Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: AmberB on August 12, 2021, 12:11:01 am

Title: Ceramic capacitors for guitar amp?
Post by: AmberB on August 12, 2021, 12:11:01 am

Hello,
A question, do people still use ceramic capacitors in the preamp of their guitar amp builds?
If not, why not?

I was just given a bag full of .02 at 1000 volt ceramic caps...

Title: Re: Ceramic capacitors for guitar amp?
Post by: Stuff4bikes on August 12, 2021, 12:35:11 am

Microphonic by nature, can be good can be bad......the guitologist on YouTube says a ceramic cap early in the circuit gives extra grit to the sound....

Title: Re: Ceramic capacitors for guitar amp?
Post by: Blueboozer on August 12, 2021, 12:59:05 am

Try it. Experiment. You might find “That” tone

Title: Re: Ceramic capacitors for guitar amp?
Post by: sluckey on August 12, 2021, 06:58:15 am

I used 3 ceramics in one of my last builds.

     http://sluckeyamps.com/smoky/4.jpg

Title: Re: Ceramic capacitors for guitar amp?
Post by: Latole on August 12, 2021, 10:10:22 am

I also use few on my builts.

Title: Re: Ceramic capacitors for guitar amp?
Post by: sluckey on August 12, 2021, 10:59:38 am

Quote from: AmberB on August 12, 2021, 12:11:01 am

I was just given a bag full of .02 at 1000 volt ceramic caps...

Build a lot of tremolo oscillators. No way to affect your tone.

Title: Re: Ceramic capacitors for guitar amp?
Post by: pdf64 on August 12, 2021, 12:32:01 pm

Ceramics are made using several types of dielectric material, resulting in at least 2 classes of cap. eg class1 high stability low loss, class2 low stability high volumetric efficiency.
So lumping them all together isn’t a good way to proceed.
At a guess, the caps you’ve got may be class 2.
https://en.m.wikipedia.org/wiki/Ceramic_capacitor

Title: Re: Ceramic capacitors for guitar amp?
Post by: AmberB on August 12, 2021, 09:23:06 pm

Quote from: pdf64 on August 12, 2021, 12:32:01 pm

Ceramics are made using several types of dielectric material, resulting in at least 2 classes of cap. eg class1 high stability low loss, class2 low stability high volumetric efficiency.
So lumping them all together isn’t a good way to proceed.
At a guess, the caps you’ve got may be class 2.
https://en.m.wikipedia.org/wiki/Ceramic_capacitor

They are the standard brick red disk caps.  The writing on the cap is as follows
Y5U
103M
1 K V
KCK

probably class 2...
I have hundreds of them if anybody needs any...

Title: Re: Ceramic capacitors for guitar amp?
Post by: thetragichero on August 12, 2021, 09:43:10 pm

so those are 10nf 20% tolerance caps (103M)
y5u is the dielectric, here's a table from wikipedia
(https://www.raviyp.com/wp-content/uploads/2017/04/images_class2.png)

Title: Re: Ceramic capacitors for guitar amp?
Post by: Willabe on August 12, 2021, 10:14:16 pm

Here's a post from PRR on ceramic caps;

https://el34world.com/Forum/index.php?topic=19534.msg203059#msg203059 (https://el34world.com/Forum/index.php?topic=19534.msg203059#msg203059)

Here's the start of the thread on if coupling caps sound different;

https://el34world.com/Forum/index.php?topic=19534.0

Title: Re: Ceramic capacitors for guitar amp?
Post by: bmccowan on August 13, 2021, 07:24:37 am

Valco used a lot of ceramic caps and their circuits all sound good to me.