[bcowen]

…be careful about eating your words…with your level of enthusiasm, your words are high in calories……long live tube rolling!

 

[28Monkey]

Due to everyone's help and direction....I have been slowly whittling down noise on the OG. @Wes S with tube selections and @jonathan c and @bcowen with recs on home A/C plug and circuit selection. I am happily at a tube mix that is quiet.....not black like some SS amps can be, but darn close (think new moon but some stars in the sky).
A friend on the East Coast is a big fan of Zu Audio loudspeakers, but also their cables. Swears by their power cables on his big boy tube amps.
I went ahead and ordered a Zu Mission power cable (https://www.zuaudio.com/power-cable/mission-power-ii). In their literature they recommend a 300 hour burn-in.....I am @ 50 hours in, and it is making an audible difference (compared to stock cabling).
I have A/B'ed the stock cable and the Zu. First of.... the Zu is 98% dead quiet with my most sensitive cans (HD800S) on the High Z with volume at 12:00 (no music of course).
I have two reference tracks I like to use (due to familiarity) to play with on various amps and two-channel systems: Khruangbin --> Late Night Tales --> Still You and Steely Dan --> Gaucho --> Gaucho. Decided difference in upper registers....more shimmer on Jeff Porcano's cymbals and on the spoken/murmured background on Still You.
Pretty happy.....looking forward to the next 100 hours.

 

[Noodlz]

intriguing. i have morrow audio power cables myself, which ive used for all my amps for a while and they're definitely better than the stock cables. Does your hum vary based on volume? I wonder if it'll make a difference in my system since my hum is there no matter what the volume setting is. Also to note, im pretty sure mine is a 60hz hum and not a 120hz one, which would suggest that it's either the tubes (most likely), or maybe just the sound of the transformers? it is definitely getting more and more quiet compared to when first received it earlier this week.

 

[bcowen]

intriguing. i have morrow audio power cables myself, which ive used for all my amps for a while and they're definitely better than the stock cables. Does your hum vary based on volume? I wonder if it'll make a difference in my system since my hum is there no matter what the volume setting is. Also to note, im pretty sure mine is a 60hz hum and not a 120hz one, which would suggest that it's either the tubes (most likely), or maybe just the sound of the transformers? it is definitely getting more and more quiet compared to when first received it earlier this week.

A true 60hZ hum could also be caused by a ground loop. Do you have all your components plugged into one outlet (or into a power strip / conditioner that is fed by one outlet)?

 

[28Monkey]

intriguing. i have morrow audio power cables myself, which ive used for all my amps for a while and they're definitely better than the stock cables. Does your hum vary based on volume? I wonder if it'll make a difference in my system since my hum is there no matter what the volume setting is. Also to note, im pretty sure mine is a 60hz hum and not a 120hz one, which would suggest that it's either the tubes (most likely), or maybe just the sound of the transformers? it is definitely getting more and more quiet compared to when first received it earlier this week.

I have gone through many iterations of hum (transformer), static (RF?) and hiss (tubes). All more or less resolved.
What I was hearing (?) was not a truly dark background. It is much better than it was and the only substitution has been the Zu.

 

[jonathan c]

intriguing. i have morrow audio power cables myself, which ive used for all my amps for a while and they're definitely better than the stock cables. Does your hum vary based on volume? I wonder if it'll make a difference in my system since my hum is there no matter what the volume setting is. Also to note, im pretty sure mine is a 60hz hum and not a 120hz one, which would suggest that it's either the tubes (most likely), or maybe just the sound of the transformers? it is definitely getting more and more quiet compared to when first received it earlier this week.

I use the Morrow Audio MAP4 power cables , the Morrow Audio DIG4 digital cable , and the Morrow Audio Elite interconnects . It is a name not often seen.

 

[Noodlz]

A true 60hZ hum could also be caused by a ground loop. Do you have all your components plugged into one outlet (or into a power strip / conditioner that is fed by one outlet)?

Hm i don't think its the issue? i've actually tried literally turning everything in the room off late at night (like lights and everything off), and only running the amp plugged into a trip lite isobar, into the wall. Tried listening to it wit absolutely nothing connected to it except power. (and also playing music connected to it from battery powered dap, wifi and everything off and playing off the files). The hum remains the same volume & tone. i'm pretty sure its coming within the unit, unless its just the general tone from the ho[use and the amp just amplifies it.

