Destroyer x Amplifier...Dx amp...my amplifier

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Nordic said:
Hi G, no the my_ref C does not fall in the standard chipamp category... the chip is used as a current pump, as well as haveing some DC protection etc... except of course its all chips... bar a few transistors in the protection parts...

It is amazeing how your ears can deceive you, after some time it sounds pretty good... but A/B versus the DX it is a little harsh sounding. As far as my testing is concerned, other gainclones need not even apply...


Hello

Ok, the one start by mauropenasa.

Gaetan
 
Exactly Nordic.... fully agreement.... roger on that!

When we go listening.... ear plus brain goes adjusting..so... long auditions make us accept every amplifier as reasonable or good.

Example:

If you want to listen your wife... a party running into your home...noisy people screaming, music playing loud...well...that mess..and you wanna listen her...and she do not use to talk loud...you concentrate and will not listen the noise.... you will adjust, will tune, will filter.... our brain is very good to do that..

"The brain listen in advance related you...the brain decide if the sound is good or not, the brain start a negotiation with your pré- conscience (advanced on time related your perception..you are disengaged in this moment)...check if it is allowed not to aprecciate so expensive, pretty, friendly amplifier.... check if the "feelings" department has connections with the owner, demonstrator, factory, country...well..check everything and decide if will like or not.... than...conscience is informed.

"Not good"

Than your humor, your health, your emotional moment will decide if you will accept that or discuss with "yourself"....

It is very common that you decide to listen more...not interesting to say "no good".... too much people say it is "good"..if you say no good, maybe they will think you are an idiot..better to think about and to listen more...ahahahahha

We go listening more and decide that sound is very good!

This is the teather i have made...on stage.... to produce example to you friends.

A to B testing must be blinded...we cannot know the one is playing
A to B testing must be fast switched...no second of time between muted.
Both amplifier having the same sound and same power and same speaker.

We fool ourself all time long.... our decisions are political, social and politically correct..the A to B is the tool we have not to be fooled by ourselves.

Harshing will disapper after long listening... brain adjust everything.... brain is not audiophile...he is not giving a ..... related your option to be a sophisticated listener...bass not good..than brain fill the gaps...treble loud...than it reduces.

We are fooled into vision, into audition and into feelings...your outside expressions of communications with others have passed into the censor department from your conscience...this is you... social, a good guy...you brain use to be fair and very bad.....also much more precise than the conclusions you will have correcting words and evaluations that would be made in the censor department. ...our conscience, that finally will produce words and communicate, is a big "boot polisher" trying to be accepted by your communitty..when the brain is hard and precise...a terrible smasher...we use to be social and adjust to the moment needs.

There are people said as "people without conscience"...those ones are hard...brain order..they do.

No problems not to accept those ideas...your self defense department will never accept that your brain can be bad..so... of course...i am wrong!

regards,

Carlos
 
Re: Exactly Nordic.... fully agreement.... roger on that!

destroyer X said:
When we go listening.... ear plus brain goes adjusting..so... long auditions make us accept every amplifier as reasonable or good.

Example:
..
A to B testing must be blinded...we cannot know the one is playing
A to B testing must be fast switched...no second of time between muted.
Both amplifier having the same sound and same power and same speaker.

We fool ourself all time long.... our decisions are political, social and politically correct..the A to B is the tool we have not to be fooled by ourselves.

Harshing will disapper after long listening... brain adjust everything.... brain is not audiophile...he is not giving a ..... related your option to be a sophisticated listener...bass not good..than brain fill the gaps...treble loud...than it reduces.

We are fooled into vision, into audition and into feelings...you are your brain....much more precise than you can be...conscience is social and adjust to the moment needs.

regards,

Carlos

Hello

That's why so much peoples pay the price of a car for an ordinary sounding amp, because they minded themself that it's the best amp in the world and the salesman know how to mind them for that.. ha ha ha

Gaetan
 
A good friend arrived here with a very expensive ear phone.

Those awfull things, we use to insert into our ears not to disturb wife that is sleeping and you want to listen something from the radio.... news for instance.

He paid a couple of hundred dollares.... good speakers can be bougth by this price here..... many times better than this earphone.

But the marketing was there...unobtanium selenium piridium sodium magnet, wire with copper without oxigen...plug double chromium plated with insulators made using synthetic rubber...case (that tiny thing inside the ear) made with hi impact plastic... a tube inside the ear piece that had some soft plastic material outside (alike sponge to clean dishes.... and the tube alike the one you use to drink Coke)...and my friend look to me really very idiot.

