(Wery) OT!!! NAD S100 question

[Tonni]

Hi!

Sorry for this OT, but....

A few days ago i got my hands on some NAD S-series pcb's. Among these were
tree S100 preamp mainboards, nearly complete...

Only parts needet are the IEC plug, and the trannie. :-(

So, does any of You RAT's know the spec's on this trannie???

Best regards
Tonni

P.S: Want a peek on such a pre?
http://user.tninet.se/~xfz720w/NAD-S100_inside.jpg

OP-Amp's Burr Brown OPA134PA

[Eeyore]

Tonni wrote:

> Hi!
>
> Sorry for this OT, but....
>
> A few days ago i got my hands on some NAD S-series pcb's. Among these were
> tree S100 preamp mainboards, nearly complete...
>
> Only parts needet are the IEC plug, and the trannie. :-(
>
> So, does any of You RAT's know the spec's on this trannie???

It would be easy to make a pretty accurate guess based on the DC supply rails.

More info ?

I'm curious about the heatsinks there btw.

Graham

[Tonni]

> It would be easy to make a pretty accurate guess based on the DC supply
> rails.
>
> More info ?
>
> I'm curious about the heatsinks there btw.
>

Hi Graham, and all!

There's two known DC Voltages a 5 and a 15 Volt.
Both positive. - The 5 V is for IR-reciever and pic.
so my own guess is that the transformer needet is on 2*15 VAC

There's two regulators a 7805 and a LM317T. - The one delivering 15 V ( Rreg
= 236r and Rdrop = 2K73 )

The triggy part is that there's no neg regulator in the psu, but there's a
set of BD139/BD140 for each OPA134.
- These are the ones sitting on the small heatsinks.
- The regulators are on the larger one...

The small transistors all are 2SA1015 and 2SC1815...

Best regards
Tonni

[Tonni]

Hi!

Forgot to mention, no schematics...

Best regards
Tonni

[Eeyore]

Tonni wrote:

> > It would be easy to make a pretty accurate guess based on the DC supply
> > rails.
> >
> > More info ?
> >
> > I'm curious about the heatsinks there btw.
> >
>
> Hi Graham, and all!
>
> There's two known DC Voltages a 5 and a 15 Volt.
> Both positive. - The 5 V is for IR-reciever and pic.
> so my own guess is that the transformer needet is on 2*15 VAC

Are you sure it's not +5v and +-15V ?


> There's two regulators a 7805 and a LM317T. - The one delivering 15 V ( Rreg
> = 236r and Rdrop = 2K73 )
>
> The triggy part is that there's no neg regulator in the psu,

Peculiar.


> but there's a
> set of BD139/BD140 for each OPA134.

That could be local supply regulation. Interesting approach. I've done something
similar once but for different reasons. I expect this is to *look* fancy rather
than do anything very useful.


> - These are the ones sitting on the small heatsinks.
> - The regulators are on the larger one...

Ok.


> The small transistors all are 2SA1015 and 2SC1815...

Where did you get the jpg ?

Graham

[Sander deWaal]

"Tonni" > said:

>Hi!
>
>Sorry for this OT, but....
>
>A few days ago i got my hands on some NAD S-series pcb's. Among these were
>tree S100 preamp mainboards, nearly complete...
>
>Only parts needet are the IEC plug, and the trannie. :-(
>
>So, does any of You RAT's know the spec's on this trannie???
>
>Best regards
>Tonni
>
>P.S: Want a peek on such a pre?
>http://user.tninet.se/~xfz720w/NAD-S100_inside.jpg
>
>OP-Amp's Burr Brown OPA134PA


Check the voltages on the electrolytics, usually the rated voltage is
about 3/4 of that what's printed on the electrolytics.
My guess is something like 2 x 15 or 2 x 18VAC for the analog part and
1 x 8VAC for the digital stuff.

The heatsinks suggets a suitable current, like at least 2A per winding
or somesuch.

--
"Due knot trussed yore spell chequer two fined awl miss steaks."

[Tonni]

"Sander deWaal" > skrev i en meddelelse
...
> "Tonni" > said:
>
>>Hi!
>>
>>Sorry for this OT, but....
>>
>>A few days ago i got my hands on some NAD S-series pcb's. Among these were
>>tree S100 preamp mainboards, nearly complete...
>>
>>Only parts needet are the IEC plug, and the trannie. :-(
>>
>>So, does any of You RAT's know the spec's on this trannie???
>>
>>Best regards
>>Tonni
>>
>>P.S: Want a peek on such a pre?
>>http://user.tninet.se/~xfz720w/NAD-S100_inside.jpg
>>
>>OP-Amp's Burr Brown OPA134PA
>
>
> Check the voltages on the electrolytics, usually the rated voltage is
> about 3/4 of that what's printed on the electrolytics.
> My guess is something like 2 x 15 or 2 x 18VAC for the analog part and
> 1 x 8VAC for the digital stuff.
>
> The heatsinks suggets a suitable current, like at least 2A per winding
> or somesuch.
>
> --
> "Due knot trussed yore spell chequer two fined awl miss steaks."

Hi Sander!

It's getting even more peculiar. ;-)
- There's only two secondaries on the tranny!
But as can be seen here:
http://s38.photobucket.com/albums/e131/oz4acl/nad%20s100/?sc=1&addtype=local
-There's another psu cirquit in it...
The last two photos shows most of the psu, and the first one, the connectors
for the frontpanel.
The photos no. 2 and 3 shows the line buffers for pre-out...

