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I have noticed recently that my system sounds best when the battery powering my Dodd Tube Buffer is running low. Why would this happen and what is this telling me?
I have noticed recently that my system sounds best when the battery powering my Dodd Tube Buffer is running low. I have tested this several times with the same result. When the battery is fully charged, my system sounds aggressive with upper-mids sounding forward and fatiguing. Any thoughts?
(1) In this case the Dodd Battery Buffer has no voltage gain, only current gain. This would mean only the output impedance is changing as the battery voltage is dropping. (2) What is likely happening is that the output impedance is increasing as the battery voltage is dropping. At low battery voltage, you might be creating system synergy.(3) A thought would be to measure the battery voltage where you like the sound. You could use a battery pack optimized for that voltage instead of the normal 12VDC AGM battery (~10.8V - 13.1V range). The A123 style LiFePO4 batteries are nominally 3.3V @2.3Ah per cell and 3 in series are in the 8.4V to 10.8V range. Depends on how many hours of operation you want as to how many you series and parallel. These style of batteries need specific battery chargers for use. (4) This will work best if you are using a 6V filament tube like the 7308, 6922, 6DJ8 and 6H30 styles as that is using the voltage regulator.
Hi. Anyway we can get access to Dodd pre-amps & buffer schematics? Save us guessing?In Dodd's site, I don't seem to read any technical stuffs about its products.Sales pitch only for Joe Blow type consumers. Nothing for technical guys like me to read.My curiosity lies on the "unique battery powered" design of the HV for the tube plate - powered by 12V batteris or what not?c-J
"My curiosity lies on the "unique battery powered" design of the HV for the tube plate - powered by 12V batteris or what not?"I think I figured it out and it is pretty trick ...John
You're not the only one that would like to get their hand on it. No way Gary or any small business owner is going to release schematics on something as unique as a battery driven tube buffer, pre, or amp. There just aren't that many guys that have figured out how to make it happen without running the battery down.