Sourcing electrolytic caps for Duocast build

[hybridpi]

Apologies if this has been answered before, but the BOM for the Duocast calls for 100, 120, and 330 uF electrolytic caps that are rated for at least 35v and also 5mm in size. I normally get Vishay or Panasonic electrolytics, but I can’t find this value/voltage/diameter combo in any brand on mouser. Can anyone else share where they found them? Thanks
Daniel

 

[Erik S]

You can fudge the size a little. These 50v 330u, and 63v 120u cheapies from tayda are a little bigger than the screenprint, but I got them in there. Just had to lift one of the 120s up a little so I could offset it. The 100u is 35v and is the right size I think.

 

[Cybercow]

FWIW, I've found that SMD electrolytic caps can easily be used in place of standard TTH electrolytic caps. They are MUCH smaller. Just straighten the pins on the SMD e-cap, remove the plastic shroud and voila! They fit right into the holes for standard e-caps and they are not nearly as tall as standard e-caps.

And if 120µF values are hard to find, standard 100µF values in place of the 120µF caps will do no harm nor create any problems in the Duocast.

 

[hybridpi]

FWIW, I've found that SMD electrolytic caps can easily be used in place of standard TTH electrolytic caps. They are MUCH smaller. Just straighten the pins on the SMD e-cap, remove the plastic shroud and voila! They fit right into the holes for standard e-caps and they are not nearly as tall as standard e-caps.

And if 120µF values are hard to find, standard 100µF values in place of the 120µF caps will do no harm nor create any problems in the Duocast.

View attachment 45985

Thanks! That’s awesome to know. I think I have some SMD caps; I’ll see if I have the size that fits. Do you know what body size you used off the top of your head?. That’s a great hack!

 

[hybridpi]

You can fudge the size a little. These 50v 330u, and 63v 120u cheapies from tayda are a little bigger than the screenprint, but I got them in there. Just had to lift one of the 120s up a little so I could offset it. The 100u is 35v and is the right size I think.

Thanks so much for your help! On a side note, good job on cutting those sockets for the transistors; I had the same idea but I’m having trouble separating the individual sockets without breaking the plastic casing though. I probably just need a sharper xacto knife.

 

[Erik S]

I buy the long strips of SIP sockets, I think they're 40 pins long. I had the same problem - I was cutting them with the side cutters I use on leads and I was scrapping a ton of them because the plastic would blow up.

Someone gave me the tip that bypass cutters do a much cleaner job, and I've been getting clean cuts ever since.

 

[Cybercow]

Thanks! That’s awesome to know. I think I have some SMD caps; I’ll see if I have the size that fits. Do you know what body size you used off the top of your head?. That’s a great hack!

I'm unsure of the body size. (I'll check when next I'm near my parts.) I just ordered an SMD Electrolytic Capacitor kit from eBay (from a stateside seller with great ratings and a return policy) for about 20 bux.

 

[Harry Klippton]

I put some on the bottom side of the board on my build to make more room

 

[hybridpi]

I buy the long strips of SIP sockets, I think they're 40 pins long. I had the same problem - I was cutting them with the side cutters I use on leads and I was scrapping a ton of them because the plastic would blow up.

Someone gave me the tip that bypass cutters do a much cleaner job, and I've been getting clean cuts ever since.

That’s awesome. I was using flush cutters (what I use for leads) and then I tried an xacto knife. I hadn’t heard of bypass cutters before, and When I look them up on google the results are mostly looking like pruning shears, like for gardening. That isn’t what you mean, is it?

 

[Erik S]

That’s awesome. I was using flush cutters (what I use for leads) and then I tried an xacto knife. I hadn’t heard of bypass cutters before, and When I look them up on google the results are mostly looking like pruning shears, like for gardening. That isn’t what you mean, is it?

Those might work too! But no, not what I’m using.

Bypass just means any cutter where the two blades pass each other like a scissors (unlike the flush cutters where the blades bump into each other).

I’m using some gorgeous knipex cable cutters, but they’re way overkill for the job.

If you have a pair of needle nose style wire strippers, those often have a nice bypass cutter on them somewhere.

 

[Feral Feline]

Yup, sometimes cutting up an IC-socket works better in some cases than using SIP-sockets. The IC sockets are more robust.

I’ve had SIP sockets from several manufacturers, none had the ability to snap off by hand cleanly. Some cheap stuff uses brittle plastic, more expensive product can be more flexible, but either way for exactly those reasons (too brittle/too flexible) the breaks are not clean and waste a lot of pins.

For example:

View attachment 24392

I won’t use the sockets with exposed pins, I’ll pop out the exposed pins and save those pins for other uses.

You can see the silver SIP socket row on the far right didn’t clip cleanly, there’s some plastic protruding that I’ll shave off for the next bit that I use. The 4-wide SIP with the two centre pins removed is what I use for diodes and resisters experimentation; the silver 4-pin with one exposed pin will be reduced to 3-pin for socketing a transistor or 3-wide with centre-pin removed for socketing a film cap; the gold 3-pin with exposed pin will be narrowed to 2-pin for socketing an electrolytic or LED, etc.

I use the sockets extensively because I like to experiment, can’t make a decisive choice (“what if I change my mind down the road?”), and don’t breadboard enough — but that’s changing, I’m doing a lot more breadboarding now, spurred on by BtR, CdB, fig and others.

Not just breadboarding, but for many other aspects of the hobby, I have to say this forum and members such as yourself have been a good influence on me.

The above quotes come from a couple other threads:

16 pin IC socket across two 8 pin on PCB

Fellow nerds. Is it ok to use a single 16 pin IC socket across two adjacent 8 pin "banks" as long as I am sure to slot the TL072 and the TC1044SCPA IC's in the correct notch orientation?

forum.pedalpcb.com

Basic Workflow Tips for Building a PedalPCB

After just looking on Tayda, is there a "breakaway" female version too? The only thing I see is the following which doesn't say it is breakaway: https://www.taydaelectronics.com/connectors-sockets/sockets/30-pin-dip-sip-ic-sockets-adaptor-solder-type.html

forum.pedalpcb.com

I use a sharp utility-knife and have found that a key ingredient to consistent CLEAN-cuts is to slide the blade (forward or back as per your preference, I slide it away from me). I say "slide" because "saw" or "sawing" conjures up actions of back-and-forth movement, but it works best if you simply apply downward force and slide the blade in one direction.

Naturally you have to keep everything square and not angle the blade.

 

[comradehoser]

Here is my "spring garden of caps" solution. Mouser sent me some really big caps that I didn't realize I ordered, so now I'm struck trying to make them fit. Like why a 100uf/50v cap can be triple the size of another?

 

[HamishR]

Funny you should ask - I got some caps from Mouser specifically for the Broadcast because the ones I was getting from Tayda were too big! For example the 100µF caps I got from Mouser were these: 667-ECA-1VM101, https://www.mouser.com/ProductDetai...ICPbxyqGQug==&countryCode=AU&currencyCode=AUD

In fact I just ordered some more because they're such a handy size and appear to be decent quality.

 

[Cybercow]

I still say the SMD e-Cap solution provides a bit more versatility with regard to physical sizes.

 

[Alan W]

I hadn’t thought of ripping into SMT caps before! Great idea. I’ve come to really like polymer caps from using them in hi-fi stuff.

 

[HamishR]

I must try those SMD caps. I didn't know they had pins at all!

 

[Cybercow]

I must try those SMD caps. I didn't know they had pins at all!

They have "pins" but they are wrapped thru a flat plastic shroud. By carefully straightening the legs, that plastic shroud comes right off and the legs are just long enough to poke thru the other side of the PCB for soldering.