Salas DCG3 preamp (line & headphone)

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lykkedk

lykkedk

Member
Joined 2002
Evening all :confused: ... :)

I am confused, so i need you guy's to help me a bit if possible!

Last night i was comparing the PSU layout, which Salas did, and the layout i do right now.
The component DC10EWA https://www.google.dk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwjZx6jVg9PPAhWC7hoKHWVoBM4QFggwMAA&url=https%3A%2F%2Fwww.kingbrightusa.com%2Fimages%2Fcatalog%2Fspec%2FDC10EWA.pdf&usg=AFQjCNFeSST4TPkaGZuZgHXyWQUhJ67Enw i created inside my pcb program, according to the datasheet.

But when i look at my pcb-design, i see that Salas's pcb is connected differently to DREF1 and DREF2... according to my component and datasheet, my schematic is correct, and salas has swapped anode/kathode connections.

Well... i surely belive that Salas is the correct one :D ... But i cannot figure out, what is wrong with my connections.

Please help me, before i go nuts ;)

(On my schematic i have not yet connected the series zigzag connection inside DC10EWA)
Jesper.
 

Attachments

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  • DC10EWA-diff.png
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  • DC10EWA.png
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  • MyPSU.png
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lykkedk

lykkedk

Member
Joined 2002
Hi...

I think i figured it out :eek:

The resistor RxJ and the DREF1 (DC10EWA led-block), must shift place, so that the DC10EWA connects to "0" pad on schematic

Same goes for RyJ / DREF2

Am i right ?

Jesper
 

Attachments

  • Screenshot from 2016-10-11 19-37-33.png
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lykkedk

lykkedk

Member
Joined 2002
Salas said:
Led blocks and Rx,y swapped positions in the boards vs shown in the schematic for same length tracks left & right. Because in series its the same circuit result.
Click to expand...

Thank's...

I simply cannot see, why it's the same ?

If i swap resistors to be on the other side of the LED block (See attachment), the pcb layout will be the same as yours.,

But if i follow the original schematic, i cannot make that layout, no matter how i do it ???

sorry for the confussion :confused::D

Jesper.
 

Attachments

  • Screenshot from 2016-10-11 19-37-33.png
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lykkedk

lykkedk

Member
Joined 2002
I just found this :

It doesn't matter if place the resistor before or after the LED because is the amount of current the resistor limits as not to burn the LED. In a series circuit the current is the same for all components and because the LED and the resistor are in series you can connect them as you want.
Click to expand...

I feel so stupid... i allway's thought, that resistor must go on positive side of LED, else it wouldent work... so embarrising :(

Sorry for all the confussing here!

Jesper.
 
Salas

Salas

diyAudio Chief Moderator
Joined 2002
Paid Member
Build guide

No worries my friend, I finished the build guide for both the pre and the supply. It has BOMs, schematics, practical steps advice you will need, with all the small details properly updated. Go to post #1 to download it and read it. I already put it there. :)
 
Salas

Salas

diyAudio Chief Moderator
Joined 2002
Paid Member
Hikari1 said:
I'm cheap, but something like this might be easier to do on a PCB with all the relays and such. But I think you learn more by doing point to point, you actually realize what the parts are doing.

But if this thing is anything like your phono stage it will be worth it.
Click to expand...

Its about ready and handy with hardwiring, not being cheap. To really finish this preamp in a box, not even too luxuriously with heavy construction and great connectors, fancy big trafos, super resistors, fine quality pot or LDR, Arduino remote ladder board & color screen etc. but just decent industrial stuff, and although it needs no coupling caps or myriads of components, it will eat way way more money till then anyway.

BTW Michael phoned late yesterday and said that his conclusion is that the superiority he felt over his beta builds and he was perplexed about is the pcb itself after all in his opinion because he tried one I gave him (I had only two spares) and all other things he did were not more influential. So if you hardwire its not bad to try follow the pcb's general idea. Its true that I had bugged Crt's life with my guides & revisions for quite a while though. Sorry Crt :D
 
Tea-Bag

Tea-Bag

Member
Joined 2006
Paid Member
Ok, I have started the process of opening a GB for all Salas boards including these.
The sign up spreadsheet is linked in my signature. (Please don't post here). The board prices are fixed, but the kit prices are not quite solid yet, as I need to line up a few items cost before fully disclosing that. So I hope to have that done ASAP, but feel free to sign up in spreadsheet to show your interest. Once pricing is finalized, I will start a GB thread that mostly focuses on getting boards and parts. Let me know if there is any problems with sign up. The DCSTB boards are on the far right. You will need to scroll over unless your using a 4k monitor!
 
A

AIM65

Member
Joined 2015
Paid Member
Tea-Bag said:
Ok, I have started the process of opening a GB for all Salas boards including these.
The sign up spreadsheet is linked in my signature. (Please don't post here). The board prices are fixed, but the kit prices are not quite solid yet, as I need to line up a few items cost before fully disclosing that. So I hope to have that done ASAP, but feel free to sign up in spreadsheet to show your interest. Once pricing is finalized, I will start a GB thread that mostly focuses on getting boards and parts. Let me know if there is any problems with sign up. The DCSTB boards are on the far right. You will need to scroll over unless your using a 4k monitor!
Click to expand...

Tea Bag,

will the board be included in the full kit ?
will the uPA68 be included in the transistor or full kit ?
It may be convenient to have them as an option of the transistor kit and full kit as some DIYer may already have them in stock or may want to try LSK389 or 489.

thanks for all, I was very happy with the execution and the parts quality of your last GB !
 
M

Morde

Member
Joined 2014
Hi there! I just couldn't help myself but to sign in to the group buy for one DCG3 transistor kit and one power supply kit. Excellent design and documentation by Salas and great that Tea-Bag is organizing this group buy. I have absolutely no idea where to stuff yet another hifi equipment, but this is truly something I can't skip!

P.S. @Tea-Bag: I removed myself from the Salas LV power supply GB.
 
Last edited:
Tea-Bag

Tea-Bag

Member
Joined 2006
Paid Member
For now I will intentionally not add details of the GB to this thread. That way later on, people can look at this as the technical thread not GB. But I will be able to provide parts, but they are going to be in smaller and larger kit forms, not ala carte.
 
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