Could you kindly share at preamp output voltage was it measured and how much the H2 and H3 distortion level in mV, dB, % or whatever you measured? Ballpark figure is ok. Thank you.
Thank you Kevin. My 2c is to remind you to also listen to the system with reversed speaker polarity connection and compare. 🙂
So more than a month later I finally took your advise...I didn’t think reversing polarity would make much of a difference...I was wrong, it makes a considerable difference. Thanks Indra1
Please elaborate. I drove myself half crazy in the late 90's with a DAC that allowed you to flip the phase back and forth. I suppose this would have a similar effect as flipping both the speaker's polarity, right? One way would sound "better" then I would be certain that later it was the other way.
Then someone suggested to me that some music may be recorded one way, other music recorded the other way. Is there some way to tell when speaker is moving out out positively to the music signal, as opposed to moving backwards? This would help a lot if indeed various recordings may have been done one way or the other?
Puzzled,
Russellc
EDIT Disconnect the speaker first!
Connect a 1.5V cell across the speaker terminals, which way do the cones jump?
With that known, scope the output of the amp and look at the leading edge of transients.
Last edited:
That is what drove me crazy before, you would need to test this with each recording.....and, with any new component. A quick switch of cables is easiest, but tiresome.
Russellc
Russellc
I noticed a difference in sound stage with the change of polarity...instruments seemed closer and the stage seemed wider. I don't think I'm imagining it (well, actually I am)...I tried flipping the cables back and forth a couple of times with the same results.
true!
for me P3 adjustment is still a dark spot...
even though I try not to think about,
I can't get it out of my head 🙁
for me P3 adjustment is still a dark spot...
even though I try not to think about,
I can't get it out of my head 🙁
Just thought I'd add my perspective to this.
Tried adjusting P3 retrofitted to an early F5. I had some difficulty getting distortion out of the weeds with my Roland interface (and not just reading the distortion of the interface itself), but I did, and set H3 to null as best I could with H2 at +90deg (which I think is out of phase)
I really didn't like it. Sounded flabby, thick and yet somehow harsh.
I went back and reset it simply to lowest overall THD, which was basically lowest H2, with H3 at about 60-80% of H2. Overall distortion figures were a lot (like a lot) lower this way.
Much improved to me - and a bit better than the halfway house as it was default. Tight, clean and ever so open. I don't know if I was doing something wrong nulling H3, or if the H2 distortion was just too high in doing so that that it ruined the sound.
Tried adjusting P3 retrofitted to an early F5. I had some difficulty getting distortion out of the weeds with my Roland interface (and not just reading the distortion of the interface itself), but I did, and set H3 to null as best I could with H2 at +90deg (which I think is out of phase)
I really didn't like it. Sounded flabby, thick and yet somehow harsh.
I went back and reset it simply to lowest overall THD, which was basically lowest H2, with H3 at about 60-80% of H2. Overall distortion figures were a lot (like a lot) lower this way.
Much improved to me - and a bit better than the halfway house as it was default. Tight, clean and ever so open. I don't know if I was doing something wrong nulling H3, or if the H2 distortion was just too high in doing so that that it ruined the sound.
Hi Friend's,
Just finished my F5T ver.2 Amp.
Now I ponder the P3 question ❓
Any new updates since time has passed?
I got in to tube preamps as of late and enjoy the tube sound.
I'm not into extreme low distortion numbers.
Found many audio components of high distortion to sound quiet good.
I just not impressed with the amp so far as my Leach amp and tube frontend seems to sound better, not sure what's going on, maybe P3?
Any advice on adjustments with no scope or not sooo expensive ways to adjust would be greatly appreciated..... Robert
Attached files of some of my builds with help from my friends here at DIYAUDIO!!
Just finished my F5T ver.2 Amp.
Now I ponder the P3 question ❓
Any new updates since time has passed?
I got in to tube preamps as of late and enjoy the tube sound.
I'm not into extreme low distortion numbers.
Found many audio components of high distortion to sound quiet good.
I just not impressed with the amp so far as my Leach amp and tube frontend seems to sound better, not sure what's going on, maybe P3?
Any advice on adjustments with no scope or not sooo expensive ways to adjust would be greatly appreciated..... Robert
Attached files of some of my builds with help from my friends here at DIYAUDIO!!
Attachments
Last edited:
Not F5, but my experience with P3 on the BA3 pre. Without measuring equipment!
Presuming that your P3 was set to the middle position.
Turn it a couple of full turns one way and listen. Then back to zero, and a couple of turns the other way.
Listen at each position.
N.B. you MUST re-bias and zero offset. after every change.
My experience, one way was harsher and brighter, (some might describe it as cleaner.)
The other way was more mellow.
Which is "best" to your ears?
Thanks for your reply, I may try that.
I checked again last night ,P3 for true center it was dead on.
My bias is 350mv with about 2 ma offset.
I like softer, mellow not too bright on the top end.