dear Anthony,
Name of ver.3 1541a DAC call 'Three Wishes'
The best Price/cost Ratio.
The best parts use in product in reasonable price.
The best development space of the diy kits which can extend products life. ( OP-amp or Fet output stage, tube buffer, pre-amp output trans).
This is the tasking when I set up the ver.3 dac.
Ver.3 is a single DAC, But still can parallel to operate. Since I test longer longer & detect one problem, its very different to match two chips. unless U can get a very close match pair chips. although R1,R2 or S1,S2 grade!! Otherwise choose back one chips or parallel two chips but share with 14 decoupling caps. If U still like to use two chips in one DAC. pls put two chips together & share 14 pcs of the decoupling caps. DAC power supply in ver.3 is much fast & can support running more chip still stable.
I had many 1541a on hand, diyers can buy more for parallel 2~4 chips.
TThe power supply was very heavy duty in ver.3, not need to worry for that.
Share with same decoupling caps was better performance unless the chips not close match!!
At last not need to worry about the chips.
I had over 300 pcs tda1541a on hands. Large amount of chips can test parallel more chips performance.
Otherwise I will choose back single chip.
Yes, the DAC had TTL input especially for the Cd-rom only.
Anthony, I open a production line in china & employ 5 engineer which was university student( part time ) job for me. This lower labour cost provide me to lower the production cost, so will lower all the product coming cost. hope more diyers will love them.
this cd-rom was free parts to diyers which follow with the ver.3 DAC because we all were computor users. Always when we update the computor, the cd-rom will uopgrade to new one. this cd-rom support all cd-rom DVD, DVD writer rom. I thought every computor at least will had excess one on hand????
right. So they can immediately play the DAC with Old CD-rom!!!!!
the ver.2 can upgrade to the pre-amp OPT.
ver.3 too.
standard will use Hi-B core. But I will supply 78% 0.1mm thickness lamination nickel permalloy core & nano-amorphous core pre-amp OPT.
thx
thomas
Name of ver.3 1541a DAC call 'Three Wishes'
The best Price/cost Ratio.
The best parts use in product in reasonable price.
The best development space of the diy kits which can extend products life. ( OP-amp or Fet output stage, tube buffer, pre-amp output trans).
This is the tasking when I set up the ver.3 dac.
Ver.3 is a single DAC, But still can parallel to operate. Since I test longer longer & detect one problem, its very different to match two chips. unless U can get a very close match pair chips. although R1,R2 or S1,S2 grade!! Otherwise choose back one chips or parallel two chips but share with 14 decoupling caps. If U still like to use two chips in one DAC. pls put two chips together & share 14 pcs of the decoupling caps. DAC power supply in ver.3 is much fast & can support running more chip still stable.
I had many 1541a on hand, diyers can buy more for parallel 2~4 chips.
TThe power supply was very heavy duty in ver.3, not need to worry for that.
Share with same decoupling caps was better performance unless the chips not close match!!
At last not need to worry about the chips.
I had over 300 pcs tda1541a on hands. Large amount of chips can test parallel more chips performance.
Otherwise I will choose back single chip.
Yes, the DAC had TTL input especially for the Cd-rom only.
Anthony, I open a production line in china & employ 5 engineer which was university student( part time ) job for me. This lower labour cost provide me to lower the production cost, so will lower all the product coming cost. hope more diyers will love them.
this cd-rom was free parts to diyers which follow with the ver.3 DAC because we all were computor users. Always when we update the computor, the cd-rom will uopgrade to new one. this cd-rom support all cd-rom DVD, DVD writer rom. I thought every computor at least will had excess one on hand????
right. So they can immediately play the DAC with Old CD-rom!!!!!
the ver.2 can upgrade to the pre-amp OPT.
ver.3 too.
standard will use Hi-B core. But I will supply 78% 0.1mm thickness lamination nickel permalloy core & nano-amorphous core pre-amp OPT.
thx
thomas
Attachments
Output impedance
Hi,
I am really confused now.
In the last week two people who know a lot more about tube amplifiers than me adviced me that the next stage after the tube buffer (6dj8) needs at least an input impedance of 50k.
Just now I read that Sceglar (page 40 in this thread I think) wrote that the output inpedance of the 6dj8 option is about 100R and should have no problems with driving a 20k input impedance.
Yet when I use the formula for SRPP on Marc Heijligers site:
http://members.chello.nl/~m.heijligers/DAChtml/Analogue/Amplification.html
I calculate an impedance of about 1k3 which does mean again that the other two where right and I need at least 50k impedance.
Could somebody please try to explain who's advice I must follow, because I am building a pre-amp with an input impedance of 20k and if this does not work right then I rather change this now then when I am finishing it.
Thanks,
Jeroen
Hi,
I am really confused now.
In the last week two people who know a lot more about tube amplifiers than me adviced me that the next stage after the tube buffer (6dj8) needs at least an input impedance of 50k.