Normally i connect my computers and monitors to a completely separate outlet on the other side of the room, and the audio gear is connected to the wall with 2 triplite isobar units (one in each of the 2 outlets), with everything right now on 1 isobar, but the zmf pendant by itself on its own isobar with nothing else connected.

Also tried an emotiva CMX-2, by itself feeding only the amp, and also tried daisy chaining the wall to CMX2 to an isobar to the amp. Same issue. Though it seems to sliiiighly help in terms of volume of noise.

Note this is all with the High-Z, testing with Sennheiser 6XX. on low Z its basically silent. On Orthos (LCD2) it's basically silent. some tubes i get the same 60hz tone at veeeerrry low level on high-z.

So far while i wait for new tubes to come in, I'm running the RFT EZ81 (nots sure what year, black plate o getter), TungSol 7189 (looks like new production?), and a Brimar 4068 made in England. The brimar exhibits the least amount of noise, but is a bit harder / more congested, though very clear. Im running a GE 12AU7 (grey plate, D getter it looks like, code 57-22) which has a much better sound stage than the brimar, and has more lifelike mids and more fluid, but does unfortunately exhibit more noise floor (same 60hz tone, louder it seems), as well as some crackling / popping when signals are near like a phone.

I've also tried the Stock JJ set individually and they all have more noise than my current set, again, same 60hz hum that is present no matter the volume. doesnt increase or decrease when i plug in inputs from my other units. Oh and also, i've tried the aluminum covering thing too. doesnt help with the better tube set, helps with the stock JJ's and the GE when phones are nearby.


And so at this point, i'm thinking its one or a combo of things:

1. The tubes aren't quiet enough. Have a couple coming in. if these aren't quiet enough will be calling up vintage tube services to get the quietest they've got to use as reference
2. Transformer itself is humming. This is probably why it seems to get better the more often i use it. Not much i can do here probably besides sending it in and upgrading the choke.
3. Power itself can use even better cleaning. I've considered upgrading my power outlet from a triplite to a ZeroSurge or a SurgeX. Also heard that there are balanced isolation transformers that could help, though i've heard mix results on those. Particularly interesting to me is if those Zu cables could help. Then again at that price point i'd rather stick to my Morrow cables & buy a Zero Surge.

TLDR; will roll more tubes. run it more. maybe find cleaner power. Enjoy the amp anyway.

 

[28Monkey]

Hm i don't think its the issue? i've actually tried literally turning everything in the room off late at night (like lights and everything off), and only running the amp plugged into a trip lite isobar, into the wall. Tried listening to it wit absolutely nothing connected to it except power. (and also playing music connected to it from battery powered dap, wifi and everything off and playing off the files). The hum remains the same volume & tone. i'm pretty sure its coming within the unit, unless its just the general tone from the ho[use and the amp just amplifies it.

Normally i connect my computers and monitors to a completely separate outlet on the other side of the room, and the audio gear is connected to the wall with 2 triplite isobar units (one in each of the 2 outlets), with everything right now on 1 isobar, but the zmf pendant by itself on its own isobar with nothing else connected.

Also tried an emotiva CMX-2, by itself feeding only the amp, and also tried daisy chaining the wall to CMX2 to an isobar to the amp. Same issue. Though it seems to sliiiighly help in terms of volume of noise.

Note this is all with the High-Z, testing with Sennheiser 6XX. on low Z its basically silent. On Orthos (LCD2) it's basically silent. some tubes i get the same 60hz tone at veeeerrry low level on high-z.

So far while i wait for new tubes to come in, I'm running the RFT EZ81 (nots sure what year, black plate o getter), TungSol 7189 (looks like new production?), and a Brimar 4068 made in England. The brimar exhibits the least amount of noise, but is a bit harder / more congested, though very clear. Im running a GE 12AU7 (grey plate, D getter it looks like, code 57-22) which has a much better sound stage than the brimar, and has more lifelike mids and more fluid, but does unfortunately exhibit more noise floor (same 60hz tone, louder it seems), as well as some crackling / popping when signals are near like a phone.

