set me straight here. The title says MX110 caps. The picture I see is a solid state and looks like a preamp. Lastly, the schematic is nothing I've ever seen in an MX-110.

So, what's the model under test, here?

Cheers,

David

 

[clinic-audio]

Hello David

you are 100% right !
these boards and schematic part are coming from MX112 not MX110 !

replacing tantale cap because many people reading forums did it is silly .
Tantale cap are much better than electrolytics and ask your self a question : why MC INTOSH did use tantales capacitors at this place if electrolytics are fine !

You can replace them if you want (that's your time and your money after all ) but you can use new tantale capacitors ...

42 years working on MCINTOSH units ...

 

[saabracer23]

I’m sorry all, it is an MX112. I have both and got confused. As far as tantalum replacement in the past I’ve done have all been values so low that films are the replacement. In this case the value is high enough I don’t think film would cut it.

Dan

 

[c_dk]

Patrice

After having to replace every Sprague tantalum cap in my SoundTech 1701 because a number had shorted out, and having to repair too many McIntosh tuners because a tantalum cap shorted out the power supply, I just do not trust them. Unlike a typical electrolyte failure mode of fading away, tantalums seem to short out catastrophically.

Add to that the general trend towards their bad effects on the "sound" of a circuit they are used in which includes much non empirical claims from various AK members, it makes no sense to leave them in.

As for your question about Mac EEs choosing to use them.......they were the "hot" ticket milspec rocket program device back then.....they made a mistake and quit using them in the next generation of products.

I have to admit I am concerned with the rampant use of tantalum caps as surface mounted devices......are we seeing the potential of issues similar to tin whiskers and EU lead free solder, because decisions are being made throughout the industry to enhance the use of machine built circuit boards?

C

 

[clinic-audio]

Hello Chris

Happy new year !

Yes , you are right but all tantale capacitors I have replaced were very old (one shorted in a KRELL KPS20i DAC) and very often in MPX board of MR77 and MR78 . But I have to confess that I have relaced tantale cap by tantale cap not by anything else .
If they are the worst cap why manufacturers does use them ?

 

[dshoaf]

Agreed on tantalum caps, they have some _very compelling_ operating characteristics (ultra low ESR, etc) that make them compelling for high-performance audio and test gear. As others have pointed out, however, their failure mode is to short out. Early versions of the 70s were also known to leak DC rather impressively.

For instance, Crown issued Service Bulletins for its tape and audio amp gear to replace them. I've also had HP o'scopes DC voltage rails pulling _lots_ of current when the tantalums on each circuit board started leaking. My general attitude is, if one is leaking and they're known to fail with those symptoms, then replace them once and for all.

I must say, however, that capacitor technology and materials have come a long way since the 70s so the reputation that tantalums got in the 70s does not apply today - well, not as much!

Cheers,

David

 

[w5hro]

In most audio applications such as low power coupling or bypass you won’t be able to tell any noticeable difference between using ceramic, tantalum or electrolytic caps. That falls into the category of Audiopoolery. That's like people saying they can hear the difference between using different cables and speaker wire. It's mostly nonsense. The only time you have an issue is when the capacitor’s voltage rating is exceeded to where it starts distorting the peak analog signal passing through it. That does happen if the rating is exceeded so the trick is to use a higher voltage cap.

Now, using different capacitor types can sometimes make a difference like in high power speaker crossovers because of the very high instantaneous voltage peaks that occur and in those cases, you want modern high-pulse, low ESR caps. Using small low ESR caps on those McIntosh circuit boards though is pointless because the resistance difference is insignificant. You are talking about differences in micro-ohms. Trying to compare 0.01uA to 0.03uA of leakage is a waste of time.

When it comes to bad caps you will occasionally have a case where a manufacturer produced a rash of bad ones due to their manufacturing process and that does still happen even today. One example is when Apple came out with the new Intel based iMac computers around 2006. The caps in those power supplies started shorting out after only a few months and I believe they were tantalums, but it was the manufacturers fault. It wasn’t a design issue.
.

 

[c_dk]

In most audio application such as low power coupling or bypass you won’t be able to tell any noticeable difference between using ceramic, tantalum or electrolytic caps. That falls into the category of Audiopoolery. That's like people saying they can hear the difference between using different cables and speaker wire. It's mostly nonsense. The only time you have an issue is when the capacitor’s voltage rating is exceeded to where it starts distorting the peak analog signal passing through it. That does happen if the rating is exceeded so the trick is to use a higher voltage cap.

Now, using different capacitor types can sometimes make a difference like in high power speaker crossovers because of the very high instantaneous voltage peaks that occur and in those cases, you want modern high-pulse, low ESR caps. Using small low ESR caps on those McIntosh circuit boards though is pointless because the resistance difference is insignificant. You are talking about differences in micro-ohms. Trying to compare 0.01uA to 0.03uA of leakage is a waste of time.

When it comes to bad caps you will occasionally have a case where a manufacturer produced a rash of bad ones due to their manufacturing process and that does still happen even today. One example is when Apple came out with the new Intel based iMac computers around 2006. The caps in those power supplies started shorting out after only a few months and I believe they were tantalums, but it was the manufacturers fault. It wasn’t a design issue.
.

