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Eventide transformer hum ?
Old 12th May 2015
  #1
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wallyburger's Avatar
 

Eventide transformer hum ?

Hi all, just got my H3000, it's great, as we all know, but it hums like a banshee,
mechanical hum from the transformer. The lid even vibrates in sympathy quite violently.
I used to own one of these years ago, and that did it as well, so I know it's a common problem, but this one is the worst I've come across. Is there any way of curing this ? Someone told me that there was a guy here in the UK who can do an upgrade ? a new transformer or something ? does anyone know anything about his ? This hum is so loud I can hear it in adjacent rooms !

WB.
Old 12th May 2015
  #2
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TheBrightSide's Avatar
Try using a stepdown transformer and run it at 110V.
That worked for a member here in the UK.
Old 12th May 2015
  #3
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Quote:
Originally Posted by TheBrightSide View Post
Try using a stepdown transformer and run it at 110V.
That worked for a member here in the UK.
Good idea, I'll try that today....will report back....

WB.
Old 12th May 2015
  #4
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Also use rubber washers to absorb vibration if racking it.
Old 12th May 2015
  #5
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TheBrightSide's Avatar
Quote:
Originally Posted by wallyburger View Post
Good idea, I'll try that today....will report back....

WB.
Cool, I'd be interested to hear if it helps.
It's 220V where I am, and I've thought about trying this, but the noise doesn't really bother me. The strange thing is, somedays it makes little to no noise, other days it is really loud. Though it's the top plate vibrating that makes the most noise.
Old 12th May 2015
  #6
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OK, been too busy wiring today to get the step down, but I have put it in the rack, and insulated the top of the case with thick tape, as a cushion for the lid. Tightened up all the transformer screws, and most effectively of all, put those stick on rubber feet on the bottom of my rack, it stops the vibrations going down into my table and stops making it act as a resonator !! It's cut down that noise a bit, but it's still not ideal, makes you wonder how they thought this was acceptable ! This is a high end piece of kit, likely to be used for serious stuff, by serious people ! who probably won't apporeciat the thing sounding like standing in front of a guitar amp on full tilt !

MouseGarden.

Last edited by wallyburger; 13th May 2015 at 04:45 AM..
Old 10th July 2015
  #7
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skythemusic's Avatar
Bump this. I am racking my H3000 D/SE and it (along with my Ursa Major Stargate 323) are by far the loudest things in an otherwise extremely quiet control room. I have "fixed" other vibrating pieces of gear with weather stripping, plastic washers, etc. but these 2 units have external transformers making those normal remedies pointless. Any ideas or do I need some kind of redone external transformer power supply?
Old 10th July 2015
  #8
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wallyburger's Avatar
 

Quote:
Originally Posted by skythemusic View Post
Bump this. I am racking my H3000 D/SE and it (along with my Ursa Major Stargate 323) are by far the loudest things in an otherwise extremely quiet control room. I have "fixed" other vibrating pieces of gear with weather stripping, plastic washers, etc. but these 2 units have external transformers making those normal remedies pointless. Any ideas or do I need some kind of redone external transformer power supply?
Please don't bother to get a step down transformer, it doesn't make any difference to the noise. There is no real cure, I did what you said with small rubber tap washers under the lid. That's about it. How Eventide got away with this is beyond belief, noisy equipment designed for a sound studio is like having to use coloured canvas if you are a painter. Unacceptable, especially when I paid nearly two thousand quid for one of mine when it was new !

Wallyburger.
Old 10th July 2015
  #9
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Hi
It probably doesn't resonate, or at least not as bad in the USA as their mains is 60Hz which is obviously not going to 'excite' the metalwork at the same frequency and the transformer probably isn't working so close to magnetic saturation so will be contained in the 'core' to a greater degree.
Running it at 110 SHOULDN'T make a difference (compared to 220) as the magnetic flux is the same (when switched correctly) however if it is set for 220 Volts AND is running at 50Hz in the UK, it is running a bit beyond the 'optimal' setting.
Replacing the mains transformer with a properly specified one for Europe and the UK is probably the only way to really sort this out.
Matt S
Old 10th July 2015
  #10
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HandCrafted Lab's Avatar
 

All of them make buzzing, and this is not a buzzing of transformer itself - but top/bottom cover. So, your device is O, good news..
Try to remove both plates, to check, in fact the device become noiseless. Mine was installed into rack for year, with no covers. Any rubbers will not help, since this buzzing is result of overloaded transformer which is a bit weak to be loaded by 3000 circuit, and transformer become like a solenoid, triggering buzzing of both covers.

