DIY - Mods on AMP

Rubber Suspension.

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any particular improvement to be had by suspending the transformer mid air like this?

AFAIK, transformers do have/produce vibrations... good to try... especially for big trans...

Sometimes this is not a good tweak as the rubber feet would eventually deteriorate due to transformer heat and mechanical vibrations.

Also, this will cause the transformer itself to vibrate more at the AC frequency and the power output will be suffer more losses.

Besides, if the transformer itself is going to vibrate so much as to need elastic isolation, then it could be quite a low grade transformer to begin with.

Worse case, if the rubber feet might accidentally defeat the transformer body's grounding, there is a higher risk of electrical hazard as well.

my thoughts the same. some transformer do get really hot that you can't even touch it for more than a few second. the trafo in my avr is the single hottest metal inside the casing. even hotter than the amp's heatsink.

rubber + heat = burning smell. and even smoke.

When I used an Audible Illusions Modulus pre-amp last time, the earlier version, I modded it by removing the integrated transformer and then housing that transformer in an external metal casing (the transformer fitted nicely into one of the DIY metal casing I found in SS2). The modification was simple because the transformer was bolted onto the preamp and other than the incoming power cable connection, only two wires were connected to the power supply PCB. So it was a simple matter of unsoldering those wires. I replaced the wires with high grade 'audiophile' wires (forgot what type though). I thought the mod worked very well indeed with excellent improvement in the sound all over. The AI is a hybrid tube preamp and so is especially susceptible to vibration.

Interestingly, later versions of the same preamp had external power supplies, done pretty much the same way as I DIY'ed mine.

For tube pre and poweramp, it's always better to have separate transformer for the high voltage and low voltage.

For me, I prefer to use transformer as big as possible for it's VA rating. For, heater, I'll use DC regulated .Especially the super fast n quiet switching power supply module from my guru(will post some photo later).

jat wrote:my thoughts the same. some transformer do get really hot that you can't even touch it for more than a few second. the trafo in my avr is the single hottest metal inside the casing. even hotter than the amp's heatsink.

rubber + heat = burning smell. and even smoke.

Hi...

It's been months on this configuration and the devices ( AMP / CDP / TUNER ) are on heavy usage. And do use industrial grade washers, which is not susceptible to heat.

To my ears there is some changes to the SQ but you be the judge of that on your own equipment.

Mugen....there is contact between the tranny and casing via the bolt and nut.

cheers

WongKN wrote:When I used an Audible Illusions Modulus pre-amp last time, the earlier version, I modded it by removing the integrated transformer and then housing that transformer in an external metal casing (the transformer fitted nicely into one of the DIY metal casing I found in SS2). The modification was simple because the transformer was bolted onto the preamp and other than the incoming power cable connection, only two wires were connected to the power supply PCB. So it was a simple matter of unsoldering those wires. I replaced the wires with high grade 'audiophile' wires (forgot what type though). I thought the mod worked very well indeed with excellent improvement in the sound all over. The AI is a hybrid tube preamp and so is especially susceptible to vibration.

Interestingly, later versions of the same preamp had external power supplies, done pretty much the same way as I DIY'ed mine.

separating the power transformer to another case could sometime be unbeneficial also. by separating the power transformer and using cables to connect it to the main casing introduces multiple grounding point. one mistake and there's ground loop all over.
and not to mention long cables introduce higher impedence to the power supply circuit. needs power reservoir cap close to the circuit rather than close to the transformer to provide sufficient reserve power.

but still it's fairly easier (with more benefit) to separate the power section and amp section rather than putting everything inside the same case. my current poweramp (refer to the other thread) also uses separate enclosure mainly because i find it too cramped to put the huge trafo inside the same case as everything else.

but for my next amp think i'll try and integrate everything inside the same case. separate case requires too much space inside the tv cabinet.

noodle88 wrote:For tube pre and poweramp, it's always better to have separate transformer for the high voltage and low voltage.

For me, I prefer to use transformer as big as possible for it's VA rating. For, heater, I'll use DC regulated .Especially the super fast n quiet switching power supply module from my guru(will post some photo later).

for me i prefer not to go overboard with the VA rating. surely higher VA rating means it will run cooler as opposed to a lower rated transformer, but it also means higher loaded (and unloaded) voltage output by the trafo. higher input voltage that have to be regulated and higher voltage to be handled by the capacitors.

E-I core (especially) have very bad load regulation.
100VA loaded at 50% (in example) could be outputting 13V when it's rated at 12V. slap in a 500VA (now loaded at 10%) and it could easily output 15V-16V because it's being so easily loaded.
if capacitors around it are rated at 16V, with some power spike then bye bye capacitors.

wingman wrote:
Hi...

It's been months on this configuration and the devices ( AMP / CDP / TUNER ) are on heavy usage. And do use industrial grade washers, which is not susceptible to heat.

To my ears there is some changes to the SQ but you be the judge of that on your own equipment.

Mugen....there is contact between the tranny and casing via the bolt and nut.

cheers

maybe i will try it out since rubber washers are so cheap.
if it doesn't sound beneficial then can always remove it.

Jay,
I'm don't know what u mean. Normally a capacitor input power supply will give out 1.414 times of the original ac voltage after diod rectifier. For a 12v ac input will give out 16.9v dc output. U can't use a 16v rating cap there, I'll use 25v rating ones. If u only get 13vdc for a 12v ac input, u may under spec your transformer.