I've also tried the Stock JJ set individually and they all have more noise than my current set, again, same 60hz hum that is present no matter the volume. doesnt increase or decrease when i plug in inputs from my other units. Oh and also, i've tried the aluminum covering thing too. doesnt help with the better tube set, helps with the stock JJ's and the GE when phones are nearby.


And so at this point, i'm thinking its one or a combo of things:

1. The tubes aren't quiet enough. Have a couple coming in. if these aren't quiet enough will be calling up vintage tube services to get the quietest they've got to use as reference
2. Transformer itself is humming. This is probably why it seems to get better the more often i use it. Not much i can do here probably besides sending it in and upgrading the choke.
3. Power itself can use even better cleaning. I've considered upgrading my power outlet from a triplite to a ZeroSurge or a SurgeX. Also heard that there are balanced isolation transformers that could help, though i've heard mix results on those. Particularly interesting to me is if those Zu cables could help. Then again at that price point i'd rather stick to my Morrow cables & buy a Zero Surge.

TLDR; will roll more tubes. run it more. maybe find cleaner power. Enjoy the amp anyway.

When I purchased here on the Classified, the previous owner reiterated to me several times that the unit had a persistent transformer hum, but while I appreciated his honesty, I was more than willing to jump in.
I was aware of that particular harmonic, but as use and time has progressed, I don’t notice it anymore. So, did it diminish…or did my brain just cancel it out? LOL….Either way, it is no longer noticeable.

 

[Noodlz]

Yea im pretty positive it diminished. I've been A/B testing back and forth between the Pendant and WA6SE to compare the noise levels the same sets of the headphones. Compared to when it arrived the hum has significantly reduced. Actually as of now the hum is at a more than manageable level. This is very much the same experience I had when i first got my WA6SE. Though the noise on the pendant was much more noticable at first, but it also diminished way quicker than the WA6SE. Seems like within a week of turning it on everyday for a few hours the hum went from like a 0.1 to a 0.001 (1 being finger nail tap on the table, 0.1 being lightly scratching the table with said fingernail. 0.001 being finger-not-nail moving across the table. you wouldnt hear it unless everything is silent and you pay attention).

again, this thing sounds AWESOME. and at this point i know im just nitpicking, but i know it can sound even better =)

 

[28Monkey]

Yea im pretty positive it diminished. I've been A/B testing back and forth between the Pendant and WA6SE to compare the noise levels the same sets of the headphones. Compared to when it arrived the hum has significantly reduced. Actually as of now the hum is at a more than manageable level. This is very much the same experience I had when i first got my WA6SE. Though the noise on the pendant was much more noticable at first, but it also diminished way quicker than the WA6SE. Seems like within a week of turning it on everyday for a few hours the hum went from like a 0.1 to a 0.001 (1 being finger nail tap on the table, 0.1 being lightly scratching the table with said fingernail. 0.001 being finger-not-nail moving across the table. you wouldnt hear it unless everything is silent and you pay attention).

again, this thing sounds AWESOME. and at this point i know im just nitpicking, but i know it can sound even better =)

Totally unrelated, but does the Woo and the Pendant share any tubes?

 

[Noodlz]

Unfortunately not. At least not the first gen that i have. i think the 2nd gen uses slightly different tubes but i also think those dont share any tubes. My woo uses 5U4G for the rectifier and 6DR7 or 6DE7 or 6EW7 driver tubes.

I've actually just put my woo up for sale on another place right now, as much as I love it i can't have both of them at the same time. The Pendant is juuust slightly better sounding overall than the woo, which has magical mids but everything else a bit looser / bloomier. The pendant also works wonderfully with my LCD2 while being fantastic with dynamics too, whereas the woo is only fantastic with dynamics, but good-but-not-amazing with planars. Will be selling it here if it doesnt move over there after a bit.

 

[bcowen]

Hm i don't think its the issue? i've actually tried literally turning everything in the room off late at night (like lights and everything off), and only running the amp plugged into a trip lite isobar, into the wall. Tried listening to it wit absolutely nothing connected to it except power. (and also playing music connected to it from battery powered dap, wifi and everything off and playing off the files). The hum remains the same volume & tone. i'm pretty sure its coming within the unit, unless its just the general tone from the ho[use and the amp just amplifies it.