In result I have resolved this issue by own mod, with two toroidal transformers for digital (5V) and analogue (+/-15V), installed at L-bracket, aluminium, on lateral side, instead of native trafo. Also, I have added another fuse for new transformer (green socket) and ferrite coils at transformers leads, to supress any cross- parasitical affecting from all sides.
See pics >>
pics before modding also presened.

Result - dead silence forever, and noticeable improving of sound, in fact, this is traditional solution for all kinds of ADC/DAC - separate transformers for digital and analogue parts.
(btw, similar modding I have did for my Waldorf Wave I. Meatttt.... )
Attached Thumbnails
Eventide transformer hum ?-3000-mod-1.jpg   Eventide transformer hum ?-3000-mod-2.jpg   Eventide transformer hum ?-3000-mod-3.jpg  

Last edited by HandCrafted Lab; 10th July 2015 at 05:58 PM..
Old 11th July 2015
  #11
Besides the iron, the psu and clock generate a lot of EMI noise. One room in LA had the H3000 mounted in the same rack as their 160X comps. That caused the dbx's THD to rise to over 1%. Removing the H3000 from the analog rack cured that.

It's not only the noise you can hear, but the noise you can't that will cause trouble.
Old 11th July 2015
  #12
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so has anyone out there found a permanent and effective solution to this?
Old 12th July 2015
  #13
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HandCrafted Lab's Avatar
 

Hmmm...... but..... ^ ^ ^

There is no other solution..... + bonus with noticeable sound improving, due to separate transformers for analogue/digital chains .
Old 12th July 2015
  #14
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SP2016's Avatar
Instead of replacing the transformer, try this:

Replace the H3000 metal top cover plate with a plexiglass cover plate.
Quite easy to make.
Same thickness, use the metal cover as a "template" for cutting the ventilation holes.
You may even make more ventilation holes…
Worked very well with quite a few H3000's I modified over the years.
Old 13th July 2015
  #15
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Buy 1 Sq metre of MLV or Mineral Loaded Vinyl grab some garden Shears or sec-cutters etc, even seriously big strong Exacto cutting knife, grab the H3000 top lid, use this as a trace and cut around the h3000 top cover, then cut a square the size for the trafo hum, cut around the top cover, the a Square, you'll also need longer lid screws, now cut take the MLV and place strips where the screws go...place a square of MLV around the Trafo, at 110 volts or 230 volts the trafo hums a vibrates in sympathy, this deadens close to 85-95% of hum.
What your doing here is dampening the noise that is made and lessening the contact.bthe great thing with MLV is its near impossible to burn, made of junk bitumen and waste minerals etc, pretty much volcanic flame ******ant etc! Also remember the power supply extends to the very back of the H3000, not just the power lump inside. The cure for all noise is simply a new trafo.....though? Even if you do that, change to a specific voltage PSU, then there is still nothing to stop the unit vibrating, many say it's the powering and the supply, I say bad design from the 2016 2 rack unit original days! I mean the units pin 3 hot, so talk about design reform - great unit in a very older version 2016/969 box!
That simple
Old 13th July 2015
  #16
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fwet's Avatar
Quote:
Originally Posted by aramism View Post
so has anyone out there found a permanent and effective solution to this?
I have, there is a tech in Los Angeles named David Kulka. He is at studio electronics.com. It's not cheap...but it's better than those mods.
Old 13th July 2015
  #17
Quote:
Originally Posted by aramism View Post
so has anyone out there found a permanent and effective solution to this?
At that LA voiceover room I left it on the floor about 20 feet from anything else. They were instructed to leave it off if it wasn't being used. It's an EMI generator.

Never mix analog and digital processors in the same rack. It's a measurable problem.
Old 14th July 2015
  #18
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You know Jim... That is a great point and I have never thought about it.

The power supply in the H3000s is fairly poor in design at least as far as how it interfaces with the motherboard.
One big bottleneck is the Molex connector where the wires bringing the voltages from the power supply onto the motherboard.
That connector gets so freakin' hot that it almost melts.
I have not seen an H3000 where this Molex connector wasn't at least discolored from heat after years of operation.
Along with the discoloration I bet that there is increased resistance at the individual pins as well.
It seems that the amperage required by the unit's circuitry is more than the Molex pin can handle.

I am not sure if any increased resistance at this Molex connector causes the hum problem, but it could be a contributing factor.

