Author Topic: Leach Super Amps (Read 33452 times)

joan2 · « **on:** Sep 01, 2003 at 02:10 PM »

these 250watt ave. continous power into 8ohm monster is hailed as one of the best sounding amps available to diy'ers...i have the magazine copy of the article and some spare boards to any one interested in building these amps..this amp can definetly give tube amps a run for the money at literally lower cost.....any one interested can email me at [email protected] or [email protected] or can call me at 6438957....tony

john5479 · « **Reply #1 on:** Sep 02, 2003 at 12:03 AM »

sir,

How about the transistors needed for this project? would you know where I can get them ?

joan2 · « **Reply #2 on:** Sep 02, 2003 at 06:58 AM »

you can get them for free thru onsemi's samples program, but get only what you need lest they become suspiciuos......these are the transistors that are required:
1. MJ15003/15004 as outputs 16 for stereo
2. MJE15030/15031 as drivers
3. MJE340/3450 as VAS
4. MPSA06/56 as small signal transsitors
on semi used to be motorola semiconductors.....
here is a good link to follow:
http://www.diyaudio.com/forums/showthread.php?s=5137a992d7be07eded0168022a1faef7&threadid=6075&highlight=leach+amps
and another:
http://www.diyaudio.com/forums/showthread.php?s=5137a992d7be07eded0168022a1faef7&threadid=7526&highlight=leach+amps
i would like you to meet prof. leach:
http://users.ece.gatech.edu/~mleach/superamp/
http://users.ece.gatech.edu/~mleach/lowtim/
http://users.ece.gatech.edu/~mleach/lowtim/faq.html

joan2 · « **Reply #3 on:** Sep 03, 2003 at 01:17 PM »

i have some transistors in stock availble for those who want to build this project....

joan2 · « **Reply #4 on:** Sep 17, 2003 at 04:52 PM »

anyone?

how about a hiraga 20 watt class A amp? this is easier to do....

treblig · « **Reply #5 on:** Sep 18, 2003 at 02:15 PM »

sir joan2

the tel. no. you posted is not working , kindly check. i am trying to contact you , i am interested to build one.

joan2 · « **Reply #6 on:** Sep 18, 2003 at 04:42 PM »

baka busy sa internet pero that is the number....
i must forewarn those interested to build this amp that this project is not for the newbies as a mistake here can cost you a lot of money, solid state amps unlike tubes, require more caution and a lot of know-how....i recomend that you study carefully the links i have posted, and i am here to assist you in any thing that you do not understand...

homer · « **Reply #7 on:** Sep 26, 2003 at 09:30 PM »

sir joan, i'm currently building a douglas self amp. may suggestion b kayo on how to fabricate a quality pcb?

joan2 · « **Reply #8 on:** Sep 28, 2003 at 12:57 PM »

since i was out of the country for a long while, i lost contact with those that deal with these pcb fabs. you can go to alexan for the photographic method, making pcbs is single quantities can be expensive, i use silksceen method....

hunter · « **Reply #9 on:** Sep 29, 2003 at 10:17 AM »

hello all!

I found an IC "TDA7265" with 25W total power. You can search it on the net. Schematics are included. This is a lot more easier to build. Recommended for those who have small room or space. If you want more power try to make it in bridge to deliver upto 50W power. Or try the TDA7295 with 80W of full power.

This IC are the one used by generic speaker manufacturer. Try openning those speaker you will see.

Regards,

GC · « **Reply #10 on:** Sep 29, 2003 at 11:36 AM »

Quote from: hunter on Sep 29, 2003 at 10:17 AM

hello all!

I found an IC "TDA7265" with 25W total power. You can search it on the net. Schematics are included. This is a lot more easier to build. Recommended for those who have small room or space. If you want more power try to make it in bridge to deliver upto 50W power. Or try the TDA7295 with 80W of full power.

This IC are the one used by generic speaker manufacturer. Try openning those speaker you will see.

Regards,

Hello! I think these are gainclone alternative IC's. Are these available in manila?

Garp · « **Reply #11 on:** Sep 29, 2003 at 05:00 PM »

the TDA7294 (100w) is available locally.

