Author Topic: Leach Super Amps (Read 33476 times)

JojoD818 · « **Reply #30 on:** Dec 11, 2003 at 09:41 PM »

Quote

can you do it just like sir tony did?

sorry, i can't...

JojoD

akyatbundok · « **Reply #31 on:** Dec 12, 2003 at 12:47 PM »

ok sir JojoD, i know the chassis is the hard part, as tony himself told me. for what he was charging at that time, i think it was a bargain. the problem though with custom built amps is that you won't know how it sounds until there's no turning back. which is why its always good to have a demo unit lying around somewhere.

tony's leach super amp

JojoD818 · « **Reply #32 on:** Dec 12, 2003 at 03:19 PM »

akyatbundok,

From what I have read, Tony is an avid amp collector, hence, has much valuable "ear" experience since he had his hands on tubes, solid state, and now the gainclone all of which have different designs. Tony has probably chosen the leach amp due to it's design topology and he has followed it since it's first version. I made the "smaller" version 4.5 amp because since it's introduction (1970s i think), many are still in love with their leach amps (frankly, so am I).

To sum it up, the leach amp, wether the super leach or it's smaller brother, is an excellent power amplifier. The word "no turning back" is not applicable to it since these amps are very good indeed and if you decide to build it or have it buiilt, you will surely be rewarded for many listeninig nights.

JojoD.

akyatbundok · « **Reply #33 on:** Dec 12, 2003 at 03:30 PM »

yes! just the kind of reassurance i need.

will chronicle the sourcing, building & listening... abangan! (might take long though)

JojoD818 · « **Reply #34 on:** Dec 12, 2003 at 03:46 PM »

Happy to have helped!

JojoD

akyatbundok · « **Reply #35 on:** Mar 25, 2004 at 03:03 PM »

as if there wasn't enough choices already, here's another one... a ready to assemble super leach amp... i took these pics when i brought in my 2 luxmans to joan2's place for repair, and last i heard he has fixed one already... he said the 60w/ch luxman can match the sound of the leach amp, except the 200w/ch super leach has much more power reserve, so i assume the leach retains its sound quality at high volume whereas my luxman kind of breaks apart when driven hard... too bad his last leach got sold already, would have been game for a shootout.

FASTBACK · « **Reply #36 on:** Sep 16, 2005 at 02:18 AM »

Sir

After I finished all my projects could you help me with this Leach Super Amp.

Thanks

blackmtx · « **Reply #37 on:** Sep 21, 2005 at 03:45 AM »

Sir, saan nyo po nabili yung mica capacitor nyo? thanks...

blackmtx · « **Reply #38 on:** Sep 24, 2005 at 03:16 AM »

Sir, mica capacitor I need, 390pf, 180pf, 47pf, 10pf

JojoD818 · « **Reply #39 on:** Sep 24, 2005 at 09:19 PM »

Tony,

tumutunog na ba? what's your idle current setting? tagal tagal naman nyan.

JojoD818 · « **Reply #40 on:** Sep 26, 2005 at 12:45 AM »

aha! mine is at 100ma now, before it was set to 200ma but the constant heat is bothering me. a better heatsink is really in order. but at 100ma it's still fine since I use the amp while working or doing pc work so it's most of the time at low levels.

i've heard other diyers at diyaudio use 250ma and they say it's really great! i wonder, with such huge heatsinks and a really really really stiff psu, why not try going up to 500mA?

now that's hot!

unfortunately, i also don't have the time to build another one of these marvels, but surely in the future it would make a great personal project indeed.

good luck on your amp sir

blackmtx · « **Reply #41 on:** Sep 27, 2005 at 02:32 PM »

Sir tony, I just want to upgrade my leach amp and super leach by changing those ceramics capacitor, Dr. leach recommends mica capacitor, and I'm planning to copy the pcb layout of jens, btw, sir ano na nangyari sa sample program ng ONsemi, kawawa naman ang mga diyer ng Pilipinas. buti na lang naka order pa ako ng mga power transistor 25 pcs each rail

blackmtx · « **Reply #42 on:** Sep 27, 2005 at 02:53 PM »

s2kov · « **Reply #43 on:** Sep 27, 2005 at 03:01 PM »

take your time!

i'm sure, pro na pro ang dating nyan!

