Yes Tony ! Double barrelled front end and only few cut/jumper(copper trace) and voilà you get an universal Leach: 6 to 12 output and +/-50vdc up to +/-95 .
I remember building one few months after publication (Audio May 80). Have been replaced only 15years later.Would like to built a modern version.
i built a lot of those, the ones published in AUDIO magazine....i liked the sound a lot that i haven't looked at any other since....
The super leach is tops in the classAB side of things imho....😀
and i used to operate an electronics repair shop in the 80's to early 90's where i acquired close aquiantaces with lots of japanese amps of those days and several american types like the gas ampzilla, haflers and soundcraftsmen amps....
i always come back to the leach for serious listening...
Last edited:
Is there any reference to what the differences are between the leech amps, Is this GB for the low tim amp?
Hi,
I updated the schematics... now with 12 output transistors!
What size cap should C21 +C27 be? diameter + pin spacing??
\\\Jens
Where I can see shematic with part value?
Hi Everyone, I am new to this forum and I am interested in the Leach 12 output and regardless of the final design, I would like 4 PCB's.
Thank you Jens Rasmussen and others for the great contributions you all make, it is because of your designs that I am drawn back to DIY.
Thank you Jens Rasmussen and others for the great contributions you all make, it is because of your designs that I am drawn back to DIY.
Just curious, did this project die? I fixed a wiki page for this group buy and nothing has happened in months.
WIKI is in CLOSED state
😕 I do not think the interest in the 12 ouput is dead, the WIKI is inactive and needs to be reactivated by the originator. I belive it should say COLLECTING INTEREST or something like that. 🙁 I would not like to miss the GB on this jewel.
😕 I do not think the interest in the 12 ouput is dead, the WIKI is inactive and needs to be reactivated by the originator. I belive it should say COLLECTING INTEREST or something like that. 🙁 I would not like to miss the GB on this jewel.
The wiki is only copied from my work but noone seems to have the energy to fill in the facts as they are now.
I have sent the files for the 12 output amp to Advanced Circuits for a quote.
To get the per unit cost below 20 dollars U.S. we will have to order at least 80 units APPROXIMATELY.
PA has so kindly established the Wiki layout for this amp. If enough interest can come to be I or PA or maybe someone else would gladly put the group buy together. As PA stated many times fill in the information at the Wiki page and we will see how it goes. I want to build the 12 output amp but, at this time can not afford the cost of a 4 or 6 board order.
Remember when you decide that a large amp such as this is not going to be cheap. To do a really stand up job with adequate heatsinks and such is going to be north of 500.00. Just the power supply is going to be a nice chunk of cash.
I would like to see this happen.
Tad
To get the per unit cost below 20 dollars U.S. we will have to order at least 80 units APPROXIMATELY.
PA has so kindly established the Wiki layout for this amp. If enough interest can come to be I or PA or maybe someone else would gladly put the group buy together. As PA stated many times fill in the information at the Wiki page and we will see how it goes. I want to build the 12 output amp but, at this time can not afford the cost of a 4 or 6 board order.
Remember when you decide that a large amp such as this is not going to be cheap. To do a really stand up job with adequate heatsinks and such is going to be north of 500.00. Just the power supply is going to be a nice chunk of cash.
I would like to see this happen.
Tad
I need to clarify something. If just 25 units are ordered the price will be 20.00 each. If a new customer was to order the boards from Advanced Circuits they would qualify for the 500.00 first time buyer discount which we could donate to DIY Audio.
Tad
Tad
I thought this was for a 10 transistor board , is it 10 or 12 ? Please advise if this is going to happen and a new link to the Wiki would be heavenly ...
wiki under development
Leach amp clone Plus extension board Group Buy - diyAudio
Scroll to the bottom to enter your interest.
The board is scored to allow use as a 12 transistor amp or 6 by removing 6 device pad sets....or anything in between by leaving pairs empty...
The link above is for the WIKI
The Advanced Circuits 1st time buyer program is a great incentive...it works
Leach amp clone Plus extension board Group Buy - diyAudio
Scroll to the bottom to enter your interest.
The board is scored to allow use as a 12 transistor amp or 6 by removing 6 device pad sets....or anything in between by leaving pairs empty...
The link above is for the WIKI
The Advanced Circuits 1st time buyer program is a great incentive...it works
Last edited:
Hi All,
Just been to the wiki and I have some questions. Is the parts kit just the inductors, whats the second board for and are the links for BOM and Schematic broken or is it not completed yet?
Ah scratch broken link question, I see Eds post says the wiki is under development🙂
Just been to the wiki and I have some questions. Is the parts kit just the inductors, whats the second board for and are the links for BOM and Schematic broken or is it not completed yet?
Ah scratch broken link question, I see Eds post says the wiki is under development🙂
Last edited:
wiki under development
Greets,
We are all in this together. 🙄
The wiki has been changed to allow more to register.
capman, your interest has been added.
What you see when you log in is a "generic" form intended for development by placing all the info regarding a group buy. Well, that development of this wiki hasn't taken place yet. Feel free to step up and contribute.
I'm sure Tad will let us know when he has more info...
Greets,
We are all in this together. 🙄
The wiki has been changed to allow more to register.
capman, your interest has been added.
What you see when you log in is a "generic" form intended for development by placing all the info regarding a group buy. Well, that development of this wiki hasn't taken place yet. Feel free to step up and contribute.
I'm sure Tad will let us know when he has more info...
Last edited:
To all,
We are up to 50 boards at this time. We can get a fairly good price if we order this quantity. Is anyone willing to step up and order as a first timer to get the 500.00 discount from Advanced Circuits. I would be willing to handle the shipping logistics if no one else comes forward.
Those interested have placed their names on the Wiki page list.
This will be for the new Jens design with the 12 output devices or less if you choose to solder in a smaller quantity.
Please respond and we can get this going.
Tad
We are up to 50 boards at this time. We can get a fairly good price if we order this quantity. Is anyone willing to step up and order as a first timer to get the 500.00 discount from Advanced Circuits. I would be willing to handle the shipping logistics if no one else comes forward.
Those interested have placed their names on the Wiki page list.
This will be for the new Jens design with the 12 output devices or less if you choose to solder in a smaller quantity.
Please respond and we can get this going.
Tad
Ok, I am in for 2 sets. I had dealt with Advanced Circuits before hence cant get the first time discount. 🙁 Sorry guys.....
Please.... the wiki page has someone messed up (I have fixed some of it) and right now people are signing up for something I can't read what it is. The responsible person here must change the wiki page so it reflects the offer. Where are the facts? Please fix this basic facts as fast as you can.
Should I take over?
Should I take over?
some facts...some questions
Thank You, P-A, the list looks much nicer 😉
the board is ~30 cm long (11 5/8"); consider your heatsink/case arrangement
85 V rails will provide ~300W output
Jens' last .pdf rendering is in Post 37. I think the 6X/6X revision took place after this.
I also have used the Adv. Circ. 1st time purchase offer. I can't do it again. It was painless.


