Not a good idea Andrew...the increase of NFB cap turns sound awfull
Do by yourself this modification and listen to it.
Make one board original and try some modifications based in your own ideas and listen...but do modifications one by one and compare with the board made using original schematic.... i have tried this modification and sound was terrible.
regards,
Carlos
Do by yourself this modification and listen to it.
Make one board original and try some modifications based in your own ideas and listen...but do modifications one by one and compare with the board made using original schematic.... i have tried this modification and sound was terrible.
regards,
Carlos
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Destroyer,
note I gave three answers to the question.
reduce C1 to 2u2F
reduce C1 to 4u7F
keep C1 @ 10uF.
The questioner has the option to do any of these three.
Read his question and you should realise that he is very likely to buy a smaller value for C1 rather than the 10uF that is shown.
note I gave three answers to the question.
reduce C1 to 2u2F
reduce C1 to 4u7F
keep C1 @ 10uF.
The questioner has the option to do any of these three.
Read his question and you should realise that he is very likely to buy a smaller value for C1 rather than the 10uF that is shown.
I might give it a shot since I have all the transistors already. Any Eagle PCB files somewhere in this thread?
As you know I was planning to use a regulated supply from ThelAudio to adjust the voltage range to exactly 36Vdc under load.I also have made a fixed PSU with an output voltage between 36Vdc and 42Vdc max under load.All my capacitors are rated 20% more than the voltage rail can I use this supply without any problems?
Having the suggested value of capacitance in your electronic supply output
Then you can use it...but keep the condenser..the big ones..as this will give you enormous surge of current when needed.
Without these condensers in the output of your electronic supply, the sound will not be the same...you can try and check by yourself.
Well...different, but this does not mean worse...so...you may like your supply without the huge condensers too...give them a try and make your own choice.
regards,
Carlos
Then you can use it...but keep the condenser..the big ones..as this will give you enormous surge of current when needed.
Without these condensers in the output of your electronic supply, the sound will not be the same...you can try and check by yourself.
Well...different, but this does not mean worse...so...you may like your supply without the huge condensers too...give them a try and make your own choice.
regards,
Carlos
Dx Blame MKII will be released December, 24
The board can be this one you have...only component values will be modified..not cut in tracks and no jumpers made of wiring..
In the case you want an amplifier able to face 2 ohms without problems..this gonna be the one to your to think about.... and i repeat, you will be able to use this board you still have.
The input impedance will increase..the offset will be unmeasurable..the input capacitor will be reduce in value, and this turns easy to use special capacitors, some fashion and high end parts.
The output will have one extra pair... a special board will be made because this extra pair.... but you can run wires if you want it to 2 ohms, installing this way a second pair using the board we already have.... Todd Johnson board or Omar Oash board (German group - the red ones)
Not more than 8 components will have different value... we are still working on it.
Todd Johnson was invited to make the new schematic, Mitchel, Rudi and Omar are already working with me in this new amplifier that will be under test till december...over 2 ohms loads.
Distortion to 2 ohms loads will rise to 0.008% THD, to 8 ohms it will remain measuring (Multisim 10) 0.002% THD
Supply voltage will be the one we are using..but for 2 ohms, it is a good idea to increase the transformer power to 300 to 350 watts, because over 32 ohms you gonna reach 200 watts.
We are still discussing, but we may have special board to this new amplifier.. to be made by Metal.
More details about..please, wait December, 24th.
regards,
Carlos
The board can be this one you have...only component values will be modified..not cut in tracks and no jumpers made of wiring..
In the case you want an amplifier able to face 2 ohms without problems..this gonna be the one to your to think about.... and i repeat, you will be able to use this board you still have.
The input impedance will increase..the offset will be unmeasurable..the input capacitor will be reduce in value, and this turns easy to use special capacitors, some fashion and high end parts.
The output will have one extra pair... a special board will be made because this extra pair.... but you can run wires if you want it to 2 ohms, installing this way a second pair using the board we already have.... Todd Johnson board or Omar Oash board (German group - the red ones)
Not more than 8 components will have different value... we are still working on it.
