I built my DAC in a chassis I used some years ago as EL84 amp:
After finishing, it will look like this gainclone:
Franz
An externally hosted image should be here but it was not working when we last tested it.
After finishing, it will look like this gainclone:
An externally hosted image should be here but it was not working when we last tested it.
Franz
Okay, so it ain't much of a looker, but IT LIVES!!! Sorry, but I couldn't resist exposing this ugly duckling, I am so delighted with it!
Thank you everybody for this thread, especially those who answered my newbie questions (legarem, Franz Gysi, Kevin Wood).
It sounds good already, even with long, dodgy interconnects. Now then, where did I put that spool of Kynar wire..! (DIY interconnects!)
Thank you everybody for this thread, especially those who answered my newbie questions (legarem, Franz Gysi, Kevin Wood).
It sounds good already, even with long, dodgy interconnects. Now then, where did I put that spool of Kynar wire..! (DIY interconnects!)
Here are my ugly dacs
There's one with lundahls and the other one has Studer uncapsulated transformers I bought from Franz. The first time I tried them, the sound was so bad so I decided to forget them.
Last night, I was thinking that Studer can't do something so bad so I decided to try them again but with a 600 ohms load like the Tams.
Humm ... It is now a real different story
Franz
If you still have a pair try them and give us your impression.
There's one with lundahls and the other one has Studer uncapsulated transformers I bought from Franz. The first time I tried them, the sound was so bad so I decided to forget them.
Last night, I was thinking that Studer can't do something so bad so I decided to try them again but with a 600 ohms load like the Tams.
Humm ... It is now a real different story
Franz
If you still have a pair try them and give us your impression.
Attachments
Somday I'll make mine like the ones I do to other peoples who want clean jobs.
Prototyping is funny. Doing cosmetics is a nightmare. I hate that !
Here is one I made a year ago when Lukasz Fikus published my LM4562 op amp mod. There is two monstruous transformers.
Later, many peoiples asked me to replace their toroids with EI transformers when they heard the difference
Prototyping is funny. Doing cosmetics is a nightmare. I hate that !
Here is one I made a year ago when Lukasz Fikus published my LM4562 op amp mod. There is two monstruous transformers.
Later, many peoiples asked me to replace their toroids with EI transformers when they heard the difference
Attachments
Nice thread!
There is som issues that makes me wonder a bit though.
First! Can anyone tell me precisely at which frequenzy the 4398´s Switced capacitor filters noise appears and eventually the amplitude.
Next!
Why use a transformer?
Transformers for linelevel is normally used in pro gear, and only because it simply is necessary to avoid humming. Most microphones uses transformers as well, but for purists the very best microphones also comes in TransformerLess versions. Both DPA, Neumann amongst others do so, and they do so because the TL versions are the better ones.
The transformer provides isolation, but as a sideeffect it also provides hysteresis, which masks low level information a lot especially at higher frequenzies.
If the core in some way could be biased with some low level HF that could be filtered afterwards, it might work better at low levels. This principple is ie. used in analog tape recorders.
Btw. if it sounds nicer than op-amps I fully understand, op-amps are imho not the best solution for audio amplifiers.
There is som issues that makes me wonder a bit though.
First! Can anyone tell me precisely at which frequenzy the 4398´s Switced capacitor filters noise appears and eventually the amplitude.
Next!
Why use a transformer?
Transformers for linelevel is normally used in pro gear, and only because it simply is necessary to avoid humming. Most microphones uses transformers as well, but for purists the very best microphones also comes in TransformerLess versions. Both DPA, Neumann amongst others do so, and they do so because the TL versions are the better ones.
The transformer provides isolation, but as a sideeffect it also provides hysteresis, which masks low level information a lot especially at higher frequenzies.
If the core in some way could be biased with some low level HF that could be filtered afterwards, it might work better at low levels. This principple is ie. used in analog tape recorders.
Btw. if it sounds nicer than op-amps I fully understand, op-amps are imho not the best solution for audio amplifiers.
Kurt von Kubik said:
Your last sentence is the answer to your question.
Op amps are used to make desings cheaper. Today, some can be considered good but discrete parts sound simply better even if they don't have specs as good as op amps.
Op amps have their gain controlled with a ton of negative feedback. This often means good numbers but bad sound.
Franz Gysi said:
Here we are reknowned to have good ac supplying electricity.
My system is feed by a 5 kva monster transformer in balanced mode. 4 - 10 gauge copper shield wire goes from the transformer to the system.
Each time I tried small line filters (corcom filters etc) I finish to take them out because they add some brightness to the sound I hate.
