No bopther i know zei has been waiting ont hem since i built the board so i owed him that atleast after such a great pre amp for its cost!
Thanx Kanifee!!🙂 It looks great.!
Regarding the rectifier, The choice of rectifer dios is your of course, If you want to use fancy nancy superfast diod then why not. 🙂 However, "normal standard" rectifier diods also work 😉
Regarding the BOM. You will al get an "up to date" BOM and i,ll see if i can add partnumber from Farnell or something like that.
Deadhead, You got mail as well.
Thanx,
I,ll order the boards this weekend
/JZ
Regarding the rectifier, The choice of rectifer dios is your of course, If you want to use fancy nancy superfast diod then why not. 🙂 However, "normal standard" rectifier diods also work 😉
Regarding the BOM. You will al get an "up to date" BOM and i,ll see if i can add partnumber from Farnell or something like that.
Deadhead, You got mail as well.
Thanx,
I,ll order the boards this weekend
/JZ
Here's my effort on the SOAP MKIII, based on the files kindly given by Zei. Thanks a lot.... I will test it this weekend, if time permits.
However, I noticed (after construction) that the design does not have a low pass filter at the input, instead it has a high pass filter (formed by C1 and R1, R2 and R3. What would happen if the position of C1 and R1 is reversed (and values adjusted accordingly) so that a low pass filter is formed? Feedback from the original designer and/or Zei will be much appreciated.
I want to use the SOAP as a pre-preamp for my el-cheapo MP3 player (powered by a single AAA battery) as the MP3 player's output is too low to drive a preamp (gain of 3) directly.
However, I noticed (after construction) that the design does not have a low pass filter at the input, instead it has a high pass filter (formed by C1 and R1, R2 and R3. What would happen if the position of C1 and R1 is reversed (and values adjusted accordingly) so that a low pass filter is formed? Feedback from the original designer and/or Zei will be much appreciated.
I want to use the SOAP as a pre-preamp for my el-cheapo MP3 player (powered by a single AAA battery) as the MP3 player's output is too low to drive a preamp (gain of 3) directly.
Attachments
I think it would be a bad idea to let the noninverting input have no connection to ground at DC.
Maybe you could put a C between the inputs or in the feedback-loop?
I would think that adding another opamp would be better. Look here for some inspiration:
http://www.linkwitzlab.com/filters.htm#2
Maybe you could put a C between the inputs or in the feedback-loop?
I would think that adding another opamp would be better. Look here for some inspiration:
http://www.linkwitzlab.com/filters.htm#2
Hello,I would like that you send me one PCB to Seville (Spain).
Can you tell me what I have to do?. And how I can to pay and many money (€).
I am very interest for this preamp.
Thank you.
Regards.
Carmelojose
P.D. My english is not very good,I´m sorry.
Can you tell me what I have to do?. And how I can to pay and many money (€).
I am very interest for this preamp.
Thank you.
Regards.
Carmelojose
P.D. My english is not very good,I´m sorry.
I have sent an email to all of you that where interrested in PCB,s for this project.
I,ll order a few PCB,s this friday so you will have until then to replay to may email 🙂
/JZ
I,ll order a few PCB,s this friday so you will have until then to replay to may email 🙂
/JZ
Sory,I cannot currently send emails to other members.
Still have you PCB,Zei?
Thank
Regards.
Carmelojose
Still have you PCB,Zei?
Thank
Regards.
Carmelojose
Sorry I need to can conect a stereo potentiometer for level sound,
Is possible with this pre?
Regards.
Carmelojose.
Is possible with this pre?
Regards.
Carmelojose.
Sorry Zei,can you tell me where the potentiometer must to be placed and his value(in place of R2 and R7?).
Thanks.
Carmelojose.
Thanks.
Carmelojose.
Hi
I have just started putting together a Farnell parts order now that I have received the latest BOM spreadsheet.
I have a few questions for the experienced amongst you…
Resistors
I currently have a wide range of 0.25w metal film resistors in my parts bin. Which resistors need to be of a higher wattage and what would you recommend?
Capacitors
C11- C14 = 100uf
Should I use a general purpose cap here or would I benefit from a ‘Low ESR’ cap like the Panasonic FC?
The reason I ask is I have heard OPAMPs can become unstable if the ESR is to low. I assume its best to stick with a rating of between 35/50v in this circuit.
C15 – C18
Can anyone recommend a good quality capacitor that can be sourced from Farnell?
Transformer
What is the recommended voltage secondary value? Is 18v to high before rectification?
Thanks for your help
Richard
I have just started putting together a Farnell parts order now that I have received the latest BOM spreadsheet.
I have a few questions for the experienced amongst you…
Resistors
I currently have a wide range of 0.25w metal film resistors in my parts bin. Which resistors need to be of a higher wattage and what would you recommend?
Capacitors
C11- C14 = 100uf
Should I use a general purpose cap here or would I benefit from a ‘Low ESR’ cap like the Panasonic FC?
The reason I ask is I have heard OPAMPs can become unstable if the ESR is to low. I assume its best to stick with a rating of between 35/50v in this circuit.
C15 – C18
Can anyone recommend a good quality capacitor that can be sourced from Farnell?
Transformer
What is the recommended voltage secondary value? Is 18v to high before rectification?
Thanks for your help
Richard
Hi Richard 🙂
I heard the Pin. !🙂
For C11- C14 = 100uf - You can use Pana FC.
For C15 - C18. You can get away with Wimas, Or more cool ones like BG, Paper in Oil etc.. I would have started with something cheap 🙂 And then maybe maybe upgrade with fancier stuff.....
35-50V for caps works..
18V transformer is also ok 🙂
/JZ
I heard the Pin. !🙂
For C11- C14 = 100uf - You can use Pana FC.
For C15 - C18. You can get away with Wimas, Or more cool ones like BG, Paper in Oil etc.. I would have started with something cheap 🙂 And then maybe maybe upgrade with fancier stuff.....
35-50V for caps works..
18V transformer is also ok 🙂
/JZ
zei said:
Thanks Zei
What about the resistors and Trim pots? What wattage should I use? What, what, what?