My solution for the burnt-up Molex connector is to remove the male side of the connector and solder the individual wires directly to the Molex pins that protrude from the motherboard.
This makes a better connection that has significantly better point of contact at each pin.
I didn't notice hum with the two units that I serviced in the last few years, but I would suggest that anyone who has one of these units has this mod done.

Another weak point in the H3000's design is with the fuse holder.
I have had to replace at least one of these and the second unit had issues with the fuse staying seated, too.
Old 15th July 2015
  #19
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Quote:
Originally Posted by Jim Williams View Post
At that LA voiceover room I left it on the floor about 20 feet from anything else. They were instructed to leave it off if it wasn't being used. It's an EMI generator.
And I have no Doubt Jim that at least someone Now is using that H3000 EMI Hum for a guitar inspired Microphone Feedback straight into into Dual 910's ....Lol.....!

I'd say if you're keeping it racked for life, in the front Rack near a Console, then Ask Mr. David Kulka to Mod out the unit with all upgrades and a PSU with shield.....though if you are going to sell it on..... not worth it!
Old 4th November 2015
  #20
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Musicesque's Avatar
 

Quote:
Originally Posted by HandCrafted Lab View Post
In result I have resolved this issue by own mod, with two toroidal transformers...

...Result - dead silence forever, and noticeable improving of sound, in fact, this is traditional solution for all kinds of ADC/DAC - separate transformers for digital and analogue parts.
@ HandCrafted - Any interest in making a "how to" guide for your transformer upgrade mod? It would be a great contribution to the Eventide user community.

Old 5th November 2015
  #21
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There is not big secrets. First, need to look onto part of H3000 circuit, in part of PSU. There we can see usual design (non impulse type) of PSU to feed digital and analogue parts, So, native transformer distribute 7V-CT-7V AC for digital, and 15-CT-15V AC for analogue. According to circuit, we can calculate rough power of transformers we need - how says rectified DC voltages - 5.2A for digital, and 0.45A for analogue parts. So, like min ~55W and ~18W respectively.
In my case like 60W and 20W.

So, we need to replace native weak transformer with two separate transformers, for each part - digital and and analogue. There only toroidal transformers can be fitted into such humble volume, one over one. I`ve used custom wound transformers.

In my case I`ve used aluminium angle with suitable size, drilling few holes to fasten both transformers, fasten this bracket on lateral side of H3000, holes for new additional fuse socket (green part on pic).

After you`ve installed mechanical parts, you need to connect leads of both transformers, for mains, with two transformers now, and one - through other fuse except native fuse holder on rear panel.
I`ve used also big ferrite coils on mains leads, to supress parasitical noises, usual solution, optional though.

Other low voltage leads of both transformers need to be connected to molex connector on PCB, pins 2, 1(CT), 3, for 15V-CT-15V, repsectively to circuit. As for 7V-CT-7V leads - need to connect to Shottky bridge (CR1), on lateral side of chassis, and +7V DC from Shottky bridge to pin 5 of molex connector, two grey ground leads to pins 7-8.

In fact, not big deal for mid skill tech even, and going in accordance with circuit/service manual for H3000.
Attached Thumbnails
Eventide transformer hum ?-h3000-mains-transformer.jpg   Eventide transformer hum ?-h3000-rectifiers.jpg  

Last edited by HandCrafted Lab; 5th November 2015 at 01:06 AM..
Old 5th November 2015
  #22
I've been slowly going through each piece of rack gear and replacing all the E/I transformers with torriods. Mostly because of acoustical hum, not EMI problems.
Old 7th November 2015
  #23
Gear Head
 
Musicesque's Avatar
 

Quote:
Originally Posted by HandCrafted Lab View Post
There is not big secrets. First, need to look onto part of H3000 circuit, in part of PSU. There we can see usual design (non impulse type) of PSU to feed digital and analogue parts, So, native transformer distribute 7V-CT-7V AC for digital, and 15-CT-15V AC for analogue. According to circuit, we can calculate rough power of transformers we need - how says rectified DC voltages - 5.2A for digital, and 0.45A for analogue parts. So, like min ~55W and ~18W respectively.
In my case like 60W and 20W.

So, we need to replace native weak transformer with two separate transformers, for each part - digital and and analogue. There only toroidal transformers can be fitted into such humble volume, one over one. I`ve used custom wound transformers.

In my case I`ve used aluminium angle with suitable size, drilling few holes to fasten both transformers, fasten this bracket on lateral side of H3000, holes for new additional fuse socket (green part on pic).

