Sansui big capacitor replacement - disappointment

[mplsbob]

I posted on this a few weeks ago, and it was seemingly deleted - possibly because my testing wasn't complete? - but I'd like to start a discussion again.

I recently purchased replacement caps for both driver boards, and the two large power supply caps and two large output caps for a Sansui 5000X. The big caps arrived first, so I decided to tackle them. After replacing all four, I reset the current and output adjustments and fired it up. To say the result was surprising is an understatement. The unit sounded like it had been neutered. The impressive low end was gone, leaving me only the option of utilizing the loudness button to make it listenable. I let it ride for a while to see if I just needed to adjust to the change in sound, but my perception just wasn't going to change - it wasn't good. I put the old caps back in, and it's back to its hearty old self.

My question is: Has anyone else had this experience replacing caps? One previous poster suggested that when caps drift out of spec over the years they can become (in my case) 2200uf caps that function like 3300+uf caps, thus allowing for a more robust - though possibly sloppy - bottom end. Another stated "silicon"(?) caps are a bad replacement for Sansuis.

Any input out there on any of this? My 2200uf replacements were Digikey's recommended part #p7364-nd.

Sorry for the long post.

 

[bluesky]

Caps

I sent my AU-717 and TU-717 to the shop about a year ago for it's first tune up to a long time veteran vintage repairman. I specifically asked him about replacement of the caps. He tuned up, adjusted, and cleaned both units up 'just fine' but didn't replace any of the caps. I can't remember exactly what he said but basically what he told me was if the caps aren't leaking, if the body isn't distorted, are not broke, and they are working fine, leave them alone. Also he told me that he does not change the other electronics if it's functioning because if you do the 'sound' will or may change and you may not like the new sound it at all. I.E. the amp may lose it's "Vintage Sansui Sound" which is what I really love, The Sansui Sound!! He did replace the all of the electrical componets which needed to be replaced, especially in the pre-amp section, and the amp sounds wonderful and true and the tuner works like a gem! Which goes back to the very old but very true saying that I have lived with all my life: "if it ain't broke, don't fix it". I am very glad he did the refirbrishment the way he did and the cost was a lot less too of course. Excellent caps aren't cheap for amps. That's about all I know about caps. If the caps look fine (not distorted or deteroriated) and aren't leaking, and the electrical componet sounds good, leave it alone. So that is the way I am approaching it from now on. Also, a bit of Sansui factory trivia, I have the priviledge of knowing, via email, one of the Sansui former employees, whom will remain nameless, who worked for Sansui during the "Vintage Years" and I remember he specifically told me that many of Sansui's electronics were specially made with values strictly for Sansui's equipment. In otherwords, electrical item A, with a specific specification number, may not be like item A that you would buy from an electronics firm with the same exact number. Some of the specifications were changed specifically for Sansui!! He did tell me that! So I agree with my vintage repairman...if it doesn't absolutely need replacing, don't replace it. Sansui Sound Forever
:thmbsp:

 

[EchoWars]

If the caps look fine (not distorted or deteroriated) and aren't leaking, and the electrical componet sounds good, leave it alone.

Tough to do on 35 year-old gear with dried-out caps everywhere. It's often a matter of 'replace the part, or say hello to your new, pretty doorstop'. If I'm into a unit, and start finding lots of dried-up caps, even the ones that look good get replaced...they are at the end of their lifespan, even on units that currently display no issues.

Properly chosen new electrolytics are light-years better than anything made in the 70's. To assume that simply because Sansui put it in there 30+ years ago, it must be better than anything you can buy now, is naive.

I don't know the application you were using the caps for mplsbob, but there are better choices than those Panasonic caps.

 

[tarior]

I've seen plenty of caps that didn't have electrolyte leaking out, or any sign of distortion on the body test wide open. They weren't doing their job at all.
Caps are cheap and easy to replace, I just recapped the P/S board on a Sansui G 9000, and I think all of the caps and a new speaker relay cost maybe $15. I even sprung extra $ for Nichicon caps and a perfect fit Omron relay.

 

[LBPete]

Mplsbob, your original post may have been lost in the recent server change. Some posts were lost in that process. I don't think anyone was singling you out for deletion.

One question to ask here, were the new caps installed correctly? Soldering leads to the little stubs on snap in caps is tricky. If not done correctly the cap may not be in the circuit. Also, make sure the polarity is correct.