Just now I read that Sceglar (page 40 in this thread I think) wrote that the output inpedance of the 6dj8 option is about 100R and should have no problems with driving a 20k input impedance.
Yet when I use the formula for SRPP on Marc Heijligers site:
http://members.chello.nl/~m.heijligers/DAChtml/Analogue/Amplification.html
I calculate an impedance of about 1k3 which does mean again that the other two where right and I need at least 50k impedance.
Could somebody please try to explain who's advice I must follow, because I am building a pre-amp with an input impedance of 20k and if this does not work right then I rather change this now then when I am finishing it.
Thanks,
Jeroen
If my calculations are correct, and I am happy to be corrected, then you will need to adjust the value of capacitor coupling on the output for full LF response.. thats about all.
And, even with1k3 :20k things are still good impedance wise, but the C output will still need upward adjustment, as was always going to be the case with 20k Zin.
1uf +
regards,
shane.
BTW, Thomas, just wondering the status on that TDA1541A replacement pair.
And, even with1k3 :20k things are still good impedance wise, but the C output will still need upward adjustment, as was always going to be the case with 20k Zin.
1uf +
regards,
shane.
BTW, Thomas, just wondering the status on that TDA1541A replacement pair.
hi shane,
very thanks U help me to answer question for diyers.
shane, I test for several pairs only & choose ost matching pair was 1989~1990.
This pair with 2 nano pulse was send to U by small airparce already.
P ost to this address already.
Shane CXXXX
6A CXXXXXXX Street
AXXXXXX(CBD), 5000
S.A.
AUSTXXXX.
pls test & let me know, U question I also collect some of the diyer call back. but looks if we cannot collect two close match chips.
Looks share decoupling caps can slove this problems.
pls see the cd-rom kit running!
thx
thomas
very thanks U help me to answer question for diyers.
shane, I test for several pairs only & choose ost matching pair was 1989~1990.
This pair with 2 nano pulse was send to U by small airparce already.
P ost to this address already.
Shane CXXXX
6A CXXXXXXX Street
AXXXXXX(CBD), 5000
S.A.
AUSTXXXX.
pls test & let me know, U question I also collect some of the diyer call back. but looks if we cannot collect two close match chips.
Looks share decoupling caps can slove this problems.
pls see the cd-rom kit running!
thx
thomas
Attachments
hi,
ver.3 had CS8412-CS, CS8412-IS & CS8414 for diyers to choose.
BTW, version three will had two version. one is cheap version, use standard grade parts but still follow with 4 pcs OPA627.
Not follow with power trans. Include postage
I will prepare 10 sets for diyers o the basic price( NIL profit) with all chips, CS8414, Nano pulse trans TDA1541a, 74HCXXXX, XO& 7220P/B & OPA 627 X4). USD 110 include posatge, after 10 set will returen to standard price USD 150 but will change to TCXO.
any diyers had interest pls let me know asap. Because only had 10 sets in this price.
USD 110 inlcude all!!
thx
thomas
ver.3 had CS8412-CS, CS8412-IS & CS8414 for diyers to choose.
BTW, version three will had two version. one is cheap version, use standard grade parts but still follow with 4 pcs OPA627.
Not follow with power trans. Include postage
I will prepare 10 sets for diyers o the basic price( NIL profit) with all chips, CS8414, Nano pulse trans TDA1541a, 74HCXXXX, XO& 7220P/B & OPA 627 X4). USD 110 include posatge, after 10 set will returen to standard price USD 150 but will change to TCXO.
any diyers had interest pls let me know asap. Because only had 10 sets in this price.
USD 110 inlcude all!!
thx
thomas
Hi Thomas,
I'm interested in testing one of your first DAC ver. 3.
Please let me know if you have one for me?
Also, could you please include a 11.2896MHz TCXO for my Twin DAC ver.2? I've been waiting for the 11.2896MHz TCXO for about 6 month now...
Thanks.
Julien
I'm interested in testing one of your first DAC ver. 3.
Please let me know if you have one for me?
Also, could you please include a 11.2896MHz TCXO for my Twin DAC ver.2? I've been waiting for the 11.2896MHz TCXO for about 6 month now...
Thanks.
Julien
hi Julien,
really, very sorry to my mistake.
Pls sign in in the non-profit thread in groups buy.
I need to accumulate the total no of diyers which had interest.
More kits will coming. Coming will be the 6EM7 with OPT Trans
loading headphone which special for AKG K1000.
I will post the PCB with the 74HCXXX & Saa7220 to U is OK.
Looks more parts U had on hand.
thx
thomas
really, very sorry to my mistake.
Pls sign in in the non-profit thread in groups buy.
I need to accumulate the total no of diyers which had interest.
More kits will coming. Coming will be the 6EM7 with OPT Trans
loading headphone which special for AKG K1000.
I will post the PCB with the 74HCXXX & Saa7220 to U is OK.
Looks more parts U had on hand.
thx
thomas
Hi Thomas,
Thanks for your reply. I'm signed up for v3.
