Enhanced Pultec - [silent:arts] version

[[silent:arts]]

as promised: my version of the Pultec PEQ1 (YET UNTESTED)

featuring 11 LF shelf drop freq. (20 - 2000Hz), 11 indipendend LF shelf boost freq. (20 - 2000Hz), 11 peak freq. (1K - 20K) and 11 shelf drop freq (3K - 28K).

my freq. calculation excell sheet is here

PCBs arrived today, so I stuffed what I have had at home (still have to order some parts):







when everything is tested and working I will post the schematics and PCB layout.

[matthias]

well done volker! that looks very nice and clean...

I never saw these transformers before..??
and where did you got the pcb's from?

[[silent:arts]]

well done volker! that looks very nice and clean...

thanks

I never saw these transformers before..??

me two. they don't look like haufe or pikatron, but measured well and are 1+1:1. I found 12 of them in an old "geräteträger" i got for free ...[/quote]

and where did you got the pcb's from?

I tried IBF - not the cheapest but the PCBs are ok.

[Infernal_Death]

Looks very cool, thanks for sharing.

Are those inductors self-wound ? I guess the amp section is based on Jakob's SRPP stage ?

Flo

[[silent:arts]]

Are those inductors self-wound ? I guess the amp section is based on Jakob's SRPP stage ?

Yes, selfwound inductor (epcos RM8, N49 Core). and yes, the makeup stage is Jacobs SRPP stage.
I can post the schematics tonight.

[[silent:arts]]

Schematic

[nrgrecording]

Hey, thats great! Verrry well done. Definately art !

[[silent:arts]]

thanks frank 8)

I never saw these transformers before..??

btw, should be easy to convert the PCB to Lundahls - there is enough space left (first I wanted to do the layout for both, but then I thought w.t.f., get ready with your unit)

[kubi]

Cute, Volker <insert thumb-up-icon here>!

Looks like Pultecs are quite popular around here at the moment.

[toff]

WOW!
Three thumbs up!

[bernbrue]

Hi Volker,
thats a very nice project. I really admire people like you being able to develop their own design, to built a costum made inductor and finally etch their own pcbs. I always ask myself: what do they know, I don´t know; what abilities do they have, I don´t have (sigh). Well, I still solder standard parts on premade pcbs, but half year ago I even didn´t think of the possibilty to built my own SSL or 1176. I´m still learning and DIY is so interesting. Keep on going with these fantastic projects so that people like me can learn from. ATM I´m working on G-Pultecs (maybe a stereo version). I stick to the standard frequencies. So, congratulations and thumbs up.
regards
Bernd

P.S: Do you plan to make the pcbs and inductors available for less experienced DIYers like me?

[[silent:arts]]

Do you plan to make the pcbs and inductors available for less experienced DIYers like me?

Hi Bernd,
first I have to finish the unit and see if it works
don't know when this will happen since I have a leck of time and money at the moment :(
doing this inductor is not hard if you can count up to 410
oh, and since those unknown transformers I used are not available the PCB should be changed to Lundahls or something else.
if you are interested in a PCB set I can change the layout to other transformers and send you the files.

[bernbrue]

Hi Volker,
yes, the layout with easy available Transformers (Lundahl or OEP) would be nice, although I´m not able to etch the PCBs myself. You said, that you had your pcbs made by a company. How much would I have to pay for a few pcbs? Are their any pcbs services with reasonable prices available?
Thanks a lot
Bernd

[laitue5]

Great one.
And thank you for your invitation in this forum.

[[silent:arts]]

You are welcome.
No update for this project yet (I'm just finishing the APIs you send me) ...
have fun