Your stereo doesn't sound like it used to? The cause might be simpler than what you expect!

Hello and welcome to my new post - it’s been quite a while since the last one. However, let me apologize for the average quality of the photos at this post; for various reasons, I used the camera of my phone instead of the dSLR.

Everything started because (again) I was feeling that my beloved stereo is not performing like it used to. It was not something in particular, but an imperceptible feeling that the pleasure that I was getting when listening to favorite tracks was much lower. In the meanwhile I had changed the resistors of the tweeters on the crossovers with metal oxide ones, so I was wondering if maybe I did somehow somewhat a kind of a harm. On the other hand, that was not a very happy period for me, so I was wondering if bad psychology was playing tricky games with my perception regarding high fidelity.

I tried to listen and listen again without prejudices, but each and every time I was feeling nervous instead of relaxing. The sound had base, but I was missing the low end energy. The sound stage was big and present, but I was missing the warmth and the affection I was feeling in the past when listening at my favorite, well recorded jazz tracks. Technically speaking everything seemed OK but emotionally speaking, the sound was somehow soulless.

This situation woke up an old, terrifying & ugly devil that many of us with vintage equipment have: maybe the electrolytic capacitors of my almost 30 years old Luxman C-03 & M-03 amps have degraded eventually, but let me come back to this after a few paragraphs.

Feeling confused, I invited my friend Panos for a listening session in order to let me know his opinion, but he said that he couldn’t spot anything wrong in particular. It was that same night that after Panos left, in a desperate move and after having already accused the electricity, the temperature, the humidity, the karma, the Feng Shui and the government I just unplugged and plugged a couple of times every RCA connector at the back of the pre amp; the problem was surprisingly solved and the magic was back!

The very next day I invited again Panos for another listening session with the same tracks we listened to last evening, without telling him anything about it. When I asked him if he could spot a difference, he said a certain and big “yes”! Just for fun, I unplugged and plugged the interconnects from my Parasound DAC and we listened again; we felt that the enormous low end of the “Paradise Circus” from the Massive Attack “Heligoland” album became even better.

To be honest, I couldn’t believe that such a simple move could make such a huge improvement; this was the reason I wanted Panos to share his opinion without telling him anything. I wanted to be sure that I was not self-submissioning myself into believing that I fixed what it was wrong, in such a simple way.

Still, the old capacitor devil kept eating my soul. I mean, OK, the system was sounding again fine but maybe the capacitors are half dead, meaning that recaping is the right thing to do?

This was probably the first time that I felt “lucky” to get a minor misbehavior. One channel at one of my M-03 power amps started to become silent when the amp was turned on and the volume was low. I had to increase the volume a little in order for this channel to wake up. After that, the channel was behaving normally even if you would turn of the amp and turn it on again. You had to leave the amp off for some time in order for this channel to “sleep” again.

I turned for rescue to our tech guru and asked if I should bring the amp for check and repair; the answer was yes and so I did. To make a long story short, since the amp had to be deassembled for the fix, we had a great opportunity to check / measure all the electrolytic capacitors; to my surprise, everything was fine.

Cleaning the inside of female RCA at the back of a Luxman C-03B pre amp.

Back to the RCA; it was very clear that the condition of the signal level plugs affected the sound in a sneaky way. It was also clear that just unplugging, plunging them back and twisting them brought the magic back. But with this hobby, nothing is eventually enough and that is why we decided for a deeper treatment with some DeoxIT products. Since we are located in Europe, we couldn’t get the spray products at a reasonable cost so we went for the 100% DeoxIT Gold and the 100% DeoxIT Red. The first is used at all ferrous metals (tin, nickel, steel, stainless, etc.) and the second is used also as an enhancer at non-ferrous metals (gold plated, bronze, brass, copper).

Our tools for the job. The pure alcohol is only missing.

The 5% spray products that we couldn't get in my country work also as a “bath”, meaning that with a single use you are done; the ones we got need to be used on clean surfaces.

The first treatment was going to be at my pre-amp. I knew that the outer, negative side of the female RCA was gold plated but didn’t know what the inside positive side of these Alpine RCA was. That is why I opened the pre-amp; eventually the inside was a ferrous metal.

The inside of the RCA inputs on the Luxman C-03B is made from ferrous metal. I was somehow disappointed finding this; then I realized that after decades, all they asked for is some cleaning.

With some smoking pipe cleaners and pure alcohol I cleaned the inside part; with some cotton swabs and pure alcohol I cleaned the outside part. I had to do it several times in order to be certain that everything is clean - the inside made the pipe cleaner dark, indicating that here was quite a bit to clean there. After that, I carefully treated the inside with DeoxIT Red and the outside with DeoxIT Gold, using only a few small drops of the product and being careful not to leave any surplus on the plugs. After 10 minutes, I cleaned again the inside part of the connectors. Last step was to vacuum clean the plugs just in case there was some fluff left behind.

