Razorback...needing power, you can bridge amplifiers
You will need a single stage with gain one.....no amplification, only phase invertion.
So...one amplifier will receive the sound directly from the source, the second one will receive the sound inverted by a small circuit.
Into the amplifier's output you will have 4 times more power compared with the single amplifier power...so... Dx standard, two units, connected this way, will produce 200 watts RMS over 8 ohms
Quality is worst..... normally very bad.... you will have a lot of distortions....only punch, only power....no quality.
But, there are applications where people want power, not quality (decibel competition into automobiles)
I do not suggest you to do dear Razorback, but answering you..here is the circuit.
I have not constructed...the risk is yours!
regards,
Carlos
You will need a single stage with gain one.....no amplification, only phase invertion.
So...one amplifier will receive the sound directly from the source, the second one will receive the sound inverted by a small circuit.
Into the amplifier's output you will have 4 times more power compared with the single amplifier power...so... Dx standard, two units, connected this way, will produce 200 watts RMS over 8 ohms
Quality is worst..... normally very bad.... you will have a lot of distortions....only punch, only power....no quality.
But, there are applications where people want power, not quality (decibel competition into automobiles)
I do not suggest you to do dear Razorback, but answering you..here is the circuit.
I have not constructed...the risk is yours!
regards,
Carlos
Attachments
The output signal will be into the positive.... the live output.
You will not use ground.... the power will be into the positive output from those amplifiers.
This is a extremelly easy way to obtain power from every amplifier..but also an easy way to destruct sound quality too.
I do not suggest you to make...just answering your needs..but i do not think this amplifier will result very good.
Not guaranteed!!!
regards,
Carlos
You will not use ground.... the power will be into the positive output from those amplifiers.
This is a extremelly easy way to obtain power from every amplifier..but also an easy way to destruct sound quality too.
I do not suggest you to make...just answering your needs..but i do not think this amplifier will result very good.
Not guaranteed!!!
regards,
Carlos
Attachments
The first problem when bridged is to match the signals to each amplifier
It is hard, because the amplifier loads the single stage, level is not the same...there are problems of impedance (signal transference) and phase too.
Each amplifier will generate its own distortion, in the output you will have both distortions added.
This is not a good idea...also the amplifiers must be the same..and they are never exactly the same.
You will have some phase cancelling sometimes.... interactions because the same supply into both bridged amplifiers.
This is a really big mess.
Not suggested..not guaranteed!
It is up to you friends.
regards,
Carlos
It is hard, because the amplifier loads the single stage, level is not the same...there are problems of impedance (signal transference) and phase too.
Each amplifier will generate its own distortion, in the output you will have both distortions added.
This is not a good idea...also the amplifiers must be the same..and they are never exactly the same.
You will have some phase cancelling sometimes.... interactions because the same supply into both bridged amplifiers.
This is a really big mess.
Not suggested..not guaranteed!
It is up to you friends.
regards,
Carlos
Hi All 
Nordic,
Excellent web site. Well done. If I'm being pedantic I'd say the schematic could do with more spacing in and around the v.reg's. Apart from that everything I've seen and read is simply wonderful
I may have a remote control volume control for you if you're interested. I say may because I've yet to fully test it, also it is very close to the Twisted Pear design - may be a problem.
Anyway, off to play Two Worlds before all those nasty Orc's break through into our reality !!
Nordic,
Excellent web site. Well done. If I'm being pedantic I'd say the schematic could do with more spacing in and around the v.reg's. Apart from that everything I've seen and read is simply wonderful
I may have a remote control volume control for you if you're interested. I say may because I've yet to fully test it, also it is very close to the Twisted Pear design - may be a problem.
Anyway, off to play Two Worlds before all those nasty Orc's break through into our reality !!
Hi Carlos,
I agree with your comments about bridging amplifiers reducing reproduction quality. It can be okay for pop/PA but not home hi-fi.
Where two amps must drive one LS the Quad hi-fi company suggest a low value series resistor connected between each channel and the LS, possibly 0.1 ohms, but I can't be sure.
Other than that it is better to increase the voltage or current capabilities of the entire output stage.
Cheers .......... Graham.