He said sound excelent.... extremelly good...from outer space.

I have listen and those terrible sounds from piezo from the sixties.... distorted bass... awfull treble..only midranges.

He just decided that the unit is fine.... advertising said that to him...he paid a bunch of money..if not good in the real world... the needed proof, testimony , that he was an idiot would be clear...than he decided not to accept.... than i gave him a cheap headphone i have here...nothing special...just acceptable.... sounded much better...than he blame the pré amplifier output..

ahahahahha...no way...really, not way...those folks really deserves to pay 10000 dollares for the unobtanium.

regards,

Carlos
 

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Listening and comparing

To Carlo's list, I would add the following :

RELAX. Have a cup of coffee and a chat with your friends first.
Turn off that PC whirring away at the other side of the room.
I often arrive at a decision in less than 30 seconds. As Carlos says, with a long listening session, your brain will make corrections for you. Believe him!
If you find that a piece of music totally relaxes you, it is often because the brain isn't having to work hard making lots of corrections. This is a good sign.
I often find that first impressions are usually the correct ones.
Much of this will come with experience. Try to have regular listening sessions with your friends. These listening sessions can not only be informative, but most enjoyable.

SandyK
 
A lot of improvment

Congratulation carlos
a lot of diyer, a lot of ear makes a lot improvement :D

For the best result for DX 100
maybe you can posting upadate schematic or
Make a new threads about update schematics Dx 100
so the schematic dont confuse the new builder

When you start the production CARLOS ? :D
 
Yes... very confused... i also think this way

There are a lot of informations...many amplifiers....many boards.

People may turn confused...but...for sure, the ones that want to construct, those ones will ask informations or will search the whole thread.

Depending how decided to costruct the one is...if weak decision, the first problem the one will give up...if real decided, he will remove mountains and drain rivers to cross the distance till obtain the informs and realise their decision.

I am moving, or...packing things to move..electronics stopped for a while...move will happens from August 30 to September 02... i will move my personal things by myself...moving company will hold only furnitures.

That confusion, i was thinking about, will work also as a filter...only the real decided ones will pass througth..... if not confused, many folks will came together and i would be crazy to give them all attention at the same time.

So.... some problems are solutions too.

The picture is Microp, or Arnis Brolishs, a single man with the power of two!

regards,

Carlos
 

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Well, here it is. Fully assembled and on a test heatsink :)

Power applied too, no smoke :) :)

I'm using the Dx test setup with 10r resisters in series with the psu, input shorted and no load.

+ve measures 238mv
-ve measures 165mv

op voltage around 3mv.

Does this look about right ?

Now the questions:

The Vbe circuit is the same as the DX with 22uf + 100nf added between collector and emitter. This circuit replaces the HiRes 220r + 610r with a single 1k trimmer. Adjusting the trimmer appears to have no effect on the current draw. I find this strange.

At first switch on I was measuring 9v across the test resisters. I adjusted the 1k trimmer as I would for the Dx, the voltage did not change. The trimmer is now set to maximum, resistance across the Vbe = 3.2k. Could this 9v condition have been caused by having the trimmer set to a low resistance ?

At second switch on, and ever since, measured voltage has been 238mv and 165mv.

Suspecting something to wrong after the first switch on I started poking around with the meter. It appears that poking in the wrong place will trip the amp into the high current draw state. This does not surprise me, but does it sound ok ?

I will go and wind the output coil and try a real speaker :bigeyes:
 

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I've been lurking here for a few weeks, enjoying the thread immensely.

I've noticed that your normal jovial attitude has been somewhat diminished lately Carlos. You mentioned, briefly some family issues.

I am sorry to hear about your troubles. I have been an idiot most of my life I guess, and have suffered some of the same trauma.

I'm not fortunate enough to know you, and don't presume to know your troubles, but feel sorry for you anyway, and hope you can enjoy some good moments soon.


Humbly,
Peter
 
amp debug

Well it amplifies. Made an op res + coil fitted on a 3 inch flying lead.

Checked op voltage 3mv.

Un-shorted the input and connected a flying single wire to the in, nothing to ground. Connected a speaker and powered on.

Slight noise due to noise picked up by the flying wire.

Holding the wire I get definite mains hum.

