The actual trafos do not have a 3 or 7 pin. When I measured, 1 to 4 and 5 to 8 each measured right about 10k. I will check again when I am redoing the filters.
Thanks McCrackers, Those are the pins I have connected, but I used the primary resistor/cap combo on the secondaries and vice versa on accident. I am going to fix that tonight or this weekend. I will report back on the results.
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Hey, I successfuly soldered a new 4398 chip to the daughter board. Got it second try, piece of cake! 😱
Time to open a bottle of Cabernet.
Time to open a bottle of Cabernet.
CS4398 Internal Volume control
Folks, has anyone tried to use the internal digital volume control? If so could you share your thoughts on how to do it? Thanks. Mark.
Folks, has anyone tried to use the internal digital volume control? If so could you share your thoughts on how to do it? Thanks. Mark.
I think you need microprocessor control to use the digital volume control. It wouldn't be too hard to do with say an Ardiuno, but if you wanted to do such a major mod to the DAC I'd recommend doing a new circuit board.
Bill -
Congrats on the chip soldering!
Sheldon
Bill -
Congrats on the chip soldering!
Sheldon
CS4398 Internal Volume control
Thanks for your inputs Sheldon.
I was reading the specs. It's a very versatile chip. Register 3h controls volume for both channels. You can gang both channels together or alter individual one and invert either channel polarity. It would be great if somebody has 'played' with these features....
Mark.
Thanks for your inputs Sheldon.
I was reading the specs. It's a very versatile chip. Register 3h controls volume for both channels. You can gang both channels together or alter individual one and invert either channel polarity. It would be great if somebody has 'played' with these features....
Mark.
CS8341 upsampling board issue
For those with up sampling board CS8341 don't you guys worried about excess voltage that being discovered in the earlier post ? The DAC supply 5V to the little board then convert to 3.3V which is pretty high. Aren't this shorten the lifespan for the chip....😕
For those with up sampling board CS8341 don't you guys worried about excess voltage that being discovered in the earlier post ? The DAC supply 5V to the little board then convert to 3.3V which is pretty high. Aren't this shorten the lifespan for the chip....😕
I was wondering if someone could help me find the specific posts of recommended mods. I will try to make a PDF with pictures of what to do as I also have lost track of this thread.
Surely the high supply voltage should be one of the first mods to do?
Surely the high supply voltage should be one of the first mods to do?
Yes I saw that one, but if interested please link to the specific mod to do. I have not tried all of them and I am not qualified enough to do other things than create a pdf like the one for the shigaclone.
I am however interested in better sound from this DAC which explains my reasoning to compile experiences into one place (as I will benefit from it too when modding my own 😉 ).
I am however interested in better sound from this DAC which explains my reasoning to compile experiences into one place (as I will benefit from it too when modding my own 😉 ).
The problem is that there are as many mods to do as there are ideas.
Here's some categories that seem to cover the bulk of this enormous thread:
Analog section:
Reduce section complexity to a single op-amp
Change op-amp types
Remove op-amps and replace with transformers
swap out electrolytic caps for film caps
Fix op-amp resistors on early boards
Digital Input:
Add coax transformer
Remove unneeded inputs like USB stuff
Fix filter components on early boards
Upsampler:
Use it
Don't use it
No discussion yet of fixing the 2.5Volt issue
Not seen yet, but interesting: Finesse noise clamp for oscillator power
DAC chip:
Not seen yet, but interesting: External Vref input from quiet reference
Power supplies:
Replace generic adjustable regulator supplies with something more exotic.
Myself, I modified the analog stage to only have a single op-amp and bypassed all the caps entirely. I'm also using a pair of OPA627s on a dip adapter.
I built a similar DAC for messing with transformer output. Frankly, I like the transformer output a whole lot better than any of the op-amp tricks I know about.