- Pete

 

[spaceman]

Hey EchoWars, what do you think about (United) Chemi-Con? That's what I plan to replace the Elna caps in my 7000 with, but if there's something better, I'd really appreciate your input. I'm assuming either Elna or Chemi-Con would be best, since that's what usually came stock in vintage gear. :scratch2: Thanx. I can understand the wisdom of preventative maintenance, but I'd sure hate to lose the Sansui Sound, so this thread kinda gave me the jitters, lol.

 

[LBPete]

UCC, Elna, Nichicon, Panasonic all offer many different specfication caps in a given value. They range from cheap general purpose caps to caps taylored for a specific application. Some offer a specific line of audio grade caps. Like audio gear, there is BOTL and TOTL. So what ever company you choose, pick caps from the top range of their line.

- Pete

 

[EchoWars]

Hey EchoWars, what do you think about (United) Chemi-Con? That's what I plan to replace the Elna caps in my 7000 with, but if there's something better, I'd really appreciate your input. I'm assuming either Elna or Chemi-Con would be best, since that's what usually came stock in vintage gear. :scratch2: Thanx. I can understand the wisdom of preventative maintenance, but I'd sure hate to lose the Sansui Sound, so this thread kinda gave me the jitters, lol.

UCC makes good caps, but like Panasonic and Nichicon, they make different grades of caps. I just stay with the Panasonic FC/FM and the Nichicon HE/PW.

For large power supply caps, there are a lot less choices.

 

[spaceman]

Thanx much, both of you. I know it seems like some of us repeat some questions over & over, but there's a lot to know, & some of us are a little dense, lol. We do appreciate your patience. :yes: BTW, the power supply caps I'm looking at clearly state that they're "ideal" for power supply applications, so I'm pretty confident there, but I'm still figuring out a few things on the smaller ones. They're not always very specific in written specs, at least as to their applications.

 

[grateful]

Well this post just illustrates a point, many people just like the sound of sloppy undampted bass response. This is also true of old capacitor coupled amplifiers many find them warmer sounding. This also explains the popularity of many low quality tube amplifiers. It is also the reason many very fine amplifiers like the Adcom 555 for example are considered sterile sounding. Many people do not like accuracy in low frequency reproduction.

 

[TheAnalogman]

Well this post just illustrates a point, many people just like the sound of sloppy undampted bass response. This is also true of old capacitor coupled amplifiers many find them warmer sounding. This also explains the popularity of many low quality tube amplifiers. It is also the reason many very fine amplifiers like the Adcom 555 for example are considered sterile sounding. Many people do not like accuracy in low frequency reproduction.

Me being a noob somewhat, what are you saying? That replacement caps will remove sloppy bass? Or that the old caps will usually produce sloppy bass? From my reading of this thread, I gathered the problem was inferior new caps (the Digikey's recommended part #p7364-nd.)


Thanks

 

[grateful]

No really the truth is caps are caps for the most part. This is certainly true for the filter caps in the power supply. As they age they lose capacity and the power supply becomes softer and has less reserve current. This softens the bass because of a decrease in damping factor and current capacity. Bass transient response is decreased. Many find it warmer because of the richness of the harmonic distortion and overhang. With the new caps the power supply is performing as designed. The cleaner sound of the properly performing power supply dissapoints the listener.

 

[Crazy]

No really the truth is caps are caps for the most part. This is certainly true for the filter caps in the power supply. As they age they loose capacity and the power supply becomes softer and has less reserve current. This softens the bass because of a decrease in damping factor and current capacity. Bass transient response is decreased. Many find it warmer because of the richness of the harmonic distortion and overhang. With the new caps the power supply is performing as designed. The cleaner sound of the properly performing power supply dissapoints the listener.

I also was told and believe "caps are caps for the most part".

I used Sprague Power Caps from Mouser in my Sansui 881.

The 881 sounds the same NOW as before as far as the "Sansui sound" goes. The difference was the new caps cured the background "buzz/hum" caused by my original & failing old caps.

In other words.....mid range priced caps = no more buzz/hum = still have the great Sansui sound.

:thmbsp:

Another note is this........My 8080DB/7070 & 771 all have original caps. They all sound great.

