Hi samoloko!
Thanks for pointing that out. I hadn't seen this before. I knew the voltage divider would have to be modified but was not expecting that it would be de only thing to be changed around the opamp. Time to order some pcbs 🙂
Thanks for pointing that out. I hadn't seen this before. I knew the voltage divider would have to be modified but was not expecting that it would be de only thing to be changed around the opamp. Time to order some pcbs 🙂
Out of curiosity... as still tempted LOL
I see that the projects here are mainly NOS... not a prob for me and probably simplier.
Having said that, I have a brand new PDM100 chip, something I received as a gift 30y ago (it came in a box from Mark Levinson with a separate board, was an $$ DAC upgrade as the chip itself couldn't be purchased alone by privateers!)... and I never managed to implement it somewhere at the end.
Any good, eventhough it might then mean going "low rate OS?
Was a nice sounding chip back then but nowadays perhaps going NOS as properly done here is the way forward?
Just asking out of curiosity, thanks!
Claude
I see that the projects here are mainly NOS... not a prob for me and probably simplier.
Having said that, I have a brand new PDM100 chip, something I received as a gift 30y ago (it came in a box from Mark Levinson with a separate board, was an $$ DAC upgrade as the chip itself couldn't be purchased alone by privateers!)... and I never managed to implement it somewhere at the end.
Any good, eventhough it might then mean going "low rate OS?
Was a nice sounding chip back then but nowadays perhaps going NOS as properly done here is the way forward?
Just asking out of curiosity, thanks!
Claude
Sorry @Michelag , I was in Pula for a few days on a business trip.
This is much better now, now a bit of optimization-shortening traces and editing 🙂 .
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You have the holy grail, with the PMD100 you can forget NOS 👍.
With a mandatory double power supply with LT3042 or ADM7150 or even better a shunt regulator, PMD does not forgive mistakes with the power supply and is therefore often rated poorly.
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Don't rush, the ADA4625 from Vunce's regulators can work at 5V but only with a 1V reference.
If you want to use the same circuit for +/-5V replace the ADA4625 with an ADA4897 and these are the new values of the specific resistors;
R420,411 1K
R421,412 1K
R426,415 499R.
Thanks for replying so quickly.
Ah, so PDM100 still a good chip then.
Is there any project here with PDM100 and AD1862 (or similar)?
Or perhaps even better: is there an easy way to "bolt on" to this community by using say Miro's AD1862 DAC and having just the PDM100 as add on "upstream". That could perhaps even allow 2 projects in 1 - such as Miro Original NOS on one side and Miro with mild OS on the other... and allowing comparisons with 2 builds.... or even switching between OS and NOS...
Not that I really need it, but that raises a lot my interest as I getting curious about the outcome!
Many thanks as ever
Claude
Ah, so PDM100 still a good chip then.
Is there any project here with PDM100 and AD1862 (or similar)?
Or perhaps even better: is there an easy way to "bolt on" to this community by using say Miro's AD1862 DAC and having just the PDM100 as add on "upstream". That could perhaps even allow 2 projects in 1 - such as Miro Original NOS on one side and Miro with mild OS on the other... and allowing comparisons with 2 builds.... or even switching between OS and NOS...
Not that I really need it, but that raises a lot my interest as I getting curious about the outcome!
Many thanks as ever
Claude
It is not a problem to configure PMD100 for AD1862, I think even the same as for PCM1702.
Depending on the signal before PMD100, data input should also be configured.
Depending on the signal before PMD100, data input should also be configured.
Even simpler to do this
No need for OS imaginary samples in the mix 🙂
No need for OS imaginary samples in the mix 🙂
That's why my friend paid almost $150 for a PMD100 which he plans to install in his NOS DAC with TDA1541A.
Tastes vary and who knows maybe the AD1862 plays better with the PMD100 than the NOS, has anyone tried it?
Tastes vary and who knows maybe the AD1862 plays better with the PMD100 than the NOS, has anyone tried it?
I've used Miro's standard pcb. Didn't put 47pF between pin 8 and 6. And also 2000pF between pin 2 and 3. Without them it works fine. I will try it. Is 2000pf realy important?
