Any good TDA1541A DAC kit?

[abraxalito]

Originally Posted by Joshua_G

If I wasn't clear enough, I'll try to make myself as clear as I possibly can.
I have a superb CDP which can serve also as a standalone DAC – the AMR CD-777 designed by Thorsten. It has a superb sound quality and I enjoy it enormously, I can happily spend the rest of my life with it.

Would I be correct in thinking that Thorsten hasn't divulged the technical specs of the DAC chip used in this player? If its not the TDA1541A then it'll presumably be another Philips/NXP family member using similar circuit (i.e. continuous calibration) techniques?

2. My financial means are meager. Hence, my only hope for better sound quality, within my budget, is a superb sound quality DIY DAC. Most probably based on TDA1541A DAC chip.

What puzzles me here is - if you have DIY capability yourself why part with (presumably) hard-earned cash for a finished item? I'm presuming you're aware how little of that cash goes on components? For the cost of that player you could in theory buy parts which, together with DIY elbow grease could beat its sound quality. But perhaps I'm making an assumption too far - you're looking for a DIY price but a finished solution which is ready to go straight out of the jiffy bag?

[ThorstenL]

Hi,

Originally Posted by abraxalito

Would I be correct in thinking that Thorsten hasn't divulged the technical specs of the DAC chip used in this player?

The Player is made by AMR, which is not my personal little playground, but a serious company, where I am an Employee like anyone else (though also a shareholder). So it is up to AMR('s Marketing Department) what information they release and which they don't. That is the way things are done and I'll have to play ball, even if I wanted to reveal more (which I do not neccessarily want anyway).

Now what has actually been released in information about the DAC?

6moons audio reviews: Abbingdon Music Research CD-777

Originally Posted by 6moons

continuous calibration concept,
fast settling time to enable 2, 4 and 8 times oversampling (serial input),
adjustable bias current for maximum dynamic range,
internal timing and control circuits,
I-squared-S bus input format (time multiplex, two’s complement, TTL up to 384KHz),
no zero crossing distortion,
low power consumption and low total harmonic distortion.
Full-scale output is 2mA,
THD at 0dB is -90dB,
A-weighted S/N ratio is -101dB and current settling time to ±1 LSB 200ns.

You need more to judge if the DAC will be acceptable for 16 Bit Digital Audio?

Originally Posted by abraxalito

What puzzles me here is - if you have DIY capability yourself why part with (presumably) hard-earned cash for a finished item?

I cannot directly answer for Joshua.

However a recent experience of mine may be telling. After loosing a lot of stuff in my divorce I had to get a decent system back, on a shoestring. So most of the stuff is based around things from diyhifisupply, which I know to be solid and affordable.

I do of course have prototypes and loaners from AMR some of the time.

The rather more extreme mods on my TDA1541 DAC where triggered by having a CD-777 prototype at home which outperformed the TDA1541 DAC by a lot, just as the work on the Ella Poweramp was down to playing with AMR's hybrid Amp's at home.

Even with all the mods applied this DAC barely matches the Prototype CD-777 and is still not a match for a CD-77 by a long stretch.

Why?

The CD-777 (and CD-77) are optimised using industrial methods and sources, not easily available to DIY Enthusiasts. This means we have for example economic access to many custom parts that you just cannot get for DIY in singles (eg. Mains Transformers wound in very unusual ways).

We use CPLD's and FPGA's and have full access to any programmable functions of any of the chips (we have a programmer on staff for that) so we can implement functionality that is very difficult do to do in traditional DIY Methods (look at Eric Juaneda's Digital Decoder page - we have similar functionalty routinely in our CPLD's and need less space than a stamp for it).

SMD is used aggressively and not with a view to reducing costs but to optimising performance. Usually each and every product goes through around a halve dozend reworks of the PCB layout before we are satisfied with performance (most DIY'ers would probably not go as far as our first cut layout). These are things that are not really that easy or that feasible for a lone DIY'er or a small DIY Supplier.

And the results are telling.

I am actually giving up on keeping DIY stuff and I'm getting an AMR DP-777, as in the final production version which I had here for a few days it betters both my own DAC and my Passive Preamp and can do 192/24 via USB as well (my current setup is limited to 96KHz). As it so happens, analog stage and the 16 Bit DAC are the same as in Joshua's CD-777 and the 16 Bit perfomance is identical.

Ciao T

[abraxalito]

Originally Posted by ThorstenL

Now what has actually been released in information about the DAC?

