Yamaha CR-2020 Phono Board help

[Electone]

I have recapped the majority of this receiver and just decided to yank out the tantalum caps from the phono board. It is an almost impossible job without removing the entire board as there are metal crossmembers underneath the pcb. I loosened the board as much as I could and removed the back panel, but it is still very tight quarters. Anyways, upon removal of the tantalums, some of the traces on the board pulled up and separated and now I have nothing to solder to and because it is such a tight space, I can't see a bloody thing.

Would it be possible to attach the caps from the top? If so, Is my logic in the following photos correct? Any help would be appreciated. I really really really do not want to remove the tuner/phono board from the chassis as it would involve re-stringing the tuner. I am only concerned about the four 220/6.3 caps:

The schematic:


My thinking:

[budm]

Re: Yamaha CR-2020 Phono Board help

Based on your drawing, that will put the electrolytics caps (they are not Tantalum) in parallel which not how those caps are connected in the circuits which will be wrong.

[Electone]

Re: Yamaha CR-2020 Phono Board help

The originals are tantalums. That photo is lifted off the net and has already had the tantalums replaced by electrolytics. Based on the circuit photo I attached how do you believe the traces would follow?

[budm]

Re: Yamaha CR-2020 Phono Board help

The originals are tantalums. That photo is lifted off the net and has already had the tantalums replaced by electrolytics. Based on the circuit photo I attached how do you believe the traces would follow?

The traces will follow per the schematic diagram, so you do want to remove the board you will have to use the schematic as the guide to find solder connection points on the top side of the board.

[Longbow]

Re: Yamaha CR-2020 Phono Board help

Those tantalums are in the signal path and specifically right at the input to the phono stage. Tantalums are expensive, so they used them for a good reason, and not just to save space. Why not replace them with new tantalums? Why would you do a "downgrade" to the phono circuit?

If you are a phono enthusiast, and find yourself working on phono e.q. circuits (which rarely cause problems), I recommend building a reverse RIAA network. That network can be easily patched between your signal generator and the phono input. Running an audio sweep will immediately tell you if your phono e.q. stage has a problem.

[Electone]

Re: Yamaha CR-2020 Phono Board help

Interesting. Thank-you. I was hoping to replace the tantalums with electrolytics. There are so many opinions about how tantalums should never be in the signal path, I was hoping that a high quality electrolytic like Silmics or Nichicon FGs would improve the sound.