Hi Ulli,
your boards have been shipped yesterday.
I've missed last shipment for your boards since I've had some problems with OneDrive sync, your details were on my work PC and not on my home one, sorry.
Thank you Dario,
SMD option received in LA CA
(left coast US) 1300 PST 2/26/2019 so any US recipient should by now have their boards!
couple of questions:
1. what is right BOM for building this SMD pre-populated board? I am confused about "EVO A" etc. My board says Rev. 2.17
.
2. There is a "budget" BOM on the list, has anyone provided any measurements as to the difference this makes. I don't much care about 10-15 euros difference per board but I do as an engineer have a lot of reservations about the claimed sonic differences of components that noone has found a way to build in a way that measures electrically better. I do not want to start a ******* contest here I'm just looking for objective info.
3. Just for my curiosity, Mauros design is rather old and far better amplifiers than the 318 are now available in terms of CMRR, PSRR, noise density, and simplicity of stabilization in this particular circuit context. Has anyone done any serious work on these issues to your knowledge?
TIA
Carl H.
Parts alternates
Some parts from the BOM are not available from Mouser but on the Google Drive BOM you will find alternates which are actually available.
The only exception is the LM3886 that should be ordered elsewhere until it is available again from Mouser.
Some parts from the BOM are not available from Mouser but on the Google Drive BOM you will find alternates which are actually available.
The only exception is the LM3886 that should be ordered elsewhere until it is available again from Mouser.
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Hi Carl,
On boards you will find the following text: "Revision 1.72 - January 2017"
So your boards should be revision 1.72.
The correct BOMs are:
Just order the first for original FE compensation or the second for the Evo A compensation (desolder R39 from both boards).
The technically better compensation is the EVO A and obviously sounds better too.
See the build guide for some more info.
All evaluations and measurements were made using the standard industrial BOM.
The budget BOM simply omits all hardware and replaces some parts with lesser ones and made sense with the first BOM revisions were a lot of costly Caddocks were in.
After v1.5 revision the standard BOM costs a LOT less and the budget BOM is no more useful.
If you look at the Google Docs BOM (which is the ONLY official one) the only 'economy' parts still in BOM are C34 (C0Gs instead of Micas) and R3 (Cement/ceramic generic resistor instead of a Caddock)
The 'economy' C34 is still a very good choice while the cement resistor is much worse than the Caddock.
JosephK modified the compensation (starting from Evo A one) to accept some other opamps, I've yet to try that mod but who did is pretty happy about it.
Dario,
I am glad keep up this thread from time to time. Vaguely remember removing R39. Will double check next time I open FE.
I assume it is mounted to the bottom like many of the surface mount components.
No desire to play with the opamps. The LM318 works fine.
My last opamp evaluation project involved quad surface mount. Spent many sweaty hours removing and installing various types. Ended right back with MC33189. Another old, cheap, low spec part that worked as well as any tested.
I am glad keep up this thread from time to time. Vaguely remember removing R39. Will double check next time I open FE.
I assume it is mounted to the bottom like many of the surface mount components.
No desire to play with the opamps. The LM318 works fine.
My last opamp evaluation project involved quad surface mount. Spent many sweaty hours removing and installing various types. Ended right back with MC33189. Another old, cheap, low spec part that worked as well as any tested.
For sure but I have to finish first the chinese batch, I still have 4 kits available.
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