There are so many people both in this AK membership as well as the high end audio community in general I will have to assert that something must be to "it" in spite of the general EE position that "it" is Audiotomfoolery.......

As I pointed out to Gordon Gow decades ago with his wife Palma refereeing our interconnect and speaker wire "discussion" dismissing outright what our local owners and his local salespeople believe they are hearing is insulting and not very good science. In his field of RF, or the design of their first amplifer, how many of his predecessors and contempories were dismissed as quacks because "it couldn't be".

I know what i have heard and what others have heard when we would set up AB demos. A researcher, a scientist would want to know why.

 

[w5hro]

There are so many people both in this AK membership as well as the high end audio community in general I will have to assert that something must be to "it" in spite of the general EE position that "it" is Audiotomfoolery.......

Unfortunately, in most cases there is nothing to "it" and it has nothing to do with someone being an EE or not. As a matter of fact, they are usually the worst ones. For example, the guy I purchased my last McIntosh receiver from was an EE and he tried to tell me that I needed to spend $800 on a special medical grade 12AX7 tube for the receiver. I just smiled and rolled my eyes when he wasn't looking.

Anyway, I think a lot of it has to do with people wanting to keep everything original so if McIntosh used tantalums and someone wants to replace them with tantalums then there is nothing wrong with that. It will keep it original, but in most cases, you won’t hear any noticeable difference.
.

 

[c_dk]

Many many decades ago a local client was unhappy with his XR7 speakers and a discrepancy between the L and R response of his speakers. I began voicing them with a MQ104 and while I could meld their response closer together the best I could do was get them within 1db of each other.

He was still unhappy and while I could hear no difference he was able to demonstrate to me using a opera soprano how her voice would shift a foot when she would hit that certain note.......this was driving him crazy.

I told him this was beyond my knowledge to solve but would do some research and get back to him ASAP.

When I got home from his house I pulled out Gow's home phone number and called him as I was invited to do when I would run into interesting challenges out in the field.

I was politely assured that my client was hearing things and I politely explained that this young man had more musical talent in his pinky than we did together.

Next morning there was a message to call Sid Coderman and I ended up in a multiway conversation with him, Russell and Gow, all who assured me the client was "hearing" things not hearable. I repeated my description of how the client showed me what he heard that I could not hear at which point Sid said "Oh" dismissed the other two from the conversation and spent the next 1/2 hour teaching me the formulas to create custom filters to solve this owners frequency response irregularities. I went back to the client's home that night, modified the filters, solved his problem and called Gordon when I got home to let him know all was no well. Side note: the MQ107 came out with added filters and response balancing options 6 months or so later.

The first retail lesson I learned at the age of 12 was how to open the till and hand a robber the cash drawer......2nd lesson I happily could hold over my dad for the next 60 years when a scruffy character bought 4 new aluminum rims from me after my dad dismissed him, that is "every one is a buyer", the corollary of that "never put your wallet in the other guys pocket". And lastly don't assume your audio client can not hear better than you or even expects or holds dear what you consider to be true quality sound......I always considered it was my job to help them get to what they wanted to get to not do missionary work for my perspective.......except for now, when I challenge those doubters to help find possible empirical evidence of what so many say they hear.

 

[w5hro]

 

[c_dk]

While I find ANY use of that fanatical mass murderer in very bad taste I will ask, What's the point?

As I ave posted in the past I have hosted a ABX amplifer demonstration with Clark and 28 or so members of the local AES as well as a few invited local clients.

Having colluded with Archibald , Stereophile's editor, before accepting the request to use my space, I made sure to keep track of who heard what, their interest in the experiment, job title within the industry, and age.

1/3 were successful identifying the A,B and X amp 6 out of 6 or 5 out of 6 times, 1/3 could not hear a difference if it had stobe lights telling them the correct answer, and 1/3 tried hard but would have been more successful if they would have smacked their fingers on the chair in front of them.

Age was a huge factor in who could hear what......and having a open mind was a close second. Being a active listener either a a mixing engineer or speaker designer showed up as being able to identify A,B, and X.

Of coarse Clark mixed in the 5 of 6 guys with the 1 of 6, averaged them together to then claim that the statistics showed there was no difference to be heard.

As usual the most interesting data comes from the outliers, what and why did 10 guys have so much success and why did 9 guys do so poorly......as card carrying members of the Audio Engineering Society, no less.

 

[w5hro]

Did you ever stop and think that your client and possibly some of the others in the past were the ones who were just nutz and it was never the technology itself? My experience has always been that there are always individuals on these bulletin boards who think they are like God and gain a big ego because no one else with any common sense or technical knowledge has ever bothered challenge them.
.

 

[c_dk]

I was 5 or 6 years old when my neighbor and his two boys hooked up a second speaker and what I found out years later was a second C8 and a new MC225 amp.

When the needle dropped on the stereo demo LP and a dragster exploded across the speakers, and then, the ping pong ball jumped from speaker to speaker I was filled with wonder, it was amazing and still today, some of the fantastic feats of music now stored away for all to enjoy still leaves me with a sense of wonder.