DDDAC1543 MK2 On order, now to decide on a ps for it?

[justblair]

Hi All

I can't really afford it just now, but I went ahead and ordered a DDDAC. But now I have to decide on a power supply.

My preferance would be for a mains powered supply, though I can see that batteries are recommended.

However reading this_page_by_simone_cappretti, the idea of SMPS power came to my attention. I already use Skynet8080's in my gainclone amp and get very good sound from them.

The advantage to myself is that I can buy these at less money than a big battery and charger or going for a linear supply.

Simone appears to note no difference in using smps.

Are there and DDDac owners out there who have tried SMPS?

I also happen to have some 12v smps units salvaged from Playstation 2s though the impression I get is that the SKynet will probably offer better quality?

 

[dddac]

Hi Blair,

I tried my self a straight forward switching supply from the shelf. Costed like 30 Euros (a 4A model) and the results were very close to the battery. The only difference I would say was a somewhat les clean highs. I must say, that this supply was pretty much stressed with the 5 towers consuming more than 3A, so may be a somewhat better filtered psupply with more "reserve" would do better. Any way, it is al very relative (no huge differences or so) and I do advise people these days, who for whatever reason, do not like the battery concept and have limited budget, to go for a switched power supply.

For large budgets, Unregulated power supplies with big Caps and Chokes are beating batteries, but you will spend more on the supply than on the dac...

The proof is always in the pudding, so what you can try is when you have a switched power supply, to take the battery out of your car and compare it In that case you have the ability to build your own opinion.

take care
doede

 

[justblair]

Thanks for the advice Doede

The SMPS 8080 is rated at 3.5amp (6amp max) on the 12v line.The quoted figures for ripple is 120mv and load regulation is +/- 5%

I have no idea how good bad or indifferent this is compared to other SMPS.

As you hopefully know by now, I went for your 12 chip usb kit. Though I intend to add more slave modules when budget allows.

I have some spare caps lying around, can I filter the ripple a little more with some caps between the 0v and 12v lines?

Unfortunately I dont have a car to try its battery. Though I thought that I could bunch up 8 1.5v batteries for a quick test.

 

[dddac]

As said, I would give it a try first and than check if the extra capacitors brings more. This unit seems right to me based on what you wrote. But on paper it is not always easy to draw conlusions

On the other hand, so far, response from dddac builders and also my self shows that the first and best tweaks which give directly a better sound are:

1. replace the ourput capacitorsto an audiphile type of your taste/choice

2. Put a large BG (or similar) capacitor directly next to the tower (where now there is a standard 100uF Electrolyte). the BG 1500uF N types are the largest available and cost relative little....
Of course value is not critical, but Size seems to matter here

Doede

PS: will get the stuff out to you this week ....

 

[soundcheck]

I spent 180€ for a Northstar NSB 90 Battery (100Ah) buffered with 8*470uf low ESRs to drive the DAC.

If you gotta a cost-no-object budget. I'd strongly recommend
that as a push-it-to-the-limits solution.

Cheers
Klaus

 

[justblair]

As said, I would give it a try first and than check if the extra capacitors brings more. This unit seems right to me based on what you wrote. But on paper it is not always easy to draw conlusions

Done. I have mailed my source to arrange purchase

On the other hand, so far, response from dddac builders and also my self shows that the first and best tweaks which give directly a better sound are:

1. replace the ourput capacitorsto an audiphile type of your taste/choice

2. Put a large BG (or similar) capacitor directly next to the tower (where now there is a standard 100uF Electrolyte). the BG 1500uF N types are the largest available and cost relative little....
Of course value is not critical, but Size seems to matter here [/B]

1. I was thinking Sonicap bypassed with very small Vishay, I like this sound in my speakers and everyone I have read posts from that uses them seems to approve of the sound per pound from these caps

2. Not sure I have anything that big that's new, Got a couple unused Nichicon Muse 470uf sitting I think. A good starting point, though I have also got four 1000uf that came from a crossover in my mission 753 speakers. Dont know how good they are right enough.

PS: will get the stuff out to you this week .... [/B]

Yee ha, looking forward to building it. Thanks Doede

I spent 180€ for a Northstar NSB 90 Battery (100Ah) buffered with 8*470uf low ESRs to drive the DAC.

If you gotta a cost-no-object budget. I'd strongly recommend
that as a push-it-to-the-limits solution.

I have that option open to me in the future. The SMPS can be reused elsewhere if I go down that route.

Thanks for the advice folk.

