and this is how everything is looking in real life....
you can see the same red dots in the second and third picture - they are painted in order for us to see them and to measure the temperature of the plates....in second picture there is almost no iduction in the plates and in the first we have the induction..
SO - stainless steel plates are no good for protecting our equipment from EMI...
the transformer station is 110/10kV facility with 2500A as a maximum current flowing through 10kV bussbars
you can see the same red dots in the second and third picture - they are painted in order for us to see them and to measure the temperature of the plates....in second picture there is almost no iduction in the plates and in the first we have the induction..
SO - stainless steel plates are no good for protecting our equipment from EMI...
the transformer station is 110/10kV facility with 2500A as a maximum current flowing through 10kV bussbars
Attachments
Destroyer X Amplifier
Carlos
Why all the talk about steel plates for shielding the modules ?
Surely if a Class A 15W/Channel with it's much higher continuous ripple current, can use a low flux toroidal transformer in the same case without any induced hum problems, then why should your
amplifier have any problems, provided due care is taken with PSU wiring and layout ? You already have 47uF capacitors and 82 ohm resistors in the front end. Douglas Self in his amplifiers advocates a 10 ohm, 1.000uF combination in the -VE rail supply only, Perhaps increasing the 47uF capacitors to 100uF would give a similar result ? IF NEEDED !
SandyK
Carlos
Why all the talk about steel plates for shielding the modules ?
Surely if a Class A 15W/Channel with it's much higher continuous ripple current, can use a low flux toroidal transformer in the same case without any induced hum problems, then why should your
amplifier have any problems, provided due care is taken with PSU wiring and layout ? You already have 47uF capacitors and 82 ohm resistors in the front end. Douglas Self in his amplifiers advocates a 10 ohm, 1.000uF combination in the -VE rail supply only, Perhaps increasing the 47uF capacitors to 100uF would give a similar result ? IF NEEDED !
SandyK
Re: Destroyer X Amplifier
Hey sandyK,
Harbuch is about 7 minutes from me, probably do it in 5 on a good day, so you must be close by. I am a Mt Colah/Kuring-gai boy. Have you bought a Harbuch toriods recently, they have gone up significantly, about $55 for a 160VA. Still worth it I guess but you could get the same rating toriod from Electus Distribution for $25 to $30 for 5 up.
regards
sandyK said:
Hey sandyK,
Harbuch is about 7 minutes from me, probably do it in 5 on a good day, so you must be close by. I am a Mt Colah/Kuring-gai boy. Have you bought a Harbuch toriods recently, they have gone up significantly, about $55 for a 160VA. Still worth it I guess but you could get the same rating toriod from Electus Distribution for $25 to $30 for 5 up.
regards
Destroyer X Amplifier
Greg
I am just down the road from Hornsby Hospital towards Westfield shopping centre.
I don't need that many transformers, but for general purpose use, I get them from Jaycar at Hornsby using a trade card. For the important ones, my friends and I go to Harbuch.
I bought another dual winding low flux transformer there recently, and I did notice the price increase. Most imported Asian transformers are reputed to use poor quality iron, which may help explain the radiated noise from them.
BTW, if you are contemplating using 600V HEXFRED diodes or similar fast types, be aware that even if they appear to be more than adequately rated current wise, that their surge ratings are much lower than the usual 400V 35A BR. If the reservoir capacitors are large, you may need to use a "surge limiter" for switch on. At least one forum member has reported them failing.
Alex
Greg
I am just down the road from Hornsby Hospital towards Westfield shopping centre.
I don't need that many transformers, but for general purpose use, I get them from Jaycar at Hornsby using a trade card. For the important ones, my friends and I go to Harbuch.
I bought another dual winding low flux transformer there recently, and I did notice the price increase. Most imported Asian transformers are reputed to use poor quality iron, which may help explain the radiated noise from them.
BTW, if you are contemplating using 600V HEXFRED diodes or similar fast types, be aware that even if they appear to be more than adequately rated current wise, that their surge ratings are much lower than the usual 400V 35A BR. If the reservoir capacitors are large, you may need to use a "surge limiter" for switch on. At least one forum member has reported them failing.
Alex
sandyK,
I was born in that hospital, many years ago.
Just incase you don't know, Electus Distrubution are Jaycar's distributors, so you get the same stuff and even cheaper prices, usually 50% to 60% of the Jaycar price. You have to pick up from Silverwater though.
On the DXamp I'm using an old AKSA psu, so it works like a charm.
regards
I was born in that hospital, many years ago.
Just incase you don't know, Electus Distrubution are Jaycar's distributors, so you get the same stuff and even cheaper prices, usually 50% to 60% of the Jaycar price. You have to pick up from Silverwater though.
