Hi Carlos,
The RAJ board has electrolytics on the PCB, but what I would describe as a 'snake-earth'.
In my own final 'star-earth' design my ground was a genuine star, like the one being worked on by Greg.
I have one large electrolytic per channel rail at the PCB, but this is on the amplifier side of the fuses. Fuses can drop up to one volt peak at signal frequency under full power load, and this is not decoupled at the output devices on the RAJ board.
I also feel that fuses should be on the rear panel of an amplifier chassis, not inside so that a serviceman needs to dismantle and locate simply to replace them.
Cheers ......... Graham.
The RAJ board has electrolytics on the PCB, but what I would describe as a 'snake-earth'.
In my own final 'star-earth' design my ground was a genuine star, like the one being worked on by Greg.
I have one large electrolytic per channel rail at the PCB, but this is on the amplifier side of the fuses. Fuses can drop up to one volt peak at signal frequency under full power load, and this is not decoupled at the output devices on the RAJ board.
I also feel that fuses should be on the rear panel of an amplifier chassis, not inside so that a serviceman needs to dismantle and locate simply to replace them.
Cheers ......... Graham.
Carlos, here's a picture of my changes. I've given different traces different colours.
It's still far from perfect imo, zobel-return should go back straight to main ps-caps (now 10.000 uF per rail).
Also local ps-caps could go back to main ps-caps.
There is now short piece of wire between signal-gnd and central gnd-connection on pcb, a lifting-resistor could be fitted here.
Bigger picture here =>
Explanation of colours:
Red are signal-gnd traces
Black wire(s) are gnd-connection of ps-caps of output-stage.
Light-blue is gnd-traces that were removed
Yellow is zobel-return
Dark-blue is gnd-return of ps-caps for front-end.
Everything is now tied to central gnd-point on left of pcb, from there a single connection to gnd between main ps-caps.
Speaker-gnd is running straight to gnd between main ps-caps.
Greetings from sunny Holland (spring has arrived
)
Klaas
It's still far from perfect imo, zobel-return should go back straight to main ps-caps (now 10.000 uF per rail).
Also local ps-caps could go back to main ps-caps.
There is now short piece of wire between signal-gnd and central gnd-connection on pcb, a lifting-resistor could be fitted here.
Bigger picture here =>
Explanation of colours:
Red are signal-gnd traces
Black wire(s) are gnd-connection of ps-caps of output-stage.
Light-blue is gnd-traces that were removed
Yellow is zobel-return
Dark-blue is gnd-return of ps-caps for front-end.
Everything is now tied to central gnd-point on left of pcb, from there a single connection to gnd between main ps-caps.
Speaker-gnd is running straight to gnd between main ps-caps.
Greetings from sunny Holland (spring has arrived
)Klaas
hehe... the way i have imagined..slowly Dx amplifier go loosing it's own character,
personality...and changes beeing made are making it less and less different from the perfect Aksa 55.
Now the lifted ground..... also used by my friend Hugh Dean...as something very needed...i was avoiding not to make the amplifier with too much things alike.
But friends have perceived better stability this way.
That effect, called reverberation...or sonic body...solid sound that came from low end bass could be found into an Aussie amplifier too, and not only in Aussie unit i have...many amplifier has that sonics characteristic...hard to perceive.... this guy...Klaas, may have a very special speakers and trained years to perceive that.
This sounds good, as i told before in this forum evaluating an Aussie amplifier with lateral fets at the output....this will give you the idea of longer bass...... and this effect i like.
Do not worry about that.... happens in very deep bass...very low frequencies..those not normally founded in normal music...and not a sonic disadvantage, as others amplifiers have much more "effects" than this one...for sure they have... some famous ones have mufled sonics (not too much)..others have harsh sonics (intermitent)..others have not good focus, nor resolution...explaining what i mean:
Two women singing...voices turns mixed in such way that you cannot concentrated in one of the voices to listen it separatelly related other ....brain work of course..but information not too much mixed must be there in the signal source and not destroyed by the amplifier....so...small problems as triangle wave over the audible spectrum are not really defects...are effects.
