Recapping my Pulsar Labs Console

[pfdoherty93]

I have a 1984 pulsar labs console that has been recapped before. The current caps are bipolar 35v 100uf electrolytic caps. I also have the schematics that say the caps that should be used are bipolar 47uf electrolytic capacitors (nothing about voltage but that doesn’t matter too much as long as I’m not going under what’s needed). My question is should I recap with 47uf or 100uf. The power supply I had to build for the console is way larger than what I thought would be needed and now I’m realizing that’s because every cap is double what was originally used. But will using larger capacitance improve sound quality or anything like that? I would think it would be best to use what the schematics suggest.

 

[Bo Deadly]

It depends on what the electrolytics are use for.

For power supply bypass electrolytics, you should just use what the schematic says. And they don't need to be bipolar. PS caps will have virtually no effect on signal. If they are dried out, too small or just wrong, you would start to get some mains hum but that's not signal, it's just noise.

For signal path electrolytics (which include caps in gain control networks and not just coupling caps), they should be sized for a very low corner frequency of 2Hz or similar. Generally electrolytics are not used for RC filtering signal. But in 1984 people were regularly playing fast and loose with rules so who knows. Never heard of pulsar labs.

If you want a more complete answer, post schematics.

 

[abbey road d enfer]

I have a 1984 pulsar labs console that has been recapped before. The current caps are bipolar 35v 100uf electrolytic caps. I also have the schematics that say the caps that should be used are bipolar 47uf electrolytic capacitors (nothing about voltage but that doesn’t matter too much as long as I’m not going under what’s needed). My question is should I recap with 47uf or 100uf. The power supply I had to build for the console is way larger than what I thought would be needed and now I’m realizing that’s because every cap is double what was originally used. But will using larger capacitance improve sound quality or anything like that? I would think it would be best to use what the schematics suggest.

In addition to what Bo wrote, remember that electrolytic capacitor technology has changed a lot between then and now. Designers had to make compromises between value and real estate.
Today not much so.
Regarding coupling capacitors, the higher the better, because LF distortion is directly inverse to value. Bo's recommandation of <2Hz cut-off is highly recommended. Personally, I target 0.5Hz. That's 100uF for a 3.3k load.
It results in only minus 0.03dB at 20Hz, but if you cascade about 10 stages, like in a typical recording situation, it results in -0.3dB overall, which does not seem much, but golden pinnae insist on having less than 0.2dB for their equipment. Of course they thoroughly neglect the fact that their speakers are at least 10dB down there.
Increasing bypass capacitors has only one detrimental effect: the PSU overcurrent protection may prevent it to start. Other than that, in terms of performance, it can only be better, but only if the grounding arrangement is correct. There are cases where increasing bypass caps can result in increased buzz, because their grounding point is not where it should be.

 

[Newmarket]

Audio signal coupling caps won't affect current demand.

Power supply caps - decoupling / bypass caps that charge to a DC voltage - can lead to excessive inrush current causing psu to fail / limit at power on.
You could look at anti-surge devices / techniques to limit this. Just ramping the voltage might be enough to overcome any problem.
Once it's all powered up it should be fine as the steady state current demand is not increased.