Left RCA out on DAC not working


Hi guys,

As per title, the Left out RCA socket on my DAC is not working properly.

It will work, but only with RCA plugs with non-metallic shrouds, such as AECO plugs. I only discovered the issue when I went to try other interconnects. I started off with my Lavri Grand ICs which have AECO plugs, but all my ICs with metallic shrouds around the pin don't work at all.

The DAC is relatively new; I contacted the distributor, and he thinks it's a badly soldered ground on the inside of the chassis. He's ordered me a new unit, but has been admitted to hospital for major heart surgery, so I may have a bit of a wait 

Anyway, is he correct in his assumption of a bad ground solder inside on the Left RCA out?

Thanks in advance

128x128painter24

The DAC is relatively new; I contacted the distributor, and he thinks it’s a badly soldered ground on the inside of the chassis.

If that is the case then why would the Lavri Grand ICs that have AECO plugs work? The AECO plugs have a metal strip on the inside of the "shroud" that makes contact to the outer ground contact of the RCA jack.

Are you sure you are plugging the RCA plug with the metal ""shroud" all the way on the DAC right channel RCA jack? It sounds like the center pin on the plug is not contacting the jacks center contact. Usually a loose and or open signal ground connection will produce a buzzing sound along with the music being played.

Make sure you are plugging both ends on the ICs all the way in to assure the center pin on the plugs are making good contact with the center contact of the jacks.

.

@jea48 HI, thanks for your reply. The AECO plugs have no metal on the plug shrouds inside, apart from the pin, whatsoever.

The Lavri/AECO work perfectly. With other ICs, that have metallic shrouds, the left channel just doesn't work. The right channel works fine no matter which ICs I use. Checked and double checked with 3 different ICs, all fully inserted.

The AECO plugs have no metal on the plug shrouds inside, apart from the pin, whatsoever.

@painter24,,

Is this what the plug looks like? I can see the signal ground contact on the bottom of the inside of the plug "shroud". Look at the bottom of the inside of the "shroud" in the photo.

Look at the photo of the cable connection plug. Note there is a center contact terminal solder connection as well as a signal ground contact terminal solder connection.

The signal ground is required. It is part of the signal circuit. Often called the signal return.

The right channel works fine no matter which ICs I use. Checked and double checked with 3 different ICs, all fully inserted.

It has to be the center pin of the plug is not making contact to the center contact in the left channel jack. It sure looks from the photo I provided the center pin on the AECO plugs have what looks like a longer center pin than normally found on RCA plugs. Is that the case or is it just the photo that makes it look that way?

.

 

@jea48  thanks for taking the time with this; I'll take another closer look.

If I'm wrong about the AECO, any idea why the left channel would only work with these plugs, but no others? Seems a bit odd, even to my ignorant brain (in these matters) 🤔🙂

@painter24,

Just to narrow the problem down to the DAC left channel RCA analog out jack did you try another set of Line inputs on the preamp to make sure it's not that left channel input that causing the problem.

Or even try swapping the right and left ICs plugs at the preamp and see if the problem follows the DAC left channel IC to the right channel of the preamp.

@jea48 thanks again; I've tried different inputs on my integrated, no problems there, and also what you described lastly. I'm kind of resigned myself with it as I am getting a replacement, but it's just the wait.

@jea48 you're correct of course re: the ground pin on the AECO plugs, and yes the centre pins are longer than normal, which may account for why the AECO plugs work......would this mean the left RCA out plug onbthe DAC is in someway faulty?

The other cables are not making good connection on one of the 4 connection points or in teh middle.

would this mean the left RCA out plug on the DAC is in someway faulty?

@painter24

Ya, that could be the problem.

Question is was the DAC RCA jack faulty to began with, or did the longer pin on AECO plug damage the center contact in the jack? Did you by chance first use your other RCA ICs on the DAC, and they worked ok then?

What make is the DAC? There is a big quality difference from panel mount RCA jacks and circuit board mounted jacks.

Jim

 

@jea48 that's the thing; the first ICs I used were the Lavri/AECO, it was only some time later I wanted to try copper ICs instead of the silver Lavri, and I discovered the problem. 

I feel it maybe as you say; the AECO's longer center pin may have damaged the jack.

My  guess is the RCA jacks on the DAC are pcb mounted and the left jack's hot pin is not soldered (not the ground). The AECO plug is longer than the other RCA plugs and pushes the hot pin back onto the pad, making electrical contact. Board mounted jacks require a large diameter pad to accommodate the hot pin and it is relatively easy to not apply enough heat to get the solder to weld.

@painter24 said:

I feel it maybe as you say; the AECO’s longer center pin may have damaged the jack.

.

I’m kind of resigned myself with it as I am getting a replacement, but it’s just the wait.

 

Just a suggestion. You might as well continue using the Lavri Grand ICs until the new DAC arrives. I sure wouldn’t use the ICs on the new DAC. Throw them things in the garbage so you won’t ever have the temptation to use them again...

.