Of course it is more precise now, without ground problems.... using lift ground (10 ohms) that Greg will include in the last board that is cooking.
You are rigth about fuses Graham....because of that i will sugest people to use a very thin wire soldered in parallel with their fuses...to have a guarantee that resistance there will be keep as low as possible.
Also... condensers, with increase values may be needed to be soldered under the board...or over the board if possible to avoid problems if someone forget to solder those "low resistance auxiliary fuses" there.
Many thanks by your researches guys....RAJ and Klaas...in special Klaas that have constructed and accepted that modification during listening tests....and perceive that klaas have the excelent amplifier...that Krell is in his home..so..he knows what is quality of sound reproduction
I am waiting your news dear nephew Nordic...happy with your progress.
regards,
Carlos
personality...and changes beeing made are making it less and less different from the perfect Aksa 55.
Now the lifted ground..... also used by my friend Hugh Dean...as something very needed...i was avoiding not to make the amplifier with too much things alike.
But friends have perceived better stability this way.
That effect, called reverberation...or sonic body...solid sound that came from low end bass could be found into an Aussie amplifier too, and not only in Aussie unit i have...many amplifier has that sonics characteristic...hard to perceive.... this guy...Klaas, may have a very special speakers and trained years to perceive that.
This sounds good, as i told before in this forum evaluating an Aussie amplifier with lateral fets at the output....this will give you the idea of longer bass...... and this effect i like.
Do not worry about that.... happens in very deep bass...very low frequencies..those not normally founded in normal music...and not a sonic disadvantage, as others amplifiers have much more "effects" than this one...for sure they have... some famous ones have mufled sonics (not too much)..others have harsh sonics (intermitent)..others have not good focus, nor resolution...explaining what i mean:
Two women singing...voices turns mixed in such way that you cannot concentrated in one of the voices to listen it separatelly related other ....brain work of course..but information not too much mixed must be there in the signal source and not destroyed by the amplifier....so...small problems as triangle wave over the audible spectrum are not really defects...are effects.
Of course it is more precise now, without ground problems.... using lift ground (10 ohms) that Greg will include in the last board that is cooking.
You are rigth about fuses Graham....because of that i will sugest people to use a very thin wire soldered in parallel with their fuses...to have a guarantee that resistance there will be keep as low as possible.
Also... condensers, with increase values may be needed to be soldered under the board...or over the board if possible to avoid problems if someone forget to solder those "low resistance auxiliary fuses" there.
Many thanks by your researches guys....RAJ and Klaas...in special Klaas that have constructed and accepted that modification during listening tests....and perceive that klaas have the excelent amplifier...that Krell is in his home..so..he knows what is quality of sound reproduction
I am waiting your news dear nephew Nordic...happy with your progress.
regards,
Carlos
Just a quick question, it would be pretty simple and easy to cut the groundplane into a star (just did it in photoshop), but do you think it is realy needed to avoid hum... ?
I ******* hate 50/100hz hum.
Carlos 1 resistor extra is no big deal, we won't invoice you for the 10c...
Uncle Charlie, you should try all these mods and let us know which SOUNDS the best.
Don't get hung up on morals, this is not the Moral Amp, make it the Best Practices amp... i.e. use bests solutions, not most humble and kind methods...
Your ears allready know the answer.
I am a little worried that there was a small issue with subsonics, you knew about and was not comfortable telling us...
And you know that I am not someone, to qoute a Carlosism, one who goes looking for snake legs.
But I am human too and have those same weaknesses.
You must have a fun day uncle Charlie, I am going to fetch my parts later today, depending on how many hours I have to que for my car licence renewal.
I also looked at transformer datasheets
250va is 26VAC x5A x 2
I know this provides 26 x 2 SQRT 2 Volts DC minus diode losses, which I assume to be closer to 2V at these currents.
