Electrolytic VS Film Power Supply Filter Capacitors!!!

[Finom1]

Electrolytic VS Film Power Supply Filter Capacitors!!!

I recently read about Film capacitors for power supply filtering instead of Electrolytic's.

I have great respect for the tube amp builders here. I have a question for you, concerning the power supply filter capacitors being Polarized, the Film filter capacitors above are not Polarized can they be used as power supply filter capacitors in a tube guitar amp?

If a Film capacitor can be used, will a Film capacitor provide higher storage capacity with better response along with better specifications than an Electrolytic in a guitar tube amplifier?

Here are the Film capacitors that Nick from https://www.hificollective.co.uk sent me:
1. 47uF/500v Obbligato Power Supply Series Capacitor - https://diyhifisupply.com/product/47uf- ... min-10pcs/
2. Mundorf TubeCap Capacitors - https://www.hificollective.co.uk/compon ... becap.html
3. ClarityCap TC, 2 Terminal PSU Capacitors - https://www.hificollective.co.uk/compon ... ap_tc.html

Nick, will be sending me information on his recommendations for high quality high storage capacity Electrolytic!!!


Thank you for sharing any thought concerning this topic!

[maxkracht]

https://www.premierguitar.com/the-immor ... -mods-pt-4

Works great, but expensive, physically very large and heavy. I don’t think you would notice any significant improvement aside from possible longevity.

[maxkracht]

For comparison, here’s 3 caps of about the same value. The giant white cap is film, the other two are electrolytic.

EDC7F321-8368-47C5-8A92-BE3AECA523D2.jpeg

[Finom1]

Thank you so much for sharing your thoughts.

You hit on the most important topic to me, the main reason that I want to upgrade my guitar tube amp, is to make a major upgrade in performance, to upgrade the reaction to the nuances of the pick attack.

Gerald Weber calls it "That Sports Car Feel" of the amp and the sensitivity of the pick attack and how fast the amp responds with robust lows.

I am looking to upgrade the components to help make the amp come alive. here is the schematic to the amp that I would like to upgrade - https://ceriatone.com/wp-content/upload ... ne2023.pdf

Thank you for any thoughts on making this happen for me. This is the last amp for me. I am 68 years old and want something to pass down to the Grandkids:)

Thanks again for sharing!!!

[maxkracht]

An easy way to get an electrolytic to respond closer to a film cap is to put a film cap in parallel with it. This was done in some trainwreck amps and a lot of hifi stuff. I doubt you would notice that much difference, if any, but it couldn’t hurt. I think I remember seeing .1 or .2uf on the preamp filter cap of some TW thing.

A more noticeable way to lower power supply sag/get a tighter response would be to add bigger filter caps all together. Looks like you have about 80uf for the reservoir, you could easily double or triple that by adding more caps in parallel or replacing the current caps with bigger ones. Film caps in those values will probably not fit in your amp.

[Finom1]

maxkracht, thank you for this information.

Would too much power supply filtering hurt the frequency response of a guitar amp?

Thanks again for sharing!!!

[maxkracht]

Wouldn’t really change the frequency response. Bigger filters don’t add bass, they just allow you to keep more bass you already have when you are pushing the amp harder. 

Think of those caps like a battery. When you hit a big bassy chord, you drain the battery for a, very, short amount of time. When the battery is drained, you don't get as much bass until it can recharge. Bigger battery, less noticeable drain, more perceived bass. 80uf is already relatively large and the amp shouldn't have a slow response with those caps and a solid state rectifier. Doubling that value will probably be a somewhat subtle change, but going higher isn't unreasonable.



There are other ways to change the feel of an amp, add touch sensitivity, compression, etc., and I am sure others will chime in with different advice, but you won’t know what you like without trying and it is relatively cheap and easy to experiment with higher and lower values. 20uf is probably fine, 220uf is probably fine. No right answers...

[Finom1]

maxkracht, that was a very good analogy of battery storage and capacity. That really helped me understand all this better.

Hearing about what other components that would add touch sensitivity, and lead to a more responsive, more lively amp would be relevant to the topic at hand. The total upgrade and understanding of capacitors is the main theme!

maxkracht, you are expanding the thought process. You touched on what I want my last amp to have. I am an old timer and would love to experience all the Emotions Of The Notes like I did back in the late 1960s & early 1970s. I would love to rock one more time for my kids:)

Thank you so much for helping me and sharing your wisdom with all of us!!!

[Finom1]

I will be reaching out to FTCAP Fischer & Tausche - https://www.ftcap.de/en/products/electr ... apacitors/. I will inquire about their, Screw Terminal, Snap In and Solder large capacity can capacitors!

I will also be asking about high Ripple Current values, low ESR, Useful Life ratings, Temperature ratings, Nominal case size.

Does anyone know of other specifications I should be asking about, please share your ideas and I will follow up on them!

Thanks everyone for share what they have learned with us!!!

[Finom1]

Nick Lucas, from https://www.hificollective.co.uk, got back to me about a electrolytic can capacitor with the specifications we were looking for. Here is what Nick sent me:
"Hi
See
CAP-100-R-22U-500V: 22uF 500Vdc Audio Note Kaisei POLAR Electrolytic Capacitor
and
CAP-100-R-50U-500V: 50uF 500Vdc Audio Note Kaisei POLAR Electrolytic Capacitor

Regards, Nick"

https://www.hificollective.co.uk/compon ... itors.html

https://www.hificollective.co.uk/catalo ... 8_462.html

Any thoughts on the capacitors that Nick sent?

Thanks to everyone who is sharing their knowledge!!!

[Finom1]

What are the benefits of putting a resistor in parallel on each filter capacitor?

How do you calculate the proper resistor value to be put in parallel for each filter capacitor?

Thanks everyone!!!

[Finom1]

Is there a specification for the Dissipation Factor for an electrolytic capacitor?

[pdf64]

I suspect you’re chasing a red herring with this cap quest.
If an Express isn’t bursting with life then there may be something wrong with it.

[maxkracht]

I suspect you’re chasing a red herring with this cap quest.

Agreed. Filter caps are important, but they aren't in the audio path and assuming you buy from a proper distributor, stick with a good name brand, and use the correct size and value, you won't notice much difference between types. I understand the impulse to pick the best components for this amp, but there really isn't a best component, only tradeoffs between many types of good ones. Assuming this is your first or one of your first amp builds, the limiting factor is going to be how well you understand the layout, lead dress, grounding scheme, and basic construction skills like soldering well, not the quality of individual parts.

There is a whole Trainwreck section of this forum. I would suggest looking through that to get a feel for what you like and don't like, then ask why people built their amps the way that they did. There is as much depth in any detail as you choose to pursue, but most of it isn't necessary for your purposes.

[Finom1]

maxkracht, very valid points. Everyone has helped me come a long way to better understand some of the functions of capacitors in my amp.

Thank you very much for sharing!!!