awkwardbydesign
02-06-2016, 14:11
I have been told I must sell, as I am spending too much on building a #26 DHT preamp. So my LDR attenuator has to go.
It has five inputs, one line out and a monitor out connected to the input I use for phono (I bought a CD recorder, so I wanted to hear what I was doing).
After making it as a manual pre, I bought a remote control kit on ebay, put it all in a bigger aluminium case, and now it has remote volume and source switching.
I have made it battery powered, with an internal charger; flick a switch once a week and recharge. There is also a digital voltmeter display on the front panel, switched, so it won't drain the battery.
As I rather like the look of Albarry amps, it has a transparent red Perspex front panel, and champagne gold knobs, with a balance control between them. As all this switching is done via the control board, there are no switches or pots in the signal path. The rhodium plated input and output sockets are silver wired directly to the LDRs, and they are turned on or off by the LEDs in the sealed packages.
Chris Daly (who makes the boards) has sent me a series of control boards to try, and I will include them. You can have fun changing them to find the sound you like. And they make a surprising difference!
The five inputs are connected to two piggybacked boards, with one control board. A (linear) PSU feeds that, with a separately rectified charging circuit. The battery is a 12V 1.3Ah sealed type from RS, and the Valab rhodium plated RCA sockets alone cost about £60! The signal earthing uses a high current ground lift connection.
I leave it connected permanently, but there is an on/off switch at the rear, and charging is initiated by a front panel switch, as is the voltmeter display.
I won't go on about the sound quality, there are enough threads on this forum doing that already, but you can modify the performance by changing control panels; I don't understand why they make such a difference, but they do! And you will get another four different versions to play with.
I will include documentation and instructions on operation for those who want such things, but as long as it is kept charged between 12.3V and 11.9V it just works! Chris uses a Quad 306 with these, which has a 33k input impedance, but I wouldn't advise going lower; after all it is a resistor attenuator. And I will be happy to answer any questions.
I am asking £180 plus £7 postage, or collection from Plymouth.
http://i1134.photobucket.com/albums/m604/awkwardbydesign/Mobile%20Uploads/20160602_103313_zpsrqa2cmvz.jpg
http://i1134.photobucket.com/albums/m604/awkwardbydesign/Mobile%20Uploads/20160602_102930_zpsdgzvvbha.jpg
http://i1134.photobucket.com/albums/m604/awkwardbydesign/Mobile%20Uploads/20160602_102148_zps5jo2fo4a.jpg
http://i1134.photobucket.com/albums/m604/awkwardbydesign/Mobile%20Uploads/20160602_103057_zpsrjyf6bfi.jpg
http://i1134.photobucket.com/albums/m604/awkwardbydesign/Mobile%20Uploads/20160602_103045_zps4ehnpkkx.jpg
http://i1134.photobucket.com/albums/m604/awkwardbydesign/Mobile%20Uploads/20160602_103024_zpsmogiu1ts.jpg
http://i1134.photobucket.com/albums/m604/awkwardbydesign/Mobile%20Uploads/20160602_144810_zpsw5y9nna5.jpg
It has five inputs, one line out and a monitor out connected to the input I use for phono (I bought a CD recorder, so I wanted to hear what I was doing).
After making it as a manual pre, I bought a remote control kit on ebay, put it all in a bigger aluminium case, and now it has remote volume and source switching.
I have made it battery powered, with an internal charger; flick a switch once a week and recharge. There is also a digital voltmeter display on the front panel, switched, so it won't drain the battery.
As I rather like the look of Albarry amps, it has a transparent red Perspex front panel, and champagne gold knobs, with a balance control between them. As all this switching is done via the control board, there are no switches or pots in the signal path. The rhodium plated input and output sockets are silver wired directly to the LDRs, and they are turned on or off by the LEDs in the sealed packages.
Chris Daly (who makes the boards) has sent me a series of control boards to try, and I will include them. You can have fun changing them to find the sound you like. And they make a surprising difference!
The five inputs are connected to two piggybacked boards, with one control board. A (linear) PSU feeds that, with a separately rectified charging circuit. The battery is a 12V 1.3Ah sealed type from RS, and the Valab rhodium plated RCA sockets alone cost about £60! The signal earthing uses a high current ground lift connection.
I leave it connected permanently, but there is an on/off switch at the rear, and charging is initiated by a front panel switch, as is the voltmeter display.
I won't go on about the sound quality, there are enough threads on this forum doing that already, but you can modify the performance by changing control panels; I don't understand why they make such a difference, but they do! And you will get another four different versions to play with.
I will include documentation and instructions on operation for those who want such things, but as long as it is kept charged between 12.3V and 11.9V it just works! Chris uses a Quad 306 with these, which has a 33k input impedance, but I wouldn't advise going lower; after all it is a resistor attenuator. And I will be happy to answer any questions.
I am asking £180 plus £7 postage, or collection from Plymouth.
http://i1134.photobucket.com/albums/m604/awkwardbydesign/Mobile%20Uploads/20160602_103313_zpsrqa2cmvz.jpg
http://i1134.photobucket.com/albums/m604/awkwardbydesign/Mobile%20Uploads/20160602_102930_zpsdgzvvbha.jpg
http://i1134.photobucket.com/albums/m604/awkwardbydesign/Mobile%20Uploads/20160602_102148_zps5jo2fo4a.jpg
http://i1134.photobucket.com/albums/m604/awkwardbydesign/Mobile%20Uploads/20160602_103057_zpsrjyf6bfi.jpg
http://i1134.photobucket.com/albums/m604/awkwardbydesign/Mobile%20Uploads/20160602_103045_zps4ehnpkkx.jpg
http://i1134.photobucket.com/albums/m604/awkwardbydesign/Mobile%20Uploads/20160602_103024_zpsmogiu1ts.jpg
http://i1134.photobucket.com/albums/m604/awkwardbydesign/Mobile%20Uploads/20160602_144810_zpsw5y9nna5.jpg