Thomas,
The parcel has arrived. Everything looks in good condition.
I will take a few days to turn this on and I will come back to you.
Thank you very much.
Jean-Charles
The parcel has arrived. Everything looks in good condition.
I will take a few days to turn this on and I will come back to you.
Thank you very much.
Jean-Charles
Hi thomas,
Have u got a deadline for sending CD Control Kit + opamp, because
i will be soon on holiday
Thanks,
RTD
Have u got a deadline for sending CD Control Kit + opamp, because
i will be soon on holiday
Thanks,
RTD
DAC up and working .....great............
I couldn't wait any longer and sat down and set up the DAC. Only change made was to put a bigger heat sink on U4 WITH silicon grease. Transformer was 15-0-15 volts 2A. However it gives 14 volts right now. I get over 18.5 volts dc. more than enough for the 12 volt regulators. U4 is hot but can be touched continuously. Will give you the temp later on.
I think the best bet might be to have a 17~18 (dc) volt external regulator ( LM317/337 or others ). That way all extra heat sinking will be done external to this board and you get better regulation. The line fluctuations can be handled by that.
Sound.
I have run it only a couple of hours. It's just about 12am ( midnight ) here.
I can't play it through speakers now - too late. Just a pair of good headphones at the moment. Right now it's being compared with the analog output of a Pioneer DV667A.
Does sound noticeably better. This is with the NE5534.
Will change opamps later. Sound is very clean , especially the piano and other percussion notes.
Couldn't pick out my test CD's and so I'm on to Elton John's Madman across the water. Sounds great.
Lots more to be done. I'll set up the external regulator to avoid messing with this board. The board looks great.
Thanks Thomas. Great buy for me.
Cheers.
Ashok.
Ever played Madman Across the Water VERY loud at midnight ?
GREAT. Yes now it's headphones but I've done this before over speakers!
Now I must have dinner and try to get some sleep !
I couldn't wait any longer and sat down and set up the DAC. Only change made was to put a bigger heat sink on U4 WITH silicon grease. Transformer was 15-0-15 volts 2A. However it gives 14 volts right now. I get over 18.5 volts dc. more than enough for the 12 volt regulators. U4 is hot but can be touched continuously. Will give you the temp later on.
I think the best bet might be to have a 17~18 (dc) volt external regulator ( LM317/337 or others ). That way all extra heat sinking will be done external to this board and you get better regulation. The line fluctuations can be handled by that.
Sound.
I have run it only a couple of hours. It's just about 12am ( midnight ) here.
I can't play it through speakers now - too late. Just a pair of good headphones at the moment. Right now it's being compared with the analog output of a Pioneer DV667A.
Does sound noticeably better. This is with the NE5534.
Will change opamps later. Sound is very clean , especially the piano and other percussion notes.
Couldn't pick out my test CD's and so I'm on to Elton John's Madman across the water. Sounds great.
Lots more to be done. I'll set up the external regulator to avoid messing with this board. The board looks great.
Thanks Thomas. Great buy for me.
Cheers.
Ashok.
Ever played Madman Across the Water VERY loud at midnight ?
GREAT. Yes now it's headphones but I've done this before over speakers!
Now I must have dinner and try to get some sleep !
Temperatures.
Here are some operating temperatures.
The board is open and heat sinks slightly tilted to improve air flow.
U4 has a new heat sink .
I'll post a picture as soon as the camera batteries are cxharged.
Transformer secondary 14-0-14 volts. rectified dc is +18.6 V and -19.5 V.
Ambient temp is 30 deg C.
The ( stabilised ) temperature in brackets is when the ceiling fan is working , causing a medium draft of air over the board.
U1 is at 48 degC ( 37 )
U2 is at 44 deg C ( 37 )
U3 is at 43 deg C ( 36 )
U4 is at 91 deg C ( 58 )
U5 is at 58 deg C ( 39 )
U6 is at 37 deg C ( 32 )
U7 is at 56 deg C ( 40 )
U8 is at 39 deg C ( 33 )
U9 is at 33 deg C ( 31 )
SA7220 is at 54 deg C ( 40 )
TDA1541A is at 48 deg C ( 38 )
So having an outboard stabilised supply and a closed box will not help much. Will have to heatsink most chips to the chassis or like what Vikash did.
