May I ask if you use an output transformer or if you connect directly?
I did some experiments with my own Soekris dam1941 with output transformers.... Lunfahl, amorphous cores from smallish ll1674 over 7903 to ll1692AM... not matter what, they add a metallic, technical sound. The direct connection to the grids of my tube stage wins anytime. Nit sure if we have no choice as ti use output transformers, but i doubt that those chinese 40$ a pair guys are better than the 500$ LL1692am which is best of the Lundahls i had on hand.... but no tramsformer in the aignal path is best.
I did some experiments with my own Soekris dam1941 with output transformers.... Lunfahl, amorphous cores from smallish ll1674 over 7903 to ll1692AM... not matter what, they add a metallic, technical sound. The direct connection to the grids of my tube stage wins anytime. Nit sure if we have no choice as ti use output transformers, but i doubt that those chinese 40$ a pair guys are better than the 500$ LL1692am which is best of the Lundahls i had on hand.... but no tramsformer in the aignal path is best.
I did try chinese, Ludhal, teramoto and bisesik transfomers from this thread:
Output transformers for DACs.
I did not tried it with Soekris (I used it the way you describe: no transfomers), but used them in another applications (AKMs,ESS,AD DACs). Bisesiks ones was the best!!! So if I ever had to use transformers I would definatelly ask bsiesk to make me one.
The DAC uses transformers, do not know which type as the transformers are not visible due to shield can.
I have read somewhere in a forum that first Signalyst DSC1 included a transistor I/V output but the transformer output should sound better. A transformer is soundwise never 100 % transparent as you could also confirm by your experience. Would like to try transformer less version of the DAC. Anyone has a Signalyst DSD w/o transformer output and can share details?
Attachments
Hmmm... the Soekris is a R2R Dac as well... and oitputs 1.3Vrms I believe with 600 ohm, so i/vconversiin is already done.
I assumed that the stardac has a similar spec? What is it output specs actually?
I assumed that the stardac has a similar spec? What is it output specs actually?
There is no I/V stage on Soekris nor in Stardac, because those are voltage out dacs. Transfomer are used to galvanically isolate those dacs from preamp or amp and maybe as LPF.
That was my understanding, thanks for confirmation... any specs on voltage level and impedance for the star dac?
1543...this means you can easily check the effect of your transformer... as tgey are basically not needed.
1543...this means you can easily check the effect of your transformer... as tgey are basically not needed.
It is not possible use the Star DAC without the output transfomers because it have a differential output stage and it is necessary an I/V like show in the DSC1 schematic.
I think is better a good output transformers than an opamp but thi si my opinion.
In the case of Soekris probably is better use no transformers on output but this is an R2R DAC very different from DSC DAC.
We have selected these output transformers after many test also comparing them with high cost transformers such as those mentioned by you.
I have a DSC2, using Pavel's V2.5.2 boards, with Lundahl LL1684 transformers and it sounds amazingly good; very organic, natural sound with no sense of a "...metallic, technical sound'. Of course, YMMV.
I agree completely with you. I also have the DSC2, but with Chinese transformers. Very organic analog sound without harshness.
Be aware, it's a full-on DIY job, there aren't assembled boards available anymore (unless you're lucky to find one for sale) so it involves getting PCBs fabricated and then you have to solder up all the smd parts.