GC · « **Reply #12 on:** Sep 29, 2003 at 05:29 PM »

Quote from: Garp on Sep 29, 2003 at 05:00 PM

the TDA7294 (100w) is available locally.

This could be the right chip i'm looking for. Anyways, i'm currently looking at diy amps at sound.westhost.com. The amplifier projects lack protection circuits but these circuits can easily be incorporated as modules.

I'm currently doing the foil pattern for the Project 3A 60-80 watt amplifier. The schematics for this amp is very simple and the components are few.

Pwede na ito for people who won't be needing a 100+ power, but want to try out transistor based amplifiers.

Pero meron din naman scaled down version ang Super Leach Power Amp, 100 watts with foil patterns available for free sa internet.

Sir Joan2, thanks for the info regarding DIY Audio. Nakita ko na yung infos na hinahanap ko.

joan2 · « **Reply #13 on:** Sep 30, 2003 at 06:37 AM »

GC, that is a good info, can you please post here where we can buy this chip, in RAON? thanks

joan2 · « **Reply #14 on:** Oct 03, 2003 at 07:06 AM »

i have with me 6pcs fr4 double sided boards for this power amp with most components already soldered in, in case any body's interested...thanks

joan2 · « **Reply #15 on:** Oct 06, 2003 at 09:09 PM »

i have xerox copies of the audio magazine article by prof. leach, i can send you hardcopies thru tha mail, just call me at 6438957...thanks

akyatbundok · « **Reply #16 on:** Dec 09, 2003 at 05:58 PM »

beauty, eh? to the sirs who have built both amps, how does your leach amp differ in sound from your gainclone? which is better?

i thought my amp had big caps w/c is beer can-sized... but this one is beer mug-sized!!

JojoD818 · « **Reply #17 on:** Dec 10, 2003 at 12:50 AM »

Aha, now we're talking about amps with attitude...

I have built and listened to Rod Elliot's P3A, Prof. Leach's Low TIM Amp (smaller version of the Super Leach), and those wonderful gainclones. They are all very good, which one you build is up to you....

BTW, someone (i forgot who) told me that ON Semi has stopped their samples program already, that's sad.

Good luck to all of you guys.

JojoD

jerix · « **Reply #18 on:** Dec 10, 2003 at 08:06 AM »

Quote from: joan2 on Sep 01, 2003 at 02:10 PM

..this amp can definetly give tube amps a run for the money at literally lower cost.....

soundz good!!

how much is your estimate sir? thnks

akyatbundok · « **Reply #19 on:** Dec 10, 2003 at 03:16 PM »

Quote from: jerix on Dec 10, 2003 at 08:06 AM

soundz good!! how much is your estimate sir? thnks

jerix, i've talked to mang tony about building one for me but he's already retired from the business and is into audio just as a hobby. problema kasi yung chassis kelangan pa fabricate or if DIY man masyado matrabaho gawin. sabi niya if i can find a chassis, the internals can be assembled easily. the super leach amp in the pic cost less than 10k but that was many years & inflations ago.

hmm... sir JojoD, which amp nga ba - super leach, leach low TIM, gainclone or hiraga class A? if ever a magnepan MMG happens to fall into my lap (i wish!!

), 250wpc can come in handy. but i like the simplicity of the gainclone... less parts, less points of failure.

JojoD818 · « **Reply #20 on:** Dec 10, 2003 at 08:45 PM »

Guys,

I really can't tell you which one to build. But in my case, budget was a major problem. Solution, build them one at a time, very slowly until I build them all and then I can compare them with each other. Not a very good solution but it works for me. I just can't stop tweaking/building amps. Though my wife doesn't approve everytime.

JojoD

jerix · « **Reply #21 on:** Dec 11, 2003 at 08:30 AM »

Quote from: akyatbundok on Dec 10, 2003 at 03:16 PM

the super leach amp in the pic cost less than 10k but that was many years & inflations ago.

hmm,, mahal din pala bro AKYAT--

thnx.

bro Jojo, kamusta na ginagawa mong amp? i dont know much about amps, pero may i ask, can this be compared with the WS preamp being talked about here bro? thnx

akyatbundok · « **Reply #22 on:** Dec 11, 2003 at 11:50 AM »

Quote from: jerix on Dec 11, 2003 at 08:30 AM

hmm,, mahal din pala bro AKYAT-- thnx.

yup, medyo... actually its alot less than 10k pero i dont want to post his price 10yrs ago kasi hindi na realistic yun sa ngayon. medyo inaawitan ko pa si sir tony kung pwede magpagawa. otherwise, a 2nd hand power amp with the same specs could cost around 15k sa buy&sell (yamaha m80), or up to 26k sa greenhills (yamaha mx-1).

