F5 Turbo Builders Thread

6L6

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Joined 2010
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SenorBarco,

The way the F5(t) works and is designed, you don't need to match the Jfets, but everything further down the chain falls into place if you do match them, or at least get them as close as you can.

Considering measuring for Idss takes merely a 9v battery and your meter, I agree with ZenMod's advice to play safe and match them as close as you can, it will pay dividends later when you bias it.


transistor_matching_jfet_idss.png
 
balanced input?

So first off thanks to all you dedicated members who have kept this community going for lurkers like me. I'm having trouble finding information that has certainly been discussed. I have a a 'fully balanced' DAC and preamp, going single ending means either using only half the digital hardware or adding a device to sum the signal.

What i really want a proper balanced input, is this feasible with F5T as 50W stereo (not 2 kit mono block) I know ba-1 and m2x are also options, also could start with an SE amp and change it up latter, same chassis and much of the same PS.

I'm still in the research and soldering practice phase, but i feel i need to buy before boards or matched fets run out.:eek:
 
huh, cant add to old posts.

I'm pretty bad at reading schematics, but it seams like using this front end balanced should be as easy as connecting the 'extra' input to link. q1 and q2 feel the voltage difference between input and link through r3 or r4.

If I got this right I'm probably just going by the boards and go for it. Last amp project was and Altoids tin ear bud amp a few years back. Picked up an old CRT tv from by a dumpster and removed then re-soldered most of the input board for practice. Feeling pretty good.
 
In L6L's build guide he mentions that the link hole was useful for balanced builds but everyone else must connect it to the neighboring ground through hole. I'm wondering if anyone has published proper use of this 'link', I wasn't sure if it was for accepting a balanced input or connecting to a balanced output stage.

F5Turbo Illustrated Build Guide

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