Again, if theres need for a full view look here:
http://user.tninet.se/~xfz720w/NAD-S100_inside.jpg

By the way, the black filtercaps are ELNA 4700mmF 50V.
The smaller psu caps are, blue: 220 or 100 mmF at 63V.
And the brown ones 470 mmF 16V.
- Hmm.....

The transformer seen in the link above, is similar in sice to a 2 * 15V 50VA
laying in my bin... :-)

Best regards
And many thanks!!!
Tonni

PS: Know I'm rusty when it comes to english, - but practise helps ( I
think ) :-D

[Tonni]

"Eeyore" > skrev i en meddelelse
...
>
>
> Tonni wrote:
>
>> > It would be easy to make a pretty accurate guess based on the DC supply
>> > rails.
>> >
>> > More info ?
>> >
>> > I'm curious about the heatsinks there btw.
>> >
>>
>> Hi Graham, and all!
>>
>> There's two known DC Voltages a 5 and a 15 Volt.
>> Both positive. - The 5 V is for IR-reciever and pic.
>> so my own guess is that the transformer needet is on 2*15 VAC
>
> Are you sure it's not +5v and +-15V ?
>
>
>> There's two regulators a 7805 and a LM317T. - The one delivering 15 V (
>> Rreg
>> = 236r and Rdrop = 2K73 )
>>
>> The triggy part is that there's no neg regulator in the psu,
>
> Peculiar.
>
>
>> but there's a
>> set of BD139/BD140 for each OPA134.
>
> That could be local supply regulation. Interesting approach. I've done
> something
> similar once but for different reasons. I expect this is to *look* fancy
> rather
> than do anything very useful.
>
>
>> - These are the ones sitting on the small heatsinks.
>> - The regulators are on the larger one...
>
> Ok.
>
>
>> The small transistors all are 2SA1015 and 2SC1815...
>
> Where did you get the jpg ?
>
> Graham
>

Hi again Graham!
- And thanks!!!

For comments on Your's above, please see my ansver to Sander!

And 'bout the photo, it was found via Google :-)

The new onesfound here:
http://s38.photobucket.com/albums/e131/oz4acl/nad%20s100/?sc=1&addtype=local
Are from the actual pcb's

Best regards
Tonni

[Tonni]

Hi Graham & Sander!

Took the chance, and threw in the mentionned 2 * 15 VAC tranny...

Wauvvv. - Had i just done that before!!!

Thanks A LOT for Your time!!!

Best regards:
Tonni

[Sander deWaal]

"Tonni" > said:

>Hi Graham & Sander!
>
>Took the chance, and threw in the mentionned 2 * 15 VAC tranny...
>
>Wauvvv. - Had i just done that before!!!
>
>Thanks A LOT for Your time!!!


Hi Tonni,

It seems to me then that the different supply voltages are derived
from the main + and - 15V via the separate stabilisers.

Well, it works, obviously! Have fun!

--
"Due knot trussed yore spell chequer two fined awl miss steaks."

[Eeyore]

Sander deWaal wrote:

> "Tonni" > said:
>
> >Hi Graham & Sander!
> >
> >Took the chance, and threw in the mentionned 2 * 15 VAC tranny...
> >
> >Wauvvv. - Had i just done that before!!!
> >
> >Thanks A LOT for Your time!!!
>
> Hi Tonni,
>
> It seems to me then that the different supply voltages are derived
> from the main + and - 15V via the separate stabilisers.
>
> Well, it works, obviously! Have fun!

It did seem like there were two separate secondaries. It's normal to use
a separate supply for the digital section to avoid common ground
currents btw.

Graham

[Tonni]

"Eeyore" > skrev i en meddelelse
...
>
>
> Sander deWaal wrote:
>
>> "Tonni" > said:
>>
>> >Hi Graham & Sander!
>> >
>> >Took the chance, and threw in the mentionned 2 * 15 VAC tranny...
>> >
>> >Wauvvv. - Had i just done that before!!!
>> >
>> >Thanks A LOT for Your time!!!
>>
>> Hi Tonni,
>>
>> It seems to me then that the different supply voltages are derived
>> from the main + and - 15V via the separate stabilisers.
>>
>> Well, it works, obviously! Have fun!
>
> It did seem like there were two separate secondaries. It's normal to use
> a separate supply for the digital section to avoid common ground
> currents btw.
>
> Graham
>


Hi again!

Both Sander & You Graham, are right!
It were the local regulation that confused me...
- No schematics...

After some diggin' i came in contact with a tech. from NAD that told me the
source is supposed to be 2 * 18 VAC

Thanks again!!!
Tonni

[Sander deWaal]

"Tonni" > said:


>After some diggin' i came in contact with a tech. from NAD that told me the
>source is supposed to be 2 * 18 VAC


That's Amplimo nr. 28014 (50VA) or 38014 (80VA), resp. 24 euro and
26,50 euro, directly from the manufacturer. Count another 15 euro or
so for shipping to DK, or find a local distributor

Info from: http://www.amplimo.nl/.

I bet NAD is a "bit" more expensive ;-)

--
"Due knot trussed yore spell chequer two fined awl miss steaks."

[Tonni]

> That's Amplimo nr. 28014 (50VA) or 38014 (80VA), resp. 24 euro and
> 26,50 euro, directly from the manufacturer. Count another 15 euro or
> so for shipping to DK, or find a local distributor
>
> Info from: http://www.amplimo.nl/.
>
> I bet NAD is a "bit" more expensive ;-)
>
Hi again Sander!

Had a 160VA iron laying in my bin... ;-)
NAD wanted 465,- DKK including tax and porto..
- That's ? 65,-

Best regards
Tonni

[Tonni]

> - That's ? 65,-
>
Should be euro... ;-)

Best regards
Tonni