Another Super High End Phono Stage! No expense spared...
- Thread starter Fasterdamnit
- Start date
Thanks Steve ! Also whishing you a happy and prosperous new year 
I'm going to start it with this nice DIY project, waiting for the boards to arrive and placing the order for the parts..
Have gone thru the 100 pages here... again thanks to Fasterdamit, HYpnotoad, Sachu888, Omishra and all the others for this nice thread
I'm going to start it with this nice DIY project, waiting for the boards to arrive and placing the order for the parts..
Have gone thru the 100 pages here... again thanks to Fasterdamit, HYpnotoad, Sachu888, Omishra and all the others for this nice thread
My design
I made this one last night and I find it sound astonishing! This is way better than any other previous preamp I made (7 models in past month with different equalisations) and it _is_ a lot better than many factory models build I have ever heard (I think).
I love passive equalization - in this circuit there are not any cap' in signal path and probably this is the trick to have that royal sound. I've made one with FET's with passive equalization but it sounds really poor - either I had fake transistors or cap's used were bad.
I've made it really small, board is 50x70mm and I am using 7815/7915 with one small transformer on another board. No noise at all even on loudest.
So this is my design (attached PCB file as well):
There are just a few modifications:
a) 3k83 +100 = 3k93. I've replaced these with 3k6 + 330 = 3k93 as these are easier to find
b) added are 2 x 1000uF/25V and 2x 100n. 100n are on parallel with 1000uF. Both are on + and - voltage to ground
c) instead parallel 33+47 = 80nF, I have used 82nF cap's measured to find 2 with exactly 80nF
d) since I did not had 500pF I have used in parallel 220+330pF. You could find 22nF with lower value of -50pF to match that addition of 50pF
In addition, there are ferrite rings on input wires.
For a case I have used one from old UPS, a bit large and really eeeempty, but it make a good impression on listeners.
(photo is from previous DIY preamp)
If you are going to use this, do not forget to put a bridge on + line to hole just above pin 8 of right OP.
Tested with 5532, then with OPA2134, both sounds very good (I can add LP rip later if needed). On the way are some 4562 and AD823...
EDIT: I forgot to add, if needed, I am using this on phono preamp output, soldered on RCA directly, but I think I will replace this with one 2uF non polar cap:
EDIT2: I draw this today, printed on laser and will be transferred at home to board. I am thinking to put in use a huge number of 12V AC transformers. I have only one +/-12V but many 12V. In original schematic there were no inductor, I add that my self. I think I have them on old PC motherboards. Note: input is AC 12V, not DC.
2 small heat sinks to be placed on 7815/7915.
EDIT3: Uploaded PCB file for AC12V to +-15VDC.
I made this one last night and I find it sound astonishing! This is way better than any other previous preamp I made (7 models in past month with different equalisations) and it _is_ a lot better than many factory models build I have ever heard (I think).
I love passive equalization - in this circuit there are not any cap' in signal path and probably this is the trick to have that royal sound. I've made one with FET's with passive equalization but it sounds really poor - either I had fake transistors or cap's used were bad.
I've made it really small, board is 50x70mm and I am using 7815/7915 with one small transformer on another board. No noise at all even on loudest.
So this is my design (attached PCB file as well):
There are just a few modifications:
a) 3k83 +100 = 3k93. I've replaced these with 3k6 + 330 = 3k93 as these are easier to find
b) added are 2 x 1000uF/25V and 2x 100n. 100n are on parallel with 1000uF. Both are on + and - voltage to ground
c) instead parallel 33+47 = 80nF, I have used 82nF cap's measured to find 2 with exactly 80nF
d) since I did not had 500pF I have used in parallel 220+330pF. You could find 22nF with lower value of -50pF to match that addition of 50pF
In addition, there are ferrite rings on input wires.
For a case I have used one from old UPS, a bit large and really eeeempty, but it make a good impression on listeners.
(photo is from previous DIY preamp)
If you are going to use this, do not forget to put a bridge on + line to hole just above pin 8 of right OP.
Tested with 5532, then with OPA2134, both sounds very good (I can add LP rip later if needed). On the way are some 4562 and AD823...
EDIT: I forgot to add, if needed, I am using this on phono preamp output, soldered on RCA directly, but I think I will replace this with one 2uF non polar cap:
EDIT2: I draw this today, printed on laser and will be transferred at home to board.