Thanks for the heads-up.

You need more to judge if the DAC will be acceptable for 16 Bit Digital Audio?

That wasn't what was behind my question. It was an attempt to assess the level at which Joshua_G would be listening at, to ascertain what might be the next step up from it.

The rather more extreme mods on my TDA1541 DAC where triggered by having a CD-777 prototype at home which outperformed the TDA1541 DAC by a lot, just as the work on the Ella Poweramp was down to playing with AMR's hybrid Amp's at home.

So this might turn out to be useful info for Joshua_G - its not so much the DAC but the way its implemented which matters. So his quest for a step up need not be limited to just TDA1541A-based kit.

The CD-777 (and CD-77) are optimised using industrial methods and sources, not easily available to DIY Enthusiasts. This means we have for example economic access to many custom parts that you just cannot get for DIY in singles (eg. Mains Transformers wound in very unusual ways).

A DIYer can most certainly wind his/her own mains transformer. After all, a DIYer is only going to be worried about his/her personal safety and doesn't have to worry about CE/UL etc. Now if the reason is not so much the 'industrial methods and sources' (which you claim) but rather a proprietary way of winding then sure. So on the surface its looking a bit as though you're smoke-screening here - the DIYer does not worry about whether a one-off is going to be 'economic' just whether its affordable.

We use CPLD's and FPGA's and have full access to any programmable functions of any of the chips (we have a programmer on staff for that) so we can implement functionality that is very difficult do to do in traditional DIY Methods (look at Eric Juaneda's Digital Decoder page - we have similar functionalty routinely in our CPLD's and need less space than a stamp for it).

Back in the days when I was working in the industry the disties were doing programming of CPLDs if you were willing to pay. FPGAs, I don't know so much about but the ones which work from external memory would only need that memory being programmed. And FPGA dev boards aren't exactly expensive compared to CD-77s. So once again I find your argument less than convincing

SMD is used aggressively and not with a view to reducing costs but to optimising performance. Usually each and every product goes through around a halve dozend reworks of the PCB layout before we are satisfied with performance (most DIY'ers would probably not go as far as our first cut layout). These are things that are not really that easy or that feasible for a lone DIY'er or a small DIY Supplier.

Well of course none of this is easy. But that wasn't my point - its possible, for the committed DIYer to get multiple layouts of PCBs done. When I worked in the industry I watched a colleague re-spin a board more than once without exhaustively testing all his functionality - the fact that it wasn't his own money he was spending probably accounted for the number of re-spins he needed.

I am actually giving up on keeping DIY stuff and I'm getting an AMR DP-777, as in the final production version which I had here for a few days it betters both my own DAC and my Passive Preamp and can do 192/24 via USB as well (my current setup is limited to 96KHz). As it so happens, analog stage and the 16 Bit DAC are the same as in Joshua's CD-777 and the 16 Bit perfomance is identical.

Presumably you won't be paying retail?

[ThorstenL]

Hi,

Originally Posted by abraxalito

A DIYer can most certainly wind his/her own mains transformer.

Sure. I did that. Also wound my own tube output transformers. Few if any will do this however as it a major PITA and timesink and it is now possible to buy electrically safe stuff of the "generic" design that would be used quite inexpensively.

Originally Posted by abraxalito

Now if the reason is not so much the 'industrial methods and sources' (which you claim) but rather a proprietary way of winding then sure.

It is actually the way the are wound. We discussed this before, no need to pretend you don't know.

If you go to any transformer winder and you ask them to make you one they will laugh at you.

If you can order a significant quantity they will consider your requirements, charge you a lot more than a generic transformer (but not forbiddingly so) and laugh behind your back at you for being so silly as to want a mains transformer wound that way, but they even will run a few different samples at cost, so you can optimise the design.

The same holds true for example for canned clock generators. Try buying a single good one to your specific spec.

Then go back with an order for two frequencies, 500pcs each and silly low levels of Jitter which they have to 100% test and certify using their test-setup. They will be quite happy to take your order (and again will be laughing behind your back) and yes, happily make a few different samples at cost.

Originally Posted by abraxalito

So on the surface its looking a bit as though you're smoke-screening here - the DIYer does not worry about whether a one-off is going to be 'economic' just whether its affordable.

Yes, the DIY'er has not to worry about economics of scale.

