Hi. I'm going to recap the preamp phono section of my old Pioneer SA 408.
I'm using Nichicon Fine Gold and Elna Silmic II audio grade and Panasonic FC for power supply and decoupling stuff.
I'm very bad when telling apart between audio caps and power supply related caps. I would say C1, C2, C11 and C12 are audio caps. So the before mention Elna or Nichicon are ok here. But I have my doubts about C6 cap. Should I use a Panasonic FC here?
I'm kind of new at this. When I see a electro from an op amp to ground I tend to think that it calls for a low ESR like the Panasonic FC, but like I said I haven't managed yet to properly identify each cap role in a schematic.
95% of this amp's caps are Elna (can't tell what series, they are blue, dark). Except the two big 4700uf Nichicon PW and four small unknown brand (two 3.3uf in the phono stage and two 0.22uf near the balance pot).
Thank you and sorry if it's not the best place to post it.
I'm using Nichicon Fine Gold and Elna Silmic II audio grade and Panasonic FC for power supply and decoupling stuff.
I'm very bad when telling apart between audio caps and power supply related caps. I would say C1, C2, C11 and C12 are audio caps. So the before mention Elna or Nichicon are ok here. But I have my doubts about C6 cap. Should I use a Panasonic FC here?
An externally hosted image should be here but it was not working when we last tested it.
I'm kind of new at this. When I see a electro from an op amp to ground I tend to think that it calls for a low ESR like the Panasonic FC, but like I said I haven't managed yet to properly identify each cap role in a schematic.
95% of this amp's caps are Elna (can't tell what series, they are blue, dark). Except the two big 4700uf Nichicon PW and four small unknown brand (two 3.3uf in the phono stage and two 0.22uf near the balance pot).
Thank you and sorry if it's not the best place to post it.
C6 is in the feedback path, so audio. The schematic has two C6's, suspect C5/C6 are the proper names for these.
Panasonic FR are better than FC.
FR is newer than FC. FM are in between.
Check ESR on FR compared to FC and higher ripple too. Also go higher in voltage can benefit
FR is newer than FC. FM are in between.
Check ESR on FR compared to FC and higher ripple too. Also go higher in voltage can benefit
Hi Steward. The ones I can easily get are the FC series. But I would get the FR if I come across them.
If I'm not wrong there's only one 220uf needed for the phono stage preamp.
Thank you.
If I'm not wrong there's only one 220uf needed for the phono stage preamp.
Thank you.
Are you considering changing the input and output caps for film types?
3.3uF and 2.2uF can be obtained in pretty small size.
What about the other RIAA caps: C7, C9, C8, C10? What types are they?
The quality and value of C13, C14 should also be considered.
Last but no least: the RIAA chip itself might be a limiting factor for better audio quality, not the capacitors.
3.3uF and 2.2uF can be obtained in pretty small size.
What about the other RIAA caps: C7, C9, C8, C10? What types are they?
The quality and value of C13, C14 should also be considered.
Last but no least: the RIAA chip itself might be a limiting factor for better audio quality, not the capacitors.
The 3.3µF on the phono input are completely too small, they need to be 100µF or so
At 20Hz 3.3µF has an impedance of 2k4 which is more than a cartridge! 100µF would be
80 ohms or so, negligible compared to almost all MM cartridges.
The 0.22µF after the volume control will affect the response curve as they have a cutoff of 7Hz of so into their 100k loads. This means they are not distortion free, the significant tolerance spread of electrolytics means the channels will not be well balanced at lowest audio frequencies either. 4.7µF electrolytics here will cure both these problems, putting the cutoff sub-Hz. Of course whether such would fit in place of the originals is a question, but film caps would be even bigger and not address the LF frequency response dips.
A good rule of thumb with LF roll-off due to electrolytics is keep it down near 1Hz or less, to avoid chipping away at the sub-bass response of the amp, and to get linear behaviour across the spectrum.
At 20Hz 3.3µF has an impedance of 2k4 which is more than a cartridge! 100µF would be
80 ohms or so, negligible compared to almost all MM cartridges.
The 0.22µF after the volume control will affect the response curve as they have a cutoff of 7Hz of so into their 100k loads. This means they are not distortion free, the significant tolerance spread of electrolytics means the channels will not be well balanced at lowest audio frequencies either. 4.7µF electrolytics here will cure both these problems, putting the cutoff sub-Hz. Of course whether such would fit in place of the originals is a question, but film caps would be even bigger and not address the LF frequency response dips.
A good rule of thumb with LF roll-off due to electrolytics is keep it down near 1Hz or less, to avoid chipping away at the sub-bass response of the amp, and to get linear behaviour across the spectrum.
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