Best way to dampen a micro-vibrating Printed Circuit Board inside an amp? Thanks!

 ”What is a recommended way(s) to dampen” discussion question

@kennyc  “Apply water;-“

Yes, some of us had a few laughs along the way with this discussion, but “we have (all) passed a lot of water since then”. Goldwynism 

what is a recommended way(s) to dampen

Apply water ;)

Thanks to all who gave positive and helpful thoughts, and vice versa.

I put “E Fusing 900 Flex” moldable, non-hardening silicone putty in long lengths under the edges of the PCBs where possible…and yes, the sound is that bit less smeared and clearer, more detailed… so it was cheap and I’m cheerful!    

I worked as an electrical engineer for over40 years and have personally designed and tested hundreds of printed circuit boards for both military and commercial designs, and have reviewed many more customer PCB designs as well.  Audible noise coming from a CCA is pretty rare in my experience, but I have seen (heard) it.  If I recall correctly the last time we tracked it down to microphonics in a multi-layer ceramic capacitor.  Had to redesign that part of the circuit to fix it.

@ awise1961  

I can remember doing those vibration tests on a military computer.  System failed almost immediately.  Opened the chassis and the inside was littered with sheared off components, mostly larger electrolytic capacitors.  We had to encapsulate them in silicone.

• @jasonbourne71 So now we’re denying microphonics?

Invalid,

If we can hear sound emanating from a video or GPS cca there is indeed a problem. Actually, if you can hear sound coming from any cca, I would estimate that a problem exists. Most of the cards we build go through a final, full functional test simulating what it is expected to do in the real world. As of late, a guidance cca for the Tomahawk missile has the most stringent of test requirements. However, in my private world, I do not sign up to reviewers of audio gear who pass judgement based solely upon test data. I’ve assembled my system based on how it sounds to me. I really appreciate your questions. You made me think. This type of healthy banter is what makes this forum so much fun.

No, the solution involves a 20kg bag of cryogenically-treated horse manure, which is what this thread deserves.

The Pre Amp' which is correct when referred to as commission built, has a Prototype SS Section already in use, which offered a Complex Internal Design for Earth Lifting, as well as a SS only Circuit which is as Transparent as can be.

When used with Valves the designer informs that it is the Valves that are only being heard, the pre is not an influence.

The Prototype Pre' was also produced with the option to add gain up to 13dB.

I have used all the options in my system and done assessments with other friends sharing a audio interest. The P'type Pre' has also been inserted into other systems.

It is so so revealing it catches one out, especially when not familiar.

So far it can be safely stated, good quality recordings are not wanted to be listened to without the pre in use once experienced.

The Valves on the final version will produce a Single Ended Pre Amp' that is solely to add two versions colour that can be tweaked to control the influences of each,  as an alternative to unadulterated transparency.

I was offered one Valve as an option that would have been very closely matching the Transparency of the SS, but that was not my objective.

Different and discernible influences were to be the goal, Tube Rolling is a favoured side hobby in Audio Equipment experiences. Additionally, I do loan owned equipment to other non owned systems on a regular basis to help others find their experiencing a produced end sound that is created to meet with their preference.  The Amp design and Tube Rolling Options will assist with others who are being investigative.      

@awise1961 does your company test CCA's with the human ear, or just measurement equipment?

@mrdecibel 

My point was that the acetic acid released during the curing process of the sealants you listed is corrosive to electronic components and circuit boards, and therefore to be avoided.

We are in full agreement about how unpleasant they are to use though. That stuff is nasty.

@davidplombier, I agree completely, as the smell of the acidity release, it is not pleasant......but after the curing/drying process, it becomes quite safe to use.  Excellent ventilation required during the application process. Almost 60 years, never an issue as a result of using it. Doors, windows, tubs and showers. It is used because it is faster drying, and yes, less expensive. It gets the job done, with a smile on my, and others, faces. 

I've watched a few of Angela-Gilbert Yeung's videos. 

If I had to hazard a guess, I would say that underneath the buffoonery lies a brilliant designer. Hence my curiosity toward their products.

@pindac 

The mono preamps you are commissioning are to have three separate,  selectable output stages, two of which are tube-powered and the third is solid state? Definitely interesting!

Angela-Gilbert Yeung is interesting.

I am at present having a Pre Amp' built that shares similarities to a Yeung design, as I will Monoblock Pre Amp's which are to have switchable Channels to enable 2 x Tube Options with different options for Gain and a SS Option with a increased range for adding gain.

