The current draw will be around 50mA for the 8 DAC chips, plus a little (1-5mA) for the HC86 buffer depending on the sample rate you run.
I had a look at Lukasz's schematic - its using valves so I'm not much the wiser for seeing it. I did notice though that its AC coupled which means you definitely need I/V resistors before those caps. Matt's board has those anyway so seems you're good. I don't know if the output impedance of ESS matches the I/V resistors Matt's using but you're going to be roughly in the right ballpark I reckon.
I had a look at Lukasz's schematic - its using valves so I'm not much the wiser for seeing it. I did notice though that its AC coupled which means you definitely need I/V resistors before those caps. Matt's board has those anyway so seems you're good. I don't know if the output impedance of ESS matches the I/V resistors Matt's using but you're going to be roughly in the right ballpark I reckon.
Thank you Abraxalito.
You prompted me to reread the Buffalo article and I realise I misread part of it relating to him using the ESS in V out mode - I had read it as I out - so thanks for catching my lack of attention (just like my teachers used to, but at least I didn't get a piece of chalk flying past my ear this time!).
Matt's board gives me options to experiment with the output stage so let's have a play and see what happens.
I finally got my first v1.6 RPi Hat DAC finished. Currently playing some of my favorite tracks, and really happy with the sound. It sounds great, even with no burn in. Familiar of course, after having v1.2 in my system forever...but this is maybe just a little better 
Matt, thanks yet again.
Matt, thanks yet again.I finally got my first v1.6 RPi Hat DAC finished. Currently playing some of my favorite tracks, and really happy with the sound. It sounds great, even with no burn in. Familiar of course, after having v1.2 in my system forever...but this is maybe just a little better
My pleasure! It's the gift that keeps on giving.
Glad you continue to enjoy it.I actually have four PCBs left. (Since there's been no interest in this project for so long, they are actually in my pile of stuff to take to the electronic recycling program in my town!)
So, anyone who wants one, speak up! No charge for boards, just cover the shipping cost. I use USPS small flat rate priority mail boxes, so $8 in the USA.
PM me if you want a board.
Thanks!
Thanks Matt! I've been listening to the TeraDak x8 HAT. Sounds incredible on my Panasonic table top radio with ceramic cartridge input. On the "big" stereo system, it has compressed dynamic range. I'm wondering if this is inherent in the chip, since it was meant for portable CD players. This seems to be a great DAC for a portable or table top speaker.
Hey hifiamps,
I tried the x8 board sold by Audiophonics that is mostly identical to yours. I didn't notice dynamic compression with it, nor did I notice it with Matt's boards. In fact, the liveliness of either of TDA1387 board was superior to the other DAC HATs I compared them with, in terms of overall dynamic power. The TDA chips are known for a soft attack on the leading edge of notes, so maybe that is part of what you are hearing. Isolation, reclocking, and separate power supplies went a long way towards bringing clarity and dynamics to RPi audio for me. Eliminating switching noise, ripple, sag, and jitter make the background blacker, and sounds jump out more when the haze is gone.
I tried the x8 board sold by Audiophonics that is mostly identical to yours. I didn't notice dynamic compression with it, nor did I notice it with Matt's boards. In fact, the liveliness of either of TDA1387 board was superior to the other DAC HATs I compared them with, in terms of overall dynamic power. The TDA chips are known for a soft attack on the leading edge of notes, so maybe that is part of what you are hearing. Isolation, reclocking, and separate power supplies went a long way towards bringing clarity and dynamics to RPi audio for me. Eliminating switching noise, ripple, sag, and jitter make the background blacker, and sounds jump out more when the haze is gone.
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I have been meaning to comment on a small discovery I made while rolling caps in the v1.6 HAT that Matt sent me. This board has room for a large electrolytic for the TDA1387's Vref pin, and the BOM calls for such. The cap you fit in this position will have an obvious effect on sound quality.
I tried many different brands and values of electrolytic caps in this position, up to 3300uF, and found that what sounded best to me were several small value film caps, especially PP. Some may like the bass with a big electrolytic there, but it sounded bloated to me.
The TDA1387 datasheet calls for 1uF, and this is what I ended up with. Here's how I fit a Jantzen Standard Z-Cap in the 5mm pitch holes. It is worth experimenting to see what you like in this spot.