Todd Johnson was invited to make the new schematic, Mitchel, Rudi and Omar are already working with me in this new amplifier that will be under test till december...over 2 ohms loads.
Distortion to 2 ohms loads will rise to 0.008% THD, to 8 ohms it will remain measuring (Multisim 10) 0.002% THD
Supply voltage will be the one we are using..but for 2 ohms, it is a good idea to increase the transformer power to 300 to 350 watts, because over 32 ohms you gonna reach 200 watts.
We are still discussing, but we may have special board to this new amplifier.. to be made by Metal.
More details about..please, wait December, 24th.
regards,
Carlos
Brazilian group buy have sold 100 kits of boards (7 units)
also 30 kits of parts (picture)...all parts to populate 2 channels.
Also have made a group buy for transformers from Toroid do Brasil...i am not sure but almost 30 guys ordered.
The group buy manager for parts and board is Mitchel
regards,
Carlos
also 30 kits of parts (picture)...all parts to populate 2 channels.
Also have made a group buy for transformers from Toroid do Brasil...i am not sure but almost 30 guys ordered.
The group buy manager for parts and board is Mitchel
regards,
Carlos
Attachments
Some amplifiers in development that will be tortured this week
The Dx Blame MKII
The big one, higher input impedance, smaller input capacitor and other modifications under the board (secret)...able to face 2 ohms impedance..made to difficult loads..supply will remain 35 volts, but power will have to be increase to 350 watts of more to each channel.
The one not assembled yet...the one using Brazilian boards..this one will be the Supercharged, and will use 2N5401 and 2N5551 small transistors and MJE15034 and MJE15035 as drivers... 4 output pairs and higher supply voltage..good for 8 and 4 ohms only (will check this)...it wil use minimum of 2 pairs in the output,and the extra transistors, not seen are below the board...also the input impedance was increased too, on order to allow folks to use smaller input capacitors.
One or two of these ones will be release December, 24.
I am inviting people to produce boards, as Omar is have some impeachment...maybe a temporary one....but we have no hurry, the Dx boards made by German group will fit..people may have to make arrangements under the board or to run wires only..the circuit,the topologie will be keept without changes...only values and parts will be changed, also output power pairs quantity and supply voltage.... a very rational and obvious development.
Todd Johnson original boards will fit too, of course, and also the Brazilian boards that are almost the same as Todd Johnson original boards..only more room to some output parts was produced re arranging some parts.
The third one is the Dx Blame ST 55 volts that gonna be used for comparison purposes.
regards,
Carlos
The Dx Blame MKII
The big one, higher input impedance, smaller input capacitor and other modifications under the board (secret)...able to face 2 ohms impedance..made to difficult loads..supply will remain 35 volts, but power will have to be increase to 350 watts of more to each channel.
The one not assembled yet...the one using Brazilian boards..this one will be the Supercharged, and will use 2N5401 and 2N5551 small transistors and MJE15034 and MJE15035 as drivers... 4 output pairs and higher supply voltage..good for 8 and 4 ohms only (will check this)...it wil use minimum of 2 pairs in the output,and the extra transistors, not seen are below the board...also the input impedance was increased too, on order to allow folks to use smaller input capacitors.
One or two of these ones will be release December, 24.
I am inviting people to produce boards, as Omar is have some impeachment...maybe a temporary one....but we have no hurry, the Dx boards made by German group will fit..people may have to make arrangements under the board or to run wires only..the circuit,the topologie will be keept without changes...only values and parts will be changed, also output power pairs quantity and supply voltage.... a very rational and obvious development.
Todd Johnson original boards will fit too, of course, and also the Brazilian boards that are almost the same as Todd Johnson original boards..only more room to some output parts was produced re arranging some parts.
