My_Ref Fremen Edition - Build thread and tutorial

[richbandit]

Guys,

Somewhere in this (very long!) thread I recall reading a preference given to replacing the Craddock at R3 with Isabellenhütte PBH Series instead - can't find that reference now as can't remember what post I saw that on!

Is that a definite recommendation, or did I simply dream it?! Would that be a worthwhile consideration in your (more experienced) opinions?

Thx

 

[Joseph K]

No You did not dream..
I hope it can be permitted, I had just stolen this zoom-in from the photo of Ripster's post (#4737 just after Your message..), a zoom-in into his installation > >
now that is an IsabellenHuette that you can observe there.. Part of the latest GB BOM..

In fact, I think some more people might assemble / swap in the part properly in these days, so hopefully more opinions coming.

Ciao, George

 

[Joseph K]

Correction.. Either IH or Mundorf..

 

[Ripster]

It is IH

 

[richbandit]

Thanks George, Ripster,

So is it considered a beneficial upgrade?

 

[Ripster]

Should C13 Auricap XO black markings outer foil be facing input connector side?

 

[ClaveFremen]

Should C13 Auricap XO black markings outer foil be facing input connector side?

So answer is YES


Obviously they're supposed to be soldered and mounted flush to the PCB, mine are 'flying' on fastons to allow rapid swapping...

 

[ClaveFremen]

So is it considered a beneficial upgrade?

V1.8 boards have been made to allow mounting them...Does it tell you something?

 

[richbandit]

Hi Dario,

Duly noted! I'll probably plan to obtain a couple in that case .....

Looking forward to starting my build in due course.

Thx

 

[ClaveFremen]

Duly noted! I'll probably plan to obtain a couple in that case .....

Prefer the Mundorfs if budget allows it.

 

[richbandit]

Aha! Just noticed this option on BOM - The Mundorf M Resist Ultra, yes? They certainly seem to be very good.

Thanks for the heads up Dario.

 

[Ripster]

So I finally connected everything and all seems OK relays click but if I connect speakers I hear buzzing on both channels... If I short input pins buzzing is gone I have toroids that have shield so I probably connected something wrong? any quick advice? thx

 

[Joseph K]

You have to connect dac.. Leaving input open, =buzzing..
Edit: I mean dac or preamp.. The input, when left open, is having a 100kohm impedance - far too high, picks up all things.

Though.. Did You measure the voltage on output terminals, DC, 200mV resolution, with input shortened?
Just a check, if it is OK

 

[Ripster]

On output shorted input on left -5 and right +5
and another strange effect I had led touching chassis and the buzz was gone

 

[Joseph K]

-5 and +5... mV, I hope!! ��

And that's ok. LED touching ground - non bueno..

Have fun! G

 

[Ripster]

Yes mV

 

[Ripster]

Thank you Joseph I connected everything to amplifier and now it is playing nicely without any buzzing

 

[bloozestringer]

Ripster, is that one of Mark Johnson’s AC/softstart boards?

 

[Ripster]

Yes it is...

 

[Joseph K]

Thank you Joseph I connected everything to amplifier and now it is playing nicely without any buzzing

But hopefully with a a warm fuzzy feeling