I tried many different brands and values of electrolytic caps in this position, up to 3300uF, and found that what sounded best to me were several small value film caps, especially PP. Some may like the bass with a big electrolytic there, but it sounded bloated to me.
The TDA1387 datasheet calls for 1uF, and this is what I ended up with. Here's how I fit a Jantzen Standard Z-Cap in the 5mm pitch holes. It is worth experimenting to see what you like in this spot.
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I have Ew's AD1865 HAT, and like it. I knew he was working on a discrete R2R project, but haven't talked to him in several months. This is exciting news! Sorry to be OT, but can you share a little more detail about the R2R HAT sound? We have both heard TeraDak/Audiophonics TDA1387, so we have that common point of reference.
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It's a fantastic sounding DAC. Honestly, much better than his AD1865, which I also have. My only critique is the output coupling caps which are silmics, electrolytics are the only thing that will fit on the board. Silmic is a really nice sounding cap, but I know a nice PP film cap will sound better, but that would be off board. Planning on doing this, but I am enjoying the sound too much to be motivated to get it done.
diyparadise review don't agree about forward presentation, but I'm just using battery to RPi micro USB. Ew said he doesn't hear much difference powering to DAC vs RPi.
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At some point, I think I will try to change the eight Vref caps on the TeraDak to film. Sounds like an interesting project. But, after looking at it, the smallest 1uF film caps I have are too big. Buying eight is too expensive. I would like to experiment with Matt's DAC.
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I just e-mailed Ew. I forgot to mention, the Audiophonics variant of TeraDak also gave constant low-level background noise in my system, most evident over headphones when audio was paused. I have never had another HAT do that, and while I did enjoy the sound of it overall, I prefer Matt's designs--even the older revision, and certainly the newest one. PM if you want to talk gear loans
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So far I've not come across an inherent dynamic range limitation in the chip itself, all my ~10 years of development with it have focussed on the I/V stage, power and filtering. I'm still not sure I've exhausted its potential.
Hi Richard, and happy holidays! I thought of you recently when I came across your better half's creation in the ornament box as my family was decorating the Christmas tree
I've been lurking on your thread. How are folks making out with your kits, and is there any consensus emerging for a favorite among the analog filters you've designed for this chip?
While we're on the topic of squeezing the most from TDA1387, I'm curious to hear your take on warm-up time. I had to chuckle when I came across this post from John Swenson where he discusses his use of a "chip heater" to enhance TDA1543 performance! I know my stereo sounds better after about an hour of on-time, but have not sussed out which components benefit most.
I've been lurking on your thread. How are folks making out with your kits, and is there any consensus emerging for a favorite among the analog filters you've designed for this chip?
While we're on the topic of squeezing the most from TDA1387, I'm curious to hear your take on warm-up time. I had to chuckle when I came across this post from John Swenson where he discusses his use of a "chip heater" to enhance TDA1543 performance! I know my stereo sounds better after about an hour of on-time, but have not sussed out which components benefit most.
Hi Kevin - seasons greetings to you too Wendy says thanks for thinking of her, its given her motivation to make more
Interesting you'd asked, I've been surprised how little feedback overall we've received from buyers of kits. Buyers of finished boards there's been a bit more but none yet concerning comparisons of filters. I'm in two minds whether 7th order might be a little bit overkill, depending on what kinds of music one prefers. Currently I'm experimenting with 5th but running 2XOS instead of NOS - it allows me to delete the EQ stage.
I can understand TDA1543 needing warm up but as 1387 is self-calibrating probably it doesn't need that. I haven't noticed any changes I could attribute to DAC warm up. Caps definitely benefit from it though, I have sketched out and even built designs where I place resistors strategically to warm up critical decoupling caps.
Wendy says thanks for thinking of her, its given her motivation to make more Interesting you'd asked, I've been surprised how little feedback overall we've received from buyers of kits. Buyers of finished boards there's been a bit more but none yet concerning comparisons of filters. I'm in two minds whether 7th order might be a little bit overkill, depending on what kinds of music one prefers. Currently I'm experimenting with 5th but running 2XOS instead of NOS - it allows me to delete the EQ stage.
I can understand TDA1543 needing warm up but as 1387 is self-calibrating probably it doesn't need that. I haven't noticed any changes I could attribute to DAC warm up. Caps definitely benefit from it though, I have sketched out and even built designs where I place resistors strategically to warm up critical decoupling caps.