I have these transformers for many years... just wondering if it’s possible to use them as output transformers? They are 1:1 ratio with many taps 50/125/333/500.
The circuit in the right schematic of post #837 is less sensitive to the transformer characteristics than the other filter circuits I came up with, so maybe it is a good idea to use your transformers with that filter. You then have to short pins 3 and 4 of your transformer, short pins 9 and 10, connect L1-C2 to pin 1, connect L4-C6 to pin 6, connect pin 7 to R3 and pin 12 to C9.
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generate the clock signal for the DAC?
Your mailbox is full. Shipping cost for the parts would be about $30,
let me know.
The main DAC PCBs shipped from PCBway yesterday (and the filter PCBs/smd stencil are already in Germany).
I should have the time available this weekend to get my Digikey through-hole component BOM to you and I'll order the smd parts for the eight boards requiring that service - I'll update the spreadsheet again for the actual costs once that's done.
Shouldn't be too much longer now.
I should have the time available this weekend to get my Digikey through-hole component BOM to you and I'll order the smd parts for the eight boards requiring that service - I'll update the spreadsheet again for the actual costs once that's done.
Shouldn't be too much longer now.
With the main DAC PCBS on their way I need to order the smd components and pay for the smd soldering service for those who have requested that element of the group buy.
As expected, buying parts in greater quantities reduced the cost by, IIRC, about £10 per board.
Below is a screengrab of my spreadsheet, can those subscribers with a balance highlighted in orange please send me a second payment via Paypal to cover the smd service costs. Please remember to use 'Family and Friends'.
For all GB subscribers, that will just leave a final payment that I will request when I'm ready to ship your boards. By then I will know the final costs (for example, I don't yet know about any import duty I may still have to pay) so this final payment will factor in the shipping cost along with any adjustments for over/under payments (and I will make any refunds that are necessary). I hope that all makes sense?
Ray
As expected, buying parts in greater quantities reduced the cost by, IIRC, about £10 per board.
Below is a screengrab of my spreadsheet, can those subscribers with a balance highlighted in orange please send me a second payment via Paypal to cover the smd service costs. Please remember to use 'Family and Friends'.
For all GB subscribers, that will just leave a final payment that I will request when I'm ready to ship your boards. By then I will know the final costs (for example, I don't yet know about any import duty I may still have to pay) so this final payment will factor in the shipping cost along with any adjustments for over/under payments (and I will make any refunds that are necessary). I hope that all makes sense?
Ray
Attachments
Update on BOMs and Digikey baskets.
Attached is a zip file containing two Excel spreadsheets listing the smd and through-hole BOMs.
Here are links to the corresponding shared shopping carts at Digikey;
http://www.digikey.co.uk/short/zfft21
http://www.digikey.co.uk/short/zfftwj
These are the BOMs I used for my build except that I have updated them to reflect Marcel's modification to the Valve DAC core trimming (see post #1). Note that the BOMs include both single and multi-turn potentiometers for RV1, RV2, RV3 and RV4 - so you will need to decide which ones you want to use and delete the others before checking out your order.
There are a few components missing from the BOMs because the values or type will be dependent on your specific project (such as output and filter caps, valves, valve bases, header pins, etc.). Note that the BOMs are for the main board and do not include parts for the reconstruction filter boards. Of course, you can substitute your favourite resistors/caps etc. as you see fit - the spreadsheet BOMs have the dimensions of the space available on the PCB.
I'm only human so I can't guarantee I haven't made an error so I recommend you check your orders before placing them. If you do find that I've made an error please let the rest of us know.
Have fun.
Ray
Attached is a zip file containing two Excel spreadsheets listing the smd and through-hole BOMs.
Here are links to the corresponding shared shopping carts at Digikey;
http://www.digikey.co.uk/short/zfft21
http://www.digikey.co.uk/short/zfftwj
These are the BOMs I used for my build except that I have updated them to reflect Marcel's modification to the Valve DAC core trimming (see post #1). Note that the BOMs include both single and multi-turn potentiometers for RV1, RV2, RV3 and RV4 - so you will need to decide which ones you want to use and delete the others before checking out your order.
There are a few components missing from the BOMs because the values or type will be dependent on your specific project (such as output and filter caps, valves, valve bases, header pins, etc.). Note that the BOMs are for the main board and do not include parts for the reconstruction filter boards. Of course, you can substitute your favourite resistors/caps etc. as you see fit - the spreadsheet BOMs have the dimensions of the space available on the PCB.
I'm only human so I can't guarantee I haven't made an error so I recommend you check your orders before placing them. If you do find that I've made an error please let the rest of us know.
Have fun.
Ray
Attachments
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I've just placed the order at Digikey for the smd components. There was a small increase in the cost of few pence each compared with the figure I gave a few days back, I'm guessing because of exchange rate fluctuations. See the spreadsheet below. I'm still waiting for some second payments (see the orange cells).
Everything is moving along nicely and I hope to be in a position to start forwarding the first unpopulated boards within a week or two.
Everything is moving along nicely and I hope to be in a position to start forwarding the first unpopulated boards within a week or two.

