Dx Blame ST together Dx Super A

[vargasmongo3435]

Eureka, it plays!!!!

My replacement transistors came it from Mouser today and I swapped out those dodgey BC556's and BD140. Said a prayer and brought it up on the variac through a light bulb nice and easy while watching the offset on the output and the ammeter on the negative rail. Everything looked great. 16mA on the rail and and 15mv offset. I checked both sides and they were almost exactly the same. I raised the idle current to 125mA on both sides and hooked up my test speakers and my Zune. Everything sounded really good until the positive input line came loose and fried my Zune.😡😡😡😡

Anyway, I fixed that and now have it hooked up to my B1 buffer. It is sounding very nice. I haven't pushed it hard yet because I didn't have it hooked up to the big heatsink. I will do that now so I can let it run for a while. I'll try to get a small video for you.

Blessings, Terry

Oh no sorry to hear that mister Terry 😕 , so the positive input line destroy your player Zune wow I be mad it that happen to me too 🙁

Regards
Juan

 

[vargasmongo3435]

OK I made a short video. I had to turn down the amp pretty low to keep from overwhelming the mic on the camera. I hope you find it somewhat helpful.

Blessings, Terry

My DX Super A

Me too mister Terry I always try to make a recording but my Sony DSC T900 is not good at recording low frequencies I just saw your video I like it anyway I betcha it sound really good 🙂 forgot to say congratulations !

Regards
Juan

 

[Earthquake]

Well done Terry glad you got it working but sorry to hear about the little bit of smoke you released 🙁

Lets hope I dont have too many issues when I stick some volts up mine 😉

 

[destroyer X]

Very good dear Terry.

I am glad you like it.

Install a fuse in series with the output...next models will have the fuse holder on board.

regards,

Carlos

 

[vargasmongo3435]

plop ! .................................................

 

[still4given]

I am glad you like it.

Install a fuse in series with the output...next models will have the fuse holder on board.

regards,

Carlos

A fuse inline with the speaker? How many amps?

Thanks

 

[destroyer X]

3, 6 and 12 amperes

to 8, 4 and 2 ohms respectively.

Slow blow fuses...if not available, then increase a little each one of them

Carlos

 

[destroyer X]

I have uploaded a video about the Dx Boom...the pcboard issue

And i am uploading another one, gonna be ready in more three hours (edition) about noises from the mains and active crossover filter adjustment.

This video has a F word in the end...sensitive guys should not watch my videos as i am free, in youtube, to use the words i want.

Our forum do not like these words, so, i will be happy sensitive people not to watch my videos...but the ones loves the freedom of f words...please, go there!

regards,

Carlos

 

[thimios]

dx super A

I am glad you like it.

Install a fuse in series with the output...next models will have the fuse holder on board.

regards,

Carlos

Hi Dear Carlos.

I didn't like fuses in series with loudspeakers.
Fuses are extremely nonlinear devices.

 

[thimios]

DX SUPER A

Very first steps....in DX SUPER A

 

[vargasmongo3435]

WOW! I hope all goes smooth for you mister thimios 🙂

Regards
Juan

 

[thimios]

DX SUPER A

WOW! I hope all goes smooth for you mister thimios 🙂

Regards
Juan

Hi Juan .
I see some corrections in this amplifier.
Can you tell me please what's this exact?
Regards.
Thimios.

 

[AndrewT]

to 8, 4 and 2 ohms respectively.

Slow blow fuses...........

These output fuse recommendations seem a bit high.
Particularly the T12A

 

[vargasmongo3435]

Sure R4 is now 82 ohms and keep Q3 as it is BC556 🙂

Regards
Juan

 

[destroyer X]

Yep! ..... fuse rating not wrong

But considering real life supply performance, back EMF and other things....8A to 10A may work

regards,

Carlos

 

[thimios]

DX SUPER A

Travel beginning!
Handmade pcb as usual

 

[AKN]

Hi,
If we assume 42V rail and 6Ω speaker Re there will be 7A current over the fuse during a maximum DC output fault. 10A fuse will never blow during such conditions.

Much better to fuse the rails as fuse current rating could be halved. Rail fuses only take half period but the whole DC fault current.

 

[destroyer X]

Very nice thimios...hand made is very good

The real DIY spirit.

Your home etching resulted very precise..... congratulations...mine ones are worse.

I was observing, there's a modification in my circuit...while testing the Biamp i found that....i do think i have posted something about...cannot remember.... memory no good anymore.

Dx Bi amplified mono system and much more! - YouTube

regards,

Carlos

 

[vargasmongo3435]

nice etching mister thimios looks really good 🙂

here is the location of that capacitor 100nF

thanks Carlos I also forgot that one too 😛

Regards
Juan

 

[thimios]

DX SUPER A

The real DIY spirit.

Your home etching resulted very precise..... congratulations...mine ones are worse.

I was observing, there's a modification in my circuit...while testing the Biamp i found that....i do think i have posted something about...cannot remember.... memory no good anymore.

Dx Bi amplified mono system and much more! - YouTube

regards,

Carlos

Thank you very much Sir.
I have spent many hours and much money in handmade pcb.
Now i'm expert in handmade.