Remote controlled PGA PREAMP for PW120 module..any advice ? Thanks..

[dyolFkniP]

Hi, I'm new in this site, even if I'm a regular reader and always appreciated Diy audio advice..
So, hello to everybody.. first of all
Recently I bought a pair of solid state mosfet power audio modules PW120 (http://www.ampli-design.com/4/power_amplifiers_1567180.html ) coupled with an external self made power supply. The project is simple and preatty good but I would like to implement a good remote controlled preamp PGA2311 based volume control equipped with a display. The power module have about 800mV input sensitivity..
I saw this one on eBay
http://cgi.ebay.it/NEW-DIY-LCD-PGA2311-Volume-Remote-Control-KIT-Free-Knob-/320581428260

looks well done.. but it has only 3 inputs, and I need at least 4 ! and more.. I need to command by remote also the ON/Standby function so I need one more output (relè or at least an open collector output) to this function...
Does anyone know links to something like that or have any experience with this kind of circuits, schematics ?

[fotios]

Here is a project - guide about the remote control of Hi-End preamplifiers.
MICROS

[dyolFkniP]

mmhh... intresting... but the original idea is the ALPS pot connected in axis with the linear pot for volume control...even if from the beginning I thought about a PGA volume chip for having more balanced levels at low volume listening and less "skratches" after few years of dayly using....

[fotios]

It is in your choice. Personally, i had never problem with ALPS Blue Velvet pots because are enough sealed. It is a solution if you want a clear analog control, not offered by PGA2311. Although i have not problem to change the MCU code for managing a PGA2311, i don't like it. There is as well many people that use the "Light speed attenuator" which is a volume control thru "photo-resistors". Take a look in this approach, is very interesting and didactic.

[dyolFkniP]

hahah.... it's a funny idea that lightspeed.. very intresting... my only doubt is regarding the resistive substrate of the coupler.. for sure a semiconductor.. while PGA2311 have an internally digitally selected resistive analog network..so at that point, an ALPS as you posted is for sure better for pure audio applications...
But it's a curious idea... I think it worths to experiment and "measure"... noise, distortion... and a good listening session...

[dyolFkniP]

in this link the PW120 uses a dantimax preamp... and seems to use an ALPS pot... isn't ?

[fotios]

It is, and i like:
1) The two nice modules PW120.
2) The two nice power supply modules of the same vendor.
3) The nice MODU (showbiz for me) case.

BE CAREFUL with Dantimax. You have to be careful with these kits. I would not recommend them to you, as the vendor is not trustable.

[theAnonymous1]

Originally Posted by fotios

didactic

Whoa, had to look that one up.

[fotios]

Originally Posted by theAnonymous1

Whoa, had to look that one up.

In Greek, the word "didactic" is used extensively instead of the word "instructive". Didactic (like a lot of other English words) has purely Greek root, is a word of academic value and has the sense of "teaching".

[dyolFkniP]

mmhh... the case is a standard 42 cm I think... the wooden knob are a little "kitch".. I prefer solid alluminium knob even for an encoder switch..

1) That PW120.. PROS: modules sounds really sweet to my ears... very natural and "trasparent"... female voices expecially in high register are never harsh .. "S" is truly "S" and never "SHHH" i.e. ... I don't know if you have an idea of what I'm saying... great "punch" !! .. I believe it's nothing new as project ( but after 70 years of discovery of transistors what sould we expect ?? hahah ) BUT really careful in dimensioning and quality search of components and well "engeenierized" ... CONS: a little expensive.. for me at least.. and gets a little hot ( about 40-45 °C ) even without signal... manufacturer says that this is because of high quiescent current and high Rds on of K1058 and J162...But I've no reason to doubt about it...
2) As power supplies I used 4 x IR 3504 bridges with 8x 10000uF/63V .. power supply of ampli-design.com are sure nice... as You said.. fast recovery diodes..ok, low ESR caps.. ok... but it was a pity to throw away mine supply components... of course with that two PS1 module supply the overall result was better estetycally ....

why do You think that dantimax have some reliability problems ? What's up with that ?