Dx Blame ST together Dx Super A

I have images of several capacitors if you want

To make your life easier to identify them.

I am preparing the Dx Supply to the Dx Super A triple.... a third channel will be used with an active low pass filter...so... a third channel only for subwoofer.

You see i am already assembling the pcboards... i will be waiting new electrolitic arrive from Dudainc (USA) as i will receive an entire box having 40 units ... a gift from Evette and Dudainc.

These capacitors (picture) are all made using plastic film... polietilene, poliestirene, Mylar and other materials... they all sound the same, some of them have a little bit more distortion than others, but you cannot listen the distortion as the level is too much low...so, it exist but cannot bother you.

Dx Supply (under construction but already tested... search for the thread about) is shown using temporary condensers... as soon i receive new ones i will replace the smaller ones, the big one is 10000uf... the ones i will receive gonna be 4700uf/63V

Here you have Dx Supply thread:

http://www.diyaudio.com/forums/powe...utput-adjustable-stabilized-power-supply.html

regards,

Carlos
 

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I have read a lot about capacitors

And i came to a conclusion... two images explains what i concluded.

One that you can find a fake one...the other is your choice.

They are not that different and not that important the selection os types.

regards,

Carlos
 

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DX Blame ST Super A SANKEN Version

Uncle Charlie,

My DX Super A SANKEN version is now singing...... and all i can say is WOOOOOOWWWWWW!!!!..... i'm very happy about the quality...;););)
So far I'm currently playing with low voltage only using my voltage transformer but high current 12-0-12VAC/30Amps. but this amp still works with very very fine in high and low frequency, i like the base soo much... but so far i did not set the bias as i'm not sure what is the correct bias using this low voltage.
But tommorow i connect to 40-0-40VDC/600VA and adjust the bias accordingly as getting late now in my place....

My dear Uncle Charlie and my freind dear Juan, Thank you soo much guys for all the effort that you have contributed and sharing this another wonderful amplifier...

More power for both of you....

Regards,
Wiljj78
 
The amp is very cold

With 10R/10W in +/- rail all components are very cold like the amp is not powered, but the sound is very clean and crystal clear using my ipod nano, sound quality doesn't need tone control to blend as it sound like it's already has tone control and completely blended perfectly from my taste.
Anyway right now I can’t play in full power, but I will do that tomorrow using the correct supply voltage and will update you.

Regards,
Wiljj78
 
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That is fantastic !!Willy I'm really happy and exited this is wonderful I feel like this guy up the hill screaming victory!!!! thank you Willy to share this, is so nice !!!!!!!:cheers: get some real cold Cold Coca Cola and celebrated dear friend!
Carlos I'm back my internet was down again lol ,but for real, this is really special for me and Carlos "emotions are running high", thank you again enjoy it "mucho"

Regards
Juan
 

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Thanks Juan....

I'm enjoying right now damn.... I can’t imagine how this amp produce this quality even in a low voltage, the base is really hard punchy, now I prove what Uncle Charlie is saying and he is right this amp has a lot of power and it convince me now to trash my existing amps. Hahahaha…
Now I’m planning to build 3 more channels on the coming months to replace my existing 4 channel modules… Guys this is the best amp i ever build and this is the one what I look for……

Regards,
Wiljj78
 
Preferred bias voltage for +/-38VDC

Uncle Charlie,

I have connected the amp supply @ +/-38VDC and i'm trying to set the bias on 10R/10W resistor but the max. voltage i can set is only 2.35V and the heatsink is warm.

Please advice what is the preferred bias voltage for +/-38VDC as my trimmer was on the maximum but bias voltage is only 2.29 on the positive rail and 2.33V on the negative rail and i'm not sure if this is the right bias according to the supply voltage.

Regards,
Wiljj78
 
It is all rigth Wiljj78... relax.... let it be this way as you're using 38 Volts

I am trying the Dx Supply once again, this time i have installed 25.000 plus 25.000uf, the amplifier is operating with 38 Volts, the supply voltage unloaded is 44 volts...loading it drops to 40 volts and keeps the output voltage stable...highly filtered as i tortured with 1 hertz and no noise from the supply, totally and absolutelly silent even when we drain high currents.

Speaker is using 4 ohms coil (it is dual coil) and i have pushed almost 100 watts RMS... due to 6 volts of voltage drop into the series pass transistors (from colector to emitter) i am having some heat into my test small heatsinks.... but when draining high current the voltage drop into series pass transistor is only 2.3 volts...this way heat is not that big.

Circuit is Dx Super A operating with one single pair in the output and i cannot push it hard because of that.... 100 watts only a few seconds.

As you can see, i have simplified the supply to enjoy it's power while i am waiting more transistors, pcboards and electrolitic condensers.

Just to be listening the Dx Super A and to have fun.

regards,

Carlos
 

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Uncle charlie i will keep the bias in 2.0V while i'm using

Temporary heat sink, but I will set and readjust the bias in max to get 2.33V when I move to the final heat sink, so far the heat sink is little hot when i supply +/-38VDC but the amp looks stable and I feel comfortable and nothing to worry about....
Today I’m having fun with super A and really it has lots of power as I can’t push it hard to the max volume I can feel my speakers can’t survive the power, otherwise will be sorry Hahahaha….

Regards,
Wiljj78
 
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Thats cool uncle Charlie....

I’d like to build your DX supply, do you think it gets more benefit for my Super A even my supply is under voltage? I mean I only have 29-0-29VAC.
Regards,
Wiljj78
 

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It is up to you, i have already informed the advantages

If you intend to push it hard, then you need an electronic fllter and stabilizer to the supply voltage...if you do not push the amplifier hard...then condensers will be enough.

By the way...nice pictures..thank you as you are sharing with us.

Also thank you by your preference in Dx amplifiers.

I just cannot decide in your place, or by you..it is up to you.
regards,

Carlos
 
My pleasure Uncle Charlie and thank you also for sharing this Super A

Yes and I have noted those advantages you have posted, but in my case I just want to hear your opinion of coarse as a master of DX corporation its valuable for me every single information you have had shared in this forum, I have built your MKIII HX and I love it more than any of my amplifier but sorry to say this Super A is my favorite now….

Regards,
Wiljj78
 
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Yes.... we feel it better than previous models

This is clear to me it is the best i have made.

About the supply, i have to check, i have made some modifications.... hold on for a couple of weeks till i have finish my research.

It is under test in my main system (computer audio amplification)... and i want to torture a little bit more, also i want to see voltage drift from the previously made adjustment, heat and some other details.

I may change something into the resistor network that feeds the output darlington that works also as a capacitance multiplier...i have to find a better compromise in between filtering and speed of attack/delay.

For a while...all i had as benefit is that i can put 1 cicle per second, full power and i have not noise from mains.... really?.... this is not that impressive....i want more and i could not feel all that advantage in dinamic sound reproduction...... i perceived it looks more clear... a little bit...so, i have to understand, and to find out, the real advantage of disadvantage because these parts also have a cost, another pcboard, some huge electrolitics, series power transistors... all this needs some study, some tests, some cost calculations and some reflections about.

You know... real life people does not goes listening (cannot even listen) one hertz full power... i want to figure out the advantage in real use..because this one hertz is just academic.... nothing that may change our listening experience..... i have to calculate if this saves money or not, as you can install a huge bank of electrolitics to have something alike.... not the voltage regulation, but the filtering.

The real work is post simulation.... after the simulation all starts...and the results depends on that, not from the simulator...things must make sense, must have decent cost/performance ratio.

regards,

Carlos
 
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