Hi,
Could you help me with the service manual or the schematic for this cambridge audio dac 3 ?
The CD input seems dead and the DAT input seems OK.
I found a copy of the output stage for the Dacmagic II/3 but unfortunaly this is sheet 3/5.
I suppose the missing sheet are describing the input stage ?
Sorry for my frenchy english
Thanks a lot
Could you help me with the service manual or the schematic for this cambridge audio dac 3 ?
The CD input seems dead and the DAT input seems OK.
I found a copy of the output stage for the Dacmagic II/3 but unfortunaly this is sheet 3/5.
I suppose the missing sheet are describing the input stage ?
Sorry for my frenchy english
Thanks a lot
Hi!
Did you ever find any solution to this? I'm asking, as I've got an old Dacmagic 3 myself, also with a dead CD input.
Thank you for reading.
Hi,
The Dac is one of my designs, you need to replace the 8-Pin DIP 9637 - its located close to the input SPDIF's BNC's.
These are damaged when exposed to High Earth Leakage currents on the SPDIF inputs - never a problem when using BNC to BNC - but if you use BNC to RCA, then the center conductor of the RCA plug makes contact first - before the Ground - resulting in any Earth leakage current to flow via the center RCA pin to the input circuit.... With BNC connectors, you don't have this problem as Ground is always made first during connection, and broken last during disconnection.
John
The Dac is one of my designs, you need to replace the 8-Pin DIP 9637 - its located close to the input SPDIF's BNC's.
These are damaged when exposed to High Earth Leakage currents on the SPDIF inputs - never a problem when using BNC to BNC - but if you use BNC to RCA, then the center conductor of the RCA plug makes contact first - before the Ground - resulting in any Earth leakage current to flow via the center RCA pin to the input circuit.... With BNC connectors, you don't have this problem as Ground is always made first during connection, and broken last during disconnection.
John
Thank you guys!
Now I know what to do, if I bother... I guess that I will fix it though, as I just can't handle the fact that something isn't working properly...
It is probably as "JohnW" says, as I was using a RCA-cable, and the BNC/RCA adapter was already inserted in the input.
Thanx a lot!
Now I know what to do, if I bother... I guess that I will fix it though, as I just can't handle the fact that something isn't working properly...
It is probably as "JohnW" says, as I was using a RCA-cable, and the BNC/RCA adapter was already inserted in the input.
Thanx a lot!
Thank you for this advice - this reason was new for me. The UA9637 about
UA9637 Datasheet pdf - DIFFERENTIALE VERDOPPELUNGLINIE EMPFÄNGER - Texas Instruments
I have replaced several times by my service work arround 1995 until today. At all the time I can't find an explantation for the reason.
P.S. great developing work, still great sounded DAC.
Hello to all involved on this old threat
I've read it and that's my problem!! My DacMagic 3 has dead BNC connections and only Optical working... After switching my DVD Player to a brand new Blu-Ray player and using frequencies higher than 48Khz (me, as an idiot, do select 96 Khz and even 192 khz)
This morning I was starting to accuse the BR player
Well, let's locate the 8-Pin DIP 9637 and replace it.
Have a nice Sunday morning!!
I've read it and that's my problem!! My DacMagic 3 has dead BNC connections and only Optical working... After switching my DVD Player to a brand new Blu-Ray player and using frequencies higher than 48Khz (me, as an idiot, do select 96 Khz and even 192 khz)
This morning I was starting to accuse the BR player
Well, let's locate the 8-Pin DIP 9637 and replace it.
Have a nice Sunday morning!!
DS9637A vs. UA9637A
The most used versions of this line drivers from DACMAGIC and DAC3 are the follow:
1) DS9637A (National Semiconductor)
http://www.national.com/ds/DS/DS9637A.pdf
2) UA9637A (TI)
Interface - RS-422 - UA9637A - TI.com
Because I have not thrown away all faulty devices, can I note, that the damaged devices are the TI version (UA9637A). The also often used version from National Semiconductor, the DS9637A is obviously better immune against high input voltage peaks (perhaps internal suppressor diodes present?). Thus I use only this version for replace.
There are also additional this versions on the marked (no own experiences):
UA9637AP/SN65LVDS9637AD (TI)
http://www.ti.com/lit/ds/symlink/sn65lvds32a.pdf
http://www.micropik.com/PDF/UA9637.pdf
LVT9637PI90LV9637U
PI90LV9637U* datasheet and application note, data sheet, circuit, pdf, cross reference, pinout | Datasheet Archive
this follow types is not suited (other internal function unit):
L9637D
http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATASHEET/CD00000234.pdf
The most used versions of this line drivers from DACMAGIC and DAC3 are the follow:
1) DS9637A (National Semiconductor)
http://www.national.com/ds/DS/DS9637A.pdf
2) UA9637A (TI)
Interface - RS-422 - UA9637A - TI.com
Because I have not thrown away all faulty devices, can I note, that the damaged devices are the TI version (UA9637A). The also often used version from National Semiconductor, the DS9637A is obviously better immune against high input voltage peaks (perhaps internal suppressor diodes present?). Thus I use only this version for replace.
