LuDEF

[grataku]

Hi Zen,
its probably an asked and anwered but does your LuDef board work with the xrk971 LU1014D adapter board? I mean is it a straight solder in fit?
thx

 

[Zen Mod]

nope

Boyz made that afterwards, for other purposes

of course, it can be used with my LuDEF pcbs, allowing montage of both channel pcbs flat on heatsink

in which case there is no need for L or T brackets, for channel pcb mounting

in fact , for that , you can mount LU in older - clamping way , outboard (of pcb) and use short wires to connect it

 

[grataku]

@xrk971 et.al.
is there any way to include the necessary flexibility in your boards to make it work in the LuDef board? Or to make a bespoke version for that?
I would definitely want to mount the LuDEF board flat on the heatsink.

 

[nautibuoy]

It shouldn't be that difficult to mount the device on one of X's carrier boards and hook it up with some wires - it's what I'm planning to do.

 

[Zen Mod]

all roads are leading to Rome

🙂

 

[grataku]

I prefer the neat and wireless connection for semiconductors. 😉

 

[xrk971]

@xrk971 et.al.
is there any way to include the necessary flexibility in your boards to make it work in the LuDef board? Or to make a bespoke version for that?
I would definitely want to mount the LuDEF board flat on the heatsink.

The necessary flexibility could be as simple as 3 pieces of 2in long 18ga silicone wires from the TO-247 adapter board to the main amp PCB.

The adapter has an on board gate snubber resistor. I have used it with 6-8in of flying leads with no issues with oscillation on the LuFo. I have also used flying leads on at least 7 other amps, no issues. I would say that the advantages of having remotely mounted output devices in terms of flexibility and ease of use to allow more mounting options to heatsinks, far outweighs any nagging concerns of amp stability or oscillations.

If you still have concerns, consider the masterpiece designed by Mr Pass - the Adcom GFA555 - all outputs (16 I believe) on flying leads to a remotely located single main amp PCB.

 

[nautibuoy]

I prefer the neat and wireless connection for semiconductors. 😉

Always my first choice too but necessity is the mother of invention 🙂

 

[TungstenAudio]

We now officially have too many choices for LU1014 device amplifiers! 😉

I only have so many line level signal transformers to work with here. There are still the Cinemag CMOQ-4LPC that I originally got for the SissySit. Then there are the Jensen JT-123-FLPCH that I got for the peasant version of the Singing Bush, still unassigned to the PCB.

And just to make things interesting, I also have a pair of Lundahl 1540 line input transformers. Question on these is, would they be suitable as a transformer gain stage, similar to the others mentioned?

 

[Zen Mod]

...... Lundahl 1540 line input transformers. Question on these is, would they be suitable as a transformer gain stage, similar to the others mentioned?

yes

also classic repeater coil

http://www.lundahl.se/wp-content/uploads/datasheets/1540.pdf

 

[TungstenAudio]

Excellent!
So the Cinemag can stay with the SissySit R.3, and the Jensen with the Singing Bush. I can make an adapter board to fit the Lundahl onto the LuDEF PCB.
🙂

 

[chromenuts]

@Tungsten

My Jensen’s ended up on perf-board...well, I actually have a second pair and two pair of Cinemags

Point being...with ZMs help in the KISS thread I have them “transportable”...currently nestled in my DCB1

Maybe a pcb with molex or other type of connectors to allow swapping transformers in and out of various circuits is a worth while endeavor?

Edit: Seems you are already on same page...still, would be cool for Jensens snd Cinemags

 

[PRR]

Excellent news. Now a chance for more Serbian newspaper....

Lots available. Serbian Newspapers : Serbia News Online

Or do you have a Serbian puppy who can only be trained on physical Serbian newspapers?

 

[Zen Mod]

I'm only having available worst yellow print, available from my Mom's neighbors

I'm still buying books, but didn't bough Newspapers or Magazine in years ......

best paper for wrapping is multilanguage printer manuals ....... but getting short with these ..... so time again for neighbor stash 🙂

 

[grataku]

The necessary flexibility could be as simple as 3 pieces of 2in long 18ga silicone wires from the TO-247 adapter board to the main amp PCB.

or an option for a narrower 3pin header that matches the LuDEF board. So one can solder a wider or narrower header as needed.
I m just saying since this thing is in the design stage why not?
Got forbid one should get it the way of wire lovers. 😉

 

[xrk971]

You could use needle nose pliers to bend the current pins inwards to match easily enough. Or solder 3 resistor leg trimmings bent to correct width directly to the board. Making a new board to keep the spacing of the LU1014D (TO-252) as is, is not something we are going to do for this GB. You are welcome to make your own layout though.

 

[Zen Mod]

@grataku

look again at LuDEF pcb

how you think is possible to arrange anything off board , without using wires?

as is, on original pcbs, I decided that simply extending LU leads (say leftower legs of 3A diodes) is safer than bending them; that, just to illustrate what I'm finding more important - do not mess too much with tiny part, mess with everything else

 

[grataku]

ZM,
It's hard without the boards in hand. I have some idea and I will try to figure it out once I get them. I PM'd you earlier.

 

[Zen Mod]

I'm late with correspondence, trying to catch up

 

[grataku]

No worries ZM.
Well worth the wait!