• These commercial threads are for private transactions. diyAudio.com provides these forums for the convenience of our members, but makes no warranty nor assumes any responsibility. We do not vet any members, use of this facility is at your own risk. Customers can post any issues in those threads as long as it is done in a civil manner. All diyAudio rules about conduct apply and will be enforced.

Jens Rasmussen Leach clone group buy

Tad, Look at the first rendering Jens posted today. There is a pair of pins for a connector just to the right of the red box cap near the center of the board. That's for the thermal compensation (diode boards). In the second rendering it looks like there's a jumper cap on one pin.

Thanks for the work Jens. What is the pin pitch on that connector? Is that a string of the same ones used on PSU2.2? Protoype testing volunteers?
 
Bob,

The pitch of the connectors is 200mil = 5.08mm.

It is possible to connect some of these types into rows, so whe using 4 pin types you must connect these and arrive at at combined length of less than 60 mm to fit on the board - can this be done with the parts you have in stock?

\\\Jens
 
I added the same type connector to the power board - Front end still in the same design as the power stage.

Should I start on the stardard type output stage now, or make data ready for the front end board?

\\\Jens
 

Attachments

  • super leach ver 5.14 (large).jpg
    super leach ver 5.14 (large).jpg
    59.1 KB · Views: 935
Hi Jens,
Is there room between the 0.2inch pin pitch to insert another pin to allow 24way 0.1inch pitch? Each pair (one small dia hole and one larger dia hole) would be on a common pad.
This would allow either the 12way 0.2inch screw terminal block as you have shown
or
a 24way pin header to be soldered in and this could be ribbon cabled or direct plugged in using paralleled pins to reduce contact resistance.
sort of like a mother and daughter board.
 
I second that proposal. Let's make some proto boards of what we have now and go from there. I can smell the smoke already. Here comes another Leach project. Thanks Jens for your involvement in this endeavor. And thanks to all who will make the boards affordable by participating in the group buy. And anyone else I left out. DIYaudio of course. Tad

I became involved in this forum to gain knowledge on a supject I knew absolutely nothing about. Through all of your efforts I have learned much, though I still have a long way to go. Thanks
 
How would you like this?

Hi,

How about this:

1) Common front end for both standard and super amp.
2) Two different output stage boards, one common, and one to be added for the super amp option.

The only problem is that the common type will have to be reconfigured if an "opgrade" to super amp is needed.

I have almost data for this solution ready.

Let me know

\\\Jens
 
Jens, The common frontend will have to be reconfigured or the common output stage?
A really good cascode frontend designed with the cascode output would be nice. Then no changes would have to be implemented to build the 16 device amplifier.

One small note. When Dr. Leach designed this amp he set the feedback at approximately 8mhz. Are the current mjl4281 devices with 30mhz appropriate for this build. They seem to work quite well with the 10 transistor version I just want to head off any potential obstacles.

Have a nice weekend all. Tad:smash: :smash:
 
Hi All,

Sorry for the delay.

I have now made the extended version also, and prepared a production panel.

I have a bit of room in the top right corner (8.6 * 6.5 cm), what shall we put here? - I thought about maybe a front end regulator ?? let me know

\\\Jens
 

Attachments

  • super leach ver 7.2 (medium).jpg
    super leach ver 7.2 (medium).jpg
    80.9 KB · Views: 829
Front end regulator board

A regulator for the front end would be a great addition to this setup!
What is the cost for a complete panel? That might be a good way to offer them to people that are interested in both output stage types.
It might also save them some money.
Thanks,
Donovan