Tapping the bare end of the wire I get the mains hum equivalent of tap tap, loud hum, quiet hum.

Firmly holding the bare end of the wire I get louder hum and after a second the reading on the meter over +ve safety resistor jumps to 9v and stays there. -ve also increases but I forget the exact value.

Switching the amp off :

If I do not provoke the problem the amp switches off gracefully with just a small phut sound.

If I provoke the problem quite quiet whistling sounds can be heard as power is lost. This must be oscillation.

I'll debug further.

Question, with the safety resistors in place the amp is not getting the full 38v. As the output increases the safety resistors drop more voltage. At some point the voltage will drop below the level required by the line regulators. Could this be causing the problem, I'm afraid to remove the safety resistors, don't want to let the magic smoke out.
 
Check carefully all connections, follow copper tracks and measure continuity

This absence of adjustment into the VBE multiplier seems circuit not complete.... connections faulting.... emitter to colector leads inverted.... for sure, an error of construction or board copper lines.

The Vbe multiplier must adjust.

Try to bypass the rail regulators, as, the way you said, maybe voltage losses is creating problems.

Use the standard Dx voltage informations.... they will be almost the same.... difference will be the VAS input that will be something around 1.2 volts, when the standard Dx has 600 milivolts there.

The HR-II is reliable.... relax and search without run...for sure there are something missed, or wrong.

Check VBEs..... this will show you were your have problems.

Do not remove rail resistances, the protective ones.... they are the guarantee you have to misadjust without burn nothing...also having transistors assembled inverted will be protected by those resistances.

I have not checked all copper lines of your boards.... they are untested...some error may remain there.

Relax... the unit was tested in my home....it is even more reliable and stable than the Dx amplifier....for sure works fine and soon you will find the problem.

regards,

Carlos
 
Yes Peter, correct Fítero....there are problems around my life.

And i am facing them.... because of that i am more busy and not tracking forum with the traditional frequence.

Thank you by the support.

Time and effort may fix things here.... i am also moving from appartment.

thank you by your worries... i have received some support from friends...this is good.

regards,

Carlos
 
Thank you Carlos. Words of reassurance always help. It's my board, don't go wasting your time, I'll start my checking with the board.

I did try removing the safety resistors, I know I'm bad boy.

With resistors when I provoke the problem the speaker cone moves in and stays there.

Without the resistors when I provoke the problem the speaker cone moves out then over about a second it moves back to normal. No whistle at switch off this way.

Off to ponder.
 
This happens when one of the differential colector is opened

Check the differential...with ohm tests..continuity buzzer or low resistance check.

If you have some audio...the soft puft after many seconds of condenser discharging...during power off period...the second differential is the one.

Check it...if using transistors in the place as colector resistances ...the way the schematic is showing, check your transistors.

Once i had that..... after switch on.... and some time after... and poof!..the speaker goes forward... the speaker did not burn because the rail resistances..without the resistances your speaker will go to the "land of no return".

Also the lifted resistance burned or disconnected from ground produces strange things.

You will find..... for sure.... it works...i have tested...go easy and you will be extremelly happy with the sonics...prepare the movie machine or the foto machine because you will dance...yeah!...dance!..so happy you will be.

Check it, observe everything with care and test continuities, transistors, connections, observe invertions, errors in position... watch alike a diamond...because the sonics is "precious"

Also crazy bias adjustment happens...also offset unstable happens when we have open 10 ohms resistance..the lifted ground one...also problems into differential create the multivibrator effect.... one off when the other one on...ahahahah..speaker off.....(forward) and speaker on (backwards)... i do not remember if was the resistance of the differential colector opened, disconnected from the circuit..but one of them produced a very crazy defects.

regards,

Carlos
 
Bug One:

I did not want the treble boost so did not fit the 15nf capacitor.

Then, at some point I've noticed the space and without thinking I've fitted a 100nf capacitor.

Just warming the soldering iron....

... Op voltage was 3mv, now, the cap is removed op voltage is now 0.3mv.
 
Bugs all be found.... take a rest, go out to have a beer and a pizza

A movie with your wife.... some friends for a chat, maybe a barbecue, one good aceleration into the motorcicle, or skid a little with you car (drift).... sleep a good nigth and try once again tomorrow or the day after.

All bugs will be found and exterminated.... one by one.

Dx Corporation Sixth guarantee:

"Bug's may come..but for sure they will not stay"

regards,

Carlos
 
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