rowemeister said:
Off the top of my head these are the mods that helped the most.
Cheap easy and good mods first.
1) opamps
2) Bypass Hdam and output caps
3) Seperate regs for DAC and Decoder
4) Upgrade caps around DAC and Decoder to Pana FC or similar
5) coax
6) Damping of chassis
7) Decoupling around opamps etc
8) Muting removal
9) Removed caps from opamps to Headphone circuit
Cheap and a little more complex
Best mods price not so important.
1) Seperate regs on as many v lines as possible
2) Clock
3) good opamp
4) Bypass HDAM and output caps
5) seperate PSU for regs
6) Black gate caps
7) change caps on servo and opamps to silver mica types with good low tol resistors
8) A star earth
9) Coax
10) Damping
The list goes on but this is pretty much my top 10
Brent
Thanks Brent, that gives me a really good insight
🙂
SimontY said:
Err, it's actually OP249, sorry.
http://uk.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=401195&N=401
http://www.analog.com/en/prod/0,,759_786_OP249,00.html
and
http://www.njr.co.jp/pdf/ae/ae04028.pdf

Evening fellow modders,
I'm taking another look at my dead display. I swapped D851 for a new diode and replaced Q851 with a 7912. Neither of these changes made any difference.
The reg voltages are:
1- 0 (ground)
2- -37
3- -26
Just as it was before I changed the reg to a -12. I have no idea what's going on with it
Ok, measured more:
R854 measures -26v EACH side.
D853 reads 725mV in the diode test.
Simon
I'm taking another look at my dead display. I swapped D851 for a new diode and replaced Q851 with a 7912. Neither of these changes made any difference.
The reg voltages are:
1- 0 (ground)
2- -37
3- -26
Just as it was before I changed the reg to a -12. I have no idea what's going on with it

