Comparing battery-powered phono pre-amps, from RS ($$) to ASR ($$$$) ... and beyond!

[D-500 Flogger]

derek92994,

Great effort & super photos documenting your 10-hour thrash on that phono preamp -- feel like I'm looking right over your shoulder despite being halfway around the world!

Reading your post I was reminded of a favorite YouTube video where the Aussies did an impromptu demo of what they can do with an older swing-wing F-111. Starts with some video with a gentle wings-out fly-by -- but at ~30 seconds into the video be sure to turn up the volume and watch closely. (Hint: The anticipatory laughter in the background says it all.)



Listen, I don't know if it's something in the water, or some shared genetic background, but I for one applaud the enthusiasts in the land of Oz for their all-out approach to the things they care about.

Here's hoping that someday you can break some windows with your own hot-rodded equipment. :0)

Keep up the good work!

3D

 

[J!m]

The Israelis have written their own avionics and engine management packages for their F100-229 powered birds (much frustration from P&W on this when engines are not performing properly).

The condition of their blades when we get them indicates they run them "at eleven"...

 

[derek92994]

Here's hoping that someday you can break some windows with your own hot-rodded equipment. :0)

Keep up the good work!

3D

I have the amp, just need the speakers, 15 inch ones. Im super happy with the Jamos though. They go loud enough, and the neighbour’s house on one side is maybe 7 feet away. Glad I got acoustic insulation put in the lounge room walls, just need to do the windows next, thats where the majority of sound escapes.

 

[derek92994]

 

[derek92994]

Replaced the input/output transistors, hell yes!!!
Recordings soon.

 

[derek92994]

I'm sure we have had enough of listening to 'Heavy Fuel' so this time I did Water of Love from the Japanese Pressing. Interesting differences in the sound graphs:

Stock Unit



Fully Upgraded Unit



Stock Unit Zoomed in:



Upgraded Unit Zoomed in:



Stock Unit Audio:
https://www.dropbox.com/s/j7actwx5y6ppb6l/Rat Shack Stock Unit 2.wav?dl=0

Fully Upgraded Unit Audio:
https://www.dropbox.com/s/dmrfw8rk44ac4kl/Rat Shack Complete Upgrade.wav?dl=0

Time to get ready for work.

 

[derek92994]

2 Hot Rodded Battery Phono Preamps, separation doesn’t get much better than that. Got the build time down to 3 hours including removing stock components from the board.

 

[derek92994]

Why not add some valves?

 

[J!m]

Don’t do it!

The noise and distortion levels of tubes make them a poor choice for a phono preamp and the tiny input signals.

But they are popular despite this…

They make more sense in a DAC but I haven’t heard one of those I like either. That could be how it is typically implemented. But the higher signal level and lack of distortion from tracking the record make it a better choice to me. Maybe once I’m making money with audio I’ll dig into that.

 

[derek92994]

I dont hear no distortion. I cant see a problem with using valves for phono preamps or line level preamps. The valve preamp you see there is taking a line level signal from the two transistor battery phono preamps. I also like the other phono pre that uses valves, the project tubebox ds.
I might hook that line level valve pre up to a battery source after work. Then if I ran it thru the T amp the system would be almost completely battery excluding the turntable, but that could also be changed too.

 

[J!m]

That sounds like a fun test actually.

 

[derek92994]

Total DC battery powered listening system, with tone controls, it had to be done! Yes it sounds excellent for 15 watts rms. Each component has its own battery

Edit: Turntable is powered by mains but the rest of the audio path is DC powered