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ClaveFremen 21st September 2013 07:57 PM

My_Ref Fremen Edition GB (interest for a third run)
Hi all,

I've recently received some requests for My_Ref Fremen Edition PCBs so this thread is about checking effective interest for a third run.

The My_Ref Fremen Edition is a variation of Mauro Penasa's My_Ref with this goals:
  • a more stable and performing amp using SMD parts
  • raise LM318's PS voltage thanks to a voltage limiter
  • better PS for LM318
I've designed a brand new PCB with these features:
  • bigger caps (16mm diameter with both 7 and 5 mm pads) for C1, C2, C9
  • large use of SMD components
  • quite all small caps and some critical resistors are still through-hole
  • very small paths thanks to SMD
  • ground planes design
  • zener limiter based on schematic 5b from this link (which seems pretty similar to My_Evo one)
  • CCS shunt PS for the LM318
  • An alternate C9/R10 arrangement
  • Different grounding
  • Different compensation
  • a double diode bridge like in most gainclones
Both PCB and schematic have been tested organizing beta and release candidate mini group buys

I've been authorized by Mauro Penasa to proceed with this My_Ref derivate amp.

You can find references on development, beta and release candidate here:

My_Ref Fremen Edition - need help on PCB evaluation - diyAudio
My_Ref Fremen Edition - Beta build/Fine tuning - diyAudio
My_Ref Fremen Edition RC - Build thread - diyAudio
My_Ref Fremen Edition - Build Thread

On my Google Drive you'll find:

Build Tutorial

There's also a shared Mouser BOM to order parts.

And a YouTube video on SMD soldering of FE modules.

Actual price will depend on number of partecipants/kits, the Group Buy is about PCBs only

Approximate prices (one kit = 2 PCBs, PayPal fees and 1€/kit donation to DIY audio included):

10-14 kits 38€
15-19 kits 30€
20-24 kits 26€
25-29 kits 24€
30-39 kits 22€
40-50 kits 20€
100 or more 16€

Shipping prices will be (for each kit, for 2 kits add 1€, more than 2 will be calculated):

Italy 7€
Europe 10€
Rest of the world apart Oceania 13€
Oceania 14€

PCBs (circa 12 x 10.5 cm) will be blue, 2mm tick, 2 Oz/70um copper, gold plated, made in Italy.

One transformer 160VA-300VA will be needed for each board (monoblock design)

BOM cost is around 76€ per board (premium industrial BOM) which can be lowered to 52€ (On a budget BOM).

A complete amp (premium industrial BOM) will cost around 450€ and up.

If interested please PM me your PayPal associated email address and fill your nickname, country (2 letter code) and number of kits on the Google Spreadsheet (please leave blank the 'PP account sent' column, I'll fill it so you have a feedbakc that I've received your data)

October, 6 price will be fixed and I'll start sending PayPal Invoices, all payments are due by October, 12

Until order is done it will be possible to partecipate to the GB

Boards will be ordered by October,13 and should be in my hands in 15-20 days, then packaged and shipped in a week or so.

Mauro Penasa for his great design and kind permission
LinuxGuru for his help on new compensation
Luka for the LM318 PS initial design
KSTR for the new C9, R10 arrangement.
Soongsc, Marce, Sebaastian, KSTR and Metal for help on PCB design
BMCBob for all support, tests and reviews

Images of boards from the first GB:

Royber 21st September 2013 09:18 PM


Fantastic! Thanks. I've just put my name down for 2 kits. I am not sure how to send you my PP account info.

Will the PCBs be blue again or can they change colour to black? It would look great with red PRP resistors. I have a Black Edition DCB1 and it is quite beautiful.



shoom 21st September 2013 11:02 PM

Hi Dario

I’m in again for another set.


Kokanee 23rd September 2013 05:20 AM

Hi Dario, Sent PM, signed up on list for 2 kits. Used CA for Canada as country???


ClaveFremen 23rd September 2013 08:47 AM


Originally Posted by Kokanee (
Hi Dario, Sent PM, signed up on list for 2 kits. Used CA for Canada as country???

It is what I've found on the spreadsheet. Correct it to the right country.

Kokanee 23rd September 2013 09:33 AM

Hi Dario,

CA is used for Canada for 2 letter abbreviation. I left spreadsheet as is


ClaveFremen 23rd September 2013 12:38 PM

When you fill in the Google spreadsheet please leave blank the 'PP account sent' coloumn.

It's my task to fill it when I receive your data and represent for you a feeback.

All partecipants so far have been registered also on my private spreadsheet with personal info and I have all I need at the moment.

burninggecko 23rd September 2013 04:35 PM


I'm in for a set. Just sent PM.


ivodonchev 23rd September 2013 05:18 PM

Hi Dario,

One set for me please

Thank you!

ClaveFremen 23rd September 2013 07:58 PM


Originally Posted by Royber (
Will the PCBs be blue again or can they change colour to black?

Hi Bertrand,

sorry for the late answer... the will be blue, as Fremen's eyes ;)

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