Ok, measured more:
R854 measures -26v EACH side.
D853 reads 725mV in the diode test.
Simon
SimontY said:Anyone tried OPA249 (says OP249 on chip, 'GP' type)?
It's a DIL-8 op-amp, which I bought on impulse from Farnell, partly to get my order over the minimum for a card spend. The specs are nothing special but I believe some have said the sound is good.
I might drop them in place of my LM6172s to see what they're like..
Simon
Simon,
Thanks for this. I've been using the AD712 in my Philips cd723 as per this suggestion http://www.diyaudio.com/forums/showthread.php?postid=384305#post384305
The OP249 is described as a replacement for AD712.
Have you tried AD8620 ? (edit: corrected from AD8260)
My "soic to dip8" socket doesn't fit my quality dip socket wich is on the board. The feet of the "soic to dip8" are to thick for the qulaitu dip8 socket.
Now i'm thinking to put the soic to dip8 socket in a cheaper dip socket, wich has thin feet and to put the cheap socket in the quality dip8 socket?
Later on i can always solder the "soic to dip8" socket straight onto the board
Now i'm thinking to put the soic to dip8 socket in a cheaper dip socket, wich has thin feet and to put the cheap socket in the quality dip8 socket?
Later on i can always solder the "soic to dip8" socket straight onto the board
ash_dac said:
Simon,
Thanks for this. I've been using the AD712 in my Philips cd723 as per this suggestion http://www.diyaudio.com/forums/showthread.php?postid=384305#post384305
The OP249 is described as a replacement for AD712.
Have you tried AD8260 ?
Hi,
I've not tried that chip, yet..
gy21 said:My "soic to dip8" socket doesn't fit my quality dip socket wich is on the board. The feet of the "soic to dip8" are to thick for the qulaitu dip8 socket.
Now i'm thinking to put the soic to dip8 socket in a cheaper dip socket, wich has thin feet and to put the cheap socket in the quality dip8 socket?
Later on i can always solder the "soic to dip8" socket straight onto the board
Just tried it, at least it works, i'm not sure it degrades the sound quality a lot.
Finally i'm listening to the AD8620 🙂
gy21 said:
Just tried it, at least it works, i'm not sure it degrades the sound quality a lot.
Finally i'm listening to the AD8620 🙂
How does it sound?
after a first listen I can see why people recommend it. it sounds way better then the AD826 and opa2134, the other two opamps i have tried.
Especially in the highs.
Especially in the highs.
gy21 said:after a first listen I can see why people recommend it. it sounds way better then the AD826 and opa2134, the other two opamps i have tried.
Especially in the highs.
As one have said - "beats them all" !
avr300 said:
As one have said - "beats them all" !
for now I totally agree, at least as dual opamp it is the best there is.
philpoole said:Ray, so what is you favourite? Valve, Bipolar or Fet? Can you tell any difference between the two transistor styles? Are you going to spend the next stage of your output stage frenzy comparing different models of transistor/valve?
Cheers,
Phil
Hi Phil,
Active little thread eh?
I have the FET and transistor stages up and running now, so i'm going to compare these two first in the coming week. The winner has to compete with the valve stage, which i'm going to fit into the player that lost. I'm away for the weekend, so not much listening in the coming days....😡
Regards,
Ray.
SimontY said:Anyone tried OPA249 (says OP249 on chip, 'GP' type)?
It's a DIL-8 op-amp, which I bought on impulse from Farnell, partly to get my order over the minimum for a card spend. The specs are nothing special but I believe some have said the sound is good.
I might drop them in place of my LM6172s to see what they're like..
Simon
So... <whistles> OPA249 anyone?? lol
Hi Simon,
I tried it when I first started modding. I didn't like it much, but it's better than the 2114.
Regards,
Ray.
SimontY said:Evening fellow modders,
I'm taking another look at my dead display. I swapped D851 for a new diode and replaced Q851 with a 7912. Neither of these changes made any difference.
The reg voltages are:
1- 0 (ground)
2- -37
3- -26
Just as it was before I changed the reg to a -12. I have no idea what's going on with it![]()
Ok, measured more:
R854 measures -26v EACH side.
D853 reads 725mV in the diode test.
Simon
Hi Simon.
Something definately wrong there.
With a 7912, the output voltage should be 12v + the zener voltage, 6.8v, = -18.8v NOT -26v
As this is the same output voltage as before with the 7918, it makes me think the fault may be in the ground. Try a wire from the ground end of D852 to the ground end of C852
Andy
6h5c said:Hi Simon,
I tried it when I first started modding. I didn't like it much, but it's better than the 2114.
Regards,
Ray.
Hi Ray,
Just what I wanted to hear, an opinion of some sort 🙂 Cheers man. Might be nicer than LM6172..
Simon
poynton said:
Hi Simon.
Something definately wrong there.
With a 7912, the output voltage should be 12v + the zener voltage, 6.8v, = -18.8v NOT -26v
As this is the same output voltage as before with the 7918, it makes me think the fault may be in the ground. Try a wire from the ground end of D852 to the ground end of C852
Andy
I'm a bit tipsy now, been out for a birthday meal and drinks, so I'll try tomorrow. Do you mean connect a wire between those two points and see what happens?
Btw there's no zener to ground anymore, but there is a good ground connection. There should be -12v output for sure..
Cheers
Simon
I'm a bit tipsy now, been out for a birthday meal and drinks, so I'll try tomorrow. Do you mean connect a wire between those two points and see what happens?
Happy Birthday Simon

Chears mate

Dave
OMG simon ts yours brthday. HAPPPY VBIRHTIDAY>. OMG, the modllesbororo gane was amaign tongin 2-1 down at 1/2 time (3-1 done on ag), thne the came back to win. WOW.
i cant believe u didnt mentio it was your bithday. OMG. hope u ahd an amazing nite, colllecting your free oap bus pass an dall that.
xxxxxxxxxxxxxxxxxxxxxx
love ad. xxxxxxxxxxxxxx
i cant believe u didnt mentio it was your bithday. OMG. hope u ahd an amazing nite, colllecting your free oap bus pass an dall that.
xxxxxxxxxxxxxxxxxxxxxx
love ad. xxxxxxxxxxxxxx
adfinni said:OMG simon ts yours brthday. HAPPPY VBIRHTIDAY>. OMG, the modllesbororo gane was amaign tongin 2-1 down at 1/2 time (3-1 done on ag), thne the came back to win. WOW.
i cant believe u didnt mentio it was your bithday. OMG. hope u ahd an amazing nite, colllecting your free oap bus pass an dall that.
xxxxxxxxxxxxxxxxxxxxxx
love ad. xxxxxxxxxxxxxx

Brent
rowemeister said:
You been drinking lol
Brent
It's amazing what 1 hour with Mavis Beacon can do !
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