Since the pre-amp was already open, I unplugged and plugged all the signal transfer connectors that I could reach, spraying a small amount of contact cleaner. Being a bit lazy, I treated only the cleaned male side of the most important connectors with DeoxIT Gold. I also cleaned and treated with Gold the plugs of the cables connected to the pre amp. 

There are some signal connectors on the main board of the pre amp. It is good to unplug them and use some contact spray.

There are a lot of signal connectors at the front of the pre amp. There are also some more underneath this board, but further de-assembly is needed to reach them.

Also, I did the same to the Luxman M-03B power amps. I assumed that the RCA (made from Alpine) have the same construction with the ones at the pairing preamplifier, so I used the Red fluid for the inside and the Gold for the outside. Since the amps were open, I unplugged and cleaned with some contact spray the voltage selector plug and I checked that the bias was still at the value I left it; I found out that in one amp, it had drooped around 1mV at both channels.

Cleaning the RCA at the power amp.

I unplugged and sprayed with contact cleaner these signal connections. There are more connectors below, but you need to remove the back in order to reach them.

Same at the mainboards; the right board has two of them (the amp can be bridged), remember to put a mark so you know which is on top!

I also cleaned the RCA at the Pioneer M-73 & M-90a used for home cinema. Since I noticed that during the cleaning procedure of the Pioneers the inside part made the cleaner tool dark like in the pre-amplifier, I assumed that I had to do with ferrous metal, so I used the Red fluid for the inside and the Gold for the outside.

Last but not least, I cleaned the RCA plugs at the active home cinema subs. Since I did this after asking DeoxIT manufacturer a relevant question (pls see at the end of this post), I used Gold both for the inside and the outside.

I feel that unplugging and plunging / twisting the connectors is enough for most cases. Cleaning them with alcohol is also good - it removes a lot of dirt. If you want an icing on the cake (provided that your connectors are not obviously oxidized, in which case the DeoxIT is not the icing, but the cake) you can use DeoxIT. Obviously, the older your equipment is, the more it will benefit.

Another tool that looks promising is this RCA cleaning tool. Hope to test it in the future.

As I said, it is very important to use these particular DeoxIT products at clean surfaces; also, you have to make sure that you don’t leave any surplus behind and clean again the surfaces that were treated with DeoxIT Red. For our American friends that are lucky to choose from the complete DeoxIT product range, the 5% sprays also wash away the dirt so with one move you are done.

At the top and out of focus, the RCA before the treatment. At the bottom in focus the treated RCA.

A tricky part is to determine what kind of metal your female connectors are. If they are shinny it means that they are plated, so you go for Gold. In my case, I had to open the device and with the help of a small magnet understand that the inner side was ferrous, since the magnet was attracted to the metal. I then had to use an old Akai open real deck demagnetizer to kill a new devil that was claiming that with the magnet I magnetized the plug and this would affect the sound.

Nevertheless, here is a useful product selection guide for DeoxIT products.

Last piece of information: what happens when you can't determine what kind of metal there is inside the RCA plug? Well, let me share with you my question to DeoxIT and their very fast response:

Q: Hello. I have DeoxIT D100L-2C & G100L-2C 100% 2ml tubes. In some equipment it is impossible to understand if the metal part inside of a female RCA plug is ferrous or non-ferrous – unfortunately it is not the same metal as the outside. Here is my question: assuming that the RCA is clean and has either no oxidation or slight oxidation and without knowing if it is ferrous or non-ferrous, which of the two products I have should I use?

Best regards

Christos

A: Morning Christos,

With slight oxidation, I would use the G100L-2C.

Best regards

As always, happy listening!

Christos

Update: After the positive effects I got by cleaning the signal contacts, I decided to make same kind of maintenance at the power electricity line. I cleaned with alcohol the male AC plugs of the equipment & I plugged them / unplugged them for some times. I went to the fuse board and after making sure that all appliances at my home are off (not even stand-by, completely off) I turned on and off several times all the ac safety breakers. 

Attention: next steps are a clear risk of fatal electric shock, please do not attempt if you don't know what you are doing. I am in no way encouraging you to do this, I am just saying I tried it.

I then opened the AC distribution panel and tightened all the screws that were holding the wires at the joints and at the safety breakers. Some of them had become pretty loose. I also cleaned the contacts and the body of the AC fuse.

And then I listened. Yes, it had a positive effect; tighter and deeper low end, bigger and well focused sound stage. This is how I remember my system sounding at it's best moments.

After the above treatments, my system is performing very well and most importantly, it does that each and every time.