ruffrecords

Re: Customising Gpultec freq bands
« Reply #20 on: October 23, 2012, 07:02:31 PM »
thanks guys, most appreciated :)

am I actually good with 63v for the caps?

Mike

PS: Would you guys actually prefer metalized caps over wimas?

63V is fine. Any film capacitor will do.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'


Re: Customising Gpultec freq bands
« Reply #21 on: October 24, 2012, 07:25:37 AM »
thanks guys, most appreciated :)

am I actually good with 63v for the caps?

Mike

PS: Would you guys actually prefer metalized caps over wimas?

63V is fine. Any film capacitor will do.

Cheers

Ian

hey there,

were the 100nF in parallel with the 330nF and 3.9nF in parallel with the 15nF a rough estimation or as close as I can get?

Is it also worth getting those caps for the low end section?

http://www.banzaimusic.com/Mundorf-MCap-630-0-1uF.html
« Last Edit: October 24, 2012, 08:04:07 AM by atticmike »

Joechris

Re: Customising Gpultec freq bands
« Reply #22 on: October 24, 2012, 01:26:46 PM »
These pultec eqs are very broad. You will hardly hear any difference between 90 and 70 hz.
I use 120 for vokal and Guitars,  and 20 for kikk or bass :-)
musicians vary +/-9dB depending on mood, drugs, and line-voltage. (PRR)

ruffrecords

Re: Customising Gpultec freq bands
« Reply #23 on: October 24, 2012, 06:14:45 PM »
hey there,

were the 100nF in parallel with the 330nF and 3.9nF in parallel with the 15nF a rough estimation or as close as I can get?
Pretty much as close as you can or need to get with 10% tolerance components. The calculated total values are 424nF and 19nF. 330+100=410 which is within 1.5%. 15+3.9=18.9 which is within 0.5%. This assumes of course that 300 and 15nF are exact values to begin with.

Quote
Is it also worth getting those caps for the low end section?

http://www.banzaimusic.com/Mundorf-MCap-630-0-1uF.html

No. Wima or Panasonic Film capacitors will be fine. Getting 3.9nF will limit your options but you will probably find plenty of polystyrene ones such as this:

http://uk.farnell.com/lcr-components/fscex-3900pf-1-160v/capacitor-3-9nf-160v/dp/9520554


and this will do fine for the 100nF if you want to avoid Wima :

http://uk.farnell.com/vishay-roederstein/mkt1813410014/capacitor-100nf-100v/dp/1612246

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

Re: Customising Gpultec freq bands
« Reply #24 on: October 24, 2012, 09:27:47 PM »
hey there,

were the 100nF in parallel with the 330nF and 3.9nF in parallel with the 15nF a rough estimation or as close as I can get?
Pretty much as close as you can or need to get with 10% tolerance components. The calculated total values are 424nF and 19nF. 330+100=410 which is within 1.5%. 15+3.9=18.9 which is within 0.5%. This assumes of course that 300 and 15nF are exact values to begin with.

Quote
Is it also worth getting those caps for the low end section?

http://www.banzaimusic.com/Mundorf-MCap-630-0-1uF.html

No. Wima or Panasonic Film capacitors will be fine. Getting 3.9nF will limit your options but you will probably find plenty of polystyrene ones such as this:

http://uk.farnell.com/lcr-components/fscex-3900pf-1-160v/capacitor-3-9nf-160v/dp/9520554


and this will do fine for the 100nF if you want to avoid Wima :

http://uk.farnell.com/vishay-roederstein/mkt1813410014/capacitor-100nf-100v/dp/1612246

Cheers

Ian

so you're saying I do not benefit from caps that have less than 10% tolerance at the low boost / cut section and less than 2,5 % for the polystyrene in the HF?

