| promitheus |
After a long time I almost have my boards ready.
I am using till now an Upsampling DAC from Elektor magazine but I want to replace the analog stage because it has opamps with something better.
I made a stereo version of the D1 I/V stage on one board direct for tweaking CD Players and DACs.
My Dac has 2 PCM 1704 and 4 opamps for the I/V and filter stages.
I will be posting pictures later on. |
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| promitheus |
This the PSU.
I use here 4x 11DQ10 Schottky diodes. MKP Wima across them and Panasonic FC caps. The ICs arenīt on the PCB yet. |
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| promitheus |
This is the actual stage with two stages on one PCB. You could actually use it for balanced signal also.
I use the signals singel ended so use only one board.
The Mosfets are missing from the PCB but all other parts are on it.
Silver Mica CAPs for the filter part. Audyn 4,7uF in series with the output. Welwyn 1% low noise resistors. Panasonic FC electrolytics. |
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| relder |
| quote: | Originally posted by promitheus
The Mosfets are missing from the PCB but all other parts are on it.
|
I was wondering where those FETs were.:scratch1: Need to read the text before I look at the pretty pictures.
I was looking to do something very similar myself to an old Denon player, D1 output + 1704, balanced out. Do you have your DAC board documented anywhere?
Keep us informed.
Rob |
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| promitheus |
I will be posting more info soon.
Gerber files an so on.
The Mosfets are missing because I donīt have the heatsinks yet. Or maybe I will use them without heatsinks. I donīt know yet.
The I/O stage is exactly the same from Nelson Passīs D1 DAC. |
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| was ist los? |
| What transformer are you using? |
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| promitheus |
| I will be using a small toroid 2 x 30 V / 30VA. |
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| promitheus |
So itīs finished at last. I could only test one channel for the moment because I have to make some changes on the DAC board.
I took the opamps off but I have to desolder a few resistors and capacitors or they will effect the signal.
Setting the DC voltage of the input isnīt so easy and stable as I thought but it stays in the range +/- 10 mV.
Does anybody know how much this should be max. ?
It doesnīt effect the sound though which I can say is super super clear.
I also made a few corrections on the PSU after burning 2 diodes in the bridge. Thatīs what happens when you try to test it 2:00 clock at night. :whazzat: |
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| promitheus |
I am also waiting to get to bypass caps MKP which are missing there in the middle.
I thought it would be good to parallel them with the electrolytics. The Panasonic FCs that are lying there. |
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| promitheus |
The inputs are at the top of the picture and you can see in the top corners the 2 small trimmers. With these you set DC offset at the input to 0V.
I use the PCM 1704 which has a current output like many DACs and the voltage there must be at 0 Volts. :att'n:
The outputs are at the bottom where the 2 Audyn Caps are. |
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| pamaz |
Hello Promitheus.
I've got somewhere at home the Elektor dac with pcm 63K which I've done several years ago.
If you're going to post the gerber files or ( for me better) pdf or any graphic file for the pcb, I'll be very happy to revamp that DAC and see what's going to happen with it and yor output stage
I'm confident that with such a design it will work much better that now.
Bye
Paolo |
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| promitheus |
I have to find a way to post it in pdf in original size.
I donīt know how yet.
Does anybody here know how to transfer traxmaker files to pdf?
If you want I could order a few board if others are also interested. |
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| nar |
Hi Promitheus,
I am interested by the circuits boards of the D1 you made
(including numeric inputs,filter,oversampling,converter,and I/V boards)
How much would it cost?
Best regards
Anael |
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| pamaz |
http://www.pdffactory.com/
Try this link for pdf.
They have a trial version to download ( about 2.8 M)
Don't know if this will work because i have not any knowledge about your pcb design system.
thanks and bye
Ciao
Paolo |
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| promitheus |
A few people have been asking for pcbs.
The reason that I donīt give any pcbs away is that I only made one.
Second the layout isnīt 100% OK. It works very very good but the mounting has a small problem for my box.
