The prices are:
Worldwide shipping: $ 9
Europe shipping: $ 5
paypal fee: 3,9%
- +/- Power Supply Module: $23 - two needed
- TDA1541A shunt regulator Module: $20 - one needed
- Shunt regulator Module for add. +5V line: $10 - one needed
- TDA1541A DAC Module: $18 - min. one needed
- Tube-I-zator Module: $32
Worldwide shipping: $ 9
Europe shipping: $ 5
paypal fee: 3,9%
Pre-Order List
+/- Power Supply Module
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qusp x 2
Shunt regulator Module for TDA1541A
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Shunt regulator Module for add. +5V line
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qusp x 2
TDA1541A DAC Module
UV101
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plenty-o-dacs already, but I needs some PSUs to power the pile of regs i'm collecting
Click on the link in my signature and add yourself
Last part to optimize
The last part to optimize is for sure the 74HC02.
This quad 2-input NOR gate technology is now ~ 20 years old and quite slow to NOR gates with current technology.
Every propagation delay of a semiconductor adds jitter and that´s what we keep as low as possible.
The propagation delay of a 74HC02 is typical ~ 15ns (at 5V; CL=50pF). Furthermore we need only one NOR gate for the DAC.
So why not use the fastest NOR gate today, the NL17SZ02 ?
My thanks for the suggestion goes to ecdesigns
This is a single 2-input NOR gate with a propagation delay of ~ 2,4ns (at 5V; CL=50pF).
This is 84% less !!!
The only problem is, that it is only build is one of the smallest SMD cases, the SOT-353.
Therefore i designed a adapter board with a size of a normal DIP14, that fits the small NL17SZ02 on top.
Really difficult to solder, but with the right iron it works.
I am really looking forward to the battle between the old 74HC02 and the new NL17SZ02.
So stay tuned!
This quad 2-input NOR gate technology is now ~ 20 years old and quite slow to NOR gates with current technology.
Every propagation delay of a semiconductor adds jitter and that´s what we keep as low as possible.
The propagation delay of a 74HC02 is typical ~ 15ns (at 5V; CL=50pF). Furthermore we need only one NOR gate for the DAC.
So why not use the fastest NOR gate today, the NL17SZ02 ?
My thanks for the suggestion goes to ecdesigns
This is a single 2-input NOR gate with a propagation delay of ~ 2,4ns (at 5V; CL=50pF).
This is 84% less !!!
The only problem is, that it is only build is one of the smallest SMD cases, the SOT-353.
Therefore i designed a adapter board with a size of a normal DIP14, that fits the small NL17SZ02 on top.
Really difficult to solder, but with the right iron it works.
I am really looking forward to the battle between the old 74HC02 and the new NL17SZ02.
An externally hosted image should be here but it was not working when we last tested it.
So stay tuned!
your dac is also acient technology... the input signals should not change faster than 10nsec (with the attenuation of 200mV around 2V). So with full 0 to 5, it should even take longer (read: be even slower). The inputs cannot keep up with faster changing signals...
propagation delay is not jitter. A propagation delay of say 2 seconds with 0 jitter just means that your music starts playing 2 seconds later (perfectly).
Always keep your logic as slow as possible. And with the 1541 it needs to be slow.
But do you really think your smd chip will be fast with the decoupling cap miles away??
propagation delay is not jitter. A propagation delay of say 2 seconds with 0 jitter just means that your music starts playing 2 seconds later (perfectly).
Always keep your logic as slow as possible. And with the 1541 it needs to be slow.
But do you really think your smd chip will be fast with the decoupling cap miles away??
Better DAC options...
I started two recent threads -- one here, the other at diyhifi,org -- to sort of address this issue. I.e., use better, modern DAC and DF ICs. So have a look there before “committing” to “pure” TDA1541 “solutions”. Also see Jocko’s/other's comments in the Refs below -- plenty o' decent advice ... if you can somehow look beyond the hubris …
Refs:
(1) http://www.diyaudio.com/forums/digital-source/3255-jocko-cd80.html
(2) http://www.diyaudio.com/forums/digital-source/4103-dac-upgrade-replace.html
(3) http://www.diyaudio.com/forums/digital-line-level/166962-classic-philips-cdps-newer-dac-src-ics.html
(4) DIYHiFi.org • View topic - Classic Philips CDPs with newer DAC and SRC ICs
Good point! I think a lot of newbies -- or DIYers w/o much experience -- can't see past what some old/"classic" CDPs come stock with. E.g. 7220/1541 chip-set. Some go the quick n’ dirty route and bypass the 7220 DF…and claim how wonderful NOS sound is (when there are better options, even with that noisy DF).