On the DXamp I'm using an old AKSA psu, so it works like a charm.
regards
Destroyer X Amplifier
Greg
I have been to Silverwater before Hornsby opened. With my proximity to Hornsby, and the smaller quantities that I need, by the time you factor in petrol and travel time, it's usually not worth it. BTW, Gary Johnston personally delivered to me at work, the kit for the old ETI5000 Mosfet Amplifier. He had just bought out Jonathon Carr and Son's store in Sussex St. Sydney.
Regards.
Alex
Greg
I have been to Silverwater before Hornsby opened. With my proximity to Hornsby, and the smaller quantities that I need, by the time you factor in petrol and travel time, it's usually not worth it. BTW, Gary Johnston personally delivered to me at work, the kit for the old ETI5000 Mosfet Amplifier. He had just bought out Jonathon Carr and Son's store in Sussex St. Sydney.
Regards.
Alex
Thanks Sparkle...was good to see your images
People can install metalic caps over the transformer.... making some holes (small in diameter) to allow convection cooling.
I had better results with those caps non grounded...alike a magnetic barrier that will "ressonate" and absorb magnetic flux.
Also, grounded will work...but...i had better results having no metalic connection, no electrical connection into the chassis...or the transformer's metalic block.
This will finish with your magnetic problems....you will be able to install your boards at the transformer sides....if protected this way...having not electrical contact with the ground...you hum induced will be extremelly small.
Attention....steel metal will be needed, not other material...that one makes oxide very fast!
regards,
Carlos
People can install metalic caps over the transformer.... making some holes (small in diameter) to allow convection cooling.
I had better results with those caps non grounded...alike a magnetic barrier that will "ressonate" and absorb magnetic flux.
Also, grounded will work...but...i had better results having no metalic connection, no electrical connection into the chassis...or the transformer's metalic block.
This will finish with your magnetic problems....you will be able to install your boards at the transformer sides....if protected this way...having not electrical contact with the ground...you hum induced will be extremelly small.
Attention....steel metal will be needed, not other material...that one makes oxide very fast!
regards,
Carlos
Attachments
Sandy.... the reason to remember folks...not you in special, is because inox is more
pretty...and people loves to make things to look good...so....copper and inox is a good option... better if avoided those things into this special sittuation, were transformers, very near boards, can induce enormous noises into the audio circuit.
Standard, normal composition, cheap steel will work better...here called 1020 or 1040 steel, will work fine...2 mm thick will be better.
The metal thickness is important.... the more thick, better will be the magnetic flux beeing blocked.... absorved, or "eated"
Sandy..you seem to know almost everything...so.... as knowledge seems not to be your problem.... hold the soldering iron man...and go ahead.
And enjoy Dx amplifier... a fine, simple and cheap amplifier...good to high knowledge people too.
DO it yourself forum, pré-supposes we gonna do something...and this is lovely, as we have, despite the forum message, tons of Supervisers, Top qualified Engineers, Theorists of first level, Around the clock consultants, figther group of discussers and some pirate parrots too (the one's repeat things readed)...ahahahaha.
You, as a constructor, is welcome....as an Aussie...twice welcome!!!....beeing Greg near friend, 500 times welcome!!!
This thread was made for constructors...also for testers.
regards,
Carlos
pretty...and people loves to make things to look good...so....copper and inox is a good option... better if avoided those things into this special sittuation, were transformers, very near boards, can induce enormous noises into the audio circuit.
Standard, normal composition, cheap steel will work better...here called 1020 or 1040 steel, will work fine...2 mm thick will be better.
The metal thickness is important.... the more thick, better will be the magnetic flux beeing blocked.... absorved, or "eated"
Sandy..you seem to know almost everything...so.... as knowledge seems not to be your problem.... hold the soldering iron man...and go ahead.
And enjoy Dx amplifier... a fine, simple and cheap amplifier...good to high knowledge people too.
DO it yourself forum, pré-supposes we gonna do something...and this is lovely, as we have, despite the forum message, tons of Supervisers, Top qualified Engineers, Theorists of first level, Around the clock consultants, figther group of discussers and some pirate parrots too (the one's repeat things readed)...ahahahaha.
You, as a constructor, is welcome....as an Aussie...twice welcome!!!....beeing Greg near friend, 500 times welcome!!!
This thread was made for constructors...also for testers.
regards,
Carlos
Destroyer X Amplifier
Carlos
Are you sure you don't men tin plate, as in canned food ?
Otherwise you would need Clark Kent , AKA Superman, to bend the steel. and a blow torch to solder the corners !