After you`ve installed mechanical parts, you need to connect leads of both transformers, for mains, with two transformers now, and one - through other fuse except native fuse holder on rear panel.
I`ve used also big ferrite coils on mains leads, to supress parasitical noises, usual solution, optional though.

Other low voltage leads of both transformers need to be connected to molex connector on PCB, pins 2, 1(CT), 3, for 15V-CT-15V, repsectively to circuit. As for 7V-CT-7V leads - need to connect to Shottky bridge (CR1), on lateral side of chassis, and +7V DC from Shottky bridge to pin 5 of molex connector, two grey ground leads to pins 7-8.

In fact, not big deal for mid skill tech even, and going in accordance with circuit/service manual for H3000.
Thanks for this overview!

Having the basic specs of the transformers will help with sourcing the right parts. With a little research and some patience, I think I'll be able to pull this off without any problems.

...I also have an Ensoniq DP4+ that hums worse than my H3000. I think it's next in line for this mod.
Old 7th November 2015
  #24
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Musicesque's Avatar
 

Quote:
Originally Posted by Jim Williams View Post
I've been slowly going through each piece of rack gear and replacing all the E/I transformers with torriods. Mostly because of acoustical hum, not EMI problems.
Jim,

Can you recommend a good source for torroidal transformers?
Old 5th April 2018
  #25
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soundmodel's Avatar
 

Quote:
Originally Posted by HandCrafted Lab View Post
All of them make buzzing, and this is not a buzzing of transformer itself - but top/bottom cover. So, your device is O, good news..
Try to remove both plates, to check, in fact the device become noiseless. Mine was installed into rack for year, with no covers. Any rubbers will not help, since this buzzing is result of overloaded transformer which is a bit weak to be loaded by 3000 circuit, and transformer become like a solenoid, triggering buzzing of both covers.

In result I have resolved this issue by own mod, with two toroidal transformers for digital (5V) and analogue (+/-15V), installed at L-bracket, aluminium, on lateral side, instead of native trafo. Also, I have added another fuse for new transformer (green socket) and ferrite coils at transformers leads, to supress any cross- parasitical affecting from all sides.
See pics >>
pics before modding also presened.

Result - dead silence forever, and noticeable improving of sound, in fact, this is traditional solution for all kinds of ADC/DAC - separate transformers for digital and analogue parts.
(btw, similar modding I have did for my Waldorf Wave I. Meatttt.... )
Hey can you give detailed info about which torroidial transformers (specs etc.) to purchase and how to install them?

Last edited by soundmodel; 5th April 2018 at 10:00 AM..
Old 5th April 2018
  #26
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Hi
As these units require a transformer with 2 'centre tapped' windings they will be almost impossible to find 'off the shelf'.
It is easy enough to get one made specially for you but will be expensive.
You could contact local transformer manufacturers. Many will help you work out what you need if you give them some information.
Matt S
Old 5th April 2018
  #27
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kosi's Avatar
I heard lot's of good things about these guys:
Power transformers - Internet shop Toroidy.pl

otherwise ebay, amazon, mouser, digikey, reichelt, etc they are everywhere.

one thought: consider building an external psu, that way you don't have to rebuild the inner goods.
Old 5th April 2018
  #28
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Hi
The transformer required will not be available in the usual places as the secondary voltages and currents are not 'standard'. It requires 15+15 AND 7+7 volts. 15+15 is very easy. 7+7 not quite so easy but not together in the same transformer.
Matt S
Old 5th April 2018
  #29
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soundmodel's Avatar
 

Quote:
Originally Posted by Matt Syson View Post
Hi
The transformer required will not be available in the usual places as the secondary voltages and currents are not 'standard'. It requires 15+15 AND 7+7 volts. 15+15 is very easy. 7+7 not quite so easy but not together in the same transformer.
Matt S
What other specs do I need to follow than the voltages?

I'd also prefer if someone figured out a great way to dampen the existing transformer. That is, that I could just hot glue it or something to make it work.

At least for now.

Although, I've read that changing the transformers will offer an improvement in sound quality, so very likely I will do this at some point anyways.
Old 5th April 2018
  #30
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Changing transformers does not 'improve' sound quality.
The mains incoming can be quite distorted then the rectifiers turn the 'nearly' sinewave power into a series of current spikes so even a perfect transformer will not affect this. In fact, transformers with much lower winding resistance can make the current spikes worse, possibly endangering the rectifiers. It can also increase the dissipation in the regulators too, possibly overheating.
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