Accepted, you get my DAC with 4 boards, 4 power supplies, wired with silver, it also has a unique Nixie display that no one has, but on the condition that you come to live in Serbia, and I move to Switzerland.
Hi...
I finally connected my Sowter 9335 Transformers to the Dac in a temporary assembly with some switches so I can easily compare Sowter vs Caps. First I used some Mundorf EVO Alu Oil caps but will soon try with a pair of older Duelunds.
Sowter clearly beats the Mundorf which was hardly surprising ;-)
Just one question for you guys. I have tried to Google if some R load resistors are needed on the Secondary side of the Transformers, but I cannot find much information about the Sowters.
It seems the recommendations is 1K8 Ohm for the Cinemag 600/600 and the new Audio Creative O.P.T.
My DDDac is a Quad-Board'er and my input impedance on the Preamp is 100K.
Any suggestions here will be appreciated.
/Martin
I finally connected my Sowter 9335 Transformers to the Dac in a temporary assembly with some switches so I can easily compare Sowter vs Caps. First I used some Mundorf EVO Alu Oil caps but will soon try with a pair of older Duelunds.
Sowter clearly beats the Mundorf which was hardly surprising ;-)
Just one question for you guys. I have tried to Google if some R load resistors are needed on the Secondary side of the Transformers, but I cannot find much information about the Sowters.
It seems the recommendations is 1K8 Ohm for the Cinemag 600/600 and the new Audio Creative O.P.T.
My DDDac is a Quad-Board'er and my input impedance on the Preamp is 100K.
Any suggestions here will be appreciated.
/Martin
Yesterday I tried Cinemag transformers again. The preamplifier has an input impedance of 50K. I loaded the transformers on the secondary with 4K7, 10K, 18K resistors and finally no load. The sound was getting better with less load, except for the bass when there is much less than with the capacitors. Also high frequencies are too present with 50K load. Everything else is good, 3D presentation, details, etc. In the end I decided to order 4pcs. Jantzen Silver Z of 4.7uF and that is a better option for this DAC. Much fuller sound and silky highs unlike a transformer. For some reason the Cinemag transformers are not a match for a 2 board DAC. When I find the time I will try them with my 4 board DAC. I also plan to rewire everything with VDH SCS18 or similar, I have some more silver-plated wires that I use, I will replace both USB and SPDIF wires with something better. I don't like how this was done with cheap wires everywhere. This DAC deserves much more than this.
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When I started making my DAC, I saw the output options you suggested. I was a little scared to connect the XLR directly so I opted for two more capacitors. All in all, it’s a small investment. I know it's better without them, but this way I'm sure that even in the event of a failure in the DAC, nothing bad will happen further in the audio chain.
by the way, this is what happens with the dddac Sowter transformer when loaded with 100k and 1k (just for testing I did this) I load the transformer with 100k in normal operational situation (= music listening) - The source impedance for this setup was 20 Ohm
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Hello Doede and DDDAC addicts,
I think when i start using the Sowters i just consulted the manual and asked Doede how to do it. I am not using a resistor on the output of the transformer so i guess they should be used without them.
If you do use them and things are not like what you have expected the first thing to do is use them as they are designed to be used and not blame the DDDAC for a sound you dont like.
Greetings, Eduard
I think when i start using the Sowters i just consulted the manual and asked Doede how to do it. I am not using a resistor on the output of the transformer so i guess they should be used without them.
If you do use them and things are not like what you have expected the first thing to do is use them as they are designed to be used and not blame the DDDAC for a sound you dont like.
Greetings, Eduard
Can an increase in the frequency range curve (+10dB at 200kHz) cause any problem to the preamplifier or amplifier or speakers? One of my preamplifiers (unity gain buffer) is an Aikido cathode follower with 6N6P. The measured frequency range is 1.5Hz to 1.8MHz (-3dB). I also have one SS preamplifier, the range is 1Hz to 1.2MHz -3db. The output amplifier is LEACH LOW TIM, it also has a very wide range (I guess over 250KHz -3dB, I didn't measure it though).
I also don't understand why there is so much less bass with Cinemag transformers compared to capacitors, when everything is connected properly? Had it not been for that shortcoming, he would probably have left them in the DAC without loading resistors at secondary.
I also don't understand why there is so much less bass with Cinemag transformers compared to capacitors, when everything is connected properly? Had it not been for that shortcoming, he would probably have left them in the DAC without loading resistors at secondary.
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Not blaming anyone, I'm just trying to solve something and understand why there is a problem with Cinemag transformers in combination with 2 decks of DDDAC. I guess someone else has that combination, to advise me what to do.
Hello,
Sorry i presumed you were using Sowter!
I know the Sowter needs 4 boards and i am a big fan of transformers, the good ones.
You could use the search function for Cinemag in this thread but i think there are many people using them with two boards.
If there are many users it must be something in your set up that is totally different from theirs? Maybe your preamp offers a bad impedance match with the Cinemag?
Greetings, Eduard
Sorry i presumed you were using Sowter!
I know the Sowter needs 4 boards and i am a big fan of transformers, the good ones.
You could use the search function for Cinemag in this thread but i think there are many people using them with two boards.
If there are many users it must be something in your set up that is totally different from theirs? Maybe your preamp offers a bad impedance match with the Cinemag?
Greetings, Eduard
My SS preamp has an input impedance of 50k (log potentiometer), and no capacitors at the inputs or outputs (DC coupling completely), amlifier is DC coupled too, so no bass issues here. The two DDDAC decks has an output resistance of 68ohm. I don't see a mismatch here. Everything is connected properly (it is a simple thing anyway). I'm still waiting for someone to show up who has that combination.
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I noticed you have an AP. so why not run (get the facts) a frequency sweep through the DAC with 1. The transformers and 2. the capacitors at the output and see if you really have less Bass ? It definitively should not be the case - very unusual and I never seen an issue like this (less bass C vs. Tr)