O.K. I exaggerate just a little bit, but you know what I mean.
It's hard enough to make a box like that,even with aluminium.
Perhaps it might be easier to fit a copper strap to the transformer ? Or won't that work ?
SandyK
Carlos
Are you sure you don't men tin plate, as in canned food ?
Otherwise you would need Clark Kent , AKA Superman, to bend the steel. and a blow torch to solder the corners !
O.K. I exaggerate just a little bit, but you know what I mean.
It's hard enough to make a box like that,even with aluminium.
Perhaps it might be easier to fit a copper strap to the transformer ? Or won't that work ?
SandyK
We both loves to exagerate...so...negative!...not that beer can or something alike
This will need some professional help to cut, bent and solder....auto workers, those ones repair car bodies can do that.
Well...metal workers.
I had, down seventies, enormous problems with noises from a motor.... was beeing captured by a phone magnetic cartridge... this was the only way i had to finish with those noises.
Noise were enormous...even with amplifier volume closed...we could listen some noise.... was entering pick up shield, tone arm, shielded cables and doing enormous mess.
I ordered the steel can to a metal worker...and finished!...volume could be bigger than 75 percent without listen the noise.... only perceive going near the speaker...ears distance was some inches from the speaker to listen the induction noise.
Some big problems needs big solutions....the amplifier case Nordic wants to use will force him to install circuit boards near the transformers...a big problem, as he will listen noises together music.
Have you readed the thread Sandy?
regards,
Carlos
This will need some professional help to cut, bent and solder....auto workers, those ones repair car bodies can do that.
Well...metal workers.
I had, down seventies, enormous problems with noises from a motor.... was beeing captured by a phone magnetic cartridge... this was the only way i had to finish with those noises.
Noise were enormous...even with amplifier volume closed...we could listen some noise.... was entering pick up shield, tone arm, shielded cables and doing enormous mess.
I ordered the steel can to a metal worker...and finished!...volume could be bigger than 75 percent without listen the noise.... only perceive going near the speaker...ears distance was some inches from the speaker to listen the induction noise.
Some big problems needs big solutions....the amplifier case Nordic wants to use will force him to install circuit boards near the transformers...a big problem, as he will listen noises together music.
Have you readed the thread Sandy?
regards,
Carlos
Re: Re: Destroyer X Amplifier
Hi Greg and Sandy,
I use Harbuch's transformers all the way over here in Perth. Quality gear, and the guys are good to deal with over the phone and can't do enough to make sure you get the transformer you want if it's a special build. As an example, a 225VA 2x21V was only $7 for freight, so that's pretty good! A 400VA 2x25V was $11 freight. Not bad for ~ 3KG over a few thousand kilometres!
Cheers
Stuey
Greg Erskine said:
Hi Greg and Sandy,
I use Harbuch's transformers all the way over here in Perth. Quality gear, and the guys are good to deal with over the phone and can't do enough to make sure you get the transformer you want if it's a special build. As an example, a 225VA 2x21V was only $7 for freight, so that's pretty good! A 400VA 2x25V was $11 freight. Not bad for ~ 3KG over a few thousand kilometres!
Cheers
Stuey
I'd expect it be hard with alu, but its not realy a flexible metal...
The only metal sheets I have are old PC cases... you know the side plates...., guess thats mild steel or something...
I don't realy mind makeing a seperate box for the Transformers... At least I will be able to carry my own amp this way... As it is, without a case, these components are allready 20+ kg, if I had to take a guess...
The hum induced is very little, testing from about 50cm away I can hear it... In fact its pretty hard to hear above the fridge and the computer's background noise...
But I will have to wait till I feel better to do construction...
Didn't know it would hurt this much to quit smokeing... its like the worst flu I ever had, everything is sore from my ears down... everything feels raw inside... and I have a rotten wisdom tooth cutting away at the side of my tongue, which I can't have removed before I have my throat scoped... and then only if I don't have an arthritis flare-up. Please pray for me, even if just a quick one.
Only good thing that came from it so far is I have not had a single cigarette since mothersday, and my mind feels like I have never smoked before... I experienced this once on acid... I have no mental longing or association with cigarettes anymore... my doctor said it is one of the strongest cases he has seen for the power of the mind... and I was absolutley the worst kind of chainsmoker you have seen...
The only metal sheets I have are old PC cases... you know the side plates...., guess thats mild steel or something...
I don't realy mind makeing a seperate box for the Transformers... At least I will be able to carry my own amp this way... As it is, without a case, these components are allready 20+ kg, if I had to take a guess...