But some things you can only get as singles or very low quantities if you do them from scratch (e.g. hand winding your own mains transformers or John Browns oscillator design with multiple series crystals etc.) and invest huge amounts of time, whereas a concern like AMR is able to actually just "buy" such items and pay someone something for the time which is recouped through product sales.

Originally Posted by abraxalito

Back in the days when I was working in the industry the disties were doing programming of CPLDs if you were willing to pay.

They still are, if you buy 1KU or more, no sweat. Same for CPLD's, MCU's and the like. Some will even do it if you buy 100pcs.

But you first have to write the program and test and debug it. By that time you already have one programmed CPLD and for your DIY project you only need one...

Now not everyone enjoys CPLD or FPGA programming (or assembler for the kind of MCU we use at that - I certainly don't)

Originally Posted by abraxalito

FPGAs, I don't know so much about but the ones which work from external memory would only need that memory being programmed. And FPGA dev boards aren't exactly expensive compared to CD-77s. So once again I find your argument less than convincing

It is not the FPGA or CPLD that costs, it is the software inside... Or rather the man-hours to develop and debug the software...

Of course I am sure anyone of the street can just come and write the necessary code, so I guess you are right, it is not worth the money.

Originally Posted by abraxalito

Well of course none of this is easy.

Sure.

In principle a DIY'er may wind his own transformers, construct his own oscillators, program his CPLD's or FPGA's and DSP chips, make PCB layouts with many more revisions and more optimisation than AMR does and so on.

Now something like the CD-777 takes AMR's team a substantial amount of time using several full time people for the "legwork" and using subcontractors time for many of the stuff that can take a lot of time.

So yes, I am sure any DIY'er with sufficient commitment, resources and knowledge could match it in maybe a year or two of concentrated full time work, maybe less as he may not have to worry about compliance with electrical safety standards, EMC Standards and some of the extended reliability testing, or maybe more if he needs to first find out stuff I know about transformers, DAC Chips etc. that he does not. It would be a formidable undertaking.

Hence my point about John Brown.

While in many areas his path differs from mine, his gear is mostly up to the same standards of implementation or even beyond (my crazyness has limits imposed upon by AMR, however slight they are). His Meta-Thread, that has been running since May 2006 and has over 4000 posts and nearly a million views, can give an insight into just what it takes to get there.

I suspect that some people take the view that their time may be better applied to other subjects and hence are happy to pay the Dealer for an AMR Product instead of doing it themselves or pay John Brown for one of his products.

Now if AMR products where just generic implementations of generic datasheet based circuitry, sure, anyone can do that quite easily, you can find the kit's in Raindrop_hui's shop, but alas they are not.

Ciao T

[Joshua_G]

Originally Posted by abraxalito

What puzzles me here is - if you have DIY capability yourself why part with (presumably) hard-earned cash for a finished item? I'm presuming you're aware how little of that cash goes on components? For the cost of that player you could in theory buy parts which, together with DIY elbow grease could beat its sound quality. But perhaps I'm making an assumption too far - you're looking for a DIY price but a finished solution which is ready to go straight out of the jiffy bag?

Well, that's easy to answer.
I do have DIY capability, being a retired electronics technician. I also worked as an electronics engineer, though I don't have engineering degree.

However, my main concern is the sound quality of my stereo setup.
Yes, in theory, for the money I paid for the CDP I could build quite a few DACs, but not of the same sound quality. Other than (potentially) John Brown's (ecdesigns) work, I didn't encounter any kit, or schematic, that would suggest a sound quality that may match that of the AMR CD-777.

To try and develop my own design?
First, I'm not sure that I have the know how to surpass John Brown and Thorsten Loesch designs.
Second, should I decide to embark such an endeavor, it will take me many years and I'd like to enjoy reproduced music right now.

So, right now I'm looking for other's designs that I may build, designs that, at least potentially, may surpass the sound quality of the CD-777. So far, I didn't see any such design. If there is one, I'm all ears.

[Joshua_G]

Originally Posted by abraxalito

That wasn't what was behind my question. It was an attempt to assess the level at which Joshua_G would be listening at, to ascertain what might be the next step up from it.

There is only one possibility for your question to be answered – find a dealer who have that CDP and listen to it.

Originally Posted by abraxalito

So this might turn out to be useful info for Joshua_G - its not so much the DAC but the way its implemented which matters. So his quest for a step up need not be limited to just TDA1541A-based kit.

Well, of course it's about a complete solution, DAC chip and implementation.
My present notion is that only a superb implementation based on TDA1541A can, potentially, be the solution. Yet, I'm open to other suggestions, based on other DAC chips.