Today I used the speakers. With the stock board and NE5534 the sound is very good. But must compare against a CD17 MKII. I am inclined to think that the CD-17 was better ( from memory ). But will try it out soon.
Cheers.
Here are some operating temperatures.
The board is open and heat sinks slightly tilted to improve air flow.
U4 has a new heat sink .
I'll post a picture as soon as the camera batteries are cxharged.
Transformer secondary 14-0-14 volts. rectified dc is +18.6 V and -19.5 V.
Ambient temp is 30 deg C.
The ( stabilised ) temperature in brackets is when the ceiling fan is working , causing a medium draft of air over the board.
U1 is at 48 degC ( 37 )
U2 is at 44 deg C ( 37 )
U3 is at 43 deg C ( 36 )
U4 is at 91 deg C ( 58 )
U5 is at 58 deg C ( 39 )
U6 is at 37 deg C ( 32 )
U7 is at 56 deg C ( 40 )
U8 is at 39 deg C ( 33 )
U9 is at 33 deg C ( 31 )
SA7220 is at 54 deg C ( 40 )
TDA1541A is at 48 deg C ( 38 )
So having an outboard stabilised supply and a closed box will not help much. Will have to heatsink most chips to the chassis or like what Vikash did.
Today I used the speakers. With the stock board and NE5534 the sound is very good. But must compare against a CD17 MKII. I am inclined to think that the CD-17 was better ( from memory ). But will try it out soon.
Cheers.
my setup for overheat solution
Hi Ashok,
I removed the U4,installed a dedicate +5V power supply(ultimate mini regulator) with tranfo for SAA7220.
Following the Dine1967’ idea I crossed a profile aluminium bar in the U’s remainder.
Now all works without overheat and the dac sounds better with the dedicate for SAA7220.
thx,
Sergio
Hi Ashok,
I removed the U4,installed a dedicate +5V power supply(ultimate mini regulator) with tranfo for SAA7220.
Following the Dine1967’ idea I crossed a profile aluminium bar in the U’s remainder.
Now all works without overheat and the dac sounds better with the dedicate for SAA7220.
thx,
Sergio
Attachments
rtd said:
Hi Thomas,
you're certainly too busy 🙂 , so when possible, could U give news about question above.
You talk about Epcos MKP for coupling caps, but for which value ( uF ? and U ?) ? I saw in your schemas that one canal has 25 uF + 25 Uf coupling caps value ? Could it be lower values if still using polarized coupling caps ? What is the Minimum capacity value and the minimum voltage ?
N.B : I put a standard TO220 heatsink on U4 ( its height just like the AWF caps), it's hot but can be touched, i let dac work for more than 6 hours, it doesn't cause any trouble.
Thanks, RTD
A simpler suggestion ...............?
It should be possible to make a separate connection to the same transformer and get a lower dc voltage for U4 . Ripple would be less than what it currently is. However supply build up will be slower than the rest of the circuit. Any problems with that ?
D1 1N4001 or equiv.
C1 470uF 25V
C2 2200uF 16 V
R1 27 ohm 2 watts
It should be possible to make a separate connection to the same transformer and get a lower dc voltage for U4 . Ripple would be less than what it currently is. However supply build up will be slower than the rest of the circuit. Any problems with that ?
D1 1N4001 or equiv.
C1 470uF 25V
C2 2200uF 16 V
R1 27 ohm 2 watts
Attachments
hi rtd,
sorry to late call back too busy, pls let me know which item I missing & late post to u.
I will post immediately & post again your detail address to thomas_siu@hotmail.com
thx
thomas
sorry to late call back too busy, pls let me know which item I missing & late post to u.
I will post immediately & post again your detail address to thomas_siu@hotmail.com
thx
thomas
tube-lover said:
Hi Thomas,
It only remains the CD control kit + opamp. I sent U email to adress thomas_siu@hotmail.com. I made a mistake and sent with my wife mail account (v...@9online.fr), don't take it into account, i sent it again with my regular mail (drabe...@9online.fr).
Thanks to check and confirm
RTD (Dominique)
Hi all,
Another question. Now i haven't got any hum left, all capas in place. I tried to use the power trans and argh...
new problem. May be U could advise. It's just to see if i have made wiring fault :
I use "Thomas power trans", in France we have 230v ( 50 Hz). I join 4 and 6 and connect 1 to phase and 9 to neutral... If i'm good the two primary 110V (Power Spec) are in series. I join 14 & 17 to form the OV and 12 and 19 are normaly ( + 15v and -15V).
