Dedicated PSU for DEQ/DCX2496

[stef1777]

Hi Folks!

I'm designing a linear dedicated PSU for the Behringer DEQ2496 (and DCX).

I need an advice. In this current draft drawing, the 10v ground is connected to the 15v ground. I don't know if I can connect 2 ground lines for 2 different transformer/rectifier.

Enclosed is my last draft.

Thanks for your help.

Stephane

 

[stef1777]

New version.

 

[altclick]

Stephane,

Didn't you already install a psu in your DEQ2496 a while back?

Vic

 

[stef1777]

Stephane,

Didn't you already install a psu in your DEQ2496 a while back?

Vic

Sorry Vic, I'm not sure to understand your question.

New version. I started to design the PCB. VK200 will be removed (no space lelft for that). All rectifier will have caps close to the pins. I changed some components references. The schematic is not yet up to date.

 

[Ryssen]

So there will be a board?

 

[stef1777]

So there will be a board?

Yes but the way is long until the paradise. ;-)

An externally hosted image should be here but it was not working when we last tested it.

.

 

[AR2]

Hi Stephane,
What is the improvement over existing PSU?Would this replace 7805 regs. that are on the board as well or they will stay?
Thank you
AR2

 

[altclick]

Never Mind - I see how this is different. You are going to replace the stock PSU altogether.
Thanks for sharing the project - this is one I would like to follow...

Vic

 

[stef1777]

Yes, true.

New version. Heat sink was too small for 3.3v and 5v. VK200 are back. Decoupling caps for all rectifiers. Ground plane. 2 types of output connector possible.

Real size.

An externally hosted image should be here but it was not working when we last tested it.

 

[Ryssen]

Making progress!🙂
Count me in for one when finnished.😎 🙂

 

[stef1777]

Still in progress...

 

[stef1777]

The PCB is over. Comments welcome. I plan to send files for 2 units prototype next week.

Large file:

http://audio.cyberkata.org/DEQ2496/pcb_alim_deq_5_big.gif

Schematics:

http://audio.cyberkata.org/DEQ2496/DEQ2496-PSU-DIY-1.7beta.pdf

.

 

[Ryssen]

Is the PCB same size as "old" PSU?What VA rating was the transformers on the picture?

 

[stef1777]

Is the PCB same size as "old" PSU?What VA rating was the transformers on the picture?

Not really. The transformer will go at the place of the original PSU. The board need to be placed around.

Transformers specs and more are wrote in the schematics. The best will be to build a dedicated transformers with optimized voltages.

Large file:

http://audio.cyberkata.org/DEQ2496/pcb_alim_deq_6_silk.gif
http://audio.cyberkata.org/DEQ2496/pcb_alim_deq_6_big.gif

Schematics:

http://audio.cyberkata.org/DEQ2496/DEQ2496-PSU-DIY-1.8beta.pdf

.

 

[giulio]

Hi,

9V is the analog supply. Any reason it is not regulated in your schematic?

I thought it was the most important one. In fact, I have just converted it to linear using a selectronic kit.

Best
Giulio

 

[stef1777]

Hi,

9V is the analog supply. Any reason it is not regulated in your schematic?

I thought it was the most important one. In fact, I have just converted it to linear using a selectronic kit.

Best
Giulio

The 9v go to the 7805 on the DSP board to generate the analog 5v to fit DACs and ADCs. For this reason, not reg on the PSU board.

I've done today some tests with various 15VA transformers.

2x15v transformer for the analog +-15v is ok. Not dissipator or small one are ok.

2x9v transformer for the rest is not ok. The system work but LM are very hot with a 4°C/W dissipators (but should be ok with a 21°C/W dissipators). The 9v is too high (10,93v) and the 7505 on the DSP goes very hot (and no space left to fit a dissipator).

I tried with a 2x6v transformer. Not working. I've not yet checked which parts is not working.

I mesured the current on the DEQ2496 (with 2x15v and 2x9v transformers):

+15v -> 87mA
-15v -> 84mA
+9v -> 207mA
Total AGND: 378mA
Total DGND: 907mA
+5v -> 554mA
+3.3v -> 392mA

A 15VA transformer is may be too short for the 5v current.

All

I don't have a 7v or 8v transformer to test.

.

 

[Ryssen]

The 9v go to the 7805 on the DSP board to generate the analog 5v to fit DACs and ADCs.

I have just converted it to linear using a selectronic kit.

Thats what the selectronic kit does,it bypasses (Replaces)the 7805 on the DSP board and uses its own LM317.
That would be the best solution,I think to use a LM317for the 10v line on the new PSU card,maybee with a heatsink.

 

[giulio]

Thats what the selectronic kit does,it bypasses (Replaces)the 7805 on the DSP board and uses its own LM317.
That would be the best solution,I think to use a LM317for the 10v line on the new PSU card,maybee with a heatsink.

Indeed, I just installed it on Saturday. Very big improvement. That is why I was pointing it out as a worthy mod to add.

Giulio

 

[stef1777]

New schematics. In fact, we need at minimum a 2x7v 20VA transformer to fit 9v, 5v and 3.3v. A 2x15v 5VA is enough for the +-15v.

Concerning the 9v. I'm pretty sure that a linear PSU for all voltages with good output noise, strong regulation and nice tunning of all components will do the same as the Kit, and more. The KIt only "clean-up" the analog PSU for DAC and ADC, not the others voltages, and only work with the DCX. The digital 3.3v, the digital 5v and the 15v for op-amps stay the same.

Now, I need to find the right transformer(s).

.

 

[stef1777]

These 2 transformers will fit very well:

Amveco 62060
2x15v 7VA
58.0x13.8x34.5

Amveco 62023
2x7v 25VA
47.0x6.0x21.5

or Talema.

If someone know an European replacement?

.