I agree with your comments about bridging amplifiers reducing reproduction quality. It can be okay for pop/PA but not home hi-fi.
Where two amps must drive one LS the Quad hi-fi company suggest a low value series resistor connected between each channel and the LS, possibly 0.1 ohms, but I can't be sure.
Other than that it is better to increase the voltage or current capabilities of the entire output stage.
Cheers .......... Graham.
Yes Graham...it seems that we need to adjust a lot to result fine.
But if think Razorback wants audio for competition...to automobile demolition playing 25 Hertz tones.
Here is a better sound quality option... can go to more than 500 watts into 2 ohms...good to demolition.
Untested real world..not guaranteed!
This was done for a friend..he asked special voltage... i have made and he did not have constructed..it seems to me that people that ask special designs have doubts to construct and ends not assembling.
This was called Dx Bomber!
regards,
Carlos
But if think Razorback wants audio for competition...to automobile demolition playing 25 Hertz tones.
Here is a better sound quality option... can go to more than 500 watts into 2 ohms...good to demolition.
Untested real world..not guaranteed!
This was done for a friend..he asked special voltage... i have made and he did not have constructed..it seems to me that people that ask special designs have doubts to construct and ends not assembling.
This was called Dx Bomber!
regards,
Carlos
Attachments
Enjoy Nordic's home page
goto:
www.dxamp.com
and receive your free ticket to happyness!
regards,
Carlos
goto:
www.dxamp.com
and receive your free ticket to happyness!
regards,
Carlos
Attachments
I am very happy with our forum folks...because of it i found my lost nephew
That is living in London.
In 2004 i have opened a thread.... moderators cooperated and the thread was keept alive into the Solid State for a good time till was moved (of course not a solid stage subject).
Because of that post...asking all Englishmen to help me to find my nephew i could bring him home again, to make contact and to invite him to a brazil Tour that will reach three states into Northeast, Southeast and Center of the Country.
I want to say that was because of this forum that i have found him... will never be able to pay the service forum made to me.... this have no price!
He was lost 23 years long...here is my Nephew.
Dx amplifier now has a "Mergulhão" support, my family name, in London.
His name is James Mergulhão Green
thanks
regards,
Carlos
That is living in London.
In 2004 i have opened a thread.... moderators cooperated and the thread was keept alive into the Solid State for a good time till was moved (of course not a solid stage subject).
Because of that post...asking all Englishmen to help me to find my nephew i could bring him home again, to make contact and to invite him to a brazil Tour that will reach three states into Northeast, Southeast and Center of the Country.
I want to say that was because of this forum that i have found him... will never be able to pay the service forum made to me.... this have no price!
He was lost 23 years long...here is my Nephew.
Dx amplifier now has a "Mergulhão" support, my family name, in London.
His name is James Mergulhão Green
thanks
regards,
Carlos
Attachments
Not only Nordic home page is helping, also Greg Erskine provided us informs in his
home page.
Enjoy the nice work those friends made.
Here the Greg Erskine Dx pages Link:
http://users.tpg.com.au/users/gerskine/dxamp/
regards,
Carlos
home page.
Enjoy the nice work those friends made.
Here the Greg Erskine Dx pages Link:
http://users.tpg.com.au/users/gerskine/dxamp/
regards,
Carlos
Carlos......thank you very much
Hola, como siempre muchas gracias. Han contestado todas mis dudas. Mejor construyo una etapa estereo. Saludos cordiales. Fernando
Hello, like always thank you very much. They have answered all my doubts. Better I construct a stage estereo. Cordial regards. Fernando
Hola, como siempre muchas gracias. Han contestado todas mis dudas. Mejor construyo una etapa estereo. Saludos cordiales. Fernando
Hello, like always thank you very much. They have answered all my doubts. Better I construct a stage estereo. Cordial regards. Fernando
My pleasure Fernando..you are welcome
Bomber is a good brand of brazilian speakers, made for heavy duty use, competition and public adress.
www.bomber.com.br
The site has audio too....visit our factory.
regards,
Carlos
Bomber is a good brand of brazilian speakers, made for heavy duty use, competition and public adress.
www.bomber.com.br
The site has audio too....visit our factory.
regards,
Carlos
Attachments
Nordic and Carlos,
Congratulations for the excelent site http://www.dxamp.com
!!!!!!!!!!