The circuit works now for almost one year and I can say I wouldnīt change it. The quality is so clear and dynamic.
If more people are interested I could make new improved boards and give them away at a very reasonable price for DIYers. |
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| pamaz |
whenever you decide to go on with such a thing, I'm in.
Thanks
Paolo |
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| promitheus |
Well it doesnīt take long to make a new improved version.
People who are interested in boards should post for how many boards they want.
Each board has 2 stages. That means if you have left right unbalanced you need 1 board and 1 power supply.
If you have left right balanced you need 2 boards and 1 power supply.
About the price it depends on how many boards you guys want and how many I will at the end order.
If a few people are interested I will ask for a price from the manufacturer.
Just keep me posted when someone is interested. |
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| promitheus |
Very tidy and good work for a p2p board.
I have a pcb for a clock from ELSO WKAK on the forum but i have never used it. Is that from guido? Is it the same person? |
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| relder |
| quote: | Originally posted by promitheus
I have a pcb for a clock from ELSO WKAK on the forum but i have never used it. Is that from guido? Is it the same person? |
No |
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| philbyx |
| quote: | Originally posted by promitheus
Very tidy and good work for a p2p board.
I have a pcb for a clock from ELSO WKAK on the forum but i have never used it. Is that from guido? Is it the same person? |
Guido Tent and Elso Kwak are not the same person, but they have good ideas about clocking and reclocking the dacs ;)
Their solutions are not the same.
Philippe |
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| axelcs |
Hi Ilias,
iīm interested in one balanced set of the D1-boards too (maybe two)!
Cheers Axel |
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| promitheus |
The D1 I/V Boards will cost around 12-15 Euro and the power supply boards will cost 7-9 Euro each.
It depends really on the number of boards that will be ordered.
Do you also need a power supply or not? |
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| nar |
Hi Promitheus ,
I am interested by the whole set of boards , if you can give pdf and schematic to mount everything
regards
nar |
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| promitheus |
I already have a parts list, the schematic is from pass D1 DAC and the pcbs will have a parts print on top in white for the placement.
Parts list for D1 I/V
16 x Resistors are low noise 1% .25W
2 x 20K vertical multiturn trimmmer
2 x 220uF/50V Panasonic FC
2 x 220uF/16V Panasonic FC
2 x 27nF silvered MICA
2 x 4u7, MKP-QS Audyn Cap
2 x 10nF MKP WIMA
2 x 100nF MKP WIMA
4 x IRF610 IR
Parts list for PSU
4 x diodes schottky or normal
4 x 22n ceramic caps
2 x 1000uF/50V Panasonic FC
4 x 22uF/50V Panasonic FC
LM317
LM337
4 x Resistor |
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| promitheus |
| This is the schematic of the D1 I/V Stage I use. |
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| promitheus |
This is the layout of the pcb.
I could only get it in pdf.
The Power supply is a normal +30V +30V Power supply using LM317 and LM337.
I have to make a few changes to the boards so I will post them later on. |
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| pamaz |
Dear Guys,
i really don't know how this could be done, as I never managed such a thing and by now i have no spare time to learn how to do it (I'm working from 7 am to 9pm. hope to change ASAP!!), but proabably a group buy could be interesting.
As already said i'll be in .
Ciao
Paolo |
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| axelcs |
Hi Ilias,
i would take a complete set, including ps ...
Cheers, Axel |
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| promitheus |
I want to thank all those who have ordered. I still have a few pcbs left so if anyone is interested please mail me for more information.
For those who have already ordered I am gathering the parts they want and I will start sending everything end of next week.
Stay posted. |
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| pamaz |
hi Promitheus.
i've sent you the order form, but I'm still waiting for a confirmation of the grand total+ shipping.
let me know, so that i can arrange the payment.
Thanks.
paolo |
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| promitheus |
Hi there pamaz.
I sent you an email on the 26 of Feb.
Anyway I sent you the email again, so check your email.
