I read all the risks and warnings Pete spelled out on his project page which is what really prompted my question. I’m planning to try battery power and wanted to build the Silent Switcher, currently unavailable in the store. Are you running your battery direct or doing some form of regulation?
My first build used a SilentSwitcher powered off a battery pack but I no longer have that build.
Another option is to run it directly off of 2x SLA batteries like Dave from Landfall.
I like the convenience of my latest build with the VRDN: there is no mains or transformer in the chassis, the PSU is extremely quiet and you don't need to worry about charging or replacing the battery
Another option is to run it directly off of 2x SLA batteries like Dave from Landfall.
I like the convenience of my latest build with the VRDN: there is no mains or transformer in the chassis, the PSU is extremely quiet and you don't need to worry about charging or replacing the battery
I finished my LR phono preamp last week and after listening all week, I'm very impressed. DC offset was set to 0.00mV after 1 hour, very easy procedure after reading this thread. I still think my Salas UFSP sounds better, however, it may be the turntable/tonearm cartridge combination.
UFSP: Thorens TD321, SME 3009 MK3, Shure V15VxMR w/ JICO SAS neo needle
LR: Thorens TD125 Mk1, SME 3009 s2 improved, Sumiko Blackbird MC High out
I've always wanted a phono preamp using batteries, so I built this with two CA1212 AGM 12v 1.3Ah batteries. I used a 4PDT switch from Parts Express for the ON / OFF/Charge, and a 1/4" phone plug for the charge port. My Battery Tender Junior works great on my Motorcycle AGM batteries, so this is my charger set up for the LR. The difference in cost from batteries to a regulated power supply is a tremendous incentive to use the batteries.
UFSP: Thorens TD321, SME 3009 MK3, Shure V15VxMR w/ JICO SAS neo needle
LR: Thorens TD125 Mk1, SME 3009 s2 improved, Sumiko Blackbird MC High out
I've always wanted a phono preamp using batteries, so I built this with two CA1212 AGM 12v 1.3Ah batteries. I used a 4PDT switch from Parts Express for the ON / OFF/Charge, and a 1/4" phone plug for the charge port. My Battery Tender Junior works great on my Motorcycle AGM batteries, so this is my charger set up for the LR. The difference in cost from batteries to a regulated power supply is a tremendous incentive to use the batteries.
Attachments
Yes! Very nice.
A comment on batteries—here's what I had laying around for charging batts on motorcycle trips... It was 3/4 charged when I pulled it from storage... I have yet to charge it up! Just keeps going driving the preamp via Silent Switcher/USB...
A comment on batteries—here's what I had laying around for charging batts on motorcycle trips... It was 3/4 charged when I pulled it from storage... I have yet to charge it up! Just keeps going driving the preamp via Silent Switcher/USB...
I am intrigued by this phono preamps as well. Another member has used Burson opamps instead of AD797.....mhhh I wonder, would OPA1655 also be an option?
Did you have to make any changes to the circuit using the Burson V6 opamps to adjust DC offset?
Nice build.
Can you post a drawing of your battery wiring?
I want to try batteries on mine, feeling a bit daft about how to wire it.
Thanks
Ed
There is no change to the circuit needed. I just made adjustment to DC offset. Do note that BursonV6 opamps I received were not tightly matched and I had to swop around to make a good DC offset adjustment
I just bought a pair of batteries, have not tried them yet do to Christmas stuff and family.
I wiil report back. Next week.
When I install one BursonV6 vivid opamp on each channel with an AD797, the lowest DC offset I can adjust to is 240mV. When I use all four BursonV6 vivid opamps, the lowest DC offset I can adjust is 416mV. Also, the change in DC offset is only about 80mV total.
Yet when I use the AD797 opamps, I can easily adjust DC offset on each channel to 0mV.
I even tried to use the AD797's in the first stage and the BursonV6 in the second stage, no change in DC offset behavior. I did send Burson an email regarding my issue, don't expect a response for a while with the holidays and all.
Here's my experience so far.
AD797 with PSU : DC can be adjusted very close to zero and very close to equal for both channels.
BursonV6 with PSU : DC can be adjusted near to zero and very close to equal for both channels.
BursonV6 with battery : DC was not able to be adjusted near to zero but can be adjusted close to equal for both channels.
AD797 with battery : Not tried
What the difference you are hearing between the original OPAMP AD797 vs Bursons?
Hi,
I'm going to build my LR Phono preamp in one chassis, and I'm investigating some layout possibilities.
Given the dimensions of the chassis, the transformer, and the PCB boards; I think I have two layout possibilities for which I have made the drawings below.
Which one do you think is the best option?
Thanks
Layout 1
I'm going to build my LR Phono preamp in one chassis, and I'm investigating some layout possibilities.
Given the dimensions of the chassis, the transformer, and the PCB boards; I think I have two layout possibilities for which I have made the drawings below.
Which one do you think is the best option?
Thanks