Good and nice work.
............................................................
Please , verify the parts list link :
http://www.dxamp.com/construcion/#
Congratulations for the excelent site http://www.dxamp.com
!!!!!!!!!!
Good and nice work.
............................................................
Please , verify the parts list link :
http://www.dxamp.com/construcion/#
ahahaha...he is out for his lunch..ahahahha
No parts lists...they call BOM......ahahahhaa.
Bom here...this sound..is other thing we use to sit having confort..natural human accessories, a fat cushion we carry in our low back portion.
Not ready Perí...not ready yet..... Nordic has no BOM!
regards,
Carlos
No parts lists...they call BOM......ahahahhaa.
Bom here...this sound..is other thing we use to sit having confort..natural human accessories, a fat cushion we carry in our low back portion.
Not ready Perí...not ready yet..... Nordic has no BOM!
regards,
Carlos
Attachments
Hey guys, still fighting with my PC... formated it yesterday... have nothing on it now exept windows and internet explorer
Finaly got the catalog to work just now, with the help of an old school friend. Now just have to get it to look like the rest of the site, and then I can add the PCBs and parts kits.
Yes, I am sorry, the documents that don't have fileseizes underneath, are not on the server yet... I had bigger fish to fry.
I thank you for your patience... there are also 1 or two small changes I want to make to the files allready there, after some feedback from people....
Thanks e-cat.. you are the second person pointing out that problem with the schematic... It, will get taken care of... the site is still very young. And needs lots of work to get all the information in, that I want... It is basicaly still in skeleton format now.
PS keep me updated on that remote control.
Damn, I am always busy when I don't want to be, got a free set of speakers (large floorstanders) and a cd player for free, from the guy that helped with the catalog scripts this afternoon, don't even have time to test it.
I'd upload pictures, but I have no camera software on the PC yet.
Finaly got the catalog to work just now, with the help of an old school friend. Now just have to get it to look like the rest of the site, and then I can add the PCBs and parts kits.
Yes, I am sorry, the documents that don't have fileseizes underneath, are not on the server yet... I had bigger fish to fry.
I thank you for your patience... there are also 1 or two small changes I want to make to the files allready there, after some feedback from people....
Thanks e-cat.. you are the second person pointing out that problem with the schematic... It, will get taken care of... the site is still very young. And needs lots of work to get all the information in, that I want... It is basicaly still in skeleton format now.
PS keep me updated on that remote control.
Damn, I am always busy when I don't want to be, got a free set of speakers (large floorstanders) and a cd player for free, from the guy that helped with the catalog scripts this afternoon, don't even have time to test it.
I'd upload pictures, but I have no camera software on the PC yet.
Never mind, be happy
You belong to the good side in this life.. if you understand what i mean.... have room to forget, to fail, well... room to be not perfect alike all of us.
There's no problem...everything working fine.
Soon you will have PC working and new speakers playing.
regards,
Carlos
You belong to the good side in this life.. if you understand what i mean.... have room to forget, to fail, well... room to be not perfect alike all of us.
There's no problem...everything working fine.
Soon you will have PC working and new speakers playing.
regards,
Carlos
Attachments
Dx amplifier, the standard one reproduces a very deep bass
Even 1 cicle movement can be appreciated into your speaker motion.... no clicks and no hum into transition and during peak consumption (depends from supply condensers...more than 10000 each rail)
The bass come from the deep troat of the hell voices...very strong....only 50 watts...but may burn your big speaker..be carefull with this small brother.
You can assemble it ugly or pretty...good parts or bad parts...because of topologie and some try and errors researches made, produces nice sonics that many folks appreciates.
Try Dx amplifier....made free for you....has not copyrigth, created based forum knowledge and influenced by very special folks.
regards,
Carlos
Even 1 cicle movement can be appreciated into your speaker motion.... no clicks and no hum into transition and during peak consumption (depends from supply condensers...more than 10000 each rail)
The bass come from the deep troat of the hell voices...very strong....only 50 watts...but may burn your big speaker..be carefull with this small brother.
You can assemble it ugly or pretty...good parts or bad parts...because of topologie and some try and errors researches made, produces nice sonics that many folks appreciates.