You got email ! |
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| promitheus |
I will be getting the parts in the next days, so I am very curious on how everything will turn out.
I will post some photos of the new boards and parts as a small hint of what they look like.
For those who have already ordered and paid I will notify you as soon as I start sending the parts. Thanks for the support and the very nice contact. I think I can send everything out next week. It depends on the delivery of some of the parts. I had to order them from different suppliers. It really sucks when it gets to ordering things. Anyway...
The communication with other diyers is what really makes DIY fun.
so keep posted I will be back with news. |
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| promitheus |
Hi everybody,
did anybody finish the PCBs yet.
I would like to know if all went ok.
Greetings Promitheus |
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| pamaz |
Thanks Promitheus. The thing is working but still i don't want to judge it as it's assembled with scrap components, just to understand its potential.
At this moment i cannot understand where the lackness of bass that i can hear is coming from the Digital side of my converter or if it's a signature of this output stage.
Probably a mixture of the two !
Bye and thanks.
Paolo |
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| Andypairo |
| quote: | Originally posted by promitheus
Hi everybody,
did anybody finish the PCBs yet.
I would like to know if all went ok.
Greetings Promitheus |
Mine is assembled and electrically tested. Not yet connected to a Dac.
A few remarks: the PCB holes in some occasions (ie the rectifier and output cap) are way too small. Apart from that a nice PCB.
Cheers
Andrea |
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| stefanobilliani |
| quote: | Originally posted by pamaz
At this moment i cannot understand where the lackness of bass that i can hear is coming from the Digital side of my converter or if it's a signature of this output stage.
Probably a mixture of the two !
Paolo |
Probably for the lack of feedback , but the bass is all there . BTW with a great clock generator the bass changes its face.
Usually the op amp with great feedback loops , pumps up bass and high ( as a perception ) and it takes more than a biscuit to feel a clean and extended bottom end |
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| promitheus |
Hi,
well a few holes on the psu are smaller than planned, only fractions of a mm.
What kind of clock do you use.
I am using the Elektor DAC with upsampled input.
Do you think that it would work better with an external clock? |
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| stefanobilliani |
| quote: | Originally posted by promitheus
Hi,
Do you think that it would work better with an external clock? |
Generally yes .
I use Tentlabs Xo . |
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| pamaz |
Caro Stefano,
such a long time that i have to give you some 12 euros!
In any case the lackness of bass I feel is perceived in comparison with my revox no-oversampling and with the best sounding cd player i've had in my system, that's a naim cdx (it's a machine costing big big money!) I had the occasion to test and that is one the best i've heard to date.
Furthermore i've tested the d1 output both on the old elektor pcm63 dac that is suffering for the low quality of the yamaha digital front end and on another old marantz cd 50 always with no oversampling mod.
Still have to try the thing on the Revox, that is my personal benchmark.
Stefano fatti vivo . Ho provato a chiamarti una decina di giorni fa, ma evidentemente eri al lavoro.
Ciao
Paolo |
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| stefanobilliani |
This is how I modified the cascode stage with Jfet :
:D |
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| Andypairo |
Ciao Stefano,
do the 2sk170 significatively improve things, since you have to use 2 of them paralleled?
Cheers
Andrea |
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| stefanobilliani |
| Yes , the jfet in parallel increases the S/N ratio . |
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| stefanobilliani |
I also use a 500ohm resistor between the dac points ( balanced version ) , but I am not
quite sure about its effects to the sound .
:cool: |
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| Bricolo |
Jfets as I/V converters...
Isn't the input impedance too high? My tests using Jfets in this applications showed a much higher input impedance that with BJTs or Mosfets |
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| Andypairo |
| quote: | Originally posted by stefanobilliani
Yes , the jfet in parallel increases the S/N ratio . |
I was meaning "does the use of Jfets bring particular advantages over the original Mosfets?"
Cheers
Andrea |
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| stefanobilliani |
I like theyr performance .