But does it provide the full 5A - losses on the DC side of the rectifier, or what? Even if I divide the 5A by 1.414 again I still get about 3.5A, but I guess the drop is not so bad...
ABOUT THE FUSES....
You said earlier that the onboard fuses where not needed, or did you mean fuses on the output?
I will die lrolling and laughin on the floor when this amp finishes up with mosfets on the outputs...
I ******* hate 50/100hz hum.
Carlos 1 resistor extra is no big deal, we won't invoice you for the 10c...
Uncle Charlie, you should try all these mods and let us know which SOUNDS the best.
Don't get hung up on morals, this is not the Moral Amp, make it the Best Practices amp... i.e. use bests solutions, not most humble and kind methods...
Your ears allready know the answer.
I am a little worried that there was a small issue with subsonics, you knew about and was not comfortable telling us...
And you know that I am not someone, to qoute a Carlosism, one who goes looking for snake legs.
But I am human too and have those same weaknesses.
You must have a fun day uncle Charlie, I am going to fetch my parts later today, depending on how many hours I have to que for my car licence renewal.
I also looked at transformer datasheets
250va is 26VAC x5A x 2
I know this provides 26 x 2 SQRT 2 Volts DC minus diode losses, which I assume to be closer to 2V at these currents.
But does it provide the full 5A - losses on the DC side of the rectifier, or what? Even if I divide the 5A by 1.414 again I still get about 3.5A, but I guess the drop is not so bad...
ABOUT THE FUSES....
You said earlier that the onboard fuses where not needed, or did you mean fuses on the output?
I will die lrolling and laughin on the floor when this amp finishes up with mosfets on the outputs...
Nordic, i don't think this grounding-discussion is about hum.
When grounding-problems cause hum, you have a HUGE problem in grounding (mostly loop(s) ).
This is about 'perfect' grounding.
Improving your grounding-layout improves sonic quality of equipment.
But to put this in perspective: If i would get a dollar for each GOOD sounding amp (diy or commercial) that had 'imperfect' grounding i could retire today.
About the fuses: They are at the worst possible place on Raj's pcb. An option would be to put them in the ps-rails between
rectifier and pcb, and use a wire-bridge on the pcb to bypass the place where fuses go on pcb.
Carlos, i always listen to well-known music, demanding in midrange and/or low-end.
The krell is good, but not unbeatable. It's a good benchmark to have. Also i have lived with the krell and speakers (acoustic energy ae-509's) for many years, knowing their strongnesses/weaknesses.
One example of a track i use is 'sail on' by Commodores.
Two male voices should be completely separate entities.
If it sounds good, it raises the hairs in my neck.
When not satisfied, it's time to heat up the soldering-iron
With best regards,
Klaas
When grounding-problems cause hum, you have a HUGE problem in grounding (mostly loop(s) ).
This is about 'perfect' grounding.
Improving your grounding-layout improves sonic quality of equipment.
But to put this in perspective: If i would get a dollar for each GOOD sounding amp (diy or commercial) that had 'imperfect' grounding i could retire today.
About the fuses: They are at the worst possible place on Raj's pcb. An option would be to put them in the ps-rails between
rectifier and pcb, and use a wire-bridge on the pcb to bypass the place where fuses go on pcb.
Carlos, i always listen to well-known music, demanding in midrange and/or low-end.
The krell is good, but not unbeatable. It's a good benchmark to have. Also i have lived with the krell and speakers (acoustic energy ae-509's) for many years, knowing their strongnesses/weaknesses.
One example of a track i use is 'sail on' by Commodores.
Two male voices should be completely separate entities.
If it sounds good, it raises the hairs in my neck.
When not satisfied, it's time to heat up the soldering-iron
With best regards,
Klaas
Negative!.. this will be the last modification done
No chance for Mosfets...any chance!
People can do it by themselves...but will never be the standard.
The amplifiers is very good the way it is..but of course, nothing is so good that you cannot tweak it to tune it to better result.
