Hi of corse it is pasible! I have disoldered org 5v stables and get new better ones from my friend Muzg on discrete smd elements. Plays better ! For now im wondering it sense to disolder analog opa's Someone have done this mod? Thanks!
Hi Soeren, hi All!
I have significant noise problems with my DAM 1021 rev.1 board. When using the amplified output after the raw circuit I get noise through line or head-phone connection. WLan and switching action by using Web- GUI of players like Moode or clients like MPDroid produce pops and crackles. The described noise also occurs with balanced connection. The raw output is absolutely quiet in any case. I suspect a ground loop, or board defect. Does anybody have an idea for a solution?
Thanx and greetingz, Robert
I have significant noise problems with my DAM 1021 rev.1 board. When using the amplified output after the raw circuit I get noise through line or head-phone connection. WLan and switching action by using Web- GUI of players like Moode or clients like MPDroid produce pops and crackles. The described noise also occurs with balanced connection. The raw output is absolutely quiet in any case. I suspect a ground loop, or board defect. Does anybody have an idea for a solution?
Thanx and greetingz, Robert
But where is this power supply tracking happening? Is it happening between the 8L05 and 9L05 regulators? as the datasheet has one tracking solution is that whats implemented in the dam?
so if we use salas to supply +/-5V so the precision matching of voltage is not required is it? as the vref circuit is going to replicate the opposite polarity supply.
think there's very little to nothing to be gained substituting the 8L05 and 9L05 regulator
vref is where it needs to be right
revision 3 and 4 vref is much better than r 1 and 2,
its quite possible with revision 3 and 4 to make vref worse with mods
there are some reports of salas type shunts working well as vref
im still using lifepo4 cells on float charge as vref on two builds a rev 1 and a rev3
i havent tried anything new with this in a few months except with subbing in the new diyinhk 768khz usb to i2s from there old one
i have a 1121 here to ill hopefully get round to eventually too
its quite possible with revision 3 and 4 to make vref worse with mods
there are some reports of salas type shunts working well as vref
im still using lifepo4 cells on float charge as vref on two builds a rev 1 and a rev3
i havent tried anything new with this in a few months except with subbing in the new diyinhk 768khz usb to i2s from there old one
i have a 1121 here to ill hopefully get round to eventually too
I've been playing my DAM1021 0.02% Rev3 for a week now and I must say is sounds good.
It's running stock firmware and filters, so was wondering if it was worth playing about with these?
Also I'm waiting on Salas BiB so at the moment it's running off 2 12v lead acid batteries for the +-12v supply through the main power connector - is this best practice?
Are the regs and caps on this rev3 board upto the job? I've seen a lot on the mod'ing of the early boards.
Thanks
It's running stock firmware and filters, so was wondering if it was worth playing about with these?
Also I'm waiting on Salas BiB so at the moment it's running off 2 12v lead acid batteries for the +-12v supply through the main power connector - is this best practice?
Are the regs and caps on this rev3 board upto the job? I've seen a lot on the mod'ing of the early boards.
Thanks
I agree. I tried powering -/+5V directly with salases (reflectors and sslv). Gain in quality is negotiable (comparing to powering the boards with salases -/+7V, which is obvious improvement to powering from raw transformer). On board Vref in rev3 and rev4 is hard to beat, even with salases. I tried powering with heavily moded reflectors and sslv @ ~4V. Again here gain in quality is little to none compering to onboard Vref.
Telling the truth some gain in quality I got from powering 3.3V line directly with salas reflectors. Powering 1.2V with linear reg does bring much (if any) improvement in my case.
So once you power soekris board with good -/+ DC regs like salases you are pretty much getting best out of it. Further mods are fun to do, but does not bring much of improvement, maybe except better reg for 3.3V line.
I am wonder comparison of lifepo4 and salases. Let us know who can ...
This is of course my subjective opinion based on my own experiences, use it carefully and keep finding your own truth ...
Thanks Soern for great product!
modding is very much at your own risk type thing
just depends what your comfortable with
unless your lead acids are some special model they will be easily bettered by the shunts
ideally each section of the board should be powered discretely
rev 3 is good to start with so modding aint the huge revelation like it was for rev 1
If compared the ver3 and ver1 (both are full batteries mod), will ver3 better sound? Or they are almost the same?
unfortunately the builds are a little different the r1 now has a sd card to i2s front end with a fixed clock on the soekris
and the r3 has the new diyinhk usb to i2s on it
so cant really say with utmost conclusivity
if i were to guess id say the modded r1 and r3 would be quite similar
unmodded would be a completely different story
I have battery mod for ver1 and play with Batteries powered SDtrans. It is happy to listen music with them. I am going to mod the ver3 with full batteries power supply, shorten i2s cable, then box them up too.
But a hurdle for ver3 is to power -6v on pwr- J2 to stop auto-mute function (am I right?) The question is that could I just wire (-) of 2 lifepo4 batteries and GND (+) of these 2 lifepo4 batteries to GND at J1, will it work?
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You can remove two small outline transistor close to raw outputs to disable auto mute function. This works. Then you do not need worry about -6V powering.
@TioFrancotirador
It is helpful for my mod
Just blind guess the transistors you mentioned. It is highlighted in red circles on attached photo, are they the one to be removed for stopping auto-mute function?
Thank
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comickitkit,
You are on the path to a fine sounding set-up. I have followed most of nige2000's advice stopping short of replacing the caps between the FPGA and the shift registers.
I sincerely love my SDTrans/SOEKRIS combo. Every time I listen to it I am amazed how good it is. Its going to take a real long time for me to tire of this.
You are on the path to a fine sounding set-up. I have followed most of nige2000's advice stopping short of replacing the caps between the FPGA and the shift registers.
I sincerely love my SDTrans/SOEKRIS combo. Every time I listen to it I am amazed how good it is. Its going to take a real long time for me to tire of this.