Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

PA Systems A forum for discussion of all parts of a sound reinforcement or DJ system: loudspeakers, mixers (desks) etc.

Konzert Amp & Speakers Website
Konzert Amp & Speakers Website
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 22nd December 2010, 03:19 AM   #1341
asia is offline asia  Philippines
diyAudio Member
 
Join Date: Dec 2010
hello all pinoy diy'rs,
sad to hear mr LEACH already died,
but his legend still lives,
i know PA ain the phils., the leach amp plays a big role in the said industry,
everybody knows every pinoy involve in PA must know WESTRACK amp,
surprisingly a leach cloned,
so leach is been there long long before,here.
besides many diy designs now readily available just one click and your there,
i maybe cannot mention it all,
but here some,
quasi,
bora,
apex ooow a lot,
also from another site,
but i will stop there,
maybe its time to share leach cloned here in the phils.,
and let interested diy enjoy the leach clone.
i know how pinoy technician need to keep a secret to catch costomer,
maybe its time to share,for it is the spirit here at diy audio,
everybody knows this
Leach SuperAmp Plans
we know this a very powerful design and open for improvement specially dealing with high power.
just help us how to handle parts replacement,and guide us upon building,
i know that this time,class d and class h is outpouring,
please let me/us experience the mother of all powerful amp diy in the philippines,
  Reply With Quote
Old 22nd December 2010, 04:54 AM   #1342
TonyTecson is offline TonyTecson  Philippines
diyAudio Moderator
 
TonyTecson's Avatar
 
Join Date: May 2003
Location: Palatiw, Pasig City
Konzert Amp & Speakers Website
hi asia,

prof leach was a teacher and audio designer in a class on his own, his designs are built by audio DIY'er all around the globe.....

i built my first super leach amp in 1984, a scaled down version using japanese output transistors, 2SC1079/2SC679 on rails of +/-63volts....and the full version a few years later....

i used that amp on a 4way speaker system using 15inch Westwell woofer, 8inch low mid, 4inch cone high mid, dome tweeter arrays.......

the sound was indeed fantastic, very clear mids and highs that is not tiring to listen to even at high volume levels, bass was fabulous, over all very clean sound.....

this leach amp is a high fidelity amplifier......sayang kung gagamitin lang sa PA.....

the secret, if you can call it as such is in the power supply....i used 47,000ufd electrolytics, a 35 ampere rectifier bridge and very heavy power transformers whose secondaries are wound bifilliar to exactly locate the center tap, about twice as heavy as other commercial power traffos....

for PA duties, the leach topology lends itself to class G operation for better efficiency....
__________________
planet10 needs your help: Let's help Ruth and Dave...http://www.diyaudio.com/forums/plane...ml#post5010547[B
  Reply With Quote
Old 22nd December 2010, 05:17 AM   #1343
asia is offline asia  Philippines
diyAudio Member
 
Join Date: Dec 2010
sir tony,
nice to hear you sir
i will quote what you said from another thread almost the same
yup...motorola dati bago naging on-semi, pwede kang gumamit ng MJL21193/MJL21194 kung pang bass....kung full range mas preffered ko yunng MJL1302/MJL3281....

yung leach amp magandang tumunog, sayang naman kung pang bass lang sya....pero pwede..
link
WestTRACK Amp
  Reply With Quote
Old 22nd December 2010, 05:19 AM   #1344
asia is offline asia  Philippines
diyAudio Member
 
Join Date: Dec 2010
i hope sir tony express this in english for the moderator
  Reply With Quote
Old 22nd December 2010, 05:26 AM   #1345
asia is offline asia  Philippines
diyAudio Member
 
Join Date: Dec 2010
another hint,
1000w possible @ 40pcs output?/channel
same thead
http://www.pinoydvd.com/index.php/topic,89268.30.html

all i have done are 250watter leach amps....leach amps are not tiring to listen to even at high volume levels...... Click the image to open in full size.

pang mobile ba? yes it is possible to do it, i have asked a friend to design a pcb for me using Leach's doubled barreled amplifier topology using 10 qauds of those ON-Semi devices, that's 40 transistors per channel output.

Last edited by asia; 22nd December 2010 at 05:30 AM.
  Reply With Quote
Old 22nd December 2010, 05:34 AM   #1346
asia is offline asia  Philippines
diyAudio Member
 
Join Date: Dec 2010
a rough scanning of doubled barrel diagram,
where to find original st(2n3439)(2n5415)
makes me think its hard to find(wala sa list ng alexan)
and where to find mica caps
  Reply With Quote
Old 22nd December 2010, 05:36 AM   #1347
asia is offline asia  Philippines
diyAudio Member
 
Join Date: Dec 2010
390pf
180pf
47pf
all mica,
a special notation not to use ceramic
,
so where to find?
  Reply With Quote
Old 22nd December 2010, 05:37 AM   #1348
asia is offline asia  Philippines
diyAudio Member
 
Join Date: Dec 2010
here what djk say about leach
Whats your view regarding parallel stage..."

The older MX2000 sounds better than the MX2000A, for what it's worth.

The Crest CA9 sounds better than those, it's class G (they call it class H, but it's linear, not a hard switch). I'm sure the OPA2604 vs the NE5532 makes a small difference, but the current limiting circuit QSC uses really makes them sound less than perfect. The dynamics are really poor. QSC uses a pair of adjustable load resistors on they output of the 5532, and depend on the current limit in the IC.

The Leach LSR&D 101 will kick either amp to the curb (with only 63V rails, two 20,000F caps, a 1KVA transformer, and three pair of MJ15011/12 per channel ). Driven slightly into clipping it still sounds cleaner than the QSC, and has a lot more slam in the bass. Funny how that works out, a 160W/8R hi-fi amp vs a 1KW/2R PA amp (the speakers used were a 2R load).
  Reply With Quote
Old 22nd December 2010, 05:40 AM   #1349
asia is offline asia  Philippines
diyAudio Member
 
Join Date: Dec 2010
leach vs. qsc
  Reply With Quote
Old 22nd December 2010, 05:41 AM   #1350
asia is offline asia  Philippines
diyAudio Member
 
Join Date: Dec 2010
another,
The QSC 2000 play a little bit louder in the midrange than the LSR&D 101, not much though. The Leach sound much cleaner in the highs, much tighter in the bass, and can actually hit harder and play louder in the bass.

Amplifier power ratings on the bench driving a resistor tell little about how an amplifier will drive a loudspeaker, you have to listen to them to really tell how they sound and what they can do.
  Reply With Quote

Reply


Konzert Amp & Speakers WebsiteHide 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

Forum Jump


New To Site? Need Help?

All times are GMT. The time now is 11:30 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki