[Zachik]

@L0rdGwyn How big do you expect the DAC chassis end up being?
I would LOVE to A/B your DAC with my Lampi Amber 3...

 

[L0rdGwyn]

@L0rdGwyn How big do you expect the DAC chassis end up being?
I would LOVE to A/B your DAC with my Lampi Amber 3...

Well let's make sure it makes sound first LOL. Let me think about the dimensions, haven't gotten that far yet...

I know for a fact it will be a 4.25" tall chassis. My isolation toroidal has a 3.3" OD and is about 1.5" tall, the tube output toroidal has a 3.6" OD and is 1.6" tall....

If I were to mount both of those on their sides, I could probably make the chassis something like 4.25" x 10" x 12" if I really squeeze things together. Incidentally, those are the roughly dimensions of my 45 amplifier, but there would be nothing mounted on top, just a box with a button, USB input, RCA output. I will probably add a small power LED this time, for me it fits thematically since it is a digital piece of gear. But not too bright!

 

[Zachik]

Well let's make sure it makes sound first LOL.

I am not worried
IF you decide to have a quick tour - PLEASE put me first... I am itching for a new DAC.
Assuming you keep the off-the-shelf transformers - can you estimate the cost (including the case and everything)? ballpark number would be good. I am trying to see where it falls compared to commercial options I am willing to consider!

Also, are you still getting the DAC from the AD chip DIY design expert in Europe? Sorry, I forget the name... You mentioned it couple months ago.

 

[L0rdGwyn]

I am not worried
IF you decide to have a quick tour - PLEASE put me first... I am itching for a new DAC.
Assuming you keep the off-the-shelf transformers - can you estimate the cost (including the case and everything)? ballpark number would be good. I am trying to see where it falls compared to commercial options I am willing to consider!

Also, are you still getting the DAC from the AD chip DIY design expert in Europe? Sorry, I forget the name... You mentioned it couple months ago.

I'll have to give that some thought! Hadn't considered a tour, well really hadn't considered selling this, no promises on that front! Maybe as a favor. Would be great to nail it the first time, I am cautiously optimistic, but you never know when a rogue oscillating component will ruin your day...

Well the cost of parts...most expensive are the Sowter transformers, around $365USD for the pair shipped. Probably with a fancy Landfall chassis, the cost of parts is around $1300ish? The chassis and the transformers make up almost half of that!

Could drop the Sowter transformers and use a resistor I/V instead with a higher gain tube output, like Russian 6E5P, would get you a 2Vrms output with a 1K output impedance, would bring the cost down to under $1K. Would need to add a low pass filter to the I/V stage however. Put it in a cardboard box, cost drops below $750

If this design works out, it could be very easily adapted for PCM63 chip, fancy.

 

[L0rdGwyn]

Oh and yes @Zachik , I still have the Audial S5 on order. I am expecting very big things from that DAC, so it will be the benchmark by which I compare my own. It is TDA1541A-based. Taking a little longer than expected though, it should ship to me this week.

 

[bcowen]

Could drop the Sowter transformers and use a resistor I/V instead with a higher gain tube output, like Russian 6E5P, would get you a 2Vrms output with a 1K output impedance, would bring the cost down to under $1K. Would need to add a low pass filter to the I/V stage however. Put it in a cardboard box, cost drops below $750

Sorry, but I have the rights to the cardboard box chassis. I suppose I could waive the royalty fee just for Zachi, but just once...

https://www.head-fi.org/threads/sch...bable-start-up.701900/page-5268#post-16440552

 

[L0rdGwyn]

Sorry, but I have the rights to the cardboard box chassis. I suppose I could waive the royalty fee just for Zachi, but just once...

https://www.head-fi.org/threads/sch...bable-start-up.701900/page-5268#post-16440552

(Sigh) papier-mâché it will have to be then! I charge by the hour, this works out well for me

 

[bcowen]

(Sigh) papier-mâché it will have to be then! I charge by the hour, this works out well for me

LOL! There's always masonite or OSB board, or with lumber prices what they are perhaps sheetrock. It's for Zachi, after all.

 

[L0rdGwyn]

LOL! There's always masonite or OSB board, or with lumber prices what they are perhaps sheetrock. It's for Zachi, after all.

The options are truly endless...for some nostalgic flair, there is also Play Doh, Lincoln Logs, or even Legos! Truly a custom chassis, and even comes with ninjas.

 

[Zachik]

I'll have to give that some thought! Hadn't considered a tour, well really hadn't considered selling this, no promises on that front! Maybe as a favor. Would be great to nail it the first time, I am cautiously optimistic, but you never know when a rogue oscillating component will ruin your day...

Well the cost of parts...most expensive are the Sowter transformers, around $365USD for the pair shipped. Probably with a fancy Landfall chassis, the cost of parts is around $1300ish? The chassis and the transformers make up almost half of that!

Could drop the Sowter transformers and use a resistor I/V instead with a higher gain tube output, like Russian 6E5P, would get you a 2Vrms output with a 1K output impedance, would bring the cost down to under $1K. Would need to add a low pass filter to the I/V stage however. Put it in a cardboard box, cost drops below $750

If this design works out, it could be very easily adapted for PCM63 chip, fancy.

Sorry to disappoint Bill, but for me - aesthetic is important. No cardboard chassis thank you very much.
$1300 in parts is not too bad. Especially if it's as good as I hope...

Keenan, what's the advantages of PCM63 chip? What is the audible difference according to the diy community?

 

[Tjj226 Angel]

(Sigh) papier-mâché it will have to be then! I charge by the hour, this works out well for me

Nah nah. You go get an unfinished project box from micahels, paint it, and tell the customer how hard it was to make such a masterpiece.

But in all reality, if you end up making more than a few chassis, I would look at send cut send for bulk work. Once you order in units of 5 at a time, your cost goes down quite a bit.

 

[Zachik]

Oh and yes @Zachik , I still have the Audial S5 on order. I am expecting very big things from that DAC, so it will be the benchmark by which I compare my own. It is TDA1541A-based. Taking a little longer than expected though, it should ship to me this week.

Is that the same chip used in Yggy?
I am VERY interested in your impressions once you get it, and how it compares to your design!!

 

[bcowen]

Sorry to disappoint Bill, but for me - aesthetic is important. No cardboard chassis thank you very much.
$1300 in parts is not too bad. Especially if it's as good as I hope...

$1300 is just the parts though. Then there's Keenan's labor (engineering and assembly), overhead, G&A costs, taxes, etc. Although 'high end' audio entities are probably all over the map with pricing structures, a general rule of thumb is 5x - 6x parts cost to establish a retail price (I'll leave cable manufacturers out of that for simplicity). So $6500 - $7800 final retail price. Still not bad for a work of art, especially with a real metal chassis.

 

[Tjj226 Angel]

Sorry to disappoint Bill, but for me - aesthetic is important. No cardboard chassis thank you very much.
$1300 in parts is not too bad. Especially if it's as good as I hope...

Keenan, what's the advantages of PCM63 chip? What is the audible difference according to the diy community?

Greater resolution, lower noise, and so on. It is a better chip in theory. But it is a much harder chip to design for. If you compared both chips with a basic opamp IV stage, the PCM63 would sound better.

But if you make a more specialized dac like what lordgwyn is doing, the PCM56 could end up sounding better.

I am actually in the midst of building a PCM63 dac, so maybe lordgwyn and I will go head to head one of these days lol.

 

[L0rdGwyn]

Sorry to disappoint Bill, but for me - aesthetic is important. No cardboard chassis thank you very much.
$1300 in parts is not too bad. Especially if it's as good as I hope...

Keenan, what's the advantages of PCM63 chip? What is the audible difference according to the diy community?

You know, I don't recall if I came across someone comparing the two chips at a granular level, I haven't read into it deeply, but most say the PCM63 is "better", but the PCM56 is not far behind, both well-regarded tonally from my reading. The PCM63 is a 20-bit chip compared to the PCM56 which is a 16-bit. BUT once you get down to bit 15, 16...and beyond, the DAC needs to be well-engineered otherwise noise will dominate at that bit depth, you won't hear the extra bits anyway! So I wouldn't think the difference is due to dynamic range. Another example - the PCM56 is generally more highly regarded than its 18-bit counterpart, the PCM61. Notable also - the PCM63 does have better distortion specs than the PCM56. If I get serious about messing around with PCM63, will look into the subjective differences further.

Another thing though - the PCM63 is becoming quite rare, especially the best binned "K" grade, even the "J" run almost $100 a piece, you need two, whereas the PCM56 is very available and cheap. Better for experimenting

Is that the same chip used in Yggy?
I am VERY interested in your impressions once you get it, and how it compares to your design!!

I believe the Yggy uses a contemporary medical grade chip from Analog Devices. The TDA1541A is OLD, a classic R2R chip, there is something of a cult following around it, it was found in many hifi CD players in the 80s.

Yes, I'm very curious myself. Pedja Rogic (Audial) is truly an expert on TDA1541A, he has been designing with it for a long, long time. He has pushed it to its performance limits, an accomplished designer whereas I am a first time schlub LOL but we have to start somewhere, will be interesting to see how they compare ONCE the DAC is working.