Try Dx amplifier....made free for you....has not copyrigth, created based forum knowledge and influenced by very special folks.
regards,
Carlos
Attachments
DX HR2 grounding scheme
Dear Carlos and Nordic,
when looking for schematic changes between the HR2 version on Greg's website, http://users.tpg.com.au/users/gerskine/dxamp/dx hrii amplifier green.pdf
versus the one on Nordic's pages, http://www.dxamp.com/images/DxHRII_amp_sch.pdf,
I noticed a difference in the grounding scheme between the two.
There is this 10 Ohm resistor (Greg: R2, Nordic: R22) connecting the signal earth to power earth, or input ground to analog ground.
First, what is this resistor about?
The difference is this:
In Greg's schematic, signal earth includes the input ground and all preamplification plus the regulators for the preamplification.
In Nordic's schematic, the input ground only connects to the input biasing and the feedback ground.
Did you test both versions? Does it change anything, sonically?
Thanks for feedback on this!
------------
konkret
Dear Carlos and Nordic,
when looking for schematic changes between the HR2 version on Greg's website, http://users.tpg.com.au/users/gerskine/dxamp/dx hrii amplifier green.pdf
versus the one on Nordic's pages, http://www.dxamp.com/images/DxHRII_amp_sch.pdf,
I noticed a difference in the grounding scheme between the two.
There is this 10 Ohm resistor (Greg: R2, Nordic: R22) connecting the signal earth to power earth, or input ground to analog ground.
First, what is this resistor about?
The difference is this:
In Greg's schematic, signal earth includes the input ground and all preamplification plus the regulators for the preamplification.
In Nordic's schematic, the input ground only connects to the input biasing and the feedback ground.
Did you test both versions? Does it change anything, sonically?
Thanks for feedback on this!
------------
konkret
To tell you the truth...this resistance is there because my dear friend Hugh Dean use
it..... said to reduce noises..the lifted ground.
I could perceive absolutelly nothing...same thing..absolutelly the difference of number 6 compared with half dozen... this is concrete audition thing..or KonKret audition..nothing abstract.
I decided to remove everything that was not sounding..but my dear Greg had (those past and early days....long time ago..when first professional styled schematic was made.....well..he made the schematic with the 10 ohms resistance..and was keept there.... and was there monday..and tuesday...and wednesday...and thursday...and them stayed there for ever.... My dear Hugh used...he was my "gurú" related the circuit.... also Doctor "a" used that.... also Doctor "b"...and i decide to keep there..this way people would think i was so intelligent as A or B.
Along the long thread..people entered to defend, others made questions, others said that created more problem than solutions, other said that would explode..that need diodes inverted because misterious unballances could cause unbobtanium losses of evaporated spirits to contaminate the waveshape or non playable sound never recorded......ahahahaha.
Others said that need to be big..very big resistance there.... 10 watts!!!!.... other use diodes to protect.
As i want to say the deep truth...it is there because not bothering..... not for sonic purposes...sounds the same.
Maybe, uses, tradition, group pressure, mania, habits, gimmicks, fashion or other reasons....i was just lazy to remove.... or ask Greg to remove.
But if you remove..some guys will say that cannot remove..have to install...if you install, some guys will say that need to remove...well... some of them love green..i love blue.... and worst are the guys that prefer the yellow.
The smea way we understnad wrods reading the first and last letter... we understand the "whole thing"...globally...same way we understand words written wrong...our brain correct details, small noises, some gaps....and small things do not sounds because brain correct and result the same..... the same way wrods and words can be readable even with failures into the way you write.... have to engage brain..of course.
If this can produce differences..maybe to instruments..... i cannot perceive nothing..so...with that resistance or not...no problems.
My friends said reduce noise...well...the amplifier do not produce any noise with that resistance and without it.
Enjoy Dx in a Konkret way my friend... construct it with the resistance..or without..and do a better job...if doubts about R2 or r22..... create your own number... "222"
ahahahha..... remember, unobtanium is the substract of inexistium.
By the way Konkret... very good name you are using...i love intelligent people...very good idea to use Concrete name
regards,
Carlos
it..... said to reduce noises..the lifted ground.
