Well, I can't tell you, as I no longer have it in my possession. And I never took the cover off to see what was in there, so color me ignorant on this.
Lampizator Valve / Tube Rolling Review Thread
- Thread starter Zero000
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Any GG3 owners? Does yours have an internal hum when turned on? Mine does when a recti is inserted and can be heard from the listening position 7-8' away. It doesn't vary with the VC, so I assume it's 120 Hz. I'm trying to figure out if this is the nature of the beast, a defective cap or something, or a ground loop. To check, I disconnected the ICs and with an extension cord plugged it into a distant outlet, but the full internal hum was still there. That suggests either the condo has a ground loop or it's the dac.
Did you try a cheater plug to lift the ground for the short time to see if hum lessons
Just tried with extension cord in distant outlet, the dac’s ICs disconnected and other sources muted or turned off. Hum still there when (any) rectifier is inserted, but none without (the other two tubes in).. Hum level seems the same between three prong and cheater. I think it’s internal.(capacitor?), but don’t know how to figure out if condo otherwise has a ground loop, to be absolutely sure, which is what Poland asked.
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Did your DAC just begin exhibiting this behavior or has it been an ongoing problem? If it's new, what changed? (I'll point out it could be internal to your system, internal to your house or even external - something the power company changed, for example.)
It’s been there since the dac came in November (GG2 to GG3 upgrade). What I don’t recall, or never noticed, is sticking my ear close to check if my former TRP 2/3 did the same thing. If it is external, why or what would cause plugging in the rectifier to be the difference, given that in the test the unit is isolated from everything but the condo’s electrical system? Normally, it like everything else is plugged into a PS Audio P15 regenerator.
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So before the upgrade, it didn't hum? Or did you initially acquire it with the GG3 upgrade?
Seems like someone with a GG3 needs to comment on theirs, though I would also expect if they could hear the hum from 8' away you'd easily find that in a forum search. You're in North America, right? It may be time to contact Lampizator NA...
Seems like someone with a GG3 needs to comment on theirs, though I would also expect if they could hear the hum from 8' away you'd easily find that in a forum search. You're in North America, right? It may be time to contact Lampizator NA...
I acquired a GG2 that became a 3 on the way. The only changes made recently were putting QSA fuses in place of SR’s, coating everything that wasn’t already with HFC’s Q45t contact enhancer and swapping in a pair of Lampi EML 45 Mesh Anniv. to replace WE 300B’s (setting adjusted). I’ve been in touch with both LampiNA and Poland. Understandably there is a heavy bias against hum being a hardware issue, which is why I asked if there are any GG3 owners were around.
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Do you know anyone local at another location then your condo you can insert your GG3 Only,replace the fuse & clean all contacts that have
HFCs Q45T change rectifier to isolate hum to GG3
A tube guy recommended that you run tubes at low volume for 100 hours to bias. Do you think that applies to Lampi dacs too? Thoughts?
Any update on this? Did you try taking it to a friend’s house or perhaps your office to see if different power solves the hum issue?
Never heard this. Doesn’t make a lot of sense to me. Tubes do need to break in, but run normally they should break in just fine. For amplifiers that do not use auto biasing, like CJs or older ARCs, it is common to check bias levels every few days in the beginning. Newer ARC amps like the 160Ms are auto biasing.
I've arranged to take it to a local AV shop next week. I also have a 60 Hz (bass) hum that started a few weeks ago, the kind one gets when a cable isn't connected correctly, but so far haven't found it the normal ways.
Which are you referring to? The 120 Hz hum is coming from the GG's chassis, even with everything else disconnected from power. It seems a little louder when everything is connected, but when not is still audible from at least a few feet. The 60 Hz hum is heard via the active speakers when the VAC preamp feeding them is also turned on, varying with the volume level of dac and/or pre.
I would test with one of these...
HumDinger DC Line Blocker
What the HumDinger will do: Block low-level DC voltage sitting on your AC power line that causes the power transformer to hum or buzz. This type of mechanical transformer hum may be caused if other devices on your power line, or devices on nearby power lines, use AC power asymmetrically. This...
avahifi.com
this could be a difference in impedance from your electricity compared to a power transformer...handy tool to have.
Power to the GG and all my system comes through a PS Audio regenerator (P15). I would have thought it takes care of the DC voltage. Have to ask.I would test with one of these...
HumDinger DC Line Blocker
What the HumDinger will do: Block low-level DC voltage sitting on your AC power line that causes the power transformer to hum or buzz. This type of mechanical transformer hum may be caused if other devices on your power line, or devices on nearby power lines, use AC power asymmetrically. This...avahifi.com
this could be a difference in impedance from your electricity compared to a power transformer...handy tool to have.
I can see where the Humdinger could be a handy tool for diagnosis, although as a keeper it comes at the price of one or two costly power cords.
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I would take the DAC to a competent engineer familiar with working with tube/valve gear.
Don't talk to or expect Lampizator to fix that. Been there, done that. Total failure and denial there was a problem. Old story.
Seriously. Get a decent engineer on it. It'll cost way less than wanking around with Lampizator. And the result will probably far exceed your expectations.
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