What voltages does the DAC v3 needs? Is the PCB assembled? Does it include a power supply? What parts do I need to have a working DAC? Does it has its own buffer? Can I use the tube buffer from v2?
Thanks,
Julien
Thanks for your reply. I'm signed up for v3.
What voltages does the DAC v3 needs? Is the PCB assembled? Does it include a power supply? What parts do I need to have a working DAC? Does it has its own buffer? Can I use the tube buffer from v2?
Thanks,
Julien
hi,
ver.3 PCB & one full assemble kit arrive, will send to my home after 1500hrs this afternoon. photos will post immediately.
hi Julien_M.
what voltages does the DAC v3 needs?
18V
Is the PCB assembled?
no.
Does it include a power supply?
yes, contain Power supply PCB, no power trans.
What parts do I need to have a working DAC?
all contain.
Does it has its own buffer?
yes, Op-amp.
Can I use the tube buffer from v2?
yes, but I will let U know the new ver.3, this will use 5687WB or EC900. still testing.
thx
thomas
ver.3 PCB & one full assemble kit arrive, will send to my home after 1500hrs this afternoon. photos will post immediately.
hi Julien_M.
what voltages does the DAC v3 needs?
18V
Is the PCB assembled?
no.
Does it include a power supply?
yes, contain Power supply PCB, no power trans.
What parts do I need to have a working DAC?
all contain.
Does it has its own buffer?
yes, Op-amp.
Can I use the tube buffer from v2?
yes, but I will let U know the new ver.3, this will use 5687WB or EC900. still testing.
thx
thomas
Hi Thomas,
Thank you for replying to my mails.
Please count me in for the v3 dac. I will be very happy to get one as soon it is available.
Keep us informed of all the options available if any.
Jean-Charles
Thank you for replying to my mails.
Please count me in for the v3 dac. I will be very happy to get one as soon it is available.
Keep us informed of all the options available if any.
Jean-Charles
hi jean,
I sign your name already.
cheap version & full assemble version will contain all parts. don't worry for this.
yes, all parts contain into it.
don't worry for it.
thx
thomas
I sign your name already.
cheap version & full assemble version will contain all parts. don't worry for this.
yes, all parts contain into it.
don't worry for it.
thx
thomas
Version 3
Hi Thomas,
I've 2 pcs of TDA1541AS2 and 2 pcs of TDA1541AR1 in my hand.
Please count me in for the v3 dac, too.
Please, can you explain the various options available.
I'm interested in the top configuration.
Thanks.
Simone.
Hi Thomas,
I've 2 pcs of TDA1541AS2 and 2 pcs of TDA1541AR1 in my hand.
Please count me in for the v3 dac, too.
Please, can you explain the various options available.
I'm interested in the top configuration.
Thanks.
Simone.
hi shane,
very thanks U help me to answer question for diyers.
shane, I test for several pairs only & choose ost matching pair was 1989~1990.
This pair with 2 nano pulse was send to U by small airparce already.
P ost to this address already.
Shane CXXXX
6A CXXXXXXX Street
AXXXXXX(CBD), 5000
S.A.
AUSTXXXX.
pls test & let me know, U question I also collect some of the diyer call back. but looks if we cannot collect two close match chips.
Looks share decoupling caps can slove this problems.
pls see the cd-rom kit running!
thx
thomas
Hi Thomas,
I can confirm that the address is correct. It has been some time now (1 month?) and the chips have still not arrived
I am wondering if they have been returned to you, as was the case with the last package that you sent containing the nano crystal pulse transformers.
Can you please confirm the date on which you posted out, so that we can work out if they have had time to be sent back to you in the event that customs saw fit to do so, as was the case last time.
Sincerely,
Shane
very thanks U help me to answer question for diyers.
shane, I test for several pairs only & choose ost matching pair was 1989~1990.
This pair with 2 nano pulse was send to U by small airparce already.
P ost to this address already.
Shane CXXXX
6A CXXXXXXX Street
AXXXXXX(CBD), 5000
S.A.
AUSTXXXX.
pls test & let me know, U question I also collect some of the diyer call back. but looks if we cannot collect two close match chips.
Looks share decoupling caps can slove this problems.
pls see the cd-rom kit running!
thx
thomas
Hi Thomas,
I can confirm that the address is correct. It has been some time now (1 month?) and the chips have still not arrived
I am wondering if they have been returned to you, as was the case with the last package that you sent containing the nano crystal pulse transformers.
Can you please confirm the date on which you posted out, so that we can work out if they have had time to be sent back to you in the event that customs saw fit to do so, as was the case last time.
Sincerely,
Shane
Tube buffer schematic
If anybody has the schematics of tube buffer and reclocker for Ver.2 dac please send me(victor.hrynchuk@sympatico.ca)
Thank you.
If anybody has the schematics of tube buffer and reclocker for Ver.2 dac please send me(victor.hrynchuk@sympatico.ca)
Thank you.
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