fully passive (no gain) pultec topology eq
- Thread starter dfuruta
- Start date
Help Support GroupDIY Audio Forum:
Great to see this project and your DIY inductors.
For those who go down that path using the ferrite cores, I would recommend using the adjustment screw for fine tuning the inductance. For example...
http://www.spulen.com/shop/index.php?cPath=41_89
These save a lot of time, especially if you are trying to match channels.
For those who go down that path using the ferrite cores, I would recommend using the adjustment screw for fine tuning the inductance. For example...
http://www.spulen.com/shop/index.php?cPath=41_89
These save a lot of time, especially if you are trying to match channels.
Interesting! So, those screws go down the middle of the inductor? One would hold them in place with nuts? My german is non-existent, sadly.
Just wanted to update; the inductor I wound in those pictures didn't change value as much as the last batch I did–it stabilized, after getting glued together, at 18mH. I must be getting better at this.
Just wanted to update; the inductor I wound in those pictures didn't change value as much as the last batch I did–it stabilized, after getting glued together, at 18mH. I must be getting better at this
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Hello,
I've successfully built a fully passive dual pultec using the schematic in the first page;
I'm using Edcord XSM 10K:10K as input trafo and XSM 10K:150 out using my mic pres as make-up.
Everything seem to work fine except i have a strange hum problem with one of my preamps.
When i use my Hardy M1 preamp as make-up gain i get a lot of 50hz hum (-74dB), and the pultec case seem to be very sensitive to every electronic device close to it.
After a lot of troubleshooting checking my ground connections i found the hum is picked by edcor out trafos, they seem to be extremely senstive to hum, if i move the xformers outside the case the hum go below -100dB;
i guess the problem could be the open core style of the Edcor, and i'm thinking of swapping them with some incapsulated trafos like Lundahl, do you think this could solve the problem ?
I've successfully built a fully passive dual pultec using the schematic in the first page;
I'm using Edcord XSM 10K:10K as input trafo and XSM 10K:150 out using my mic pres as make-up.
Everything seem to work fine except i have a strange hum problem with one of my preamps.
When i use my Hardy M1 preamp as make-up gain i get a lot of 50hz hum (-74dB), and the pultec case seem to be very sensitive to every electronic device close to it.
After a lot of troubleshooting checking my ground connections i found the hum is picked by edcor out trafos, they seem to be extremely senstive to hum, if i move the xformers outside the case the hum go below -100dB;
i guess the problem could be the open core style of the Edcor, and i'm thinking of swapping them with some incapsulated trafos like Lundahl, do you think this could solve the problem ?