There are both Single Ended Inputs / Outputs and a Balanced Input / Output 

@mrdecibel 

The Silicone Solutions SS-101 sealant that you recommend is acetoxy cure, as are most GE silicones. Acetoxy cure sealants release acetic acid.

Acetic acid is corrosive to electronics and PCBs.

See the gear Angela-Gilbert Yeung makes.

Never had a chance to listen but always been curious. 

Silicone Solutions SS-101......I have also used certain Silicon caulks by Dap and GE clear (applies white, becomes clear when settled). Another is Frost King Rubber Pipe Insulation Tape. And, of course, Dynamat, Peel & Seal roofing repair tape to do the entire chassis/horns. It all damps very well, when used properly. My best, MrD.

The thread premise question is with regards to the CCA's, not the piece of equipment it goes into. I would absolutely agree that transformers, relays, vacuum tubes, and other non-CCA items are indeed sensitive to vibrations. Again, the question was with regards to the circuit card assemblies. Every CCA my company produces for mil use is supplied with electrical test data. 

@awise1961 It can be assumed substantial data is recorded?

When Temperatures are kept close to typical home temperatures, does Data have variances in the measurements collected as a result of other test parameter changes being added during the testing period?

How would variances in measurements recorded, especially Data Taken at Temperatures that are representative of a Typical Home, be described by those qualified to comment on graph tracings? 

@awise1961 

You are amused? Why? Because you doubt that vibration of a circuit board can influence the sound quality of the output? All your examples seem to be about maintaining functionality or continuity not about the nuances of output. Most audiophile equipment is incredibly heavy because vibration control and interference is considered within the device to extreme degrees throughout the device. Aftermarket devices are effective when stabilizing the whole device and improving sound quality... whether DAC, amp, or preamp. 

Being in the profession I am in, I find this thread to be somewhat amusing. I started my career in the early 80's as a PWB (printed wiring board designer) then into Engineering Manager, then Director, and then finally where I'm at as a VP/GM of an aerospace/defense contract manufacturer. For over forty years I've been involved in building things which ultimately go into things that fly and/or blow up. We do quite a bit of shock and vibe testing on most everything we build. Big vibe tables that look like a huge woofer facing upwards with a plate on it to hold an assembly down while completely wired up to electrical test equipment. Beyond that we have ESS (environmental) test chambers fed by liquid nitrogen so that the circuit under test can be thermal cycled up and down from -30 degrees C to +150 degrees C. Quite a few of these circuits are very complex containing a plethora of cap's resistors, diodes, transistors, BGA's, and with RF content as well. These circuits have to provide communications, video, GPS, etc...all while bouncing off the deck of an aircraft carrier, or being dropped from the likes of a B52. A CCA (circuit card assembly) in a hifi system lives a much easier life, so that is why this is somewhat amusing to me. Then again My Naim ND555 DAC/Streamer has its main CCA's mounted to brass plates weighing over five pounds each which are in turn are suspending on springs. When I was researching the unit prior to purchase, I found that to be amusing as well. It does produce lovely music.

The Individual who worded the following quoted description or approved the wording of the following, is with a substantial career training to be an authority and is many many years involved in R&D into Acoustics and Quality of a Produced Sound. 

There are measures described and which are also adopted to be used, that strongly suggest there is mitigation needed for the influence of local ambient energies and what is to be imparted on a selection of electronic components.    

 " The Chiara’s crossover is a masterful combination of minimalist theory and the highest quality execution. Not only is the bass-mid leg run wide open, relying entirely on the superior mechanical performance of the drive unit (and its superior mechanical termination by the cabinet) the high-pass element employs only the highest quality Mundorf / Dueland Cu Cast components, all hard-wired with highest quality silver alloy cable. The topology itself is unique, based on not just output level, but dispersion through the transition point. Once carefully hand built, the entire crossover is then “potted” in resin to protect its critical components from mechanical energy. But that’s not all. By including an EMI absorbent material in the resin, we significantly reduce RFI/EMI affects on the crossover, as well as creating an RFI sink to prevent the speaker acting as an entry point or aerial, allowing EM energy to contaminate the rest of the system. Finally, the potted crossover is coupled to its own dedicated acoustic labyrinth, thus preventing it from becoming a single resonant lump. "

@pindac 

I appreciate your post. 

Microphonics is a known and documented phenomenon, chiefly relating to vacuum tubes. Once one understands how tubes are made and how they work, it's not hard to understand why. But the effects of microphonics are bound to be more... subtle when it comes to SS circuits, including PCB-mounted ones per OP.

