Experience with this DIY DAC ?

@Chris
Then the Monacor LTR-110 would be a good choice, cheap as it gets and still gives a flat response and a good sound...


Hi ch33ta
I use this DAC with OPA LM4562 and a Tube stage anode follower 6N6P lampizator diagram. The DAC via OPA has a line output at 2.5Vrms at 1 KHz, can you tell me when you use an output transformers how big is the output level?
Thanks
I get 1.7Vrms at 1kHz on the output, high enough for my needs. So far it drives my headphones perfectly, didn't expect that :)
 
Franz, which Lundahls should i get now?

LL1690 or the other ones?

@ch33ta
ill check the monacors too

it doesnt need to be the cheapest, but the trannis that i buy should deliver a good quality for the price

edit:
i found this ones here:
http://www.thomann.de/de/monacor_ltr110.htm

10€ is quite cheap and the shop is not far from me

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the line transformator only has the job to change the output impedance right?

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edit2:
just to be able to test the dac i could also buy two transformators, one with 13v and one with 8v right?


this one for the dac:

Print Netz Trafo
prim 230 V,
sek1=8 V 15 VA
sek2=8 V 15 VA
Maße: L= 63 , B = 54, H= 54 mm.
Typ U 4062 1 St. 4,25 €



and this one for testing with the OPVs:
Print-Netz-Trafo prim 230 V sek 1 = 8 V 1,6 VA sek 2 =13 V /8,6 VA
Maße L=50, B=42, H=34 mm.

Typ U 8311 1 St. 1,75 €
 
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I have an Onkyo DX 6850 CD player, on analog has the same output level 2.5v RMS so when I compare the DAC with the CD player I can have an opinion about the sound quality between them because the output level is the same, but if the signal is less or above the 2.5v the cooperation is unfair, if is more then 2.5v the sound is more dynamic. In my opinion if we want to compare more output stage together in an A/B test and chose the right one all must have the same output level
 
@Chris
The first one is good, but to power the opamps you need a center taped transformer, 2x12VAC to 2x18VAC, something like this:

NTR 5188
230
2 x 12 V, je 3 A - oder 24 V, 3 A
EI78

It says on the site it is not availabile, but you get the point... Any transformer with 2x12V output (or more)...
 
Wow this is really very complicated.

Maybe I should have orderer the transformator too, then I could test if everything is fine.

*sigh*

The only thing I know so far is that I would love a potted ( i hope its the right word) toroid transformer for the dac-section. so this one cant cause any hum.

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For testing OPVs:
"30 VA, 2x 12 V, 2x 1,25 A" ~15€

For DAC-section:
"10 VA, 2x 9 V, 556 mA" from talema, "potted" and only ~12€

Is this good now? Or am I too stupid xD
 
Wow this is really very complicated.

Maybe I should have orderer the transformator too, then I could test if everything is fine.

*sigh*

The only thing I know so far is that I would love a potted ( i hope its the right word) toroid transformer for the dac-section. so this one cant cause any hum.

----------------------------------------------------------------------------------

For testing OPVs:
"30 VA, 2x 12 V, 2x 1,25 A" ~15€

For DAC-section:
"10 VA, 2x 9 V, 556 mA" from talema, "potted" and only ~12€

Is this good now? Or am I too stupid xD

Perfect :)
 
Dac:
Gigaworks

Case:
Hifi Galaxy 230x280

------------------
Transformators:
10VA, 2x 9V, 556 ma
30VA, 2x 12V, 2x 1,25 A

Board for first transformator 75mmx100mm
Clamps for input/output
distance bolts

power connector
usb connector
2x RCA
switch

i dont use coax or optical input for now, maybe in some years :D

i think this is all i need now?

:D
 
Disabled Account
Joined 2007
I can understand that some people want to spend as little as possable on output transformers, but for the good sound you need to at least get something of quality.

The A-20's or if buying new, the Cinemag CMOQ-2H quadfilars sound great! and the pricing is about the same as what you pay for the A-20's.
 
I can understand that some people want to spend as little as possable on output transformers, but for the good sound you need to at least get something of quality.
But it also doesnt make sense to buy output transformators that cost more than the DAC ?! i dont want to spend as little as possible but i want a good quality for the price and not just something that is maybe 5% better and costs 300% more

For the AC mains connection, I strongly recommend to use an IEC adapter with included switch, fuses and RF-filter.

It is good for safety reasons and also to avoid dirty power.

Franz

hm well thats maybe an easier solution. do you know a shop where i can get one?

else i use my power connector with included fuse and an extra switch, i think thats ok too because my multiple socket already has a filter included.


greetings,
Chris

edit i found some but it costs 17€.. well maybe i should get it

which fuse should i use?
 
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But do what ever makes you happy, that's what all this is about :D

True.

But did you compare the sound with a second DAC of this type? Ur $100 trannies vs cheaper ones?

edit:
The Monacor LTR-110 might be my first choice atm because they are cheap and seem to be quite good

edit2:

why are the recommended trannies always so old? couldnt find the newer one yet
 
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Disabled Account
Joined 2007
No, but a mate of mine not only designs high end valve amps but also winds his own transformers for his amps and I trust his opinion, and I also did a lot of research into it while looking at transformers.

But you should go with what you feel is best for you, and you can always look at others later if you feel the need.
 
Disabled Account
Joined 2007
I'm sure thay will be leaps ahead of the opamp stage, no worries there :)

Recommended transformers?
Plenty of good new ones out there, though some cost a fair bit, that's why I looked hard and settled on the Cinemags as they looked very close to the best on offer from other companies but at much lesser cost.

After all, I'm a Scot' :D
 
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Those look like the ones I'm using, seem to be pretty good as far as I can tell.

Acually improved the signal quality over some cheaper ones I was using before them.

Well then I should try them. But usually also cheaper ones should have the same sound quality, as long as the contacts and isolation are good, imo.

Better transformers sound better. I've done quite a few blind tests. They all sound different, some better than others.

Is there a special thread for transformers and the comparisons? that could be interesting.