Remember, I'm not the one who spec'd 25V for C1 & C2. I'm just wondering where everyone else was, including N.P. with this. I would not really expect to see more than 6V on the 100 and the pot||cap together. You need about 1V on the source R, 2Volts Vgs add some signal and mabe thats 2 more volts, and a little more for when the drive gets tough. But it's a pre. So a 6.3V might work but I'm not goin there. A 10V at min and I think thats doable. My 16V caps are 12.5mm and they fit but my 25V caps are all 18mm!
Hey guys, I'm at a point where I need more gain in my system, especially for the digital front end. So, I'm thinking of adding the BA-3 at the output of the DCB1 (the current pre). My question is, can the BA-3 be used this way? From what I can tell, its output impedance is about 300 ohms and should be fine as a standalone preamp into amps other than the BA series.
Yeah, but I'm thinking of just stuffing it in the same chassis... you know how much work a new chassis is.
I think I'll keep the DCB1.. it allows many inputs and does a good job of buffering the sources... Planning to put a switch to flip the BA-3 in and out of the system. I really don't need the gain for the analogue source (Pearl II).
I think I'll keep the DCB1.. it allows many inputs and does a good job of buffering the sources... Planning to put a switch to flip the BA-3 in and out of the system. I really don't need the gain for the analogue source (Pearl II).
Well just compare BA3 front end with BA2 output stage vs BA1 output stage.
Then think BA1 output with more grunt is what you will get with BA2/current source. It is a bit of a compromise for difficult/reactive loads.
If you don't need the grunt, then BA1 output or Aleph output is all you need.
With or without these tweaks the amp will sound sensational.
Then think BA1 output with more grunt is what you will get with BA2/current source. It is a bit of a compromise for difficult/reactive loads.
If you don't need the grunt, then BA1 output or Aleph output is all you need.
With or without these tweaks the amp will sound sensational.
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Hi buzzforb,
We were talking about thermal drift on the BA-3 but I don't think we decided how much heatsink was enough. I was getting a variable dc offset, certainly not rock solid, using the same heatsink as in Nellson's picture in his build plans except mine had two more prongs.
Did you end up using something more substantial? Technical details or a picture would be appreciated.
Chris
We were talking about thermal drift on the BA-3 but I don't think we decided how much heatsink was enough. I was getting a variable dc offset, certainly not rock solid, using the same heatsink as in Nellson's picture in his build plans except mine had two more prongs.
Did you end up using something more substantial? Technical details or a picture would be appreciated.
Chris
If you are still getting drift and your fets are cool or at least warm to the touch, it is probably more circuit related than the heat related. I believe this is the primary reason for such a large cap. Mine is torn down right now, as I am in the midst of the F5T, but will be reinstalled on the sinks when I am done testing.