I could perceive absolutelly nothing...same thing..absolutelly the difference of number 6 compared with half dozen... this is concrete audition thing..or KonKret audition..nothing abstract.
I decided to remove everything that was not sounding..but my dear Greg had (those past and early days....long time ago..when first professional styled schematic was made.....well..he made the schematic with the 10 ohms resistance..and was keept there.... and was there monday..and tuesday...and wednesday...and thursday...and them stayed there for ever.... My dear Hugh used...he was my "gurú" related the circuit.... also Doctor "a" used that.... also Doctor "b"...and i decide to keep there..this way people would think i was so intelligent as A or B.
Along the long thread..people entered to defend, others made questions, others said that created more problem than solutions, other said that would explode..that need diodes inverted because misterious unballances could cause unbobtanium losses of evaporated spirits to contaminate the waveshape or non playable sound never recorded......ahahahaha.
Others said that need to be big..very big resistance there.... 10 watts!!!!.... other use diodes to protect.
As i want to say the deep truth...it is there because not bothering..... not for sonic purposes...sounds the same.
Maybe, uses, tradition, group pressure, mania, habits, gimmicks, fashion or other reasons....i was just lazy to remove.... or ask Greg to remove.
But if you remove..some guys will say that cannot remove..have to install...if you install, some guys will say that need to remove...well... some of them love green..i love blue.... and worst are the guys that prefer the yellow.
The smea way we understnad wrods reading the first and last letter... we understand the "whole thing"...globally...same way we understand words written wrong...our brain correct details, small noises, some gaps....and small things do not sounds because brain correct and result the same..... the same way wrods and words can be readable even with failures into the way you write.... have to engage brain..of course.
If this can produce differences..maybe to instruments..... i cannot perceive nothing..so...with that resistance or not...no problems.
My friends said reduce noise...well...the amplifier do not produce any noise with that resistance and without it.
Enjoy Dx in a Konkret way my friend... construct it with the resistance..or without..and do a better job...if doubts about R2 or r22..... create your own number... "222"
ahahahha..... remember, unobtanium is the substract of inexistium.
By the way Konkret... very good name you are using...i love intelligent people...very good idea to use Concrete name
regards,
Carlos
Attachments
DX HR2 Grounding scheme
Carlos
As you are aware, the purpose of the 10 ohm "earth lift" resistor
is to prevent hum loops when another piece of equipment which is also earthed via it's 3 core mains lead, is plugged into another powerpoint, and a hum results.
Much of the other equipment being plugged into it these days uses only a 2 wire mains lead, so there SHOULD be no problems.
However, these days, more and more ancillary equipment is using a Switchmode Power supply.It is not generally known that this
type of equipment will have an AC voltage on it's earthed side of the RCA output jacks, of between 80-120V AC (230V system) due to a special high voltage capacitor connected between the mains side of the SMPS supply and the "earth" side of the power supply output. Being at low current, it is not dangerous, but may give a "tingle" if you touch the case or output jacks, especially if plugging in leads to an earthed power amplifier. This same AC voltage may also result in a low level hum. In this case, I wonder if the inclusion of an earth lift resistor may worsen the situation ? This may be a question that Graham or Hugh, are better equipped to answer ?
Regards
SandyK
Carlos
As you are aware, the purpose of the 10 ohm "earth lift" resistor
is to prevent hum loops when another piece of equipment which is also earthed via it's 3 core mains lead, is plugged into another powerpoint, and a hum results.
Much of the other equipment being plugged into it these days uses only a 2 wire mains lead, so there SHOULD be no problems.
However, these days, more and more ancillary equipment is using a Switchmode Power supply.It is not generally known that this
type of equipment will have an AC voltage on it's earthed side of the RCA output jacks, of between 80-120V AC (230V system) due to a special high voltage capacitor connected between the mains side of the SMPS supply and the "earth" side of the power supply output. Being at low current, it is not dangerous, but may give a "tingle" if you touch the case or output jacks, especially if plugging in leads to an earthed power amplifier. This same AC voltage may also result in a low level hum. In this case, I wonder if the inclusion of an earth lift resistor may worsen the situation ? This may be a question that Graham or Hugh, are better equipped to answer ?
Regards
SandyK
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