I don't know of other advantages. |
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| acaudio |
| quote: | Originally posted by stefanobilliani
This is how I modified the cascode stage with Jfet :
:D |
Very nice Stefano,
has you tried this circuit already?
I would omit R1-R4 and going to 2SK389 for better symmetry.
Regards
Adam |
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| stefanobilliani |
| quote: | Originally posted by acaudio
has you tried this circuit already?
I would omit R1-R4 and going to 2SK389 for better symmetry.
Adam |
Of course both .
I have forgotten to mention that IMHO the circuit plays better
with a load between the outputs, say 10k ohm . |
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| stefanobilliani |
| quote: | Originally posted by Andypairo
I was meaning "does the use of Jfets bring particular advantages over the original Mosfets?"
Cheers
Andrea |
They are quieter. |
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| Jaap |
just installed the D1 in my Philips dvd963sa.
I am listening now to thundering bass:smash: and a beautiful soundstage:note:
Well 5 minutes is too early too judge :judge: but I am very glad that promitheus :Pirate: sold me those pcb's.
:wave2: |
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| promitheus |
Hey cool,
I am also happy everything worked out.
Have fun listening to music. |
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| Nelson Pass |
Happy to see that you guys have done such a nice job.
:cool: |
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| Jaap |
I used four big silver mundorf caps (2,2 uF) parallel with four 2,7 uF Hovland musicaps in the output.
These big caps are spread all over the cdp because there is of course no room. I didnot expect much from it with the 16 long leads all over the player. The layout is a mesh but the sound is good and I hope will become better if everything has "burned in". |
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| commstech |
| My DAC consists of 2 x TDA1541 in parallel. With the Idac of two TDA1541, is the D1 a suitable candidate for IV stage? Any adjustments to make? |
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| Andypairo |
| quote: | Originally posted by commstech
My DAC consists of 2 x TDA1541 in parallel. With the Idac of two TDA1541, is the D1 a suitable candidate for IV stage? Any adjustments to make? |
IMHO the D1 doesn't care that much about the DAC's current.
Provided you trim it for the correct voltage on the iout pin of the DAC (0V for the TDA1541A) and use a adequate value for the drain resistor of the "sensing" Mosfet (where the I/V conversion is actually made) you should have no problems at all.
Cheers
Andrea |
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| commstech |
| quote: | Originally posted by Andypairo
IMHO the D1 doesn't care that much about the DAC's current.
Provided you trim it for the correct voltage on the iout pin of the DAC (0V for the TDA1541A) and use a adequate value for the drain resistor of the "sensing" Mosfet (where the I/V conversion is actually made) you should have no problems at all.
Cheers
Andrea |
Dear Andrea, would u be kind enough to point out to me this drain resistor that i have to take note of? R6 (1.5k) in the schematic?
http://www.diyaudio.com/forums/attachment.php?postid=579762&stamp=1108892604 |
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| stefanobilliani |
| quote: | Originally posted by commstech
My DAC consists of 2 x TDA1541 in parallel. With the Idac of two TDA1541, is the D1 a suitable candidate for IV stage? Any adjustments to make? |
I can confirm to you that the D1 works perfectly with the 1541A .
Just trim the mosfet source point to O volt before connecting the dac and than do the final adjustments . |
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| Andypairo |
Here is my D1 stage, used to convert the iout of a TDA1545A DAC into useful voltage ;)
The first impressions are quite good, but I'm heavily biased and my wife claims to be deaf :D :smash:
Soon I'll bring to a friend to get his opinion:confused:
Cheers
Andrea |
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| promitheus |
Very nice done there!
What kind of capacitors do you use there at the output?
Whats that black thing between them? It looks like a heatsink. |
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| Andypairo |
The capacitors are russian PIO 10uF/160V.
The heatsink between them is there to keep them in place without destroying their terminals (they are quite heavy).
Further details: The DAC/receiver section is fed with a battery (12V 1.2Ah SLA, since the consumption is about 40-50mA max), with Oscons all around an double regulation for each section.
