Fabios 1272 finished

I finaly finished Fabios 1272, and since I do not see them here very often (and couldn't find too much help while searching) I decided to post the results.
some pics of my unit:

I used Sowter transformers for the input, Carnhill for the output)
the output with zobel and termination:

Elma Gain Switch:


my unit has some strange issues, but most important: sounds great

Amazing. inspiring. i have 2 boards waiting to be done.
i'm gonna use oep at the input and still not sure of what tx at the output.
one question what means "Zobel"??

again amazing

Nice build, Volker! That's quite a full box. I'm building a pair of these at the moment, so it's nice to see another one done. I'm using Sowter in and Lynx out, so mine will be in a 2U. Can you expand on the "strange issues" statement?

:thumb:
A P

p.s. What's up with the relays? Are they soldered underneath?

im still waiting on my BA boards .. can't wait though.. looks great

-richie

Wow!... Thats very nice.
I really like how you've mounted the resistors om the Elma rotaty :thumb:

Well, I like my boards stuffed by you guys, a lot cooler than stuff by me! :thumb:

Hope you solve the issues...

:guinness:
Fabio

Great work! 100% better than my fabio 1272 pres...

Im wondering how the DI inputs are supposed to be connected (polarity?) I couldnt get mine to work.

I also managed to wire my gainswitch so that two gainsettings have the same gain, but thats a whole other story... :green:

/Jonas

Looks very Neve-ish with the yellow isolation :thumb:

Michael

[quote author="3nity"]... one question what means "Zobel"??[/quote]
thanks for the kind words - the "Zobel" is a rc network for transformers.
do a searxh for "zobel network" in this forum.

Can someone clarify the relay question? Am I going to have to desolder 4 of these things because I mounted them topside?

A P

A P, the relays have to been soldered underneath.
My issues are worse noise on the left channel when the case is closed ???
Polarity inverse on the right channel is 5 dB less noise (???)
anyway, the issues are all with my racking, you will be more save with 2Us.
btw, my left channel measures 10 dB better with the top of the case off ....

[quote author="AnalogPackrat"]Can someone clarify the relay question? Am I going to have to desolder 4 of these things because I mounted them topside? A P[/quote]
I had to do that

[quote author="radiance"]Wow!... Thats very nice.
I really like how you've mounted the resistors om the Elma rotaty :thumb:[/quote]
just like neve, eh ?
recomended - doing it like this is meditation

[quote author="[silent:arts]"]A P, the relays have to been soldered underneath.
My issues are worse noise on the left channel when the case is closed ???
Polarity inverse on the right channel is 5 dB less noise (???)
anyway, the issues are all with my racking, you will be more save with 2Us.
btw, my left channel measures 10 dB better with the top of the case off ....[/quote]

Thanks for the answers. Guess I'll be digging out the solder wick. :sad: Is your noise hum/buzz or hiss? Hope you can work it out.

Oh, I'm also planning on soldering the gain resistors to my switch...only I'm using a solder lug grayhill which is going to make it, uh, fun.

A P

alo volker
very good work.
congrats.
i also did two fabio`s boards,and they are geat.
as a matter of fact,i`m planing on doing two more,as soon as fabio as more boards.
one channell has sowter,and the other two jlm trannys.
the output i used jlm on both.i`m very happy with them.
btw:where did you connected the black wire of the sowter input tranny?.
best regards
pedro

Instead of desoldering the relays you can swap 5V and GND the on the PSu conector at the mainboard :wink: ... Neeno did this with success! :thumb:

Fabio

[quote author="Bauman"]Instead of desoldering the relays you can swap 5V and GND the on the PSu conector at the mainboard[/quote]
but don't forget to get the diodes out (or reverse them)

[quote author="louder"]btw:where did you connected the black wire of the sowter input tranny?[/quote]
Pedro,
the black wire is connected to Audio GND - I tried it both ways (GND and Mains Earth / Case) but haven't had a diffference.

Yes, inspiring! How did you mount those switch-plates to the front panel? Does the FP have studs? Can't tell from the pics.

[quote author="Bauman"]Instead of desoldering the relays you can swap 5V and GND the on the PSu conector at the mainboard :wink: ... Neeno did this with success! :thumb: [/quote]

Thanks, Fabio! I took a quick look at it last night to see if there was anything simple I could change to avoid desoldering those relays, but that simple idea did not occur to me. I'll swap the relay power polarity. And the diode polarity (thanks, Volker).

:thumb:
A P