source for capacitors:

[MrDEB]

building an EQlizer and need lots of capacitors. Probllem is finding the ones I want
checked Jameco, Digikey and Mouser--no such luck
need low noise = poly type I understand I need
330pf, 43pf, 82pf
found ganged liner pots at $1 each.

 

[Nigel Goodwin]

I suspect you will find out that you can buy an equaliser for a fraction of the cost of the parts you're going to spend?.

 

[MrDEB]

yes but it's a learning experience

I am the merit badge counselor for the electronics merit badge and have a scout wanting to build such a project.
the 25W stereo amp was going to be DIY for $70 but found a ready built for $30.
scout is designing his own circuit boards and going to home etch as well.
LOTS of work ahead for sure.
It makes me feel good that after I introduced this young man to electronics he wants more.
thats the idea behind merit badges

 

[Nigel Goodwin]

No problem with learning, but you didn't mention the reason.

 

[MrDEB]

My best guess is he is interested

took a liking to electronics.
he is a quick learner. Just hope I can keep up-he showed me some short cuts with expresspcb.
will mention to him about pic's. I wish I was younger and could pick up on pic programming etc.
having enought trouble with this EQlizer circuit.
found a chip to sub for the lm837 (mouser dosn't carry the LM837 so shipping comes to play)
found an MC33274APG quad op amp , low noise. almost same as the LM837

 

[MrDEB]

Oh found capacitors over at Welborne Laboratories

 

[audioguru]

The LM837 is a low noise audio quad opamp.
The MC33274 is an ordinary quad opamp with 4 times as much noise (hisssss).

 

[MrDEB]

they say its low noise??
Was hoping to purchase all the componets from one source and Mouser dosn't carry the LM837--dang it.Not real up on op amp data sheets. What to look for??
Then trying to order only a few resistors etc from Jameco or Digikey forget it. Only in quanities of 100+

 

[audioguru]

The last time I bought resistors was an assortment of 480 1/4W 5% carbon film resistors by Velleman from a local store.

An LM833 is a dual opamp that uses the same opamps that are in the LM837 quad.

 

[phil7890]

they say its low noise??
Was hoping to purchase all the componets from one source and Mouser dosn't carry the LM837--dang it.Not real up on op amp data sheets. What to look for??
Then trying to order only a few resistors etc from Jameco or Digikey forget it. Only in quanities of 100+

For the opamp, maybe check the datasheet of a TI/Burr-Brown OPA4134 (good stuff) to see if it'll work. Mouser and Digikey has some, and/but may be the SOIC type.

 

[MrDEB]

Thanks but they are really high end
$3+
we need 6.
will check digi key but kinda want dip setup
and the capacitors need to be polyester type. not carbon or other

 

[audioguru]

A high end opamp costs less than a cup of coffee in a restaurant. Are you unemployed and homeless?

 

[MrDEB]

I am not the one buying the parts.
A boy scout, a junior in high school using his Christmas money so cost is a concern.
He has purchased a 25w stereo amp for $30. his speakers are only 30w.
the parts count in my project manager at mouser is already up to $50 plus the polysterene capacitors from Welborne Labs then some ics from Digikey or Jameco.
this project is getting expensive for a young person.
If I was footing the bill I would buy all 1% parts, matched and high end chips.
Still need to design a vu meter for 10 frequencies.
looking at using a LM3915 in conjuction with an Allergo A6279EA-T
the circuit https://www.electro-tech-online.com/attachments/audio-spectrum-analyzer-en-pdf.15065/
is kinda what I am looking for but it uses transistors. The Allergo chip might do a better job. Just need to figure out how to build it.
Any thoughts?
It was suggested to use 10 LM3915's but that could get to be expensive.
I have ordered the Allergo chip (6 samples for FREE).
If it dosn't work then the chips will end up on my LEDTRICKS Christmas light display.

 

[chemelec]

Especially Considering he has a CHEAP AMP and SPEAKERS.

The Real Audiable Difference in the output Does NOT Justify the cost of 1% resistors, And it Definately DOESN'T justify the cost of Polysterene Caps.
I Doubt you could actually hear Any Difference.

And I Even doubt you could descern a Listening Difference, Using a LM741 op-amp.

Yes you would see a difference in lab tests.

But in your situation, what a waste of money.

** As to the LM3915's, I could possibly have a Great deal for you, But you don't say where you live.
*******************************************

I am not the one buying the parts.
A boy scout, a junior in high school using his Christmas money so cost is a concern.
He has purchased a 25w stereo amp for $30. his speakers are only 30w.
the parts count in my project manager at mouser is already up to $50 plus the polysterene capacitors from Welborne Labs then some ics from Digikey or Jameco.
this project is getting expensive for a young person.
If I was footing the bill I would buy all 1% parts, matched and high end chips.
Still need to design a vu meter for 10 frequencies.
looking at using a LM3915 in conjuction with an Allergo A6279EA-T
the circuit https://www.electro-tech-online.com/attachments/audio-spectrum-analyzer-en-pdf.15065/
is kinda what I am looking for but it uses transistors. The Allergo chip might do a better job. Just need to figure out how to build it.
Any thoughts?
It was suggested to use 10 LM3915's but that could get to be expensive.
I have ordered the Allergo chip (6 samples for FREE).
If it dosn't work then the chips will end up on my LEDTRICKS Christmas light display.

 

[Hero999]

The last time I bought resistors was an assortment of 480 1/4W 5% carbon film resistors by Velleman from a local store.

Carbon film are very noisy, use metal film for low noise.

 

[chemelec]

Carbon film are very noisy, use metal film for low noise.

Yes but noise is also a function of the Resistance value.

Designing around lower resistance values will result in less noise than higher resistances.

 

[audioguru]

I always used metal film resistors in microphone preamps then switched to carbon film and didn't notice any noise.

 

[Nigel Goodwin]

I always used metal film resistors in microphone preamps then switched to carbon film and didn't notice any noise.

Well they were making low noise preamps before metal film resistors were available, and they always worked fine.