The "signal lock" output of the CS8414 is used to detach the battery charger (which is re-attached after 1 min of no signal)
Cheers
Andrea |
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| commstech |
| quote: | Originally posted by Andypairo
Here is my D1 stage, used to convert the iout of a TDA1545A DAC into useful voltage ;)
The first impressions are quite good, but I'm heavily biased and my wife claims to be deaf :D :smash:
Soon I'll bring to a friend to get his opinion:confused:
Cheers
Andrea |
Looks fantastic, and i believe sound even better. Did u use a volume control right at the output? the Passlab D1 has one...just wondering if the o/p is high and therefore Passlab put volume control. |
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| Andypairo |
No, I didn't use a volume control since the DAC is connected to a preamp.
Cheers
Andrea |
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| promitheus |
I didnīt use a volume control either.
Thats the reason that on the PCB there are 4,7uF DC blocking caps and not the 220uF ones like in the original DAC schematic. |
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| promitheus |
Jaap| quote: |
holy cow Post #52
just installed the D1 in my Philips dvd963sa.
I am listening now to thundering bass and a beautiful soundstage
|
Did you make any photos of the CD with the D1 boards inside? |
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| Jaap |
No i have not made pictures. Perhaps I make some next week.
It looks like a mesh so i will send them privately to you.
Main reason is that i used big caps that do not fit on the pcb's. |
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| sugarn |
JAAP,
I'm interested in D1 installed to PHILIPS 963SA. Could you please show your modifications details? |
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| Jaap |
I took the first opamp after the dac out. I used to contacts on the pcb to connect the D1. I soldered very thin coax on it.
I added toroid transformer in the left side of the 963 (on the bottom under the 220 volt connector). |
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| sugarn |
Jaap.
From DAC 1955 the signal is + / - current then the signal after D1 will be +/- voltage.
Did you make balanced or unbalanced output?
If you've done unbalanced output, please suggest how you combine 2 phase signals. |
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| promitheus |
The circuit doesnīt convert balanced to unbalanced, so if you dont want a balanced output signal you just use the in phase + signal and leave the - signal out.
Or what would be very complicated.
You use both signals with 2 I/V Stages you get balanced out signals and then with a circuit like the Balanced lline stage you take both signals at input and then mix them into one and get a single ended signal at the output.
I dont see any advantages for something so complicated. :bigeyes: |
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| Jaap |
| I did not combine but only used one of the signals |
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| sugarn |
Jaap,
You've told that you just took opamp AD8022 out then connect IOUT from there.
From 963SA schematic there are +8V_OpAmp series 1k8 to IOUT and also there are 100R + 100p parallel with 470R + 180R connected to AD8022 output and then also connected to output stage AD8032.
So these circuits will also be connected to input of D1. I think these circuits will have effect to D1.
Please advise what you have done. |
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| Jaap |
| but I just tried it and it worked |
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| sugarn |
Hi Promitheus,
I'm interested in 1 pcb of D1 I/V stage.
What is the cost of this pcb?
What is the post office airmail shipping cost to Bangkok, Thailand?
Can you accept PAYPAL for payment? |
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| DragonMaster |
What PSU do I use?
Also, how can the PSU from the service manual of the Pass D1 give +30v & -30v from 7815 and 7915 regulators? |
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| dieringe |
| quote: | Originally posted by DragonMaster
Also, how can the PSU from the service manual of the Pass D1 give +30v & -30v from 7815 and 7915 regulators? |
by lifting their grounds with zener diodes |
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| DragonMaster |
| Is there a TL431 or LM317 scheme possible? |
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| Nelson Pass |
| quote: | Originally posted by dieringe
by lifting their grounds with zener diodes |
We use 1N4739's like popcorn around here.
:cool: |
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| promitheus |
Hello,
for power supply with LM317 I use the following
In place of RA, Rb, Rc and Rd use 2 trimmers to set the voltage correctly. I think that Rb and Rc shouldnīt be exactly the same or you dont get the voltages matched all the time.