Quote from: 2ny on Sep 25, 2005 at 08:15 AM

sorry, but this diy project is for me, no one commisioned me to do so i am doing it on my own time, besides i wanted to do it right! i have my sights on conrad engineering heatsinks after which the chassis follows.

when finished, it will have an idle current of 150mA at output stage for a quiscient dissipation of 15 watts, therefore this amp, will operate at about 2watts or less, class A for that bias level!

the conrad heatsinks will enable me to up the quiscient bias later should i find the need. but first i have to find them

blackmtx · « **Reply #44 on:** Sep 27, 2005 at 03:40 PM »

thanks sir tony, yes I paid $20.00 for the shipment. But when i get back to order again some samples, the website tells that this country cannot process. I cant post the image of my pcb layout , paano ba sir tony?

blackmtx · « **Reply #45 on:** Oct 02, 2005 at 05:26 PM »

Sir tony, the big capacitor in leach amp board is also imported or available here in Philippines? I need at least 1000uF/63V or lower capacitance but the same voltage. thanks

blackmtx · « **Reply #46 on:** Dec 10, 2005 at 05:02 PM »

Sir tony, jens' s leach amp PCB is very nice and good, thickier than PC motherboard, thanks for the freebies

,

blackmtx · « **Reply #47 on:** Dec 10, 2005 at 11:56 PM »

yes, downloaded already, although there are resistors to be defined, computations of short circuit protection.

blackmtx · « **Reply #48 on:** Dec 11, 2005 at 01:11 PM »

Sir tony, I' ll be using MJL3281A/MJL1302A and my x' former is 44-0-44V. Kay jens ba galing yung capacitor (10000 uF) nyo? At this time, I'm still looking for some parts like, fuse holder gaya sa inyo, silver mica(very costly), non polar capacitors . Thanks for the info, metal film resistor is available at alexan.

blackmtx · « **Reply #49 on:** Dec 13, 2005 at 08:42 PM »

Thanks sir tony...

blackmtx · « **Reply #50 on:** Dec 14, 2005 at 08:43 PM »

sir tony, I'll be using 44-0-44V, 20A, I don' t have the x' former yet by Pangilinan electronics enterprise. Planning to order silver mica, film capacitor, fuse holder at farnell.

blackmtx · « **Reply #51 on:** Dec 16, 2005 at 03:46 PM »

Sir tony, i didn't order yet, i'm still contemplating to use toroidal x' former. btw, what good preamp do I used in Leach amp? thanks...

blackmtx · « **Reply #52 on:** Dec 16, 2005 at 09:22 PM »

yes, sir tony, toroidal is very expensive it cost more or less 5,000 psos, at farnell rating 1kva,45-0-45V. I dont have any idea about tubes, even my instructor in electronics did not discuss about tubes, although, pwede nating pag aralan. the only thing I know about tubes, tube likes very low impedance to drive.

blackmtx · « **Reply #53 on:** Dec 19, 2005 at 09:38 AM »

Sir tony, you've got pm.

blackmtx · « **Reply #54 on:** Dec 19, 2005 at 10:39 PM »

next year na lng sir tony...

blackmtx · « **Reply #55 on:** Jan 08, 2006 at 09:59 AM »

Sir tony, thanks a lot...

blackmtx · « **Reply #56 on:** Jan 17, 2006 at 01:34 AM »

Sir 2ny, can I used Pb-free transistors?Thanks.

blackmtx · « **Reply #57 on:** Jan 17, 2006 at 10:28 AM »

MPSA56/MPSA06(MPSA92/MPSA42) and MJE350/MJE340

odyopayl · « **Reply #58 on:** Jan 17, 2006 at 10:59 AM »

Quote from: blackmtx on Jan 17, 2006 at 01:34 AM

Sir 2ny, can I used Pb-free transistors?Thanks.

HI, Pb-Free is just an environmental issue in Semiconductor Industries. Before plating uses Sn/Pb combination now Pb was already banned they are using either pure Sn (tin) or Silver/Gold combi some high-end products use Pt (Platinum) for any plating of lids of any IC or Transistor.

Function are not affected by Pb-free as far as i'm concern.

rascal101 · « **Reply #59 on:** Jan 17, 2006 at 11:02 AM »

Quote from: odyopayl on Jan 17, 2006 at 10:59 AM

HI, Pb-Free is just an environmental issue in Semiconductor Industries. Before plating uses Sn/Pb combination now Pb was already banned they are using either pure Sn (tin) or Silver/Gold combi some high-end products use Pt (Platinum) for any plating of lids of any IC or Transistor.

Function are not affected by Pb-free as far as i'm concern.

Yes, this is specially true in Europe. The directive is in FY 2006 products shipped should be lead free.