Sheldon
Here's some categories that seem to cover the bulk of this enormous thread:
Analog section:
Reduce section complexity to a single op-amp
Change op-amp types
Remove op-amps and replace with transformers
swap out electrolytic caps for film caps
Fix op-amp resistors on early boards
Digital Input:
Add coax transformer
Remove unneeded inputs like USB stuff
Fix filter components on early boards
Upsampler:
Use it
Don't use it
No discussion yet of fixing the 2.5Volt issue
Not seen yet, but interesting: Finesse noise clamp for oscillator power
DAC chip:
Not seen yet, but interesting: External Vref input from quiet reference
Power supplies:
Replace generic adjustable regulator supplies with something more exotic.
Myself, I modified the analog stage to only have a single op-amp and bypassed all the caps entirely. I'm also using a pair of OPA627s on a dip adapter.
I built a similar DAC for messing with transformer output. Frankly, I like the transformer output a whole lot better than any of the op-amp tricks I know about.
Sheldon
Hi sheldon, thx for the update.
I think many would do the voltage mod and modify the analogue stage by either a better opamp (I also have some opa627 I would like to try) with upgraded electrolyes or by bypassing the opamp stage completely like the lampizator mod. Balanced is also an option in this regard.
The more audiophilic option would be to use transformers (wasn't there concensus about the UTC-A20 or lundahl something or edcor for budget?).
I think many would do the voltage mod and modify the analogue stage by either a better opamp (I also have some opa627 I would like to try) with upgraded electrolyes or by bypassing the opamp stage completely like the lampizator mod. Balanced is also an option in this regard.
The more audiophilic option would be to use transformers (wasn't there concensus about the UTC-A20 or lundahl something or edcor for budget?).
A couple other things.
Change RCA input to true 75 ohm BNC at both ends.
Convert Opt input to another BNC or RCA.
Add a fourth input.
I would only recommend the A-20s for a very lean system, they are very bass heavy. There are so many trafos to try it is an endless search.
Change RCA input to true 75 ohm BNC at both ends.
Convert Opt input to another BNC or RCA.
Add a fourth input.
I would only recommend the A-20s for a very lean system, they are very bass heavy. There are so many trafos to try it is an endless search.
I would like to try another chip besides the 4397/4398. I'm looking for a cheap DAC that I would be able to use my 10K/ 1:1 trafos with. Any suggestions?
Interessting,might try this.
Great idea,can they be made to work at the same time,without using a swithch?
Hey Mccrackers, I think the Wolfson chips are diff voltage out.
Should be able to enable the fourth input with the jumper matrix, havent looked if there is a board trace for the input though.
Google (finesse voltage regulator) or Wenzel Associates.
Should be able to enable the fourth input with the jumper matrix, havent looked if there is a board trace for the input though.
Google (finesse voltage regulator) or Wenzel Associates.
Not without extra hardware. The receiver chip has two logic lines (RXSEL0, and RXSEL1), pulling those lines to VL or GND sets the input (RXP0 - RXP3). So to have it done automatically, you'd need to craft an input sensing circuit.
Sheldon
Thanks Bill. I checked out a link from a thread on this forum for a DIY Wolfson 4.0 DAC but the seller(Raindrop) does not appear to have it listed anymore. Too bad you can't just roll DAC chips like opamps.
I'm itching to do "something" to improve my setup.
I thought maybe removing the wireless card in my Squeezebox would be a solution to the I2S ---> DAC mod. If not I might try and pick up an SRC2496 which has AK diff v-out chip. Apparently they sound AWESOME with trafo output and a few tweaks.
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I thought he meant an extra switch. You can operate the matrix with a 4 pos/2 pole rotary switch mounted on the front panel.
I just bought a couple more trafos off of Ebay. They are listed as RE 11-DM. I believe they are Jensens that were built for a commercial customer. JE 11-DM is the Jensen #, they are one of Jensen's best OPTs. $29 apiece shipped, only a few hours left, he had 9 left after my purchase. They are 600 ohm/ 80%nickel if they are the real thing.