If I was to stick with the 10% tolerance caps, would they be better than wimas?

http://www.banzaimusic.com/Evox-Rifa/

Also, what about those?:

http://www.banzaimusic.com/Nichiden-Audio/

And you're sure those are useless?

http://www.banzaimusic.com/M-Cap-Series/

Re: Customising Gpultec freq bands
« Reply #25 on: October 25, 2012, 02:33:56 AM »
You could also measure the caps for less tolerance if you want to build a stereo version...

http://www.pollin.de/shop/dt/NTA3OTYxOTk-/Messtechnik_Uhren/Messtechnik/Multimeter/Digitales_Kapazitaetsmessgeraet_MASTECH_MY6013A.html

ruffrecords

Re: Customising Gpultec freq bands
« Reply #26 on: October 25, 2012, 01:33:29 PM »

so you're saying I do not benefit from caps that have less than 10% tolerance at the low boost / cut section and less than 2,5 % for the polystyrene in the HF?

Tolerancing can be a difficult exercise. However, in this instance you first need to consider the pots that work with these capacitors to determine the turnover frequencies. Most pots have at best a 20% tolerance and you can sometimes get 10% ones without paying to much money. If the pots are only 10% tolerance there is little point in making the capacitors any better than 5% (the resulting overall tolerance is 11% ). If you want to make a really accurate and repeatable EQ then you need to use switched attenuators in place of regular pots. Then it would be worthwhile seeking out 1% capacitors.

Quote
If I was to stick with the 10% tolerance caps, would they be better than wimas?

http://www.banzaimusic.com/Evox-Rifa/

Also, what about those?:

http://www.banzaimusic.com/Nichiden-Audio/

There is nothing wrong with them, they are simply over specified. For normal use in an equalizer, 50V working types are quite sufficient. The ones you have linked to are 630V working types. They will work fine but they will be rather larger than the 50V working equivalent. I do not expect there will be any audible difference from the Wimas.

Quote
And you're sure those are useless?

http://www.banzaimusic.com/M-Cap-Series/

They are not useless, just over specified. These will be perfectly adequate:

http://www.banzaimusic.com/Panasonic-SMF-0-1uF.html

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

Re: Customising Gpultec freq bands
« Reply #27 on: October 25, 2012, 02:12:48 PM »
What if I am measuring pots?
Will the value then be more accurate (for a stereo version) for example in the middle of the pot also?

ruffrecords

Re: Customising Gpultec freq bands
« Reply #28 on: October 25, 2012, 06:32:41 PM »
What if I am measuring pots?
Will the value then be more accurate (for a stereo version) for example in the middle of the pot also?

For the LIN pots the answer is yes. The law of LOG pots is very poorly controlled in manufacture so for all but the most expensive ones the answer is no.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

Re: Customising Gpultec freq bands
« Reply #29 on: November 07, 2012, 05:11:19 AM »
What if I am measuring pots?
Will the value then be more accurate (for a stereo version) for example in the middle of the pot also?

For the LIN pots the answer is yes. The law of LOG pots is very poorly controlled in manufacture so for all but the most expensive ones the answer is no.

Cheers

Ian

But they're still formidable for the job since I got a few lying around from a tube project? Talking about the mundorf.


Re: Customising Gpultec freq bands
« Reply #30 on: November 07, 2012, 05:46:10 AM »
But they're still formidable for the job since I got a few lying around from a tube project? Talking about the mundorf.
there's only so many ways to say "yes!"  knock yourself out.  they're film, they're caps, they're good for >50v, they're presumably the right values or close.  they're just expensive and probably not worth it in terms of cost vs. benefit.  they may also be large and inconvenient to fit on the board, so check lead spacing and diameter against the available real estate.  better yet, build one of each and see if you can hear the faint "cha-ching" of the cash register.  ;)
« Last Edit: November 07, 2012, 05:55:33 AM by grantlack »
There's nothing like the right tool for the job.
And -usually- that's what I end up using...
..nothing like the right tool for the job!

ruffrecords

Re: Customising Gpultec freq bands
« Reply #31 on: November 07, 2012, 05:59:41 AM »

But they're still formidable for the job since I got a few lying around from a tube project? Talking about the mundorf.

If you already have them then by all means use them, they will work fine.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'


 

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