Power Follower (P.Macura) some question? - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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 Search this Thread
Old 12th October 2005, 05:10 PM   #1
diyAudio Member
 
Join Date: Jan 2004
Location: Bulgaria
Send a message via ICQ to bezobraznia
Default Power Follower (P.Macura) some question?

Hello,
I finaly decide build Power Follower version from Pavel Macura with DoZ preamplifer on it:
Power Follower by Pavel Macura
But i have some question:
First of all, i suceed getting original IRFP350 (IR) and TIP142 (ST)
but there, in Bulgaria is no chance getting high (even middle level) capacitors
Is there any mod possible for parts of this sheme ?
What is proposal of trimer-pot, and how i have to set it?
Is it posible for power amount 15-17VAC, because i have that type transformer around?
Is it ok if i had a chance getting 2uF (or 2.2uF) capacitors instead of 2 x 1uF?
Is there any tolerance for replace passive parts with closest parameters?
And most importand what parts are on the "way of the sound" and i have to strive replacing them with better quality?

Thank you in advance!
Best reggards
Niki / BG
__________________
WELCOME TO THE WORLD OF HIFI
SE + FULLRANGE RULEZ!
  Reply With Quote
Old 12th October 2005, 05:33 PM   #2
Electrons are yellow and more is better!
diyAudio Member
 
peranders's Avatar
 
Join Date: Apr 2002
Location: Göteborg, Sweden
Blog Entries: 4
Most parts aren't extremely critical in order to get it working. Try to get similar parts. If you have come up with something I'm sure people here can tell you if it's OK or not to use them.
__________________
/Per-Anders (my first name) or P-A as my friends call me
  Reply With Quote
Old 12th October 2005, 06:53 PM   #3
PMA is offline PMA  Europe
Design engineer, consultant
diyAudio Member
 
PMA's Avatar
 
Join Date: Apr 2002
Location: Prague
Hi Niki,

regarding your questions:
- do you have any chance to buy IRFP240, 244?
- TIP142 can be replaced by NPN Darlington with collector current rated at least at 8A,
- the trim pot VR1 is set to obtain half supply voltage between collectors of Q2 and Q3,
- yes you can use 1uF capacitors in parallel,
- the circuit is quite tolerant to component changes, but ZD3V diode (BZX83 3V0, 0.5W), this must not be changed, see comments on my web page, that were recently added.

P.S. I have no PCBs by now, it would be necessary to start next production lot of 8 pcs at least, depends on interest.
  Reply With Quote
Old 12th October 2005, 07:47 PM   #4
PMA is offline PMA  Europe
Design engineer, consultant
diyAudio Member
 
PMA's Avatar
 
Join Date: Apr 2002
Location: Prague
Default Darlington replacement

You might try Sanken 2SD2390 as a Darlington.
  Reply With Quote
Old 12th October 2005, 10:11 PM   #5
diyAudio Member
 
Join Date: Jan 2004
Location: Bulgaria
Send a message via ICQ to bezobraznia
Uh... i feel so stupid...
i so, and so looking for a IRFP350 ... because i've read it in some other post that this is the best choice for Power Follower
BZX83 i dont finding but i find similar zener for 3V0 about 0.4-0.5W i think it will work ok
my ideia is to use not 2 x 1uF but 1 x 2uF capacitors
VR trim pots i find - many turns...
You don't say nothing about power supply?
I will search for 2SD2390's

I decide for PCB's - I will make two independant PCBs with chemical pencil and Fe2Cl3 - fully amater work LOL ...
for stereo and if amplifier is okay sounding to me after (i think) several future replace mods i think i will talk with my friends for collective order

Thank You and Best reggards from BG
Niki
__________________
WELCOME TO THE WORLD OF HIFI
SE + FULLRANGE RULEZ!
  Reply With Quote
Old 12th October 2005, 10:24 PM   #6
PMA is offline PMA  Europe
Design engineer, consultant
diyAudio Member
 
PMA's Avatar
 
Join Date: Apr 2002
Location: Prague
Do not forget to check voltage on that Zener in the real circuit, it must be between 3 - 3.3V.
2uF capacitor makes no problem.
For power supply, you should use 500VA transformer for 2 channels. About 28Vac rms secondary.
And you can make hand made PCB - this design does not change its properties with PCB much.
Trim pot - yes, I use 10 or 20 turn pot.
  Reply With Quote
Old 13th October 2005, 12:03 AM   #7
diyAudio Member
 
Join Date: Jan 2004
Location: Bulgaria
Send a message via ICQ to bezobraznia
Very fast answer Pavel, appraise that
Ok, i will check is everything ok with voltage

And for power supply if i have to buy some trafos, i think that best choice is two independant transformers - i really like more "3D soundung scene" thanks to independent power...
And also i have some big and oldiest (but working ok) Siemens 33000uF capacitors... maybe i will use following configuration:
Transformer 250VA -> fastrecovery diode bridge -> C-33000uF Siemens -> 5000uF (Tesla) -> 2200uF (another siemens) -> amplifier... Is this good configuration?

And i will try finding IRFP240 or IRFP244 from manufacturer International Rectifier , and will make sound tests with different transistors ...
Is this correct: only IRFP n-mos make difference on sound quality, but TIP142 - no?
__________________
WELCOME TO THE WORLD OF HIFI
SE + FULLRANGE RULEZ!
  Reply With Quote
Old 13th October 2005, 06:49 AM   #8
PMA is offline PMA  Europe
Design engineer, consultant
diyAudio Member
 
PMA's Avatar
 
Join Date: Apr 2002
Location: Prague
Regarding 3D soundstage, the most important is placement of speakers in your listening room. Keep them far from rear wall (at least 1.5m), if they are bookshelf speakers, put them on the stands. If your speakers were placed inside furniture or on a desk at the rear wall, you would never achieve 3D soundstage.
  Reply With Quote
Old 13th October 2005, 06:12 PM   #9
diyAudio Member
 
Join Date: Jan 2004
Location: Bulgaria
Send a message via ICQ to bezobraznia
hm... Pavel,
I've look at Your sheme and I think that Doz preamp is not so good choice for Power Follower... maybe he will give specific transistor sound to complette amp, but i don't want this.
Maybe some tube stage? Is it possible for You remake PCB for only Power Follower without doz-preamp on it, but with parts importand for connection Tube stage + Power Follower ? I mean that maybe PowFoll. will need some different capacitets or resistors or similar ... i really don't know...
Thank You in advance & best reggards!
Niki
__________________
WELCOME TO THE WORLD OF HIFI
SE + FULLRANGE RULEZ!
  Reply With Quote
Old 13th October 2005, 08:06 PM   #10
PMA is offline PMA  Europe
Design engineer, consultant
diyAudio Member
 
PMA's Avatar
 
Join Date: Apr 2002
Location: Prague
Tube stage would be excessively loaded by MOSFET Power follower input capacitance.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Pavel Macura's MOSFET Power Follower soundNERD Solid State 30 2nd November 2014 09:43 PM
Macura dispre with mosfet power follower? sopapo Solid State 10 8th May 2006 09:08 AM
Mosfet power follower (Pavel Macura) naim35 Solid State 8 22nd January 2005 10:51 PM


New To Site? Need Help?

All times are GMT. The time now is 03:31 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2