Originally Posted by abraxalito

A DIYer can most certainly wind his/her own mains transformer.

The power supply is the least of my concerns, since I'm convinced I can design and build a good enough power supply. May be not as good as Thorsten's, bud good enough.

Originally Posted by abraxalito

Back in the days when I was working in the industry the disties were doing programming of CPLDs if you were willing to pay. FPGAs, I don't know so much about but the ones which work from external memory would only need that memory being programmed. And FPGA dev boards aren't exactly expensive compared to CD-77s. So once again I find your argument less than convincing

I have zero programming skills, so to program my own FPGA is out of the question for me.

Originally Posted by abraxalito

Well of course none of this is easy. But that wasn't my point - its possible, for the committed DIYer to get multiple layouts of PCBs done.

I can afford a custom multi-layer PCB, I only don't have the skill and experience of designing PCBs, so this is also out of the question for me.

[studiostevus]

If you're looking for a holy grail.. It's not there. Enjoy your AMR player.

Sayonara.

[abraxalito]

Originally Posted by Joshua_G

Well, that's easy to answer.
I do have DIY capability, being a retired electronics technician. I also worked as an electronics engineer, though I don't have engineering degree.

I do have one of those - doesn't count for much other than looking good on a CV. It gets interviews if interviews are sought. But my degree had null to say on the subject of audio - beyond some maths on Fourier transforms.

However, my main concern is the sound quality of my stereo setup.
Yes, in theory, for the money I paid for the CDP I could build quite a few DACs, but not of the same sound quality. Other than (potentially) John Brown's (ecdesigns) work, I didn't encounter any kit, or schematic, that would suggest a sound quality that may match that of the AMR CD-777.

Since an audio system is a system, what leads you to consider the D/A part of yours to be the weakest link?

Second, should I decide to embark such an endeavor, it will take me many years and I'd like to enjoy reproduced music right now.

OK, I got the picture For me the joy is in the journey, not the destination so we're cut from rather different cloth

So, right now I'm looking for other's designs that I may build, designs that, at least potentially, may surpass the sound quality of the CD-777. So far, I didn't see any such design. If there is one, I'm all ears.

Do you not consider it unlikely that if such designs existed they'd be leveraged with higher margins than are typical for DIY-type products?

[abraxalito]

Originally Posted by ThorstenL

It is actually the way the are wound. We discussed this before, no need to pretend you don't know.

I can't figure out why you're pretending I'm pretending here

But you first have to write the program and test and debug it. By that time you already have one programmed CPLD and for your DIY project you only need one...

Yep, been there, done that. Which is why it was odd to me that wasn't your first argument. This reason makes perfect sense.

Now not everyone enjoys CPLD or FPGA programming (or assembler for the kind of MCU we use at that - I certainly don't)

I guess I'm kinda fortunate in that I really love assembly code programming. Have loved it since my first foray into MCUs in the 1970s. Oh but that was more hexadecimal machine code TBH. It took me a while to catch on to the advantages of symbolic assembler over hand assembly. I think this happened in my first year at uni.

It is not the FPGA or CPLD that costs, it is the software inside... Or rather the man-hours to develop and debug the software...

Indeed - something DIYers have fistfuls of.

Of course I am sure anyone of the street can just come and write the necessary code, so I guess you are right, it is not worth the money.

Straw man?

I suspect that some people take the view that their time may be better applied to other subjects and hence are happy to pay the Dealer for an AMR Product instead of doing it themselves or pay John Brown for one of his products.

Yep - I'd suggest by far the majority do.

[Joshua_G]

Originally Posted by ThorstenL

…
In principle a DIY'er may wind his own transformers, construct his own oscillators, program his CPLD's or FPGA's and DSP chips, make PCB layouts with many more revisions and more optimisation than AMR does and so on.

I have the skill and experience for none of the above.

Originally Posted by ThorstenL

Hence my point about John Brown.

While in many areas his path differs from mine, his gear is mostly up to the same standards of implementation or even beyond (my crazyness has limits imposed upon by AMR, however slight they are). His Meta-Thread, that has been running since May 2006 and has over 4000 posts and nearly a million views, can give an insight into just what it takes to get there.

Indeed, John Brown is person I have very high regard of.
I have neither his knowledge and experience nor his passion and dedication for DIY.
To my view, a person would better acknowledge both ones' capabilities and shortcomings. I cannot do what John did, and continue doing.