Hence my curiosity with regard to the actual electromechanical processes involved in the perceived sound degradation.

Again I ask: If vibrations, let alone micro-vibrations, have a deleterious effect on the sound quality of non-mechanical, non-vacuum-tube components, then why aren't speakers' passive crossovers externalized? At the very least high-end ones'?

@devinplombier has made the statement:

" The question (asked more than once but not answered yet) remains, do these vibrations affect the sound quality of purely electronic audio components (say, amps or preamps as opposed to analog mechanical transports such as turntables)? "

In all my time working with TT’s and working towards a TT that is having a condition that protects the Stylus from not being in contact with the LP Modulation, where the environment the Stylus functions in is not optimised for the Interface to occur. I have never been involved in a discussion that suggests a component used in a electronic circuit is a cause for a concern and should be found and eradicated for the negative effect produced.

A component used in a electronic circuit has been made known to be responsible for a failing found in a Turntable, that has not been delivering an optimised performance.

My experiences are simplistic, End Sound being produced can be tidied up and be able to present with a increased attraction towards the sound, when audio devices are mounted on an Isolation that functions satisfactorily in the environment is is selected to be used in.

If the system user is looking for the only sound wanted to be heard, to be produced as a result of the Audio System being Operated. Where sound produced comes from an amplified electric signal tracking through a range of Circuits laid out to a certain Topology and in conjunction with Cables. What is being effected by the addition of Isolation to be referred to as a Tidied Up End Sound?

I have experienced external Isolation taken to within the Chassis and then focused on a few select Components and can only say from my having experienced the end result, discernible changes were detected and the improvement made was quite discernible.

I have not got any Objective Data to substantiate what I making known.  

Yes, it all matters, for the better. There is much available to read on the subject. Microphonics is for real, and taming/reducing/eliminating them, is audible to my ears, in every case. Whether it is measurable, well, this is a common argument that continues to go on forever. Measurements vs hearing? Enjoy! MrD.  

@mrdecibel 

I would hope no one questions the fact that certain components emit vibrations. Transformers, as you pointed out, are a prime example.

The question (asked more than once but not answered yet) remains, do these vibrations affect the sound quality of purely electronic audio components (say, amps or preamps as opposed to analog mechanical transports such as turntables)?

If so, it would be interesting to understand the mechanisms through which sound quality is negatively impacted.

Electronic components are known to perform to spec under harsh conditions. Witness automotive, aerospace, etc. applications.

In the hifi world, ordinary, inexpensive components, passives and semiconductors, are routinely exposed at length to extreme vibration and shaking in plate amps and crossovers. It is not known that these devices’ performance is negatively impacted in any way; in fact, if it were, you could be certain that passive crossovers in all high-end speakers would be outboarded to separate enclosures, and obviously that’s not the case.

I am actually really interested in learning about this.

I modify, dampen quite a lot inside a chassis, even those with point-to-point wiring. I start with isolating the onboard power supply transformer from the chassis, as all transformers vibrate / resonate, which is one of the reasons transformers are "potted" in some designs. I use many different materials, such as a Dynamat type product and some heat pipe tape. Types of silicon are also excellent. Ignore those nonbelievers. Amazing what chassis damping can do for the performance. Enjoy! MrD.

@panzrwagn “what frequencies did the micro-resonances occur?”

Don’t hold your breath or bank on an answer

Tubes can have microphonics, and they are easily measured and heard. Soli state, not so much. P-P wiring does away with PCBs, but the wires can ring - audibly and measurably in a P-P wired tube amp also. So at what frequencies did the micro-resonances occur? You can change the frequencies by mass loading the PCB or you can absorb them by mounting the PCB on Sorbothane.

@mylogic - +1 for your powers of recall/association. Now you mention it, yes - I do indeed remember that discussion.

Let's see if we find out this time.

I note that it has a PCB, so all the point to point wired tube amp owners can rest easy in their beds.

@yoyoyaya Holy Grail Record

Do you remember a previous discussion about a rare $1,200 record for customs declaration. We never found out what that record was either.

@mylogic. RIP Brian Wilson.

I'm glad you took my comments in the spirit they were intended.

I'm pickin' up good micro vibrations, she's giving me micro excitations - doesn't have quite the same ring to it...

@yoyoyaya Tony ha ha ya ya

This discussion is as nuts as mine. I think it may be a good idea to start another one…..”Are there any amplifiers you just can’t listen to?”