Even if your mains is good, Toroidal transformers by their high bandwith will transfer some garbage from the mains to the component.
Question of sound, EI transformers gives a more relax sound. Toroidal seems to give 'faster' 'zippy' forward sound I don't like.
Some peoples (mainly engineers) thought that i'm crazy with what i'm saying but when they try, they discover that they have ears to hear something.
Legarem
for power the dac which of the following trafos you will recommend and why
1) http://www.reichelt.de/?;ACTION=3;L...wQARwAAAksfd8d35bb22d84b6d3c7f2741e6b516d47ed
2) http://www.reichelt.de/?;ACTION=3;L...wQARwAAAksfd8d35bb22d84b6d3c7f2741e6b516d47ed
3) http://www.reichelt.de/?;ACTION=3;L...wQARwAAAksfd8d35bb22d84b6d3c7f2741e6b516d47ed
for power the dac which of the following trafos you will recommend and why
1) http://www.reichelt.de/?;ACTION=3;L...wQARwAAAksfd8d35bb22d84b6d3c7f2741e6b516d47ed
2) http://www.reichelt.de/?;ACTION=3;L...wQARwAAAksfd8d35bb22d84b6d3c7f2741e6b516d47ed
3) http://www.reichelt.de/?;ACTION=3;L...wQARwAAAksfd8d35bb22d84b6d3c7f2741e6b516d47ed
Samoloko
I am not Legarem, but I can answer your question: they are all to small.
Use as minimum an 24VA, better a 30VA or bigger version.
While I am not an engineer
and I have very big ears (they seem to physically grow while aging, but the roll off is at 13kHz today), I just attached an EI tranny to the DAC and I also have the impression of softer sound.
Franz
I am not Legarem, but I can answer your question: they are all to small.
Use as minimum an 24VA, better a 30VA or bigger version.
While I am not an engineer
and I have very big ears (they seem to physically grow while aging, but the roll off is at 13kHz today), I just attached an EI tranny to the DAC and I also have the impression of softer sound.Franz
BTW:
Because of all this tests and comparisons on my side, I got aware, that I have not enough bass in my nearfield setup (Fostex FE83E in the recommended enclosure).
Actually I plan to build an active crossover and refurbish a bridged LM3886 amp, to drive a subwoofer speaker.
And I will convert my desk to a big open baffle:
Just attach a big panel on the backside of the desk, between the legs. And another two panels sidewards of the desk.
In the backwall I will install a nice 10" driver. And move the desk a little bit away from the wall.
Next four days: holidays
Franz
Because of all this tests and comparisons on my side, I got aware, that I have not enough bass in my nearfield setup (Fostex FE83E in the recommended enclosure).
Actually I plan to build an active crossover and refurbish a bridged LM3886 amp, to drive a subwoofer speaker.
And I will convert my desk to a big open baffle:
Just attach a big panel on the backside of the desk, between the legs. And another two panels sidewards of the desk.
In the backwall I will install a nice 10" driver. And move the desk a little bit away from the wall.
Next four days: holidays
Franz
Franz Gysi said:
Hi Franz.
I would but for two reasons:
1) I don't have (well not yet...) the appropriate test gear to see if a change I am making to the sound is actually a GOOD change, or just one that initially sounds good, but is in fact resulting in the DAC/tranny not working as well as it should - hope that makes sense.
2) I am suffering from an illness which means I do not get as much time to experiement as I'd wish. I just want to build something that I know works well and spend more time listening to the music, at least until I am on the road to recovery
I am going to try the 10R resistors this weekend however, and will report back.
- John
Marc
Yes, it is burned in
Why I believe in burning in audio trannies?
Because the magnetic parts have some hysteresis.
This means, the actual state is depending from a predecessing status.
We could it also describe as following: the history of the magnetic state does influence the actual state.
Thats why I can accept, audio transformers are depending on the magnetic history and this can influence the actual performance.
For MUSIC! Fast bursts, a wild mix of waves of different frequencies.
But for mains transformers, situated in front of regulators and driving mostly digital equipment?
How would you explain to me the influence of the burning in process for a 50Hz sine?
Kind regards
Franz
Yes, it is burned in
Why I believe in burning in audio trannies?
Because the magnetic parts have some hysteresis.
This means, the actual state is depending from a predecessing status.
We could it also describe as following: the history of the magnetic state does influence the actual state.
Thats why I can accept, audio transformers are depending on the magnetic history and this can influence the actual performance.
For MUSIC! Fast bursts, a wild mix of waves of different frequencies.
But for mains transformers, situated in front of regulators and driving mostly digital equipment?
How would you explain to me the influence of the burning in process for a 50Hz sine?
Kind regards
Franz