I prefer to use choke input power supply.

anyone ever do diy from akai M8 to a mono block amp before?
pls share you experience

thanks in advance

Transformer is hot, by using aluminium or Cu casing helps to reduce the heat, as AL & cu can transfer heat faster, so the whole casing act as heat sink as well.

So i was reading on one of he internet based hifi forums that the transformer & power supply caps in amps, dacs, cd players, generate vibration that muddies the sound quality.

Forgive me if my hifi terminology is inaccurate. My electronics knowledge is very limited.

What i did do, was to cut small pieces of Dynamat...i got this from KK Lau car audio shop. you could get similar butamine sheets in most of the bigger car audio dealers. it's about RM190 or so a sheet.

I stuck these small pieces on to the transformer of my power amp, my dac, and my cd player. i have a Buffalo II from twisted pear.

I also stuck small pieces of dynamat on to the caps in what i assumed to be the caps in the power supply.(the bigger beasties within the chassis, near the transformer).

I went on a limb and applied a small piece on to what looked like the crystal clock on the dac.

I am one of those cloth eared sods who strains to hear a difference. I truly love my MMGs because they allow me to hear a difference. I got a set of Black Diamond Racing Cones 3 under my cd player , and quite honestly i can't really notice much difference with and without them. If i were to do A-B testing with the cones and without, i would probably fail. I can, however, hear a difference with cones under my speakers.

I mention this so you will know a little about my ability to discern changes in set up.

This morning, once i had done the above dynamat thing, i warmed up the system (Eastland sound cd player as transport, going into Buffalo ii dac, into home made preamp, into Vincent 330 power amp. Interconnect Cables by DH labs, Analysis plus and power cables by Gotham), i sat transfixed, in utter disbelieve. When it came time to bet my bum out of the chair and off to work, i almost could not.

A layer of white sheen that i did not even know was there was removed. The music flowed so so well, some 'strain' that also i did not know was there was similarly removed, leaving the music to be better focused, i was able to decern layers, locate individual voices in the space before me, and notice how wide the sound stage was. I suspect this was always there, but 'clouded' by noise/glare.

Oh my i can't wait to go home this evening.

bal.

Bal....

These are small doses of "DIY" stuff that brings pleasure to the ears....sweat at first....but its a tangible pleasure...

Did you say you stuck this on to your "tranny" or "CAPS"...do take in consideration of heat dissipation from any one of these items. Would it restrict the heat dissipation....?

You may get one advantage but may incur another disadvantage.... or I could be wrong in my observation all together.

Thats my two cents of an opinion.

Thanks for sharing.....

cheers

hi Moderators....

The timings of the posts is not right .....

Wingman,
zoom zoom. The trannies (in amp, dac and cd player) all covered in plastic save for the top metal plate. So that's were i stuck the dynamat, on the top metal plates.

For the larger caps, i cut a thin strip of dynamat and stuck it to the side of the cap, smaller caps i just stuck a wee small piece to the tops of the caps.

Plenty of room for them to breath me thinks...


Bal.

Bal...

No worries. Just my observation.

Enjoy the new realm that your mods have taken you....

cheers

Thanks W,
makes me feel safe and welcome to share. Where are you located? If in kl some where perhaps we could meet and exchange notes...

Bal 012-3058090

Instead of dynamat I use bluetack.

bal wrote:So i was reading on one of he internet based hifi forums that the transformer & power supply caps in amps, dacs, cd players, generate vibration that muddies the sound quality.

Forgive me if my hifi terminology is inaccurate. My electronics knowledge is very limited.

What i did do, was to cut small pieces of Dynamat...i got this from KK Lau car audio shop. you could get similar butamine sheets in most of the bigger car audio dealers. it's about RM190 or so a sheet.

I stuck these small pieces on to the transformer of my power amp, my dac, and my cd player. i have a Buffalo II from twisted pear.

I also stuck small pieces of dynamat on to the caps in what i assumed to be the caps in the power supply.(the bigger beasties within the chassis, near the transformer).

I went on a limb and applied a small piece on to what looked like the crystal clock on the dac.

I am one of those cloth eared sods who strains to hear a difference. I truly love my MMGs because they allow me to hear a difference. I got a set of Black Diamond Racing Cones 3 under my cd player , and quite honestly i can't really notice much difference with and without them. If i were to do A-B testing with the cones and without, i would probably fail. I can, however, hear a difference with cones under my speakers.

I mention this so you will know a little about my ability to discern changes in set up.

This morning, once i had done the above dynamat thing, i warmed up the system (Eastland sound cd player as transport, going into Buffalo ii dac, into home made preamp, into Vincent 330 power amp. Interconnect Cables by DH labs, Analysis plus and power cables by Gotham), i sat transfixed, in utter disbelieve. When it came time to bet my bum out of the chair and off to work, i almost could not.

A layer of white sheen that i did not even know was there was removed. The music flowed so so well, some 'strain' that also i did not know was there was similarly removed, leaving the music to be better focused, i was able to decern layers, locate individual voices in the space before me, and notice how wide the sound stage was. I suspect this was always there, but 'clouded' by noise/glare.

Oh my i can't wait to go home this evening.

bal.

There is in fact an explanation for the phenomenon you describe and why damping mechanical resonances may improve the sound. Morgan Jones in his book Valve amplifiers 3rd Edition gives a good explanation for this at pgs 227 and 228 for capacitors.