The third one is the Dx Blame ST 55 volts that gonna be used for comparison purposes.
regards,
Carlos
DX BLAME ST 55 volts
Hello Uncle Charlie,
Where can I get hold of the DX Blame ST 55V version info.....I somehow missed this version. The board, schematic and placement files please.........I will build this amp....some feedback on my DX ST. Used it last week at its first party....the amp performed very good...no problems at all......even without a fan.......very good design and sounding amp.......😀😀😀 I want to build the 55V version please.......need more power so that everybody can hear the DX Corporation playing😛😛😛😛
Regards,
Macd
Hello Uncle Charlie,
Where can I get hold of the DX Blame ST 55V version info.....I somehow missed this version. The board, schematic and placement files please.........I will build this amp....some feedback on my DX ST. Used it last week at its first party....the amp performed very good...no problems at all......even without a fan.......very good design and sounding amp.......😀😀😀 I want to build the 55V version please.......need more power so that everybody can hear the DX Corporation playing😛😛😛😛
Regards,
Macd
Macd, my dear... the release of the Supercharged will be December, 24
There are several guys searching for that in Brazil, and i cannot release the new model because they will stop to build.... they are 100 that have bougth brazilian boards in the brazilian group buy... and 97 have not build, because they are waiting the delivery of packages having parts to assemble (group buy to parts).
They had also group buy to transformers.
If i inform you, then i will be kicking them out... as they want to build this one...because more powerfull (darn powerholics in Brazil)...and i am hiding from them the informations about... i want them, first, to assemble the Dx Blame ST.... some of them track this forum...i dennied them to show schematic before December, 24.
The reality is.... the Supercharged is killing the Dx Blame ST, at least in Brazil.
I am in a struggle to find someone to make a board the way i want...having not only part numbers, but also values printed ...all numbers aligned horizontal, transistors up, positive at rigth side, negative at left side, ground below, with fuses on board, protective resistance on board, small letter to silk screen, big distances in between copper tracks, squared format not long alike a strip...not a rectangle...the Golden ratio from Greeks is what i want.... alike the shape of the Partenon.... well....i could not have boards my way...i think i will have to do by myself..have some offers..but no one of them was acceptable to be transformed in standard board.
Todd Johnson is not making boards anymore..have not time and resigned to make boards.... Metal is having long vacations and may not return to this activity...i am searching for someone to help me...or i will have to learn to make boards by myself (I hate that..i dislike to operate Eagle..do not even know how to).
But i can give you some clues...increase your voltage to 55 Volts (or something around that..even higher).... include one more, or two more pairs (depending if you gonna use 8 or 4 ohms)... substitute all capacitors to 64 volts units or higher voltage..substitute all transistors by higher voltage versions, alike 2N5401/5551...use MJE15034/15035 as drivers and second VAS (or other that can hold more than 120 volts from colector to emitter)...use good heatsinks in the drivers, also in the second VAS...use good power transistors..the big Sankens or the ones i am attaching.,,, each extra power transistor must have their own power emitter resistances, and also stop base resistances.
The Supercharged can use the same board as the Dx Blame ST, runing some wires to extra transistors..but there are several other modifications in the circuit values too.... and will be playing today..the torture test will start.
I have Alex mm, but i have to test the circuit first.... Alex may match my needs... despite he use long strip...and this format is not the one i want for this design.
regards,
Carlos
There are several guys searching for that in Brazil, and i cannot release the new model because they will stop to build.... they are 100 that have bougth brazilian boards in the brazilian group buy... and 97 have not build, because they are waiting the delivery of packages having parts to assemble (group buy to parts).
They had also group buy to transformers.
If i inform you, then i will be kicking them out... as they want to build this one...because more powerfull (darn powerholics in Brazil)...and i am hiding from them the informations about... i want them, first, to assemble the Dx Blame ST.... some of them track this forum...i dennied them to show schematic before December, 24.
The reality is.... the Supercharged is killing the Dx Blame ST, at least in Brazil.
I am in a struggle to find someone to make a board the way i want...having not only part numbers, but also values printed ...all numbers aligned horizontal, transistors up, positive at rigth side, negative at left side, ground below, with fuses on board, protective resistance on board, small letter to silk screen, big distances in between copper tracks, squared format not long alike a strip...not a rectangle...the Golden ratio from Greeks is what i want.... alike the shape of the Partenon.... well....i could not have boards my way...i think i will have to do by myself..have some offers..but no one of them was acceptable to be transformed in standard board.