The OP avoids direct questions so perhaps the amp should just be buried along with the hidden evidence asked for.

I’m thinking of good vibrations… it’s giving me ex-cit-tations… blab blab blab blab.

My friends don't call me TonyYaYa for nuttin:))

@yoyoyaya 

The best answer yet. After filling with lead shot, chuck it all in the sea gangster style. That’s the best way to get rid of problems.

@OP. Fill the amp with a plastic bag full of lead shot. 

Excellent!  

This is the sort of logical, fail proof, easy to do fix I was looking for!  

Thank you 😊

Townshend Seismic podium are best for any damping or vibration issues but being large, they will not fit inside the amp. So you will need to move the PCB out of the amp by extending any cables attached to the PCB and lay it on the podium.

These podiums also need a minimum weight to be effective. So just add 10-20kg of weights on top of the PCB.

@jasonbourne71 +100

Some of the Best Tube Amp's are Point to Point Soldered, no Circuit Boards and a Schematic that is designed with a Topology for the shortest Signal Path achievable that does not generate noise.

Start adding components to such a Circuit and there is still be the likelihood Microphonics is able to be produced, hence  those in the know and experienced in addressing such matters are quite confident their methods for attaching a part to a chassis, has addressed the issue and is to be a component fitted with an Isolation as part of the mounting.

It is best to take on the idea, it is the Component that has a Microphonic not the Part that enables it to be added to the circuit.       

As a debate about whether these vibrations exist at all seems to be brewing, I’ll throw out my solution:  avoid amps with printed circuit boards.

@pindac is correct, there are any number of companies concerned with this, I presume they did due diligence. My Joule Electra pre did this with signal board containing tube sockets, I could see how this could reduce tube microphonics.

@bruce19 +1

To OP,  However you determined this phenomenon, will you be able to tell if "the cure" works as advertised?

I would absolutely do the least intrusive remedy. Simply to ease your brain.

A healthy amount of blue tack placed strategically might be your ticket. Let us know

Or if you're all in on this...get a tube of green glue and spread it liberally on the offending board. Beware it will wander.

This poster is not responsible for any misadventures you may have.

Regards,

barts

How did the OP determine that these mysterious "micro-vibrating circuit boards" had an impact on sound? 

I have my personal doubts and feel it's just creating another excuse for substandard music reproduction from over-engineered, high-end audio equipment.

Enjoy the music and stop being hypercritical of "ghosts" in the system that are less than a rounding error in the reproduction chain.

A question for someone to ask, who doubts PCB's pick up Vibration which can be detrimental to the Signal being generated and transferred.

Ask Audio Note why they are having PCB's produced from Panzerholz, which as a a material has the value of the intrinsic properties for Damping/Dissipation well documented.

Ask Taiko why there are components used in their Topology that are Interference Fit into a Panzerholz Periphery Ring. 

I would feel quite comfortable with the notion, both AN and Taiko are making the designs available as a result of Objective Evaluation and not the typical methodology seen on forum, which usually equates to voicing ones "Contempt Prior to Investigation"     

@carlsbad2 

How did you identify a problem with micro-vibrations?

@vinylfun 

Measuring was easy 😊

@vinylfun

Pray tell, how did you measure the micro-vibrations?

I'm somewhat embarrased to say, that a few years ago I was 'experimenting' with a couple of Naim pre-amps, a 122x and a 202(x?) (both garbage btw), and both had 'floating' main boards. They, Naim, even went so far as to say in the owners manual that movement of the DIN sockets was normal and supposed to be that way, as they believed that a floating MoBo gave better sonics. Maybe this is where the OP is getting his ideas from?

Having said that, and I'm in no way endorsing or agreeing with the practise; the bat sh*t crazy people at Naim also have a machine that SHAKES their cables - yes, all it does is hang the cables vertically in a tall frame and shake them vigorously; again claiming sonic benefits!

There's also someone on the tube (! where else!) who recomends that rear panel sockets on DACs and pre-amps should have their retaining screws loosened slightly so they don't 'grip' and hold them securely to the circuit board they're attached to, claiming real sonic benefits from decoupling the sockets from the chassis. This is easily done should anyone wish to try it, as it's easily returned to standard.

First, how in the world did you determine that this "micro-vibrating Printed Circuit Board" is vibrating?

Second, assuming this isn't absolute hokum, have a professional address the issue.

Lastly, never buy anything from that company again!

 BTW:  what is the name and model number of this alleged amp?

Try Blu-tack putty. Easily removable