My moto with anything is ...............

If it ain't broke-------> DON'T mess with it.

Unless you just love tearing stuff apart for giggles. ( and I personally DO NOT, )

 

[grateful]

Well sure you replaced the failing caps and the hum problem went away. I fully agree with that. My assertion is that working and new 2000 mfd caps are all pretty much the same as long as they are not broken.

 

[hpsenicka]

If "caps are caps for the most part"... then "transistors are just transistors", and therefore, "amps all sound alike".

I personally don't believe any of the above statements!

Manufacturers make caps with different performance specs for a variety of applications, and not all of them are necessarily suitable for audio use.

You could convince me that in most applications any good quality new capacitor can likely be substituted with a competitors "equivalent" without discerning much, if any difference in the sound quality, but there is no way that a 30 year old electrolytic capacitor will perform as well as a modern one, especially if it is in the signal path.

 

[riverrat]

This thread is interesting to me because I’ve received some conflicting information on the topic of cap replacement on my Sansui AU-D11 II.

After I bought it, I had a tech who is familiar with this amp and owns one himself look it over and adjust the offset. He’s worked on a number of them and is regarded as an expert.

After I used the amp for awhile, I noticed some humming that did not come through the speakers. I’ve read that bad caps is a common cause of this symptom, and spoke with the tech about recapping it. He told me he'd experimented with cap replacements on the AU-D11 II and found that sound quality declined. So now he stockpiles original Sansui caps from AU-D11 II donor units and uses those instead of new ones. He suspected that something to do with the synergy among the various original caps was why the AU-D11 II is such a great sounding amp, and concluded that it was better not to mess with that unless absolutely necessary.

Later, I emailed back and forth with another tech who has done complete restorations on a number of AU-D11 II’s. He found the advice about using donor caps off old units dubious to say the least, and wondered if the quality of the new replacements had anything to do with the sound quality declining. He suggested that high quality “low noise” caps should produce a different result. He is of the opinion that most if not all old caps should be replaced when restoring an older amp because even if they are currently working, they probably will not have nearly the lifespan of new ones.

Now I am decidedly NOT technically knowledgeable, but I’ve decided to cast my lot with the latter opinion- it just makes more sense to me. It might be different if I was technically proficient myself, and could just repair stuff if and when it breaks. But I'm not, so I'm having my AU-D11 II restored with virtually all new caps.

Depending on what options I'm provided with, I plan to have him use the best quality caps available, within reason price-wise. It just makes sense to me to put in new ones- my amp was built in 1984, 23 years ago. I would rather do it right the first time than do it over later, especially given the cost and risk of repeatedly shipping the amp around and having problems diagnosed.

It will be interesting to find out how the amp sounds after the restoration is complete.

 

[Robisme]

If "caps are caps for the most part"... then "transistors are just transistors", and therefore, "amps all sound alike".

I personally don't believe any of the above statements!

Manufacturers make caps with different performance specs for a variety of applications, and not all of them are necessarily suitable for audio use.

You could convince me that in most applications any good quality new capacitor can likely be substituted with a competitors "equivalent" without discerning much, if any difference in the sound quality, but there is no way that a 30 year old electrolytic capacitor will perform as well as a modern one, especially if it is in the signal path.

Circuit design plays a big part in how a unit sounds.

Rob

 

[EchoWars]

I've said it 100 times...the topology of the amp determines its sonic character, not individual components.

This assumes, of course, that the components used are appropriate for the job, and aren't worn-out 30 year-old parts.

Scrounging parts from ancient gear is the goofiest thing I've heard in a while. Allow me a giggle or two.

 

[grateful]

Your logic there HPsenicka is kind of goofy. I will agree that caps are caps and transistors are transistors. It is how they are put together that determines the sound of the amplifer As Echo said circuit topology. Unfortunately it is the perception of what is good sounding is often flawed. A good amplifier has no sound of it's own. It is not warm , cold , fat or anything else. It is a straight wire with gain.

 

[xoaphexox]

I use Panasonic SU for bipolar replacements, THA/TSHA for power supply replacements, and FC for everything else.

I have yet to be disappointed.

EW - Is there a better alternative to the SU or THA/TSHA that has a decent bang-for-buck? The only reason I was getting them was so that I could get all the parts I needed from the same vendor (DigiKey)