Amp Camp Amp - ACA - Page 73 - 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 14th January 2013, 10:31 PM   #721
diyAudio Member
 
Danger Mouse's Avatar
 
Join Date: Nov 2011
Location: beautiful Oberpfalz Bavaria
Yes its Block trafo from reichelt.

I take the 50VA 24V version. This gives me ca. 30V unregulated Rails.
Because i want to regulate the voltage like in zen var. 3 --> this is the next step
In the moment i burn the voltage down with resistors to desired level.
Works really well but resitors run a little bit hot.

If you would do it without active regulation, probably 15V secondary should be ok.

correct me if i`m wrong ---but this should give ca. 19V at the supply

greets alex
  Reply With Quote
Old 15th January 2013, 12:03 PM   #722
diyAudio Member
 
JRKO's Avatar
 
Join Date: Dec 2003
Location: U.K.
Send a message via AIM to JRKO
Question for you more technical types:

My vanilla ACA will be driving 109dB/W/m horns and I'll be using Lpads on the speaker level to bring them in line with the the bass output. I also need a vol pot for gain matching. What pot value should I use 50k/100k etc etc?

tnx chaps

James
__________________
In the interests of full disclosure JRKO = James Rupert Kingsley Osborne. And yes, my parents will pay for it when I choose their retirement home
  Reply With Quote
Old 15th January 2013, 12:47 PM   #723
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
lowest ; you didn't read last severalposts ?

10K

btw - if you're feeding just one way with ACA , L-pads are redundant (and bad for sound) , having pot in front of ACA
__________________
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 15th January 2013, 01:44 PM   #724
diyAudio Member
 
JRKO's Avatar
 
Join Date: Dec 2003
Location: U.K.
Send a message via AIM to JRKO
Aw rats. I searched 100k, 50k & 25k but not 10k!! tnx ZM

LPads were recommended by Pano but will be the fixed (calculated value) type

now to find a good stereo 10k pot
__________________
In the interests of full disclosure JRKO = James Rupert Kingsley Osborne. And yes, my parents will pay for it when I choose their retirement home
  Reply With Quote
Old 15th January 2013, 01:58 PM   #725
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
repeat : if you have pot in front of ACA , you don't need attenuation right in front of driver

any sort of L-padding ( variable or fixed ) will kill the grunt

try , listen and then decide
__________________
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 15th January 2013, 02:51 PM   #726
diyAudio Member
 
JRKO's Avatar
 
Join Date: Dec 2003
Location: U.K.
Send a message via AIM to JRKO
Quote:
Originally Posted by Zen Mod View Post
btw - if you're feeding just one way with ACA , L-pads are redundant (and bad for sound) , having pot in front of ACA
when you say 'one way' do you mean full range? because my ACA will drive highs and another amp the lows?
__________________
In the interests of full disclosure JRKO = James Rupert Kingsley Osborne. And yes, my parents will pay for it when I choose their retirement home
  Reply With Quote
Old 15th January 2013, 02:54 PM   #727
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
I meant as you wrote - one amp (channel) - one driver

having two attenuators in chain is same as having two steering wheels in car ; leave one which is less influent ( in a bad way)

in car - leave either your , or wifie's

(depending who's better driver)

__________________
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; 15th January 2013 at 02:57 PM.
  Reply With Quote
Old 15th January 2013, 02:57 PM   #728
diyAudio Member
 
JRKO's Avatar
 
Join Date: Dec 2003
Location: U.K.
Send a message via AIM to JRKO
Oh, okay.

Pano's reasoning was this - "Horns are very efficient. That means all the hiss, hum, buzz, rizz, etc. that you don't notice on normal speakers will be plenty obvious on the horns. Dropping the horn's level 6-12dB will get the amp's output up out of the dirt. Yes, you'll need more power, but that's rarely a problem in domestic settings."
__________________
In the interests of full disclosure JRKO = James Rupert Kingsley Osborne. And yes, my parents will pay for it when I choose their retirement home
  Reply With Quote
Old 15th January 2013, 05:00 PM   #729
bcmbob is offline bcmbob  United States
diyAudio Member
 
Join Date: Dec 2009
Location: Bay City, Michigan
This pot is very good and preferred over the Alps Blue by many users. I consider it a real bargain. It is not top build quality but the performance is excellent.

DACT Type 21 Stepped Attenuator
__________________
Bob M.
"Arrange Whatever Pieces Come Your Way."
  Reply With Quote
Old 15th January 2013, 05:47 PM   #730
diyAudio Member
 
JRKO's Avatar
 
Join Date: Dec 2003
Location: U.K.
Send a message via AIM to JRKO
I've gone with this one - 500K Tocos Cosmos RV24 Stereo Potentiometer Hifi Collective - lesser than Nobles wtc but a step up from Alps Blue Beauty
__________________
In the interests of full disclosure JRKO = James Rupert Kingsley Osborne. And yes, my parents will pay for it when I choose their retirement home
  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
Amp Camp Amp #1 Nelson Pass diyAudio.com Articles 33 15th May 2014 04:52 PM
Amp Camp! Jason Site Announcements 2 30th June 2012 02:57 PM
Best D camp config for Tweeter amp Zero One Class D 0 24th February 2010 04:57 AM
better the Pass camp? rick57 Tubes / Valves 6 26th March 2005 06:04 AM


New To Site? Need Help?

All times are GMT. The time now is 08:14 AM.


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