After replacing the opamps, I decided to have a go at the PSU.
Now I have 4 x Hexfred 4Amps replacing the stock rectifier bridge, 2200 Pana FC for smoothers, LM317 / 337 rayregs for +-15v and after those I placed two 470uF 16V BG FK.
I noticed a big increase in detail and stereo presentation.
Vinyl now is killing my heavily moded CD53.
Maybe I should replace the rayregs by some Spowers (Brent´s Magic).
Ricardo
Now I have 4 x Hexfred 4Amps replacing the stock rectifier bridge, 2200 Pana FC for smoothers, LM317 / 337 rayregs for +-15v and after those I placed two 470uF 16V BG FK.
I noticed a big increase in detail and stereo presentation.
Vinyl now is killing my heavily moded CD53.
Maybe I should replace the rayregs by some Spowers (Brent´s Magic).
Ricardo
Op-amps are not the best place to use S-Powers in terms of sound quality per pound / dollar spent. They will improve in all areas but not as much as the various circuits in CD players, or a discrete buffer/amp where power supply noise is more critical.
However, if you do use some Sercal S-Power regulators and later upgrade to a discrete solution - simply re-use them!
Simon
However, if you do use some Sercal S-Power regulators and later upgrade to a discrete solution - simply re-use them!
Simon
Thank you Simon
I will save the spowers for my new preamp.
I am still waiting for Lee to provide me some info. I want a clone of your pre.
Any hint about the tantalum in signal path ?
Can I replace it by a better but smaller capacitance cap ?
I do not want to loose any bass of course but I have read bad things about tants.
Ricardo
I will save the spowers for my new preamp.
I am still waiting for Lee to provide me some info. I want a clone of your pre.
Any hint about the tantalum in signal path ?
Can I replace it by a better but smaller capacitance cap ?
I do not want to loose any bass of course but I have read bad things about tants.
Ricardo
I don't know what it's doing but if it's just a typical DC blocking cap (older Naim gear is supposedly full of tant caps in the signal path) then go ahead and replace with a 100uF BG N type or similar.
This buffer I have in my pre is lovely, you will not be disappointed.
Mine is the Pedja Rogic buffer, here's one thread about that circuit:
http://www.diyaudio.com/forums/showthread.php?threadid=116193
Simon
This buffer I have in my pre is lovely, you will not be disappointed.
Mine is the Pedja Rogic buffer, here's one thread about that circuit:
http://www.diyaudio.com/forums/showthread.php?threadid=116193
Simon
I will do that 
Now another question, I replaced the stock PSU after regs caps with 470uF BG and sound is quite good now but these caps are 25mm high and i can not close the lid.
I searched and found some correct size ones: 470u 16v BG N 24mm high
Can I use BG N caps in the psu with confidence ?
Ricardo
Now another question, I replaced the stock PSU after regs caps with 470uF BG and sound is quite good now but these caps are 25mm high and i can not close the lid.
I searched and found some correct size ones: 470u 16v BG N 24mm high
Can I use BG N caps in the psu with confidence ?
Ricardo
Just for pleasure
Now I am able to report the improvements following the PSU mod:
The LM317/337 +-15v regs gave uge improvements in headroom and speed.
The Hexfred bridge replacing the stock industrial W04 provided high levels of detail and attack.... but in the process the sound became very light lacking previous bass presence.
I left the pre settle for a week and the improvements where slight regarding bass response.
Yesterday I dreamed about the speaker connections and remembered that meridian 103 has strange misleading markings in the speaker outputs so I decided to check.
After verifying the DC offset in each speaker, I reversed the connections on left side (that gave negative offset reading)
Now I have the reward... everything came into focus, the bass duplicated and the soundstage gained in size and depth.
The CD53 is sounding UGE... (and I did not do the coax mod yet).
The TT also benefits from this in terms of spaciousness and presence.
Ricardo
Now I am able to report the improvements following the PSU mod:
The LM317/337 +-15v regs gave uge improvements in headroom and speed.
The Hexfred bridge replacing the stock industrial W04 provided high levels of detail and attack.... but in the process the sound became very light lacking previous bass presence.
I left the pre settle for a week and the improvements where slight regarding bass response.
Yesterday I dreamed about the speaker connections and remembered that meridian 103 has strange misleading markings in the speaker outputs so I decided to check.
After verifying the DC offset in each speaker, I reversed the connections on left side (that gave negative offset reading)
Now I have the reward... everything came into focus, the bass duplicated and the soundstage gained in size and depth.
The CD53 is sounding UGE... (and I did not do the coax mod yet).
The TT also benefits from this in terms of spaciousness and presence.
Ricardo
SimontY said:I'd try just one and see what happens. Live dangerously
Just replaced the 100u 3v tant coupling caps by 47u 6.3v BG NxHiQ.
Remenber that these are used as coupling caps betwen the MM amp and the RIAA eq stages.