There are also additional this versions on the marked (no own experiences):
UA9637AP/SN65LVDS9637AD (TI)
http://www.ti.com/lit/ds/symlink/sn65lvds32a.pdf
http://www.micropik.com/PDF/UA9637.pdf
LVT9637PI90LV9637U
PI90LV9637U* datasheet and application note, data sheet, circuit, pdf, cross reference, pinout | Datasheet Archive
this follow types is not suited (other internal function unit):
L9637D
http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATASHEET/CD00000234.pdf
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Many thanks for this info
I'm going to fix this unit with the help of a friend who's much better than me using the soldering iron and he will be back in town next week.
Once he's able to work with my Cambridge Audio, we will search for a replacement such as DS9637A (National Semiconductor) and keep my DAC covered for future damages.
Probably also I will spend little money in some upgrade of the machine. There's a well-know article from Hi-FI News date January 1999 that proposes a lot of changes. I'll take this like a guide for upgrading.
I'm going to fix this unit with the help of a friend who's much better than me using the soldering iron
and he will be back in town next week.Once he's able to work with my Cambridge Audio, we will search for a replacement such as DS9637A (National Semiconductor) and keep my DAC covered for future damages.
Probably also I will spend little money in some upgrade of the machine. There's a well-know article from Hi-FI News date January 1999 that proposes a lot of changes. I'll take this like a guide for upgrading.
Mean you this magazine from the attachement (found by ebay) ?
Perhaps you can post the article.
Attachments
ask by
Richer Sounds - The UK's Hi-Fi, Home Cinema & Flat Panel TV Specialists!
for service manuals from older cambridge audio devices because
Cambridge Audio - Your music + our passion
haven't SM's.
Richersounds was the supplier/wholesaler for Germany's distributor and the sales manager was Mr. Mike Gavin at those day's (arround 1995-1997).
Richer Sounds - The UK's Hi-Fi, Home Cinema & Flat Panel TV Specialists!
for service manuals from older cambridge audio devices because
Cambridge Audio - Your music + our passion
haven't SM's.
Richersounds was the supplier/wholesaler for Germany's distributor and the sales manager was Mr. Mike Gavin at those day's (arround 1995-1997).
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Hello
First of all, according to kind explanation of tiefbassuebertr I've purchased this, just for repairing my DacMagic
SPARES FOR REPAIRING DAMAGE
Secondly, I've made a list of all components involved on the upgrade project as shown on magazine and now I'm searching for all... I'll keep you @ll update about that. Sorry but I will try to avoid to spend 200 GBP on it...
And in third position, Mr. tiefbassuebertr, sorry for not understeanding with my poor spanish english the idea you gave me about SM from Richer Sounds.
Your idea was contacting Mr.Mike Gavin and ask for it? If it is so I will but sorry, not myself sure about that.
First of all, according to kind explanation of tiefbassuebertr I've purchased this, just for repairing my DacMagic
SPARES FOR REPAIRING DAMAGE
Secondly, I've made a list of all components involved on the upgrade project as shown on magazine and now I'm searching for all... I'll keep you @ll update about that. Sorry but I will try to avoid to spend 200 GBP on it...
And in third position, Mr. tiefbassuebertr, sorry for not understeanding with my poor spanish english the idea you gave me about SM from Richer Sounds.
Your idea was contacting Mr.Mike Gavin and ask for it? If it is so I will but sorry, not myself sure about that.
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Yes, this was my idea.
But I have more ideas:
1) find out the formerly distributor of Cambridge Audio in your country and Portugal (easy to find out in test magazines between 1995 and 1997)
2) find out the formerly distributor of Cambridge Audio in Countries from South American/Latin American.
Maybe from an old distributor you can get schematics.
Maybe use also therefore this forum in your language.
Hello
First tests show unit is working in all 3 positions of the selector. Just a lot of noise from BNC ones. So, after fixing minor bugs with soldering ironing (communicated paths and nice stuff like this) my DacMagic II will be completely recovered.
I've used the recommended DS9637A as per indication of Mr.tiefbassuebertr
Many thanks to all people involved on this.
Anyway I'll try to obtain the Service Manual and put here the links
First tests show unit is working in all 3 positions of the selector. Just a lot of noise from BNC ones. So, after fixing minor bugs with soldering ironing (communicated paths and nice stuff like this) my DacMagic II will be completely recovered.
I've used the recommended DS9637A as per indication of Mr.tiefbassuebertr
Many thanks to all people involved on this.
Anyway I'll try to obtain the Service Manual and put here the links
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