Todd Johnson is not making boards anymore..have not time and resigned to make boards.... Metal is having long vacations and may not return to this activity...i am searching for someone to help me...or i will have to learn to make boards by myself (I hate that..i dislike to operate Eagle..do not even know how to).
But i can give you some clues...increase your voltage to 55 Volts (or something around that..even higher).... include one more, or two more pairs (depending if you gonna use 8 or 4 ohms)... substitute all capacitors to 64 volts units or higher voltage..substitute all transistors by higher voltage versions, alike 2N5401/5551...use MJE15034/15035 as drivers and second VAS (or other that can hold more than 120 volts from colector to emitter)...use good heatsinks in the drivers, also in the second VAS...use good power transistors..the big Sankens or the ones i am attaching.,,, each extra power transistor must have their own power emitter resistances, and also stop base resistances.
The Supercharged can use the same board as the Dx Blame ST, runing some wires to extra transistors..but there are several other modifications in the circuit values too.... and will be playing today..the torture test will start.
I have Alex mm, but i have to test the circuit first.... Alex may match my needs... despite he use long strip...and this format is not the one i want for this design.
regards,
Carlos
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I will invite Alex mm to produce boards soon, but i have some demands
and i am not sure if he will match my needs...as he has his own ideas about.
I have already, some brazilians doing boards..but long strip.... and this is not what i want.
I will invite Mitchel to make brazilian boards too.
Here you can see my demands about.
This board had the original layout from Todd Johnson, small modification made by Miguel Nabuco (Mitchel)...it is all rigth...very well made the original and also the small modifications made..need silk screen having values (not only identification as R1, C3, Q4) and some details..the same board modified will match my need.
I would like to have two versions..one International, made by Alex mm for instance (he will be invited soon) and another brazilian, we gonna see if Soundbuster or Mitchel...the one have time and fill the demands.
regards,
Carlos
and i am not sure if he will match my needs...as he has his own ideas about.
I have already, some brazilians doing boards..but long strip.... and this is not what i want.
I will invite Mitchel to make brazilian boards too.
Here you can see my demands about.
This board had the original layout from Todd Johnson, small modification made by Miguel Nabuco (Mitchel)...it is all rigth...very well made the original and also the small modifications made..need silk screen having values (not only identification as R1, C3, Q4) and some details..the same board modified will match my need.
I would like to have two versions..one International, made by Alex mm for instance (he will be invited soon) and another brazilian, we gonna see if Soundbuster or Mitchel...the one have time and fill the demands.
regards,
Carlos
Attachments
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Dx electronic supply..in the reality, designed by Ampex, down the seventies
Was used to power big Video Tape Recorders..open reel, 2 inches wide tape.
YouTube - DC supply, adjustable and stabilized, a series pass from 70's
regards,
Carlos
Was used to power big Video Tape Recorders..open reel, 2 inches wide tape.
YouTube - DC supply, adjustable and stabilized, a series pass from 70's
regards,
Carlos
I share similar Regulated PSU in thread: http://www.diyaudio.com/forums/solid-state/173462-studio-reference-amplifier-5.html
Regards
Yep...this one is used world wide since the seventies
I am glad to know you're using it.
I build the first in 1975 i think...was for a Radio Transceiver..then several friends asked me to assemble to them...well..there are almost hundred units around..all them worked till now a days.
regards,
Carlos
I am glad to know you're using it.
I build the first in 1975 i think...was for a Radio Transceiver..then several friends asked me to assemble to them...well..there are almost hundred units around..all them worked till now a days.
regards,
Carlos
I received my boards from Rudi's German GB. Now I have some questions about parts... Some of the parts spec'd in the BOM are NOT available and I'm wondering about substitutions...
Any problem with using WIMA film caps - are MKS or MKP preferred???
How about Metal Film resistor (for the 1/4 & 1/2 watt parts)???
Looking forward to putting this together.
Regards,
Any problem with using WIMA film caps - are MKS or MKP preferred???
How about Metal Film resistor (for the 1/4 & 1/2 watt parts)???
Looking forward to putting this together.
Regards,
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