Normally i connect my computers and monitors to a completely separate outlet on the other side of the room, and the audio gear is connected to the wall with 2 triplite isobar units (one in each of the 2 outlets), with everything right now on 1 isobar, but the zmf pendant by itself on its own isobar with nothing else connected.

Also tried an emotiva CMX-2, by itself feeding only the amp, and also tried daisy chaining the wall to CMX2 to an isobar to the amp. Same issue. Though it seems to sliiiighly help in terms of volume of noise.

Note this is all with the High-Z, testing with Sennheiser 6XX. on low Z its basically silent. On Orthos (LCD2) it's basically silent. some tubes i get the same 60hz tone at veeeerrry low level on high-z.

So far while i wait for new tubes to come in, I'm running the RFT EZ81 (nots sure what year, black plate o getter), TungSol 7189 (looks like new production?), and a Brimar 4068 made in England. The brimar exhibits the least amount of noise, but is a bit harder / more congested, though very clear. Im running a GE 12AU7 (grey plate, D getter it looks like, code 57-22) which has a much better sound stage than the brimar, and has more lifelike mids and more fluid, but does unfortunately exhibit more noise floor (same 60hz tone, louder it seems), as well as some crackling / popping when signals are near like a phone.

I've also tried the Stock JJ set individually and they all have more noise than my current set, again, same 60hz hum that is present no matter the volume. doesnt increase or decrease when i plug in inputs from my other units. Oh and also, i've tried the aluminum covering thing too. doesnt help with the better tube set, helps with the stock JJ's and the GE when phones are nearby.


And so at this point, i'm thinking its one or a combo of things:

1. The tubes aren't quiet enough. Have a couple coming in. if these aren't quiet enough will be calling up vintage tube services to get the quietest they've got to use as reference
2. Transformer itself is humming. This is probably why it seems to get better the more often i use it. Not much i can do here probably besides sending it in and upgrading the choke.
3. Power itself can use even better cleaning. I've considered upgrading my power outlet from a triplite to a ZeroSurge or a SurgeX. Also heard that there are balanced isolation transformers that could help, though i've heard mix results on those. Particularly interesting to me is if those Zu cables could help. Then again at that price point i'd rather stick to my Morrow cables & buy a Zero Surge.

TLDR; will roll more tubes. run it more. maybe find cleaner power. Enjoy the amp anyway.

If you enjoy the amp, that's all that really matters of course.

One other thing you might try is a cheater plug. **** This will lift the earth ground on the amp, and if the hum goes away that will indicate that 1) there is a ground loop between interconnected components, or 2) an internal grounding issue in the amp, or 3) possibly mis-wired (or loose wired) wall outlets. If the hum remains the same, it will indicate (not assure, but indicate) that it's NOT a grounding issue either internally or externally.

https://www.amazon.com/Cable-Matters-Polarized-Grounding-Adapter/dp/B01M0FXMFK/ref=sr_1_3_sspa?crid=2AUCORL8LJPFY&keywords=cheater+plug&qid=1642464513&sprefix=cheater+plug,aps,86&sr=8-3-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExWlRPRjFJQk01Vkw3JmVuY3J5cHRlZElkPUEwNTc4NDMyM0RDTTNXMVlON1dBNyZlbmNyeXB0ZWRBZElkPUEwODQ4NzgxM1JFQTVVM1VONUo4UiZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

****NOTE: I am NOT suggesting and certainly not recommending that you leave a cheater plug in place on the amp (or any component with a 3-conductor mains cord). The earth ground is required for safety. Only suggesting to try it on a very temporary basis to help with diagnosis.

 

[Noodlz]

nice! ordered and will report back after i get it

 

[Noodlz]

Just got the grounding plugs~ Reporting back: hum stays the exact same. So just as i suspected no grounding issues at all, it's likely the transformers, the tubes, and or the clean-ness of the power itself. Going to roll through some tubes to see how far i can get to get things towards silence

 

[28Monkey]

Just got the grounding plugs~ Reporting back: hum stays the exact same. So just as i suspected no grounding issues at all, it's likely the transformers, the tubes, and or the clean-ness of the power itself. Going to roll through some tubes to see how far i can get to get things towards silence

Or all of the above. I think for me, it was a little of everything and changes were incremental but cumulative.