Attachments
The main DAC PCBs are at the Fedex facility in Germany, the filter boards/stencil have left Germany en-route to the UK and the SMD components have shipped from Digikey.
Oh, and the first PCB has been delivered to torb in Finland.
Latest spreadsheet status attached - thank you.
Oh, and the first PCB has been delivered to torb in Finland.
Latest spreadsheet status attached - thank you.
Attachments
The tracking information on the PCBs, main DAC and filters, are likely to be delivered to me today or tomorrow so I should be able to start sending packages on over the weekend.
First thing I'll need is a delivery address for each GB subscriber - Paypal 'Family and Friends' doesn't provide me with that information. Could each of you send me a PM with the address please.
Once I know how much import duty I'll have to pay on the boards I'll make the final cost adjustments, add in the cost of onward shipping and that will give the amount for the final payment. I'll refund any over payments once everything bottoms out.
@luchoh, I'm still waiting on your second payment?
Cheers
Ray
First thing I'll need is a delivery address for each GB subscriber - Paypal 'Family and Friends' doesn't provide me with that information. Could each of you send me a PM with the address please.
Once I know how much import duty I'll have to pay on the boards I'll make the final cost adjustments, add in the cost of onward shipping and that will give the amount for the final payment. I'll refund any over payments once everything bottoms out.
@luchoh, I'm still waiting on your second payment?
Cheers
Ray
So what do we have here...
My experience with Fedex is that they deliver and then bill you for any import duty a couple of days later so I should be able to make any final cost adjustments soon. In the meantime I'll be packing boards ready for despatch and getting the shipping costs. I'll be sending boards on their way very soon.
I also received the smd components from Digikey today so I'll be taking everything over for the soldering service at the weekend.

My experience with Fedex is that they deliver and then bill you for any import duty a couple of days later so I should be able to make any final cost adjustments soon. In the meantime I'll be packing boards ready for despatch and getting the shipping costs. I'll be sending boards on their way very soon.
I also received the smd components from Digikey today so I'll be taking everything over for the soldering service at the weekend.
Full house with respect to staged payments, thank everyone.
I've been in touch and the guy who is doing the smd soldering is literally in the middle of moving house so I'm sorry to say there will be a short delay before he gets his workshop up and running to be able to do the work - hopefully just a week or so. I'll let you know progress in due course.
Ray
I've been in touch and the guy who is doing the smd soldering is literally in the middle of moving house so I'm sorry to say there will be a short delay before he gets his workshop up and running to be able to do the work - hopefully just a week or so. I'll let you know progress in due course.
Ray
Attachments
I shipped the first of the bare PCBs this afternoon and will do the remainder when I get delivery addresses. I've PM'ed the relavant GB subscribers with tracking references.
Please hold off from making final payments until I get the bill for the import duty so we have final definitive costs. I'll request final balance payments, or make refunds, in due course.
I'm hoping that there will soon be a second operational build of Marcel's DSD Valve DAC!
I'm listening to mine while I'm typing this and continue to be delighted with just how good it sounds - I don't think you'll be disappointed.

Please hold off from making final payments until I get the bill for the import duty so we have final definitive costs. I'll request final balance payments, or make refunds, in due course.
I'm hoping that there will soon be a second operational build of Marcel's DSD Valve DAC!
I'm listening to mine while I'm typing this and continue to be delighted with just how good it sounds - I don't think you'll be disappointed.


