Golden Gate DAC. Is normal to have a little mechanical hum?

Dracule1 · « **on:** 8 Aug 2015, 01:56 am »

I've noticed 60 Hz mechanical hum emanating from the GG DAC, presumably from the transformers inside this wonderful DAC. Have GG DAC owners experienced this? It's not loud enough to be intrusive but notieable. Also, when the volume is crank up, there is the same hum through the speakers. Again, not loud enough to be intrusive but noticeable during quiet passages of music. Any way to get rid of the hum?

Gopher · « **Reply #1 on:** 8 Aug 2015, 02:39 am »

Hi Dracule,

To go through a couple of the obvious steps, did you try lifting the ground? Are your ICs shielded? Does your unit have volume control?

Where are you located? I'm happy to help trouble shoot.

Best,

Fred

FullRangeMan · « **Reply #2 on:** 8 Aug 2015, 02:59 am »

My 2 cents are:
AC mains over the nominal also may cause hum.

Folsom · « **Reply #3 on:** 8 Aug 2015, 03:19 am »

There's probably a break in the ground of one of your IC cables or connectors. Do you have any DIY stuff?

Dracule1 · « **Reply #4 on:** 11 Aug 2015, 04:25 am »

Hi, sorry for the delay.

The ICs are shielded. The hum isn't present through the speakers using other DACs using the same ICs. By lifting the ground, you mean using a cheater AC plug? The GG doesn't have volume control option. This issue only came about when the GG was introduce into the system.

My question: Is it normal for GG to have a little mechanical hum by itself? I'm not referring to the hum through the speakers.

BTW, the hum through the speakers gets louder as the volume is turned up.

Thanks.

Folsom · « **Reply #5 on:** 11 Aug 2015, 05:13 am »

Quote from: Dracule1 on 11 Aug 2015, 04:25 am

Hi, sorry for the delay.

The ICs are shielded. The hum isn't present through the speakers using other DACs using the same ICs. By lifting the ground, you mean using a cheater AC plug? The GG doesn't have volume control option. This issue only came about when the GG was introduce into the system.

My question: Is it normal for GG to have a little mechanical hum by itself? I'm not referring to the hum through the speakers.

BTW, the hum through the speakers gets louder as the volume is turned up.

Thanks.

The EI core transformers on it are likely to make a tiny bit of noise, but nothing you could hear unless you where either standing with it at maybe chest level, but more likely if you put your ear up to it.

Lifting the ground could be done with a cheater.

I bet it just has a bad connection to an RCA jack or such. You shouldn't hear anything in the speakers. That DAC isn't at the level where you'd expect to, it's one of the nicer DAC's one can get.

How are your skills with a multimeter?

sfox7076 · « **Reply #6 on:** 11 Aug 2015, 10:39 am »

Could also be DC on the line to the transformer. Do you have any other tube gear?

Dracule1 · « **Reply #7 on:** 11 Aug 2015, 04:16 pm »

It really sounds like transformer mechanical hum, and it's louder than the EI power transformer in my 200 watt tube monoblock amps. I can hear it from the listening seat, but the listening room is very quiet and is dedicated for audio with extensive acoustic absorber and diffuser treatment.

What's worrying me is that you all are saying I shouldn't hear any hum through the speakers, but I obviously do. I'm not sure if Lampizator recommends lifting the ground. Does anyone know if this is a safe thing to do?

I do know how to use a multimeter, but I'm not willing to open up the GG as that will void the warranty.

I doubt is a bad RCA connection (unless it's from the RCAs on the GG) because the hum problem is not apparent with other DACs with exactly the same RCA connections.

tdinut · « **Reply #8 on:** 11 Aug 2015, 04:51 pm »

I've had problems in the past with transformer hum on many pieces of gear. It was so bad on some amps that I could hear the transformers hum from across the room. It turned out to be excessive DC on my AC lines. I have since put in new, dedicated circuits/outlets and now use a power conditioner that actively removes DC from my outlets. SO MUCH BETTER! No problems since. It's quiet with a black background.