Parts dont give symmetric voltage. |
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| promitheus |
I ordered new boards for the D1 I/V Stage.
Check the pdfs out. |
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| promitheus |
This is the PSU.
I didnt change much.
Made some pads bigger for better soldering.
The holes are now correct for the parts with thick terminals.
There are 2 more holes for bigger caps.
10uF MCap from Mundorf can be used on the board.
The Ground track is corrected. |
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| DragonMaster |
Looks clean!
Can I use your PCB designs if I tell you made them? |
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| promitheus |
You can only use it for your own diy.
No commercial use. |
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| DragonMaster |
That's for sure. I doubt Nelson Pass would want that Pass Labs designs be used for others to make money anyways.
I forgot to mention: it would be that, once my DAC will be done, I'll create a web page with all schematics, PCBs(Layouts, not for sale), and without forgetting credits to people like you and many others and links to the posts.
So, I'd write: |
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| promitheus |
| Thatīs no problem. |
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| promitheus |
DragonMaster how is your DAC going along?
For those who have ordered PCBs, I will get them next week.
I will post more info and photos when I get them. |
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| DragonMaster |
Not going pretty far. There's so much parts to select and only 60 hours of Internet per month so it's practically impossible to make a list.
For the resistors and caps, I still have to make the choice between Xicon and Panasonic. Maybe I'll use drops in the I/V stage.
I don't want to spend tons of :$: on them as I will build more than one and money is not coming in very fast.
I at least now selected what I will use to build it.
Pedja Rogic DAC + SPDIF part,
TNT Audio PSU,
74HC157 input switch,
D1 I/V stage,
cm's EIAJ to I2S converter(If I need it),
PCM2706 USB input,
maybe others I forgot.
I just need to find which resistors are going around the TL431 I'll use to power the 74HC157.
An other problem, batteries or tranny_. |
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| promitheus |
I just got the new pcbs.
I have a picture here.
The Layout is a bit better, there is also space for a bigger cap at the output.
The Mundorf 10uF MCaps can fit on there. |
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| Nelson Pass |
It seems to me that you gentlemen are ready to apply the
new power JFETs to a D1 style I/V. Which of you is going to
do it?
:cool: |
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| DragonMaster |
| Me when I'll finally finish and order a parts list. (It's surely not tomorrow that it will happen) |
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| DragonMaster |
| quote: | | Me when I'll finally finish and order a parts list. |
Not ... I'll stick with what has been done.
Hey, your Ra to Rd are not placed for multiturns...
Btw, what value are the multiturns? The nearest is 5k. |
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| DragonMaster |
Hi, I was trying to make a parts list for the PSU. The scheme and parts list are not telling the same thing.
First, in the parts list, there are no 47nF while in the scheme there are. In the scheme, you call some 220uF electrolytics some multiceramics.
Other things like this are on it. That's the other kind of problem I encounter when trying to do a parts list. |
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| promitheus |
DragonMaster
Ra to Rd are normal resistors.
The tip to use multiturn resistors was if you make it yourself.
47n are the caps across the diodes in the bridge.
the multilayer are 100n across the input and output of the ICs. |
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| DragonMaster |
| quote: | 47n are the caps across the diodes in the bridge.
the multilayer are 100n across the input and output of the ICs. |
That doesn't tell me why some 220ĩF caps are listed as multilayer ceramics in d1psulowres.jpg |
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| promitheus |
ok now I found it
C9, C10, C11 and C12 are multilayer
and C5, C6, C7, C8, C13 and C14 are Panasonic FC.
I will get a new schematic uploaded. |
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| promitheus |
| This is the correct schematic |
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| relder |
| quote: | Originally posted by Nelson Pass
It seems to me that you gentlemen are ready to apply the
new power JFETs to a D1 style I/V. Which of you is going to
do it?
:cool: |
Are said Lovoltech FETs sourceable by mere mortals as of yet? :angel: If so I would be willing. :smash: |
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