I didn't connect the secondary (12,19 and intersection of 14,17) to the DAC and i Directly plug 1 and 9 to main supply and
, no noise but quickly the power trans became really hot, platic insolating primary began to "inflate"
So to your opinion, have I made wiring fault
?
If not was it because in France we have rather 230V or 240V (peak) ?
N.B : i use an old NAD power trans for the moment, All is ok. By the way the AWF caps makes bass deeper. Sometimes too much but I think it's just because AWF didn't show ( perhaps it did ) as much improvement in Mid or high.
Another question. Now i haven't got any hum left, all capas in place. I tried to use the power trans and argh...
new problem. May be U could advise. It's just to see if i have made wiring fault :I use "Thomas power trans", in France we have 230v ( 50 Hz). I join 4 and 6 and connect 1 to phase and 9 to neutral... If i'm good the two primary 110V (Power Spec) are in series. I join 14 & 17 to form the OV and 12 and 19 are normaly ( + 15v and -15V).
I didn't connect the secondary (12,19 and intersection of 14,17) to the DAC and i Directly plug 1 and 9 to main supply and
, no noise but quickly the power trans became really hot, platic insolating primary began to "inflate" So to your opinion, have I made wiring fault
?If not was it because in France we have rather 230V or 240V (peak) ?
N.B : i use an old NAD power trans for the moment, All is ok. By the way the AWF caps makes bass deeper. Sometimes too much but I think it's just because AWF didn't show ( perhaps it did ) as much improvement in Mid or high.
hi rtd,
your case must be the pri winding was wrong connection.
the pri was.
Pls see the photos of the isolate power trans. I was afraid the phase was invert in your connection, if invert will short circuit& the plastic will blow up get hot with bad smell of the epoxy burn. May be the power trans was damage already.
pls see the photos.
the left side was sec winding small white wire was connet for two winding.
the large two white was 15V, small white wire with the black wire was 0V.
so the left side was 15~0~15V.
the right side was pri winding.
green colour wind was connect two winding in pri winding.
the red & white was ac 220or 230V input.
OK,
this is isolate power trans. In your case. I was worry will,be damage.
thx
thomas
your case must be the pri winding was wrong connection.
the pri was.
Pls see the photos of the isolate power trans. I was afraid the phase was invert in your connection, if invert will short circuit& the plastic will blow up get hot with bad smell of the epoxy burn. May be the power trans was damage already.
pls see the photos.
the left side was sec winding small white wire was connet for two winding.
the large two white was 15V, small white wire with the black wire was 0V.
so the left side was 15~0~15V.
the right side was pri winding.
green colour wind was connect two winding in pri winding.
the red & white was ac 220or 230V input.
OK,
this is isolate power trans. In your case. I was worry will,be damage.
thx
thomas
Attachments
h rtd,
the AWF cap need time to run in!!!!!!
this is a very good cap.
I will use in all my coming DAC.
Your old pwer trans may be not a isolate power trans so han,t this phase connect problem but will catch much noise from pri to sec. Isolate was more clear in digital area.
thx
thomas
the AWF cap need time to run in!!!!!!
this is a very good cap.
I will use in all my coming DAC.
Your old pwer trans may be not a isolate power trans so han,t this phase connect problem but will catch much noise from pri to sec. Isolate was more clear in digital area.
thx
thomas
Hi Thomas,
thanks for tech support. So I was wrong in my wiring. I will try tonight with the right one (Power trans is in general strong).
The AWF was runing for about 15 hours, i'm ok it needs some burning.
Without any burning in fact they are already better than the ELNA, so I will wait.
Have U receive my mail Thomas ?
thx
RTD
thanks for tech support. So I was wrong in my wiring
. I will try tonight with the right one (Power trans is in general strong).The AWF was runing for about 15 hours, i'm ok it needs some burning.
Without any burning in fact they are already better than the ELNA, so I will wait.
Have U receive my mail Thomas ?
thx
RTD
hi RTD,
I return email to U already, pls check, since your email & your wife email account show the detail of the post address had some code not word. It not clear, pls let me know asap.
thx
thomas
I return email to U already, pls check, since your email & your wife email account show the detail of the post address had some code not word. It not clear, pls let me know asap.
thx
thomas
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