I am thinking to put in use a huge number of 12V AC transformers. I have only one +/-12V but many 12V. In original schematic there were no inductor, I add that my self. I think I have them on old PC motherboards. Note: input is AC 12V, not DC.
2 small heat sinks to be placed on 7815/7915.
EDIT3: Uploaded PCB file for AC12V to +-15VDC.
Last edited:
Thanks.
Yes, it is actually very good. I will try few more OP's (4862, 823), and probably will raise a gain as it is not enough (probably by changing that 150 Ohm resistor to 100 or 50).
Also I have made it work on AC12V (second board). It is also super quiet.
Running on batteries is not an option as it will suck dry two batteries in 2 days (I think) and I always leave it on power. If I run it on 2x 9V I will bought rechargeable batteries and also I will bought charger and take out electronic. Then I will put one double switch and charger into preamp case so - they can be charged while on stand-by and work on batteries while listening.
Fasterdamnit
Super Member
Very nice work! Where do you hail from?
Thanks both! I am going to make a second one with a bit different design - both boards onto one and packed into one old nice case of USRobotics 14.4 modem. This one is going to be used on new stereo amplifier which has built-in phono already (H&K), as this one sounds better.
I took out electronic from two 12 DC wall wart making it 12 AC, then those caps (quality one!) can be found also on old USR modems (full capacity, measured) and some other old boards... I bought some more Wima caps, but still it is really cheap and what is more important it works the best of all I have build in past 25 years starting with BC109C transistors. I feel bad when quality and working parts are going into garbage, so I recycle whatever is possible.
Greet's from Eastern Europe
This one is going to be used on new stereo amplifier which has built-in phono already (H&K), as this one sounds better.I took out electronic from two 12 DC wall wart making it 12 AC, then those caps (quality one!) can be found also on old USR modems (full capacity, measured) and some other old boards... I bought some more Wima caps, but still it is really cheap and what is more important it works the best of all I have build in past 25 years starting with BC109C transistors. I feel bad when quality and working parts are going into garbage, so I recycle whatever is possible.
Greet's from Eastern Europe
sachu888
Spare the tigers, kill me
Did anyone try LME49720HE(Metal can version),suggested by one diy audio member.I have earlier tried LME49720,plastic casing(DIP version) and it was ok.Today I tried LME49720HE(Metal can version) and it sounds veryy good in my system,best till date.I am attaching few pics here:
NOTE: Stay away from Opamp rolling I ended up trying almost 15 different types of Opamps.
Regards,
Sachin
NOTE: Stay away from Opamp rolling I ended up trying almost 15 different types of Opamps.
Regards,
Sachin
Hi Sachi, OM and all members sharing your stories here in this forum. I was absent for quite sometime with my son's health issues, Leukemia, but he's in remission now for over a year. It's been busy on my end. I was reading these threads and it is getting very interesting by the minute. I have to work on my system and isolate the ground so that will be a project for the weekend and I will post about my results. I am using the OPA2134 and sounds fine to me but I need to take care of a 60Hz Hum hence working in isolating the ground in the system. Also, I am working in modifying an 10 band MXR 114 equalizer. I have replaced every single one of the resistors and tomorrow I will get the Film Capacitors. This should be very interesting as I have two of these equalizers one stock one modified. It also uses 12 OPAMPS for which I am replacing the original ones with OPA2134. This may be a new topic somewhere else but I wanted to stop by and say hi. Sachi it will be very interesting in trying the LME49720HE on the CNC. I may do that in the next few days and report my personal finding.
Cheers everyone. Rafael
Cheers everyone. Rafael
sachu888
Spare the tigers, kill me
Welcome back Rafael.Your build was one of the best here.Post your findings when you try different Opamps in CNC.
Regards,
Sachin
Sachin OpAmp rolling is a disease, OpAmpRollusItis, it will soon be recognized by the World Health Organization. 
Which do you prefer the LME49990 or the LME49720HE, the latter being a dual circuit, do they make a single circuit version?
I just answered my own question, its the LME49710HE, I have tried regular LME49710's and they are not nearly as good as the LME49990 IMO.
I wonder if they will make a metal can version of the LME49990?
Which do you prefer the LME49990 or the LME49720HE, the latter being a dual circuit, do they make a single circuit version?
I just answered my own question, its the LME49710HE, I have tried regular LME49710's and they are not nearly as good as the LME49990 IMO.
I wonder if they will make a metal can version of the LME49990?
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sachu888
Spare the tigers, kill me
Sachin OpAmp rolling is a disease, OpAmpRollusItis, it will soon be recognized by the World Health Organization.
