Go Back   Home > Forums > >

Analog Line Level Preamplifiers , Passive Pre-amps, Crossovers, etc.

PO89ZB , an inline DC filter for SMPS wall warts . Preamps, HPA, Korg NuTube, etc
PO89ZB , an inline DC filter for SMPS wall warts . Preamps, HPA, Korg NuTube, etc
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools
Old 21st January 2021, 01:31 AM   #341
kasey197 is offline kasey197
The Dastardly Dad of Three
diyAudio Member
 
Join Date: Sep 2009
PO89ZB , an inline DC filter for SMPS wall warts . Preamps, HPA, Korg NuTube, etc
Quote:
Originally Posted by Mark Johnson View Post
Excellent! Please tell members here the voltage dropped (the reduction) from input to output of your cap multiplier, so they can decide whether it would be acceptable in their own application.
That's a good point - I tried a number of logic level mosfets. The one with the lowest drop was the IRL640. With this mosfet, at a load of 1A, the voltage drop was about 2.5V. That total drop includes some (0.3V?) dropped across the passive filter too....
The schematic i used was (post#51): Mean well vs generic power adapter vs audio oriented smps

Quote:
Originally Posted by Mark Johnson View Post
You might also consider uploading the Gerber files of your design, so that other builders can order PCBs and try it out for themselves.
Built mine on veroboard!
Attached Images
File Type: jpg capmultiplier.jpg (617.0 KB, 228 views)
  Reply With Quote
Old 21st January 2021, 02:59 AM   #342
longspeak is offline longspeak  United States
diyAudio Member
 
longspeak's Avatar
 
Join Date: Sep 2015
Location: Colorado
PO89ZB , an inline DC filter for SMPS wall warts . Preamps, HPA, Korg NuTube, etc
Thanks for the book links Mark, I love the subtitles "A Handbook of Black Magic" and "Advanced Black Magic" .

Very good point about the ground being noisy in a poor setup preventing meaningful measurements. I used a differential configuration (pin 2 to PSU+ and 3 to PSU- on an XLR, using blocking caps in both) to feed the ADC it seemed to help reduce common mode noise. I just got the boards from konst so I'll get a couple of filters built for experimenting.
  Reply With Quote
Old 23rd January 2021, 12:39 AM   #343
music2myear is offline music2myear  Canada
diyAudio Member
 
Join Date: Jul 2018
Has anyone installed this circuit inside the Korg Nutube B1 pre- amp case or is this a no no? thanks
  Reply With Quote
Old 23rd January 2021, 01:22 AM   #344
elwood625 is online now elwood625  United States
diyAudio Member
 
elwood625's Avatar
 
Join Date: Jan 2013
Location: Elkhart Lake, WI
I've installed it inline with my B1 Korg Balanced version, works very,very well! Mark Johnson even suggested using two in series, I just finished another to try that as well. The B1 Korg is exactly what this filter is for, I have seen external versions inline, and the filter installed inside the enclosure with the B1 Korg.
  Reply With Quote
Old 23rd January 2021, 02:33 AM   #345
music2myear is offline music2myear  Canada
diyAudio Member
 
Join Date: Jul 2018
Thanks, reading and seeing in in a small external box but no images of it actually in a Korg case got me thinking maybe there is a reason that I am not seeing . cheers
  Reply With Quote
Old 23rd January 2021, 06:40 AM   #346
safesphere is offline safesphere  United States
diyAudio Member
 
Join Date: Oct 2014
Location: Kansas City
I'd love to get a couple boards for my NuTube preamp. What is the best way of getting them? Is there some sort of a group buy or does anyone have extras? I'dbe glad to pay my share. Thanks!
  Reply With Quote
Old 23rd January 2021, 07:44 AM   #347
ClaudeG is offline ClaudeG
diyAudio Member
 
Join Date: Jan 2015
Quote: Has anyone installed this circuit inside the Korg Nutube B1 pre- amp case or is this a no no? thanks

It is a YES YES!

Absolutely recommended and no problem whatsoever to be in the same casing.
Tried daisy chaining 2 but (perhaps as...) my B1 Korg is already tweaked re PS (low ripple PS + 2200uF caps), it made no real difference - but of course always worth a try.

Next step is to try Mark's enhenced version with the better caps and daisy chaining aswell. Whatever is best will come in the casing permanently with my B1 Korg.

Mark's filters are really good and nonexpensive, it is IMHO always worth to build a few more: you will always find an application sooner or later and of course you can experiment a lot of combos that way.

Have fun

Claude
  Reply With Quote
Old 23rd January 2021, 08:02 AM   #348
SuppersReady is offline SuppersReady  United Kingdom
diyAudio Member
 
SuppersReady's Avatar
 
Join Date: Oct 2002
Location: UK
PO89ZB , an inline DC filter for SMPS wall warts . Preamps, HPA, Korg NuTube, etc
Quote:
Originally Posted by safesphere View Post
I'd love to get a couple boards for my NuTube preamp. What is the best way of getting them? Is there some sort of a group buy or does anyone have extras? I'dbe glad to pay my share. Thanks!
Hi safesphere,

I have several boards left over from a recent order. Please pm me with your address and I'll let you know the shipping cost. The boards are free.
__________________
A poor life this if, full of care
We have no time to stand and stare.

Last edited by SuppersReady; 23rd January 2021 at 08:24 AM.
  Reply With Quote
Old 23rd January 2021, 08:09 AM   #349
SuppersReady is offline SuppersReady  United Kingdom
diyAudio Member
 
SuppersReady's Avatar
 
Join Date: Oct 2002
Location: UK
PO89ZB , an inline DC filter for SMPS wall warts . Preamps, HPA, Korg NuTube, etc
Quote:
Originally Posted by music2myear View Post
Has anyone installed this circuit inside the Korg Nutube B1 pre- amp case or is this a no no? thanks
I'll be installing the filters inside the nutube case when the bench is clear of its current project. The plan is to use the slots in the sides of the case for mounting them without having to drill any holes.
__________________
A poor life this if, full of care
We have no time to stand and stare.
  Reply With Quote
Old 23rd January 2021, 08:24 AM   #350
SuppersReady is offline SuppersReady  United Kingdom
diyAudio Member
 
SuppersReady's Avatar
 
Join Date: Oct 2002
Location: UK
PO89ZB , an inline DC filter for SMPS wall warts . Preamps, HPA, Korg NuTube, etc
Which leads me to another thought. The plan is to permanently install these filters in all of my current preamps (AKSA Lender, B1K, ACP+, Starving Student x 2). At some point in the near future I aim to put together a linear power supply to compare with the SMPS.

Is there any issue with using a linear power supply with these filters in circuit? I can't see that there would be, but I'm no expert in these matters.
__________________
A poor life this if, full of care
We have no time to stand and stare.
  Reply With Quote

Reply


PO89ZB , an inline DC filter for SMPS wall warts . Preamps, HPA, Korg NuTube, etcHide this!Advertise here!
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Korg NuTube B1 guide 6L6 Pass Labs 8 14th October 2020 07:59 AM
Korg Nutube B1 Pre-Order Q&A Jason The diyAudio Store 33 14th October 2020 07:55 AM
Korg Nutube pmoyle111 Tubes / Valves 6 24th April 2020 11:41 PM
Korg NuTube is now available online pmillett Vendor's Bazaar 156 24th December 2019 12:33 AM
WTB: Firstwatt Korg Nutube B1 (or just PCB) Brzzl Swap Meet 2 4th September 2019 10:54 AM


New To Site? Need Help?

All times are GMT. The time now is 04:53 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio
Wiki