Curious about extra electrolytics in Son of Ben Preamp — I Reverse engineered original.

[kcy8520]

Hi all,


I recently got curious about the schematic from Son of Ben Preamp schematic, so I purchased the original pedal and reverse engineered it myself. The overall topology is almost identical, but I noticed something odd.


The PedalPCB version uses three electrolytic capacitors, while the original only has one, which is in the power filtering section. Interestingly, there are no pads on the original PCB for electrolytics at the typical JFET source decoupling positions—in fact, those positions use MLCCs instead. You can see what I want to say in those pictures.


I’m wondering why PedalPCB chose to use electrolytics in those spots. Was it a design choice, cost consideration, or just convention?


Has anyone else looked into this?


Thanks in advance!

 

[HamishR]

I guess that most of the PCBs here are designed for through-hole components, as they are generally easier for hobby builders like us. And in through-hole builds it's normal to use electrolytics for values over 1µF. You could use whatever sort of 10µF cap you liked really. It's a little unusual to use a 10µF tantalum or MLCC in that value for a through-hole design. I often use a tant where it will save space in a Vero build but rarely for 10µF. No reason other than that's what I'm used to. FWIW I use SMD 10µF caps all the time on Vero because they're tiny. Just take the plastic bit off the bottom and you're good to go. (I learnt that trick here!)

 

[Robert]

Was it a design choice, cost consideration, or just convention?

The PCBs are designed for through-hole components whenever possible.

You can install MLCC in those spots if you'd prefer.

 

[drew.spriggs]

Hi all,


I recently got curious about the schematic from Son of Ben Preamp schematic, so I purchased the original pedal and reverse engineered it myself. The overall topology is almost identical, but I noticed something odd.


The PedalPCB version uses three electrolytic capacitors, while the original only has one, which is in the power filtering section. Interestingly, there are no pads on the original PCB for electrolytics at the typical JFET source decoupling positions—in fact, those positions use MLCCs instead. You can see what I want to say in those pictures.


I’m wondering why PedalPCB chose to use electrolytics in those spots. Was it a design choice, cost consideration, or just convention?


Has anyone else looked into this?


Thanks in advance!

View attachment 97204View attachment 97207View attachment 97208

You can use any kind of capacitor your want there. Electrolytics are cheap, and in that position they're out of the audio path so no need for anything super fancy. There's not even much DC derating of caps to worry about.

Most people would prefer to work with THT electros over a SMD MLCCs

 

[spi]

Has anyone else looked into this?

This site is not what it seems. We've been unraveling conspiracies piece by piece. Wait until you hear about how he hides his schematics or weakens the pads on pcbs. The ruse is up @Robert (or is it buggs? hmmm so many identities)

 

[Locrian99]

This site is not what it seems. We've been unraveling conspiracies piece by piece. Wait to you hear about how he hides his schematics or weakens the pads on pcbs. The ruse is up @Robert (or is it buggs? hmmm so many identities)

And no fathers day sale?!?!?!? What is the world coming to?

 

[Robert]

Don't forget the reviews.....

 

[szukalski]

The Electrolytic Capacitor cabal got to PPCB long ago..