No amplifier is perfect...the most perfect one...or near the perfection, in my point of view is Aksa...but... this one is a comercial one..you have to pay... for free, Dx amplifier is a nice option for poor guys alike i am.
Really...beeing rich enough...better to go to Aksa...or other one you evaluate as excelent.
Do not bother with sounds you will not listen....this detail Klaas perceived is very subtile.... hard to listen....means a 280 milivolts peak to peak 0,5 hertz fluctuation of your speaker....or you will bother with the noises your hairs are making to grown up?
Also triangle waves around 40, or 60 or 70 or 80 kilohertz...depending the Miller size you use.... this will not bother you..unless you are a Bat
I am accepting those "evolutions" because final boards from Greg did not arrived.... they landing here will be dead end line...people can suggest and i will tell them thanks and suggest they open a thread with their discoveries.
As Dx amplifier revisited
Once again with Dx amplifier
Dx amplifier another turn
Dx amplifier by Us
Dx amplifier after a year
Dx amplifier Evolution IV
Dx amplifier by RAJ
Dx amplifier by Klass
Ahahahhaa..... beeing Dx amplifier...probably they will be excelent...as topologie is nice ...hard to kill this amplifier quality..even if people make mistakes on it.
Has not critical double differential in the input....nor sucking charges ideas...nor double negative feedback or correction and those things....sounds good...clear and enougth to the price people will pay by the parts needed to construct it.
And people are paying new parts because they want it.... you can construct it with junk and it will sound perfect...as new parts do not increase sonic qualities.
Also junk parts do not produces junk sonics...those magic movements people use to do, to guarantee qualitiy are not something better than big magic...new parts do not guarantee sucess.
Klaas have a very good ears...poor friend he is...he will sing the song:
I" can get no satisfaction"...from the Rolling Stones, as with those ears that could perceive defects in Krell and details, as subsonics fluctuations in Dx amplifier,...no chance to be happy dear Klaas.... travelling to Brazil...please, Recife may be a good place for our meeting and we gonna cry our destiny...the tragedy to have good ears...ahahahahha!
I am laughing..but that time is a "nervous laugh"...as i am afraid that people will not construct my amplifier anymore....if they perceive that something goes wrong...even infrasonics...people will feel unsafe....
regards,
Carlos
No chance for Mosfets...any chance!
People can do it by themselves...but will never be the standard.
The amplifiers is very good the way it is..but of course, nothing is so good that you cannot tweak it to tune it to better result.
No amplifier is perfect...the most perfect one...or near the perfection, in my point of view is Aksa...but... this one is a comercial one..you have to pay... for free, Dx amplifier is a nice option for poor guys alike i am.
Really...beeing rich enough...better to go to Aksa...or other one you evaluate as excelent.
Do not bother with sounds you will not listen....this detail Klaas perceived is very subtile.... hard to listen....means a 280 milivolts peak to peak 0,5 hertz fluctuation of your speaker....or you will bother with the noises your hairs are making to grown up?
Also triangle waves around 40, or 60 or 70 or 80 kilohertz...depending the Miller size you use.... this will not bother you..unless you are a Bat
I am accepting those "evolutions" because final boards from Greg did not arrived.... they landing here will be dead end line...people can suggest and i will tell them thanks and suggest they open a thread with their discoveries.
As Dx amplifier revisited
Once again with Dx amplifier
Dx amplifier another turn
Dx amplifier by Us
Dx amplifier after a year
Dx amplifier Evolution IV
Dx amplifier by RAJ
Dx amplifier by Klass
Ahahahhaa..... beeing Dx amplifier...probably they will be excelent...as topologie is nice ...hard to kill this amplifier quality..even if people make mistakes on it.
Has not critical double differential in the input....nor sucking charges ideas...nor double negative feedback or correction and those things....sounds good...clear and enougth to the price people will pay by the parts needed to construct it.
And people are paying new parts because they want it.... you can construct it with junk and it will sound perfect...as new parts do not increase sonic qualities.