I believe it's not the Lampizator but your electricity.

Dracule1 · « **Reply #9 on:** 11 Aug 2015, 05:15 pm »

There are AC filter/surge suppressor both in the audio room and in the main circuit breaker. Not sure if it filters out DC. It's hard to argue it is an AC line problem when this was never a problem in the past, at least not to this extent.

sfox7076 · « **Reply #10 on:** 11 Aug 2015, 05:35 pm »

Sadly, most AC power filters ignore DC completely. I would send it to get diagnosed, but I would also look at an AVA humdinger or another DC filter. Over time, I have had really expensive tube amps with humming transformers. Also, have you switched tubes in the DAC? A weak 5U4G once caused me a lot of grief before i thought to change the tube. Could be a bad tube as well. I had a bad phase inverter tube on an amp once and it caused a ton of hum.

morganc · « **Reply #11 on:** 11 Aug 2015, 05:40 pm »

I have a lite 7 that I bought recently and it was making some very strange sounds out of both speakers. I assumed it wasn't a tube problem, but when I changed tubes the noise disappeared. The key with tubed gear and hums and noises is just to try every possible solution until it is resolved. Often the problem does lie in the tubes in my experience.

Dracule1 · « **Reply #12 on:** 11 Aug 2015, 06:06 pm »

Thanks all for the advice.

That's a good idea. Perhaps the tubes are the problem. Since the hum is coming from both channels, a different rectifier tube may due the trick. May be contacting Lampizator is a good idea too.

Sending the GG for diagnosis would be a PITA at this point. A DC filter is another option to try.

jriggy · « **Reply #13 on:** 11 Aug 2015, 07:44 pm »

You could easily have two issues going here...

The internal hum (most likely) from the transformer, could be due to DC on the lines OR it needs tightened up a bit. I even read of some putting thin cork sheeting under a problem humming/vibrating transformer in other gear, elevating the issue.

Your hum from the speakers, that raises with the volume level is going to be something else... Hmmm...

Dracule1 · « **Reply #14 on:** 11 Aug 2015, 07:56 pm »

I'm sure the internal hum is from one of the power transformers. Unfortunately, the GG is "sealed" so that if the seal is broken by opening up the chassis, warranty is void. So one can not open the unit to see if anything is loose.

avahifi · « **Reply #15 on:** 11 Aug 2015, 08:11 pm »

The HumDinger may fix your hum issue. If it doesn't, well, it does have a satisfaction guarantee.

Frank Van Alstine

Berto · « **Reply #16 on:** 11 Aug 2015, 09:26 pm »

Quote from: Dracule1 on 11 Aug 2015, 07:56 pm

I'm sure the internal hum is from one of the power transformers. Unfortunately, the GG is "sealed" so that if the seal is broken by opening up the chassis, warranty is void. So one can not open the unit to see if anything is loose.

Im the Co-North American distributor for Lampizator. I PM'ed you Dracule. If you communicate with me, perhaps I can help you

Thx
Rob

Dracule1 · « **Reply #17 on:** 12 Aug 2015, 02:59 am »

Hi Rob, I got in contact with Lukasz. Let me see what he says. Can you PM me your phone number in case? Thanks for your interest in helping.

Berto · « **Reply #18 on:** 13 Aug 2015, 02:50 pm »

Curious Dracule1 What kind of amps are you running with the GG?

Dracule1 · « **Reply #19 on:** 15 Aug 2015, 01:52 am »

I'm planning to try the Sophia Electric Princess 274B rigid plate rectifier tube to see if the hum through the speakers go away. It can handle up to 160 mA. Can someone confirm this tube is OK for the GG? I don't see a reason why it shouldn't be compatible, but you never know. Currently my GG uses the stock EL 5U4G.