 

[crazy_bob_uk]

super regulator

How about a super regulator e.g. the ALWSR:

http://www.at-view.co.uk/alwsr.htm

The specs it claims seam very impressive, and doesn't cost the earth (about £25 to £30).

 

[pburke]

Re: super regulator

How about a super regulator e.g. the ALWSR:

http://www.at-view.co.uk/alwsr.htm

The specs it claims seam very impressive, and doesn't cost the earth (about £25 to £30).

doesn't look like this thing would handle the load of a DDDAC tower. Nice for the clock or USB board maybe, but not to support multiple amps.

 

[protos]

I am using ALW supereg for 24 dac DDDAC.I think this is the only PS option that can beat batteries according to my experience.Of course you need another PS (15-16V) in front whether regular or switching.One idea which is worth investigating as I have already posted is to get rid of the lm 317 regs for the towers and power the dac with 8.5v from the supereg.This gives the best sound and allows you to use a simple and cheap(er) 12v supply in front.
Batteries give a very natural sound at mid and high freq but may be a little slow in dynamics.I just got fed up charging-remembering to switch off etc etc.
The ALW supereg in front of a 12v PS gives much better dynamics and detail retrieval while sounding natural.

 

[dddac]

More and more it seems coming down to the fact that the 1543 tower likes to see a low as possible impedance.... My experience is, that large low ESR Capacitors improve things

still interesting, that it does makes an adible difference, what happens before the lm317 regulator....

I like the idea of the shunt regulator directly in front of the tower. Should be easy to integrate on a next version I guess.....

Question: do you use one shunt regulator per tower or one shunt regulator at 8.5 v, just feeding the whole thing ?

 

[protos]

At the moment just one reg feeding the two modules directly.I still have not gone up to 48 dacs even though they are sitting in my workshop.But the one reg manages well enough for the 24 dacs.I may try one per module .I think the sound of the PS is critical for the dac.
I have not tried any switching supplies but any regular LM317 or even mosfet/zener type do not sound as good as battery or of course the supereg.

 

[justblair]

More and more it seems coming down to the fact that the 1543 tower likes to see a low as possible impedance.... My experience is, that large low ESR Capacitors improve things

still interesting, that it does makes an adible difference, what happens before the lm317 regulator....

I like the idea of the shunt regulator directly in front of the tower. Should be easy to integrate on a next version I guess.....

Question: do you use one shunt regulator per tower or one shunt regulator at 8.5 v, just feeding the whole thing ?

Very interested in the recent posts

I am trying my best (e-mail problems) to purchase the skynet power supply as I type.

I have 8 panasonic HFQ 4700uf coming to me that I picked up nice and cheap from e-bay.

B]Are these any good for improving the sound, if so, where should I place them?[/B]

Protos. I like the look of the kit you refer to, Best still because I can go with the cheaper option just now and upgrade to the ones you refer to later.

 

[soundcheck]

The impedance is for sure an issue.
You'll notice any changes on the supply rail.

Just take out the switch or fuse and listen.
My battery comes with 2mR compared to standard 10Ah 20mR.
That makes quite a big difference .

Doede:
I think shunt regs might be a serious improvement.
http://www.tnt-audio.com/clinica/tnt1541_e.html

Cheers
Klaus

 

[maxlorenz]

Hi,

I got tired of the battery too and made my own PS to power my 16DDDAC MK I.
I am the first to confess that I don't know what I am talking about but anyway the PS works great, even better sonics than battery: more extended up and down, softer sound, better and deeper bass (always with gyrator), more dinamics.

I used a 50VA EI, external to the DAC box (secondary V is too low, I have to change it for another TX), a gyrator based on a home made Darlington and big film cap after big and cheap elcaps, then a LT1085 reg (3A max) for the tower and a L7809 as pre-reg for the digital sections. Big heatsinks for each PS actives and BIG heatsink for the 16*tower. Everything stays cool.

I made a "star ground" for BC547's base and both regulators which is the ground connection point for the next sections.
One positive point is that it can be always ON.

Sorry for the bad quality drawing, from memory...should be a mistake or two...

Any advice will be very welcome!

Bye,
M

 

[nicoch58]

from my experience on dddac the tent clock made the difference, if the amp have caps on input ,remove the out caps and 100k....Rload 180R made great difference on sound for now I use kiwame ,very sweet sound ,the stock sound very harsh... I will tray riken-tantaliun -vishay for fine sound twiking but do not use stock R !!!

hope this help

manu