Also junk parts do not produces junk sonics...those magic movements people use to do, to guarantee qualitiy are not something better than big magic...new parts do not guarantee sucess.
Klaas have a very good ears...poor friend he is...he will sing the song:
I" can get no satisfaction"...from the Rolling Stones, as with those ears that could perceive defects in Krell and details, as subsonics fluctuations in Dx amplifier,...no chance to be happy dear Klaas.... travelling to Brazil...please, Recife may be a good place for our meeting and we gonna cry our destiny...the tragedy to have good ears...ahahahahha!
I am laughing..but that time is a "nervous laugh"...as i am afraid that people will not construct my amplifier anymore....if they perceive that something goes wrong...even infrasonics...people will feel unsafe....
regards,
Carlos
Attachments
And it is the only way to go..to learn by ourselves, constructing and trying to
increase sonics.
the way i have learn some, and was exactly this way.
Also i have learned that if people perceive that the amplifier is not perfect...they will give up to construct.
Upgrade modifications, usually shows clearly that the amplifier is not perfect....we know that because we are very old and experienced...but there are many folks that dream with the perfection...when the world has more with the Caos theories than with some Einstein ideas.
Those "dreamers".... fast understand that if some amplifier had room to increase something..that it is not perfect...and this means death of the unit.
The reality is that the guy will never find that perfect one...maybe he will have the luck to find some schematic that was not focused by people to re-design, update, re-create or evolute.....but even this one that was not under focus...has room to evolute too.
Not knowing that some electrons travelling inside the circuit can deviate to "phisiologic needs"...they will go thinking that all electrons goes harmonically into the ground....and this is not the reality.
Do not be sad..... let those things to me...as those discoveries are killing my dear amplifier... and killing me softly (this is a nice music) and i cannot be against you...as you are beeing good, nice, competent, cooperative and friendly...and i am entirelly sure that you has the best possible intentions...to cooperate.
I think will be good idea to continue...not to stop...if people give up from Dx amplifier....they may apreciate Dx by Klaas...and this is something that, in the reality, is not so different related number 6 and half dozen.... the same thing...as topologie still be there... i will be thanking you to hold the thread.
You have perceived...Nordic did not apreciated the mess..as when he decided to construct...people findings discovered that fuse was in the wrong place...hehe...not perfect...he is inserting his feet deeply into the brake pedal...let's see if he will release his foot or not.
Dear Klaas..relax and have a drink with me...my daugther told me you have a very nice name...i do think the same.
regards,
Carlos
increase sonics.
the way i have learn some, and was exactly this way.
Also i have learned that if people perceive that the amplifier is not perfect...they will give up to construct.
Upgrade modifications, usually shows clearly that the amplifier is not perfect....we know that because we are very old and experienced...but there are many folks that dream with the perfection...when the world has more with the Caos theories than with some Einstein ideas.
Those "dreamers".... fast understand that if some amplifier had room to increase something..that it is not perfect...and this means death of the unit.
The reality is that the guy will never find that perfect one...maybe he will have the luck to find some schematic that was not focused by people to re-design, update, re-create or evolute.....but even this one that was not under focus...has room to evolute too.
Not knowing that some electrons travelling inside the circuit can deviate to "phisiologic needs"...they will go thinking that all electrons goes harmonically into the ground....and this is not the reality.
Do not be sad..... let those things to me...as those discoveries are killing my dear amplifier... and killing me softly (this is a nice music) and i cannot be against you...as you are beeing good, nice, competent, cooperative and friendly...and i am entirelly sure that you has the best possible intentions...to cooperate.
I think will be good idea to continue...not to stop...if people give up from Dx amplifier....they may apreciate Dx by Klaas...and this is something that, in the reality, is not so different related number 6 and half dozen.... the same thing...as topologie still be there... i will be thanking you to hold the thread.
You have perceived...Nordic did not apreciated the mess..as when he decided to construct...people findings discovered that fuse was in the wrong place...hehe...not perfect...he is inserting his feet deeply into the brake pedal...let's see if he will release his foot or not.