I started two recent threads -- one here, the other at diyhifi,org -- to sort of address this issue. I.e., use better, modern DAC and DF ICs. So have a look there before “committing” to “pure” TDA1541 “solutions”. Also see Jocko’s/other's comments in the Refs below -- plenty o' decent advice ... if you can somehow look beyond the hubris
…Refs:
(1) http://www.diyaudio.com/forums/digital-source/3255-jocko-cd80.html
(2) http://www.diyaudio.com/forums/digital-source/4103-dac-upgrade-replace.html
(3) http://www.diyaudio.com/forums/digital-line-level/166962-classic-philips-cdps-newer-dac-src-ics.html
(4) DIYHiFi.org • View topic - Classic Philips CDPs with newer DAC and SRC ICs
Yes, and that's how I originally understood your comment: that the 1541 -- and not dvb-projekt/Oliver's project -- is "ancient". Tho' based on your reply, I dunno if that came across clearly in my response.
IAC, and on this note, Oliver (or anyone willing): how about developing a drop-in PCB that uses newer, better technology? Say, a PCM1794 or AD1955-based daughter PCB -- one "simply" plugs/solders into 1541 socket or footprint? In reality, it won't be so "simple" -- dissimilar pin routing; pins w/diff. functionality; diff. output current, diff. supply voltages, etc. However, I don't think there are any major obstacles to this project. And there are further opportunities, such as incorporating a HQ XO ckt on the same daughter PCB. Thinking three-dimensionally, and esp now that we're dealing with SMD TSSOP and SOIC sizes, we can use both sides of the PCB ... so add options for I/V + output opamps, SRC "upsamplers", maybe even SMD PSU regs.
See my threads and Refs in the above post for more ideas.
Hi,
What on earth for? The AD1955 and PCM1794 are not even the subjectively best sounding chip's in their respective manufacturers ranges. They do offer the highest "on paper spec" performance, but that rarely translates directly into good sound.
I find that for playing back CD's there is only a choice between AD1865 and TDA1541 Non-Os CORRECTLY IMPLEMENTED (that includes power supplies that take account of the peculiarities of either chip, other supporting circuitry as required, layout, surrounding passive parts and correctly implemented analog filtering) for best sound quality.
Also, to be clear, for me "best sound quality" means something that is most easily mistaken for real music, given suitable recording. I care very little about "the basses", "the trebles", "the soundfield" and other such artificial criteria, which is really meaningless, about as much as performing vivisection on beautiful model to investigate her beauty from detailed inspections of the parts and innards.
Ciao T
What on earth for? The AD1955 and PCM1794 are not even the subjectively best sounding chip's in their respective manufacturers ranges. They do offer the highest "on paper spec" performance, but that rarely translates directly into good sound.
I find that for playing back CD's there is only a choice between AD1865 and TDA1541 Non-Os CORRECTLY IMPLEMENTED (that includes power supplies that take account of the peculiarities of either chip, other supporting circuitry as required, layout, surrounding passive parts and correctly implemented analog filtering) for best sound quality.
Also, to be clear, for me "best sound quality" means something that is most easily mistaken for real music, given suitable recording. I care very little about "the basses", "the trebles", "the soundfield" and other such artificial criteria, which is really meaningless, about as much as performing vivisection on beautiful model to investigate her beauty from detailed inspections of the parts and innards.
Ciao T
Hi,
Better design such stuff into the PCB. The adapter is not going to improve things much. Also, why not use a discrete circuit with some really fast BJT's, if you are concerned about this area?
Ciao T
Better design such stuff into the PCB. The adapter is not going to improve things much. Also, why not use a discrete circuit with some really fast BJT's, if you are concerned about this area?
Ciao T
Hi Thorsten,
the recommendation from ecdesigns comes after the final layout and independently of this,
my main goals for the DAC module were normal parts.
From my side, i am not concerned about the 74HC02 but if ecdesigns has made good experiences with the much faster chip,
why not give it a try on the module for myself?
Best regards,
Oliver
Hi,
I use a similary fast chip in my modified TDA1541 DAC (diyhifisupply.com Satch), but I use a discrete circuit in my commercial designs.
Ciao T
I use a similary fast chip in my modified TDA1541 DAC (diyhifisupply.com Satch), but I use a discrete circuit in my commercial designs.
Ciao T
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