JojoD818 · « **Reply #23 on:** Dec 11, 2003 at 02:06 PM »

Jerix,

WS preamps are line level preamps. Not power amps. Preamps are for signal conditionind and/or attenuation.

The 150W amp was delivered a week ago. Leiko wants to audition a gainclone which I am currently finishing now on a piece of wood

.

akyatmountain,

What if a stereo super leach amp can be realistically built for 11K? What would you do?

JojoD

akyatbundok · « **Reply #24 on:** Dec 11, 2003 at 03:01 PM »

Quote from: JojoD818 on Dec 11, 2003 at 02:06 PM

What if a stereo super leach amp can be realistically built for 11K? What would you do?

hmm... that's more than the gainclone but then again the specs are higher. can you do it just like sir tony did? he used gigantic caps & a transformer thats bigger than anything ive ever seen. and a brushed aluminum chassis to match? hehe... hirap gawin nung chasis.

now i have too many options: a gainclone, a super leach, a hafler, a tube amp... woohooo! ok talaga dito sa pinoydvd...

ok sa hobby pero di ok sa bulsa...

sebman · « **Reply #25 on:** Dec 11, 2003 at 03:05 PM »

Quote from: akyatbundok on Dec 11, 2003 at 03:01 PM

hmm... that's more than the gainclone but then again the specs are higher. can you do it just like sir tony did? he used gigantic caps & a transformer thats bigger than anything ive ever seen. and a brushed aluminum chassis to match? hehe... hirap gawin nung chasis.

now i have too many options: a gainclone, a super leach, a hafler, a tube amp... woohooo! ok talaga dito sa pinoydvd... ok sa hobby pero di ok sa bulsa...

pre para sa yo.. oks lahat.. malalim bulsa mo e.. hehehehe

iceman90a · « **Reply #26 on:** Dec 11, 2003 at 03:07 PM »

Quote from: akyatbundok on Dec 11, 2003 at 03:01 PM

hmm... that's more than the gainclone but then again the specs are higher. can you do it just like sir tony did? he used gigantic caps & a transformer thats bigger than anything ive ever seen. and a brushed aluminum chassis to match? hehe... hirap gawin nung chasis.

now i have too many options: a gainclone, a super leach, a hafler, a tube amp... woohooo! ok talaga dito sa pinoydvd... ok sa hobby pero di ok sa bulsa...

if it's just like what akyat said - you might get 2 orders

akyatbundok · « **Reply #27 on:** Dec 11, 2003 at 03:20 PM »

Quote from: sebman on Dec 11, 2003 at 03:05 PM

pre para sa yo.. oks lahat.. malalim bulsa mo e.. hehehehe

nyeheh... sayo ako uutang dahil mas malalim... ang karanasan mo sa audio.

akyatbundok · « **Reply #28 on:** Dec 11, 2003 at 03:38 PM »

Quote from: iceman90a on Dec 11, 2003 at 03:07 PM

if it's just like what akyat said - you might get 2 orders

iceman, on the lookout ka rin ba ng match para sa preamp? hehe tiyak galing niyan pre, inip na nga ako eh pero lapit na.

iceman90a · « **Reply #29 on:** Dec 11, 2003 at 03:54 PM »

Quote from: akyatbundok on Dec 11, 2003 at 03:38 PM

iceman, on the lookout ka rin ba ng match para sa preamp? hehe tiyak galing niyan pre, inip na nga ako eh pero lapit na.

tumitingin tingin din - di nga maka decide eh:

a) tube amp - MA B2 speakers ang kaya
b) power amp - for Audience 52 (di pa rin all tubes)

haayyy sana may pera para sa lahat, tsaka may lugar sa bahay..