Dear Klaas..relax and have a drink with me...my daugther told me you have a very nice name...i do think the same.
regards,
Carlos
Attachments
Dear uncle Charlie, my foot slipped, and I hit the gas... Infront of me are all the electronic components, except for one output transistor I forgot to order it seems...the easy one to get... at least..
I did not buy transformers and heatsinks yet, as it was very expensive to buy the wrong things....
Thought i would bring what I can get to you and ask your advice how to proceed....
The only "reasonably" sinks I could find were about R200 each ($=+-R7).
The dimentions are 20cm x 20cm x 4cm, base is 1cm, fins 3cm
No anodation, just the bare aluminium... It has 20 rather thick fins, about 5mm thick fins at the base, tapering to maybe 3mm at the ends...
I need to know asap, as they must cut it in Johannesburg and fly it here...
The transformer choice is even more steep...
EI - 24 x 2 x 250va R360 EACH, 300va - R390 EACH... I think the small one is 5A per rail, large one 6A... I can get or have other ones made, but the prices went up alot since last year... i,.e. even more expensive...
Definately the most expensive amp I ever built... and will build for a long time I guess....But then again, I can only begin to imagine what a bought amp, with this high component cost, would go for in the shop.
Would this heatsink and transformer combination work?
I would probably take the 300va as it is only about $10 diffirence for the two...
Everyday has been a step closer!
P.S. in our language, and I guess in Klaas's too (similar) the guy who puts the sand in your eyes when you sleep is called Klaas Vaakie (Klaas Sleepy).
I did not buy transformers and heatsinks yet, as it was very expensive to buy the wrong things....
Thought i would bring what I can get to you and ask your advice how to proceed....
The only "reasonably" sinks I could find were about R200 each ($=+-R7).
The dimentions are 20cm x 20cm x 4cm, base is 1cm, fins 3cm
No anodation, just the bare aluminium... It has 20 rather thick fins, about 5mm thick fins at the base, tapering to maybe 3mm at the ends...
I need to know asap, as they must cut it in Johannesburg and fly it here...
The transformer choice is even more steep...
EI - 24 x 2 x 250va R360 EACH, 300va - R390 EACH... I think the small one is 5A per rail, large one 6A... I can get or have other ones made, but the prices went up alot since last year... i,.e. even more expensive...
Definately the most expensive amp I ever built... and will build for a long time I guess....But then again, I can only begin to imagine what a bought amp, with this high component cost, would go for in the shop.
Would this heatsink and transformer combination work?
I would probably take the 300va as it is only about $10 diffirence for the two...
Everyday has been a step closer!
P.S. in our language, and I guess in Klaas's too (similar) the guy who puts the sand in your eyes when you sleep is called Klaas Vaakie (Klaas Sleepy).
Each heatsink will hold 160 watts amplifier...or...2 units with 80W of power
To use a single heatsink to both channels will not be so good if you intend to use 4 ohms
And two of those may be too much for two channels.
Better to accept to work over 8 ohms only or to install a fan blower over a single heatsink that will hold two channels.
The 300 Watts transformer will be enougth... as your power will be smaller because the smaller voltage transformer (that could be 27 plus 27 AC)...but no problems..you will have 40 or 45 rms over 8 ohms and maybe 80 to 90 over 4 ohms...each channel.
The bigger transformer will be a better idea...as you may use it to 4 ohms loads.
One heatsink will be good for 2 channels using 8 ohms
One heatsink will go better with a fan over 4 ohms...but may go without the fan too..depending how loud you use to play.
Dear nephew...you can make it with your 25 volts supply..using your transistors and heatsinks...you will have a nice sounding unit.
If you prefer this way...go ahead!
Two heatsinks will be too much.
regards,
Carlos
To use a single heatsink to both channels will not be so good if you intend to use 4 ohms
And two of those may be too much for two channels.
Better to accept to work over 8 ohms only or to install a fan blower over a single heatsink that will hold two channels.
