Styroflex caps in a pultec

[jeroddumas]

Can styroflex caps be used as filter caps in a gyraf pultec peq1? I have all values of the filter caps needed, but a couple or styroflex. Can they be used?

 

[nrgrecording]

I'd seen mastering pultecs from manley with Styroflex inside and many other audio equipment...
They have small tolerances and the grid dimension is more variable instead of wima foil caps. :wink: I bought more than 10.000 of them (ebay). :wink:

Will work very good in the passive filtersection of the peq1.

Frank.

 

[digichild]

[quote author="nrgrecording"]I'd seen mastering pultecs from manley with Styroflex inside and many other audio equipment...
They have small tolerances and the grid dimension is more variable instead of wima foil caps. :wink: I bought more than 10.000 of them (ebay). :wink:

Will work very good in the passive filtersection of the peq1.

Frank.[/quote]

hi frank,
sounds interesting-so for a stereo pultec i could use styros instead of matched wimas?

thanx digichild

 

[nrgrecording]

As far as i know the wimas have 20% tolerance and the styroflex capacitors have 2,5%. You could match the styroflex as well if you want to get lower tolerances. :wink:
Frank.

 

[gyraf]

You can get both types in just about any tolerance you may want. But the styroflex'es are generally rated as some of the best types for precision works..

Jakob E.

 

[Rossi]

Most WIMAs are available in either 5 % or 20% tolerances. Unfortunately most local dealers carry only 20 % ones. Some better online shops such as Reichelt in Germany (www.reichelt.de) offer both

 

[digichild]

[quote author="Rossi"]Most WIMAs are available in either 5 % or 20% tolerances. Unfortunately most local dealers carry only 20 % ones. Some better online shops such as Reichelt in Germany (www.reichelt.de) offer both[/quote]

that`s right...but i thought for a stereo pultec the tolerances should be below 5 %...and still i don`t know how i should choose the potentiometers...

 

[nrgrecording]

...and still i don`t know how i should choose the potentiometers...

What do you mean exactly? How to get potentiometers with less tolerances?
What about stereo potentiometers or stepped attenuators?

Take a look at the manley pultec :wink: (pic from ebay)

 

[Infernal_Death]

Now those switches look like lorlin ? :shock: :?

Flo

 

[nrgrecording]

[quote author="Infernal_Death"]Now those switches look like lorlin ? :shock: :?
Flo[/quote]

Yes. At least the boost/atten switches.

 

[digichild]

[quote author="nrgrecording"]

...and still i don`t know how i should choose the potentiometers...

What do you mean exactly? How to get potentiometers with less tolerances?
What about stereo potentiometers or stepped attenuators?

Take a look at the manley pultec :wink: (pic from ebay)

[/quote]


stereo pots have tolerances of 10% or more-ne?

stepped attenuators are a cool idea,on the manleys the boost/cut has about 10 steps only?
not so much for 18 or something db...

 

[nrgrecording]

stereo pots have tolerances of 10% or more-ne?

stepped attenuators are a cool idea,on the manleys the boost/cut has about 10 steps only?
not so much for 18 or something db...

I don't know... maybe 12 steps or so!? (lorlin 1x12) (at the mastering version from 1992)

But these enhanced manley pultecs have pots for boost/atten :

 

[digichild]

so on the master eq they use switches also for boost/atten.?

and if you build a double mono eq for mastering(calreq eq) then the use of potentiometers seems to me funny (tolerance +/- 20%) when using caps and resistors of 1 % :?: :?: :?:

 

[jensenmann]

How about matching your components? DIY!!!!!
Get your LCR meter out and go for it, you lazy.....
:grin:
cheers
Jens

 

[digichild]

[quote author="jensenmann"]How about matching your components? DIY!!!!!
Get your LCR meter out and go for it, you lazy.....
:grin:
cheers
Jens[/quote]

thanks for your advice-so what you think:how much have the potentiometers to match?also 1 or 2% ?

by the way its not my lazyness that i ask stupid questions here all the time but rather my unexperience :wink:

 

[gyraf]

That depends on what the potentiometer does, and what tolerances you'll need on what parameters.

For stereo EQ's, the important spec IMHO is to get the frequencies tracking accurately - specially if you run high Q's. The lift/cut and Q-regulation are much less chritical - just keep them tracking within 0.25-0.5 dB, and you're good.

The pots in the pultec are for lift/cut and Q regulation, and are thus not very chritical to match accurately.

Jakob E.

 

[digichild]

[quote author="gyraf"]For stereo EQ's, the important spec IMHO is to get the frequencies tracking accurately - specially if you run high Q's. The lift/cut and Q-regulation are much less chritical - just keep them tracking within 0.25-0.5 dB, and you're good.

Jakob E.[/quote]

can you please tell me how should i do that?

 

[gyraf]

..build the unit as-is, and see how it behaves. And then change components if the result is not good enough..

That's the way I'd do it..

Jakob E.