I imediately detected big improvements in bass detail and extension.
Must wait until things settle down so I can report on other improvements.
Ricardo
Benz ACE M Loading
After reading a lot about cart loading, I decided to experiment.
My 101b has a MM RIAA with 47kohm load and 120pF.
1st - replaced 47k by 1k8 and sound became shut in... no good.
2nd - replaced 1k82 by 464 ohm... very tight bass and good treble but stage size is confined between the speakers.
3rd - replaced 464ohm by 27kohm... now stage size is acceptable, bass is full if a little loose, transients attack is present and the treble lost the "fizz".
I will try 22k ohm and report.
Did not change 120pf... do not know what to expect here. Any comments will be apreciated.
Ricardo
After reading a lot about cart loading, I decided to experiment.
My 101b has a MM RIAA with 47kohm load and 120pF.
1st - replaced 47k by 1k8 and sound became shut in... no good.
2nd - replaced 1k82 by 464 ohm... very tight bass and good treble but stage size is confined between the speakers.
3rd - replaced 464ohm by 27kohm... now stage size is acceptable, bass is full if a little loose, transients attack is present and the treble lost the "fizz".
I will try 22k ohm and report.
Did not change 120pf... do not know what to expect here. Any comments will be apreciated.
Ricardo
After trying several loading caps on the RIAA I decided to settle with 330pF Silver Mica and 27kohm for my Benz ACE M 0.8mv.
Quite good detail and attack but lacking bass.
Today I replaced the coupling caps between head amp and RIAA.
Stock: 100uF 3V Tant
1st mod: 47uF 6.3V BG NxHiQ .... ultra detail, very clean... like a silver wire but lacking bass.
2nd mod (Actual setup): 100uF 6.3V BG Nx.... very good bass, good soundstage, very good overall frequency balance, very detailed, sweet treble.
At the same time I replaced the 470uF BG FK by 680uF 35V BG Nx after the +-15v rayregs. This mod provides a very good soundstage, very deep bass, cleaner trebble and very good balance between frequencies. Much better than the 470 FK.
Note: 680uF Nx short leg (s) mounted on GND in the psu.
100uF Nx long leg on the output of head amp and into the RIAA.
Note 2: In the photo you can see the hexfred bridge replacing the stock W04...... Great improvements in detail and dynamics.
Conclusion..... Nx rules..
Now back to the CDP Coax mod....while waiting for Lee´s RIAA boards
Ricardo
Quite good detail and attack but lacking bass.
Today I replaced the coupling caps between head amp and RIAA.
Stock: 100uF 3V Tant
1st mod: 47uF 6.3V BG NxHiQ .... ultra detail, very clean... like a silver wire but lacking bass.
2nd mod (Actual setup): 100uF 6.3V BG Nx.... very good bass, good soundstage, very good overall frequency balance, very detailed, sweet treble.
At the same time I replaced the 470uF BG FK by 680uF 35V BG Nx after the +-15v rayregs. This mod provides a very good soundstage, very deep bass, cleaner trebble and very good balance between frequencies. Much better than the 470 FK.
Note: 680uF Nx short leg (s) mounted on GND in the psu.
100uF Nx long leg on the output of head amp and into the RIAA.
Note 2: In the photo you can see the hexfred bridge replacing the stock W04...... Great improvements in detail and dynamics.
Conclusion..... Nx rules..
Now back to the CDP Coax mod....while waiting for Lee´s RIAA boards
Ricardo
Attachments
BG Nx rules
Several hours latter, the small 100u 6.3v Nx (used as coupling between head amp and riaa amp) lost it´s edgy sound.... must hear more but I already have much better bass than with the 47u 6.3v NxHiQ (the trebble is not as detailed as before).
The big difference seems to be the "after +-15v rayreg" caps.
The 680u 35v Nx are much more silent than the 470u FK.
The bass is powerfull and reaches the lower octaves but seems perfectly integrated with the rest of the freq spectrum.
This is really an important improvement. The highly modded CD53 sounds much sweeter and with better subtle detail diferentiation.
Maybe I should try one of the metal can opamps in place of the LM4562 on the 101 output buffer.....
Hope someone is interested.... any comments will be highly apreciated.
Ricardo
Several hours latter, the small 100u 6.3v Nx (used as coupling between head amp and riaa amp) lost it´s edgy sound.... must hear more but I already have much better bass than with the 47u 6.3v NxHiQ (the trebble is not as detailed as before).
The big difference seems to be the "after +-15v rayreg" caps.
The 680u 35v Nx are much more silent than the 470u FK.
The bass is powerfull and reaches the lower octaves but seems perfectly integrated with the rest of the freq spectrum.
This is really an important improvement. The highly modded CD53 sounds much sweeter and with better subtle detail diferentiation.
Maybe I should try one of the metal can opamps in place of the LM4562 on the 101 output buffer.....
Hope someone is interested.... any comments will be highly apreciated.
Ricardo
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