The 300 Watts transformer will be enougth... as your power will be smaller because the smaller voltage transformer (that could be 27 plus 27 AC)...but no problems..you will have 40 or 45 rms over 8 ohms and maybe 80 to 90 over 4 ohms...each channel.
The bigger transformer will be a better idea...as you may use it to 4 ohms loads.
One heatsink will be good for 2 channels using 8 ohms
One heatsink will go better with a fan over 4 ohms...but may go without the fan too..depending how loud you use to play.
Dear nephew...you can make it with your 25 volts supply..using your transistors and heatsinks...you will have a nice sounding unit.
If you prefer this way...go ahead!
Two heatsinks will be too much.
regards,
Carlos
Dx amplifier will work with the supply you have.
A very flexible amplifier...having optional boards, optional termical control...and some different ideas can be included in your own amplifier.
Boards will be mine one, First board from Greg, Board from RAJ and in a matter of days, or hours, we will have the final board from Greg.
You can choice the transistors you like....resistances can be new or old...condenser may be the ones you have.
This amplifier can be a solution...using that poor lonely transformer you have with strange voltages...that poor one abandoned receiving dust......those old transistors that use to be sligthly underpowered for modern amplifiers....an amplifier that will not create problems...will be a solution to make those parts usefull to you.
To adapt it to your voltage will be fast and easy...i can provide the adjustment values to you gladly...adequated to your own supply and parts used.
regards,
Carlos
A very flexible amplifier...having optional boards, optional termical control...and some different ideas can be included in your own amplifier.
Boards will be mine one, First board from Greg, Board from RAJ and in a matter of days, or hours, we will have the final board from Greg.
You can choice the transistors you like....resistances can be new or old...condenser may be the ones you have.
This amplifier can be a solution...using that poor lonely transformer you have with strange voltages...that poor one abandoned receiving dust......those old transistors that use to be sligthly underpowered for modern amplifiers....an amplifier that will not create problems...will be a solution to make those parts usefull to you.
To adapt it to your voltage will be fast and easy...i can provide the adjustment values to you gladly...adequated to your own supply and parts used.
regards,
Carlos
So are you saying 1 shared transformer of 300W is enough for both channels? if it is then I will order it now... I want to keep my 26V transformer form my chi"M"p amp, maybe use it to drive just the tweeters or wofer or whatever... also have another set of speakers to repair, then I could put it in the bedroom for some Mambo no 5.
50W is way more than enough for my small house...
I don't have 4 ohm speakers luckily!
Big chubby 8" 8 ohms 70W 140 peak... Drivers about 4 months old, well run in.
http://www.sos.sk/a_info/resource/e/tvm/arn226054.pdf
I think it is easier to make a Cube with the 2 sinks as the sides, than dealing with makeing a 1 sink box.
Still waiting to hear if I need 1 or 2 transformers, those are EI core, i.e. BIG, if I need 2 I will make my first true monoblocks.
I must scratch around, I know I have 2 spare IRF610 fets around here somewhere I want to send to you, so you can hear how nice they sound. Treble is magic, bass is tubelike.
When a woman sings, it feels like just her and you in the room, never heard vocals like that before my poor man's zen headphone amp.
50W is way more than enough for my small house...
I don't have 4 ohm speakers luckily!
Big chubby 8" 8 ohms
70W 140 peak... Drivers about 4 months old, well run in.http://www.sos.sk/a_info/resource/e/tvm/arn226054.pdf
I think it is easier to make a Cube with the 2 sinks as the sides, than dealing with makeing a 1 sink box.
Still waiting to hear if I need 1 or 2 transformers, those are EI core, i.e. BIG, if I need 2 I will make my first true monoblocks.
I must scratch around, I know I have 2 spare IRF610 fets around here somewhere I want to send to you, so you can hear how nice they sound. Treble is magic, bass is tubelike.
When a woman sings, it feels like just her and you in the room, never heard vocals like that before my poor man's zen headphone amp.
