Dx Blame ST - Builder's thread - post pictures, reviews and comments here please.

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#142
many times in the past and also now days many of us have to pay our respects to uncle Charly for his work

It is not really importand if the DX or the Blame is the best or the worst amplifier presented in the forum ....what makes sense and its more useful is that there is a non stop effort to make DX products better and better

Respect .... uncle Charly .
 
#145
Alternative Parts

Because I had such a hard time finding alternates to the transistors i needed, I've decided to create a list of alternatives for all the transistors. Hopefully this will help anyone looking for alternates.

BC556: MPSA56, MPSA55
BC546: MPSA06, MPSA05
BD139: BD179
BD140: 2N4920

I don't understand why it's so hard to get the transistors i need. I still don't have half the transistors i need... I only have three BC556, and one 2SC5200...
 
#146
Try BC547 and BC557 in the place of BC546 and BC556

this is connected to country tradition...i can find these ones in thousands of shops... they may have no solder that people that sells electronics always have.... as this is alike hamburger style of sandwich without meat..... so.... electronic shop without solder is alike hamburger sandwich without meat...or hot dog without sausage.

If you find here, one shop that has not solder, for sure it will have hundreds of BC548, BC547, BC557, BC548, BC556, BD135, BD139 and BD140...because these ones are Universal substitutes..... till 35 volts they can substitute any transistor.

You know what i mean..in brazil you can find a shop that has not solder...an electronic shop that has not solder to sell... also you can find hot dog without sausage..but you cannot find a shop that has not these transistors..they are standard...talking about transistors is the same to say BC546 here.

It is interesting these things... fame.... in England (UK) i know people have, always..the same way their hot dog has sausages, these MPS transistors.... and we do not have them!...we know our BCs can do the same job, reason why we do not bother to have those ones here.

It is a pitty you are facing that.... brazilian junk yards are filled with these transistors.... the shop that fixes television, repair shop, put enormous old television having hundreds of these BC transistor inside...we use them to automobile relay..electronic lamps flashing....to everything...even electronic lamps..intercommunicators, telephone sets and centrals... everywhere...it is standard in this giant country that may have ten thousand electronic shops..and you will not find a single one that has not these ones.

Well...keep searching...or.... desperatelly, try the 2N5401 and 2N5551.... i am afraid of them as i had troubles once, in this same amplifier...but maybe was that hell transformer that was creating me problems.

For drivers you can try TIP41 and TIP42...also MJE15032 and it's complementary..but do not use MJE340 because i have burned all units i had..the hell unit oscilates very easy...i want to have the devil inside my home and not have MJE340 and MJE350!... to the first VAS...try to use BC546 if possible.

I cannot guarantee you will succed..but you should try.... other ones...but be prepared o face surprises.

Well... you can assemble, just to try, with the ones you found... them, slowly, without hurry, you go searching for the ones suggested in the schematic.

Transistors use to work without create too much troubles.... maximum colector to emitter voltage is something to worry about.... gain is another thing...maximum dissipation too, and if PNP or NPN...and in almost all cases the amplifier works...not perfectly, but almost perfectly...measuring you find small differences and simulating the distortion changes a lot depending the transistors...but these changes in distortions are not important, as the distortion is below your threshold of audibility...say...below 0.1% no one perceive differences...so... a transistor replacement that increases the distortion from 0.002% to 0.023% is not even perceived..as both values are below the levels of distortion we can perceive.

I can guarantee the ones i am using..the ones i have tested...others.... try them under your own risk..... who knows...the sound can be even better...we never know... at least i do not know.

regards,

Carlos
 
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#149
I have anything sophisticated here.... just a DVD player from Philips, a computer

audio board that generates my music and some Flac recordings.

The system here is simple, sounds good.

People using better speaker and better sources, may have even better performance.

I cannot afford to have expensive equipment, so, i use to do the best i can with the resources i have.

Also, i think to have good sonics with simple equipment, not spending money, is better (more pleasant and more heroic) than to obtain quality with expensive units..... i am DIY...i am inside a DIY forum because of that same reason...i am on topic for this forum....i am not someone that buy audio...i cannot, and even if i could...i will never do that.... reduces the fun this way.

To have the best buying the best?..... not very good..better to have the best sound with ordinary, regular, common and standard audio sources and speakers.... well.... this is my opinion.

I cannot discuss brands my friend..i am not able...i do not know them...so, i am ignorant in that subject.

This thread, just to remember, is about Dx Blame amplifier, to build, a diy thread.

regards,

Carlos
 
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#151
Too much big to be uploaded Kanwar

Also i have no Brazilian music in Flac format...the one may have is Mr. Professor.

I have one, but was traditional PCM format (wave)...and the one is even bigger.

My upload speed is slow.... maximum of 100 kbps.... the upload speed is 10 times bigger.

To send Flac or wave, represents 30 minutes of upload. (average)

regards,

Carlos

.......................................................................................................

BTW... is really you that is using Workhorse nickname?.... you seem different.... or your brother, or even Sami is using by you?
 

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#156
This brazilian friend made Dx Blame test using DAC and a pré amplifier

A tube pré amplifier called Aikido.

His name is Hudnes, he lives in Maceio, Capital of the state of Alagoas.... Northeast of brazil too... this state touches mine, has border with Pernambuco at south of my place.

YouTube - MY DIY STEREO, DX BLAME ST, AIKIDO

Video is not fine...but audio is nice.

enjoy,

regards,

Carlos
 
#158
zeraphine said:
Am I correct.
Click to expand...
no.
A 50W into 8ohm amplifier must output 20Vac to an 8r0 load. P=Vac^2/R
The peak voltage will be 28.3Vpk.
You will lose ~2V through the amplifier so the PSU should supply ~+-30Vdc, when fully loaded, to the amplifier power terminals.
The PSU voltage will rise ~4V when unloaded. Expect the PSU to be ~+-35Vdc for a 50W amplifier.

If you start with +-25Vdc, then maximum power is likely to be 20W to 25W into 8r0.

If you listen to average levels of ~-20dB ref maximum power then your 25W amplifier will be delivering 250mW to the speaker when turned up to maximum with that 20dB overhead to prevent clipping of peak transients.
 
#159
AndrewT said:
no.
A 50W into 8ohm amplifier must output 20Vac to an 8r0 load. P=Vac^2/R
The peak voltage will be 28.3Vpk.
You will lose ~2V through the amplifier so the PSU should supply ~+-30Vdc, when fully loaded, to the amplifier power terminals.
The PSU voltage will rise ~4V when unloaded. Expect the PSU to be ~+-35Vdc for a 50W amplifier.

If you start with +-25Vdc, then maximum power is likely to be 20W to 25W into 8r0.

If you listen to average levels of ~-20dB ref maximum power then your 25W amplifier will be delivering 250mW to the speaker when turned up to maximum with that 20dB overhead to prevent clipping of peak transients.
Click to expand...
That's so informative, thanks so much andrew
 
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