The hum induced is very little, testing from about 50cm away I can hear it... In fact its pretty hard to hear above the fridge and the computer's background noise...
But I will have to wait till I feel better to do construction...
Didn't know it would hurt this much to quit smokeing... its like the worst flu I ever had, everything is sore from my ears down... everything feels raw inside... and I have a rotten wisdom tooth cutting away at the side of my tongue, which I can't have removed before I have my throat scoped... and then only if I don't have an arthritis flare-up. Please pray for me, even if just a quick one.
Only good thing that came from it so far is I have not had a single cigarette since mothersday, and my mind feels like I have never smoked before... I experienced this once on acid... I have no mental longing or association with cigarettes anymore... my doctor said it is one of the strongest cases he has seen for the power of the mind... and I was absolutley the worst kind of chainsmoker you have seen...
Destroyer X Amplifier
Nordic
Are you 100% certain that it is induced hum ? Douglas Self found that most of the problem was the lower supply rejection of the
-VE supply rail, and inserted a 10 ohm resistor and 1,000UF capacitor to help.It does seem to help with some amplifiers that I have tried it on. You could try a larger value capacitor than at present on the -VE rail at the front end. If that doesn't help, you will have to do some metal bashing as Carlos said.
I hope you have the willpower to get rid of those "coffin nails"
Kind Regards
SandyK
Nordic
Are you 100% certain that it is induced hum ? Douglas Self found that most of the problem was the lower supply rejection of the
-VE supply rail, and inserted a 10 ohm resistor and 1,000UF capacitor to help.It does seem to help with some amplifiers that I have tried it on. You could try a larger value capacitor than at present on the -VE rail at the front end. If that doesn't help, you will have to do some metal bashing as Carlos said.
I hope you have the willpower to get rid of those "coffin nails"
Kind Regards
SandyK
moveing it closer = more hum, moveing it away = less, a little limited by the length of the prototype wireing, but I'm reasonably sure, I'm right. Guess it won't hurt adding some capacitance... there, I have one very nice Vishay cap here somehwere although its also 220uf, its a very nice low ESR type... Don't you just hate haveing to buy bags of 5, always have an odd component left...
I don't regret anything in my life, as much as starting smokeing...
but I realy think I'm mentaly cured now... instead of wanting to ask for a smoke when I see someone else do it... I feel like telling them how stupid they are acting...(but I don't)
I don't regret anything in my life, as much as starting smokeing...
but I realy think I'm mentaly cured now... instead of wanting to ask for a smoke when I see someone else do it... I feel like telling them how stupid they are acting...(but I don't)
Destroyer X Amplifier
Nordic
If the hum level is that low, perhaps you could try a steel plate bolted to the chassis using a couple of small brackets, between the transformer and the modules. Try a piece from a steel can to see if it helps or not. It obviously can't be as effective as Carlos's suggestion, but it may be just enough. If it works you can do the job properly . I presume you are using a steel chassis ?
Regards
SandyK
Nordic
If the hum level is that low, perhaps you could try a steel plate bolted to the chassis using a couple of small brackets, between the transformer and the modules. Try a piece from a steel can to see if it helps or not. It obviously can't be as effective as Carlos's suggestion, but it may be just enough. If it works you can do the job properly . I presume you are using a steel chassis ?
Regards
SandyK
Was a flu that made me stop to smoke Nordic
I turn into more sensitive after that flu.... i realised the way i was stinking..... awfull bad smell..... polutes the house, clothes.
Healing from the flu i felt horror related cigarettes.
This happened 13 years go.... i was smoking alike a steam train for 29 years long... i have burned a lot of amplifiers... as the money i had spent could pay for many..... i burned the money smoking...that money could be better used, not destroying my health... i cannot believe, till today... that i did that for 29 years long.
My Idiotic level cannot be described....my case exceeded any value humans can give...what a damn thing i have made!
My fingers tip were yellow...my teeth too...not only stinking cigaretes, but i used to smoke pipe too.....aaaagh!
regards,
Carlos
I turn into more sensitive after that flu.... i realised the way i was stinking..... awfull bad smell..... polutes the house, clothes.
Healing from the flu i felt horror related cigarettes.
This happened 13 years go.... i was smoking alike a steam train for 29 years long... i have burned a lot of amplifiers... as the money i had spent could pay for many..... i burned the money smoking...that money could be better used, not destroying my health... i cannot believe, till today... that i did that for 29 years long.
My Idiotic level cannot be described....my case exceeded any value humans can give...what a damn thing i have made!
My fingers tip were yellow...my teeth too...not only stinking cigaretes, but i used to smoke pipe too.....aaaagh!
regards,
Carlos
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