Which do you prefer the LME49990 or the LME49720HE, the latter being a dual circuit, do they make a single circuit version?
I just answered my own question, its the LME49710HE, I have tried regular LME49710's and they are not nearly as good as the LME49990 IMO.
I wonder if they will make a metal can version of the LME49990?
Hi Phillip,
I have tried 49720 DIP version earlier in CNC and I didn't like them,but Metal can sound different.LME49990 and LME49720 both sound excellent in my system.I guess Metal can has something to do with shielding,so less noise only music.My preference now is:
1LM.49990/49720HA
2.OPA2107/LM4562
3.OPA2134
4.AD823
Regards,
Sachin
Renron
Active Member
Agree with your observations
Had to write something here as thread 'bot required at least 3 characters
I actually enjoyed soldering those tiny little legs........ :yes:
World Health Organization.
Oxymoron
I have tried regular LME49710's and they are not nearly as good as the LME49990 IMO.
+1
Had to write something here as thread 'bot required at least 3 characters
I actually enjoyed soldering those tiny little legs........ :yes:
captouch
Addicted Member
This has probably been brought up before, but don't see any links in the #791 post (and hopefully this isn't a Bartertown only question):
Are any AK'ers selling these pre-assembled? Or is everyone buying the PCB somewhere and getting parts from Mouser, etc.
I don't mind DIY, but if someone is offering something all ready to go in a nice enclosure, it saves some work given the projects I have in queue - I think you all can identify with long project lists.
Thanks.
Are any AK'ers selling these pre-assembled? Or is everyone buying the PCB somewhere and getting parts from Mouser, etc.
I don't mind DIY, but if someone is offering something all ready to go in a nice enclosure, it saves some work given the projects I have in queue - I think you all can identify with long project lists.
Thanks.
Hi Rafael, welcome back. I wish your son good health ahead.
I tried rolling all kind of combinations with AD823, LME49990, OPA2134 and LME49720(DIP plastic). The best suited to my taste was 2X49990 in first position towards input and AD823 at output of CNC phono. For my Shure97xe I loaded with 47K ohm and added input capacitance 68pF into cable capacitance.
While lme49990 in first position-
Lme49990 in second position sounded little bright, 2134 in second position sounded little mellow, 49720 sounded same like 49990 but little harsh-unclear and AD823 in second position somehow takes away that brightness but same time gives more thick vocals (specially female voice) with preserving details. Last combination also tames clicks and pops of record dust.
Thanks OM for your kind words and for the well wishes to my son. He's much better and ready to start his life as a college graduate. Yes, he graduated from University of Maryland while very sick with Leukemia and receiving chemo and radiation and God only knows how many other things to include a Total Left Hip Replacement last year four days after graduating.
Great information and thanks for sharing it with all of us. Right now I am concentrating this weekend in getting the hum and the ground isolation taken care of. I am also replacing old resistors from the Bose 901 Active Equalizer as well as the CAP's were replaced last week and sounding much better. I have finished recapping, changing resistors and OPAMPS on an MXR 114 equalizer and I am now testing and breaking it up. The EQ with OPA2135's sound much more subtle. The original AD823's were to bit over the top on BASS and TREBLE but still manageable. Still I have an extra MXR 114 EQ that I have ordered parts yesterday for it and I will keep the AD823's since I had ordered them for my previous EQ. At the last minute I decided to order 12 OPA2134PA and leave the 12 AD823's for my second EQ. Nevertheless, very interesting this hobby and the sound quality of components and the opinions of the AK members here.
Looking forward to more projects in the future.
Rafael
Great information and thanks for sharing it with all of us. Right now I am concentrating this weekend in getting the hum and the ground isolation taken care of. I am also replacing old resistors from the Bose 901 Active Equalizer as well as the CAP's were replaced last week and sounding much better. I have finished recapping, changing resistors and OPAMPS on an MXR 114 equalizer and I am now testing and breaking it up. The EQ with OPA2135's sound much more subtle. The original AD823's were to bit over the top on BASS and TREBLE but still manageable. Still I have an extra MXR 114 EQ that I have ordered parts yesterday for it and I will keep the AD823's since I had ordered them for my previous EQ. At the last minute I decided to order 12 OPA2134PA and leave the 12 AD823's for my second EQ. Nevertheless, very interesting this hobby and the sound quality of components and the opinions of the AK members here.
Looking forward to more projects in the future.
Rafael