"Solar" amp - diyAudio
Go Back   Home > Forums > Amplifiers > Pass Labs

Pass Labs This forum is dedicated to Pass Labs discussion.

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 31st August 2014, 03:34 PM   #1
diyAudio Member
 
Join Date: Sep 2010
Default "Solar" amp

I live "off the grid" in Panama. It is actually very comfortable, but that is another story. One result of this is that I have a HUGE 48V battery bank (800aHr @ 48V) just sitting there asking to be used as a power supply for an amp. Now "48" is really 50-58VDC most of the time. Since most of my listening is at night, we are talking seriously CLEAN DC power. The only caveat is that it is single ended power, not balanced. I was thinking of building a Zen 9 power amp and Bride of Zen preamp, but then I saw the jfet-boz which looks interesting and the Tube Zen (which i started a different thread about - does it exist?)
The rest of my system is a home made speaker system modelled on the JBL Paragon using 14" JBLs with a JBL horn mid/hi driver (Quite efficient) with CD player or mp3 player for input (I know, but I just couldn't transport all my vinyl and turntable, etc. to Panama.)
I have made my own pcbs in the past, but they are rather amateurish so being able to use existing pcbs would really help ( or a design I can wire ptp).
What about it? Any one done this? Any thoughts or suggestions?
Thanks for the input.
  Reply With Quote
Old 31st August 2014, 04:04 PM   #2
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
forget tube zen - you'll get better sound if you build , say , PLH with doubled outputs , or ZV2 with BOZ (Bride of zen)

look at articles page at FW site
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa...© by Mighty ZM

Last edited by Zen Mod; 31st August 2014 at 04:10 PM. Reason: mixed few things
  Reply With Quote
Old 1st September 2014, 03:13 AM   #3
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
If you run balanced outputs, it's pretty easy to build a direct coupled
amplifier with a single clean DC rail by creating a ground between two power
resistors in series from V+ to V-. As this ground will only have to conduct low
currents (not output current) it will work fine and you can get as much as 100
watts or so of output into 8 ohms.

  Reply With Quote
Old 2nd September 2014, 01:41 AM   #4
diyAudio Member
 
Join Date: Sep 2010
I have seen this done in low power situations (preamps, etc.) but did not think it could handle power amp applications.
  Reply With Quote
Old 2nd September 2014, 05:58 AM   #5
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
look at psu solution in Quad 306 and 606 (caps and divider)

that way you can make any FW amp

take F5 for instance

when that's clear , grasp how to make F5X with same ; in that case , when load is gnd-free , you don't need Quad's solution for small signal gnd , simple resistance divider is enough ........ and everything is DC coupled , as long you're using small signal gnd for entire signal chain
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa...© by Mighty ZM
  Reply With Quote
Old 2nd September 2014, 01:56 PM   #6
diyAudio Member
 
Join Date: Sep 2010
Quote:
Originally Posted by Zen Mod View Post
look at psu solution in Quad 306 and 606 (caps and divider)

when that's clear , grasp how to make F5X with same ; in that case , when load is gnd-free , you don't need Quad's solution for small signal gnd , simple resistance divider is enough ........ and everything is DC coupled , as long you're using small signal gnd for entire signal chain
That is interesting and I will definitely need to noodle through it at some point. For this project, however, I wanted to make a simple SE Class A amp like the Zen 9. The discussion of voltage dividers has me thinking about a different use for them. Since the jfet BoZ wants about 24V, SE, and I have about 50, could I run them from a divider? One would operate from +50 to +25 and the other from +25 to 0. Since the signal is NOT DC coupled, it shouldn't care and as long as each channel of the preamp is looking at 25VDC, it shouldn't care unless there would be some problem with the DC - ("ground") of one channel being attached to the DC+ of the other. I will try to work out a schematic of what I am talking about and post it, but it may have to be hand drawn. I know it seems off the wall, but the more I think about it, the more I think it might work. After all, nothing in the amp will have reference to EARTH ground. As long as I keep the signal "ground" separate from the power +/-, would it work?
  Reply With Quote
Old 2nd September 2014, 02:35 PM   #7
diyAudio Member
 
Join Date: Sep 2010
Default Schematic

OK here is schematic. (time expired to edit)
Attached Images
File Type: jpg dbl-jboz.jpg (339.9 KB, 209 views)
  Reply With Quote
Old 2nd September 2014, 02:38 PM   #8
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
it'll work , but ..... even if JFet Boz is tiny consumer , it's still better and cleaner solution to just shave positive rail , especially if you're going to use power gnd as gnd for your amp
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa...© by Mighty ZM
  Reply With Quote
Old 3rd September 2014, 02:01 PM   #9
diyAudio Member
 
Join Date: Sep 2010
Default Shaving the rail

Quote:
Originally Posted by Zen Mod View Post
it'll work , but ..... even if JFet Boz is tiny consumer , it's still better and cleaner solution to just shave positive rail , especially if you're going to use power gnd as gnd for your amp
OK, help me with the math here. This seems too simple. If the "sweet spot" is around 16V as NP said in another thread and it draws 5mA (another NP post) and I have 50V, 50V-16V=34V and 34V/5mA=6800R, so a 6.8k (?1/4W is fine?) resistor followed by a cap (?what size?) would drop my 50V to 16V for this preamp, correct? (would need to do one for each channel)
What am I missing???
Thanks
  Reply With Quote
Old 3rd September 2014, 02:20 PM   #10
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
P=U x I for resistor dissipation , then factor 3

however , it's better to make zenner follower series reg

with small NMos

if you need help for drawing it , say
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa...© by Mighty ZM
  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
Joe Rasmussen "Trans-Amp" - 40 Watt Transconductance "Current Amplifier" Joe Rasmussen Chip Amps 66 14th August 2014 06:22 PM
"WTB" "The Wire AMP" Class A/AB Power Amplifier based on the LME49830 with Lateral enantra Swap Meet 3 23rd December 2012 06:36 PM
Frugal Mono Full-range, Solar-Charging, Battery-Powered "Ashiko" Speaker xpheolix Construction Tips 2 13th June 2012 02:51 PM
"TECHNO"Amp building in progress-using "Iron Method" zox2003 Solid State 23 30th March 2010 08:42 PM
WTB: Focal & Audiom & Volts 11", 12", 13", 15" woofer gengis Swap Meet 0 17th March 2005 02:29 AM


New To Site? Need Help?

All times are GMT. The time now is 04:42 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