I used to try NOS PMD100 with some AD and PCM dacs. This chip making huge improvement over the other oversampling ICs and nos too. I cant explain why? I dint even used deglitch option, And You will be amased how many CDs are actually HDCD encoded, without label... 🙂
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But it has needy power suply, actually 2 power suplies, as I am remeber well i measured around 150mA consumption! And that is not small, but chip is not going to overheat even without IC heatsink on top. Probaly will be even better with it?
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I still have some new PMD100to use.
In stand alone mode PMD100 is 8X ovesampling. BUT with proggraming can be lowered to 2X OS.
Pacific Microsonics done rely great job with that chip.
Even simpler to do this
No need for OS imaginary samples in the mix 🙂
I d like to see what happen in the Mhz range. Second resistor is not compensated, and anyway the L should be a ferite béad and not à wirewound coil . I am not sure it is well optimised for best dynamic behavior.
Why not use a T network instead to lowisch the R value into 2 resistors? A passive filter before the I/V and à simple SINC filter after ???
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Also a good way for those streaming from USB is to use a source that does filter and upsample from the pc.
Of course if you still use the jittered spidf w/o reclocking after, i e compact disc as a source, the filter/oversamplind chip is your only choice.
Frankly going from spidf to usb if you don t have post reclocking is a major upgrade soundwise. It is nigth and day.
Of course if you still use the jittered spidf w/o reclocking after, i e compact disc as a source, the filter/oversamplind chip is your only choice.
Frankly going from spidf to usb if you don t have post reclocking is a major upgrade soundwise. It is nigth and day.
I don't like imaginary samples inbetween true ones 😁 But if you intend to use OS, yes pmd100 and x2. X8 is way too many samples i wouldn't like, pmd or any. Unfortunately i haven't seen pmd200 code floating around, so it may be lost forever for us diy fellas. So pmd100 only.
If NOS droop is a concern, above linked is a quick and dirty fix for that, which works well, more dynamic and resolute outcome. Ad1862 tested.
If NOS droop is a concern, above linked is a quick and dirty fix for that, which works well, more dynamic and resolute outcome. Ad1862 tested.
We should ask the AI of Microsoft which bougth Pacific Microsonic.... I heard some émulated the pmd100 in a Foobar2000 plugin but d'une if true.
@Zoran , maybe your ears are sensible to the aliasing that is why you liked it? I don t remember if it was Hiraga or a close dude of la Nouvelle revue du son, that inputed back then, HDCD chip improved all the CD...strangly. perhaps it was just the reconstruction filter ?
I would be tempted to use some pre passive filtering before the i/V in plus of the upsampling then a 12 dB post Bessel filter in plus of the 6db feedback opa filter?
I think @abraxalito made à lot of works there and may enligth us....
Also read the NEC chip equivalent is worthing it.
I would be tempted to use some pre passive filtering before the i/V in plus of the upsampling then a 12 dB post Bessel filter in plus of the 6db feedback opa filter?
I think @abraxalito made à lot of works there and may enligth us....
Also read the NEC chip equivalent is worthing it.
we (more of us listeners, together) examined the same plug in vs PMD - and it is not the even close thing... 🙁
Strange, but thera re no reconstruction filters. just standard HF. It was PCM56 2x dac, 200ohm Riv initially,
and diskrete OP amp circuit, by E. Borberly from Hafler DH110 preamp line amplifier. Except BC550/560 wea swaped with BC327/337. I think tat slight more current was trough output darlingtons, because they are slightley warm... Configurated as non inverting gain OP amp with feedback... (Offcourse tone contol circuit was omitted)
BTW this diskrete circuit (OP amp) really rocks. It was before maybe 30 years but i remember well.
I can reccomend this OP as very good sounding one in smaller signal as DAC output ranges. 🙂
One IV, diskrete, SE, Non-complementary, good for use with tube DAC end and transformer.
This version is for +-12V and 2mAp-p Io without current injection.
And it is classic transimpedance circuit, but with IGBT concept based from @Lazy Cat member for power audio IGBTs
I adopted this for smaller currents and IV purposes.
IMHO very very good results.
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This version is for +-12V and 2mAp-p Io without current injection.
And it is classic transimpedance circuit, but with IGBT concept based from @Lazy Cat member for power audio IGBTs
I adopted this for smaller currents and IV purposes.
IMHO very very good results.
.