I have those IRF610 and some 630 too...maybe 6 units
I have already listened...they sound nice...for sure.
You can use a single transformer..but better to use the bigger one...that 300VA transformer.
As you want to use two heatsinks...good that!..your amplifier will run cool
Interesting those speakers....the more interesting is that the magnet do not seem to be very big...may be special Samarium Cobalt unit or something even better...because the size is for a 30 watts speaker....nice speaker this one....and strange letters too....hehe....hard to understand meaning.
Some carefull will be needed...the amplifier can produce very deep bass with maximum power..sounds hard to listen, alike 10 hertz, if present, will have a lot of power (100 watts over 4 ohms) and this may melt your speaker (Melt mine 150 watts unit!).
Because of that, i suggest you to tune your speaker, carefully, to reproduce clear low deep bass.... those tubes, carton tubes, inserted into the speaker (rounded holes) will be good to adjust...
Use a generator into 25 hertz and send this signal to the amplifier....then adjust the tube length (size inside the speaker) to a length that will make you listen better those 25 Hertz.
The problem, when we have a mistuned speaker, is that we do not listen those deep bass...and them we go increasing volume listening those 50 or 100 hertz normally present in common music....but the amplifier will be pumping enormous energy into 25 hertz too.... the speaker can be very hot driving that frequency that the audiophile cannot be listening because mistuning or home acoustics.
My amplifier gone because not perfectly tuned to 20 Hertz...and a Japanese playing drums with some thunder sound in the background (was not really background...my speaker mistuned was not reproducing normally)...that thunder sound was constant and kill one of my units.
Dx amplifier, as other amplifiers that transfer the maximum power in very low frequencies....can kill speakers.
regards,
Carlos
I have already listened...they sound nice...for sure.
You can use a single transformer..but better to use the bigger one...that 300VA transformer.
As you want to use two heatsinks...good that!..your amplifier will run cool
Interesting those speakers....the more interesting is that the magnet do not seem to be very big...may be special Samarium Cobalt unit or something even better...because the size is for a 30 watts speaker....nice speaker this one....and strange letters too....hehe....hard to understand meaning.
Some carefull will be needed...the amplifier can produce very deep bass with maximum power..sounds hard to listen, alike 10 hertz, if present, will have a lot of power (100 watts over 4 ohms) and this may melt your speaker (Melt mine 150 watts unit!).
Because of that, i suggest you to tune your speaker, carefully, to reproduce clear low deep bass.... those tubes, carton tubes, inserted into the speaker (rounded holes) will be good to adjust...
Use a generator into 25 hertz and send this signal to the amplifier....then adjust the tube length (size inside the speaker) to a length that will make you listen better those 25 Hertz.
The problem, when we have a mistuned speaker, is that we do not listen those deep bass...and them we go increasing volume listening those 50 or 100 hertz normally present in common music....but the amplifier will be pumping enormous energy into 25 hertz too.... the speaker can be very hot driving that frequency that the audiophile cannot be listening because mistuning or home acoustics.
My amplifier gone because not perfectly tuned to 20 Hertz...and a Japanese playing drums with some thunder sound in the background (was not really background...my speaker mistuned was not reproducing normally)...that thunder sound was constant and kill one of my units.
Dx amplifier, as other amplifiers that transfer the maximum power in very low frequencies....can kill speakers.
regards,
Carlos
Ok, I don't know what the magets are made of, but they sure are very strong, and you are right, they are about the same size magnets as I have on the 40W drivers that went funny (one only plays very softly).
They just laugh at my My_ref C, wich I thinks puts out a bit north of 40W per channel, in class AB. Even when I turn the volume up all the way, they never start distorting, you can hear the amp go a little off-colour in the last few Watt.
They just laugh at my My_ref C, wich I thinks puts out a bit north of 40W per channel, in class AB. Even when I turn the volume up all the way, they never start distorting, you can hear the amp go a little off-colour in the last few Watt.
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