Attachments
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Well done with the group purchase Ray! The circuit boards look very nice!
Are you planning to test the filter PCB version with better "transformer parasitics" yourself, e.g design from post #837. Or are you content with current version? I can go for the current version. But If you plan to order yourself new filter PCBs perhaps me and some others can join in and have the main board sent when another version of the filter PCB is ready.
Micke
Are you planning to test the filter PCB version with better "transformer parasitics" yourself, e.g design from post #837. Or are you content with current version? I can go for the current version. But If you plan to order yourself new filter PCBs perhaps me and some others can join in and have the main board sent when another version of the filter PCB is ready.
Micke
Thanks Micke 
To be honest, regarding the revised filters, I've not thought it through yet - I took on a new team at work this week (an interesting experience with everyone working from home) - but I'm planning a second build and want to try alternative output stages, such as the CD-Enhancer that Raj has shown, with Valve DAC and my DSC2 so I'll probably modify the boards at some point. I'm also collecting parts for an amp with a balanced input so an output stage without transformers looks attractive.
If I do a new version of the output boards I'm more than happy to order a batch if there is interest, or simply make the gerbers available.
Ray

To be honest, regarding the revised filters, I've not thought it through yet - I took on a new team at work this week (an interesting experience with everyone working from home) - but I'm planning a second build and want to try alternative output stages, such as the CD-Enhancer that Raj has shown, with Valve DAC and my DSC2 so I'll probably modify the boards at some point. I'm also collecting parts for an amp with a balanced input so an output stage without transformers looks attractive.
If I do a new version of the output boards I'm more than happy to order a batch if there is interest, or simply make the gerbers available.
Ray
DSD Recordings
If it's of interest to anyone, 'Native DSD' are offering a short, but free, DSD sampler, available at various data rates. I'm currently downloading the DSD256 and 512 files.
NativeDSD Music's Free Starter Pack - NativeDSD Music
I have a couple of DSD recordings from NativeDSD and have been impressed with the recording quality.
If it's of interest to anyone, 'Native DSD' are offering a short, but free, DSD sampler, available at various data rates. I'm currently downloading the DSD256 and 512 files.
NativeDSD Music's Free Starter Pack - NativeDSD Music
I have a couple of DSD recordings from NativeDSD and have been impressed with the recording quality.
Too late?
Ciao from Italy by a long time lurker 🙂
Am I too late for a couple of PCBs?
Best,
Mirko
Ciao from Italy by a long time lurker 🙂
Am I too late for a couple of PCBs?
Best,
Mirko
You are in luck Mirko!
I have just two Main PCBs left, plus sufficient filter boards so you are able to scrape into the GB.
I will PM you with payment details so that you can secure the boards.
Ray
I have just two Main PCBs left, plus sufficient filter boards so you are able to scrape into the GB.
I will PM you with payment details so that you can secure the boards.
Ray
Attached is the latest update to my GB spreadsheet, including Mikky1975 joining the GB.
With Mikky1975 joining the unit costs of the PCBs has fallen some more as the costs have been spread more widely.
All main DAC PCBs have been accounted for so the GB is now well and truly closed.
Regarding the spreadsheet, if your DIY Audio name is higlighted in orange I am still waiting for your home address for delivery of the boards.
Apart from Mikky1975, I don't require any further payments at this time - when the final definitive costs are known I will contact you to request a final payment (or issue you with a refund if you have overpaid).
Cheers
Ray
With Mikky1975 joining the unit costs of the PCBs has fallen some more as the costs have been spread more widely.
All main DAC PCBs have been accounted for so the GB is now well and truly closed.
Regarding the spreadsheet, if your DIY Audio name is higlighted in orange I am still waiting for your home address for delivery of the boards.
Apart from Mikky1975, I don't require any further payments at this time - when the final definitive costs are known I will contact you to request a final payment (or issue you with a refund if you have overpaid).
Cheers
Ray
Attachments
- Home
- Source & Line
- Digital Line Level
- Valve DAC from Linear Audio volume 13