For anyone willing to consider it, there will likely be some discussion between Adv. Circ. and themselves to resolve any issues they may find with the board, before fabrication. That is normal, and a good thing.
Question for Jens: Are tap locations available on the board to run a regulated front end?
For Jens & all: Do the PS caps NEED to be on-board? Off board gives greater flexibility. You comments, please.
Thank You, P-A, the list looks much nicer 😉
the board is ~30 cm long (11 5/8"); consider your heatsink/case arrangement
85 V rails will provide ~300W output
Jens' last .pdf rendering is in Post 37. I think the 6X/6X revision took place after this.
I also have used the Adv. Circ. 1st time purchase offer. I can't do it again. It was painless.



For anyone willing to consider it, there will likely be some discussion between Adv. Circ. and themselves to resolve any issues they may find with the board, before fabrication. That is normal, and a good thing.


Last edited:
Hi Ed,
Go here for the placement and pads:
www.noermoelle-rasmussen.dk/DIYaudio/Leach_ver_1.03.12_placement.pdf
Yes there are pads to connect a regulated supply for the frontend.
Yes the PS caps need to be on the board to provide the best possible dynamics...I tried with and witout and far prefer when some C is present on board.
\\\Jens
Go here for the placement and pads:
www.noermoelle-rasmussen.dk/DIYaudio/Leach_ver_1.03.12_placement.pdf
Yes there are pads to connect a regulated supply for the frontend.
Yes the PS caps need to be on the board to provide the best possible dynamics...I tried with and witout and far prefer when some C is present on board.
\\\Jens
Last edited:
- Status
- Not open for further replies.
- Home
- Group Buys
- Leach Amp pcb group buy interest