Its low gain and is in need of every bit of oomph in the bass. DC and low Zo helps it, full DC path. IMHO of course. Having heard the F5 with DCB1, 6V6 as buffer, on my 95dB speakers they are closer in musical weight. F5 needs 12dB+ line gain and 95dB+ 8 Ohm flattish Z speakers to start partying, IMHO again. ~ 50W single output pair Andrej's SSA goes ''bigger'' easier on lazy speakers but its not a finished simple form DC steady kit yet. Apples to oranges VS F5. DCB1 was firmer VS #26 also on Baby Huey with Hashimoto OPT in Vgeorge's Lynn Olson's Beyond The Ariel line of thought 100dB 4 way system (90Hz up, subs active 300W). But #26 had a golden like harmonic hue (was not there in source) very beguiling without pushing back clarity. Still a bit shallower even with line level XLR OPT and autoformer pot. No DC path again, bass & midbass love straight paths it seems.
It appears i have to retract my apparent affection for the 6V6 preamp. I just dont know amymore😀
Mekanixz, it is standard BA3.
Mekanixz, it is standard BA3.
no need to do that, just state your facts, and everything will be fine 😀
still dont understand why BA-3 works better with 6V6 than the F5
I really thought it would be the other way round, due to the known F5 lowish gain 😕
some say they miss the 'grunt'
but I guess it also relates to your speakers, and listening 'habbits', music, etc etc
First sch. Tomorrow pics.
C1 at the moment. 4 * K42Y-2 caps. Each 0,047uF. 2 Wired in one direction. 2 In the other.
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What exactly are the facts? What do they suggest about the 6v6 vs DCB1?
I think the gain on the BA3 and F5 are pretty similar.
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I was trying to make a joke, and Im not good at that either 😀
regarding F5 vs BA-3 gain
I think Nelson have stated 30db for BA-3 pre driver, and isnt F5 something like 24db ?
f5 is 15db.
I still don't understand what do you mean when you say ba3. According to NP's document ba3 is a front end. Are you using ba1 or ba2 output?Or something else?
yes, BA-3 frontend or pre driver, same thing to me
note that Nelson calls his article Burning Amplifier BA-3
http://www.diyaudio.com/forums/diyaudio-com-articles/194809-burning-amplifier-ba-3-a.html
says that BA-3 is a complete concept
and yes, it also holds the BA-3 Frontend
BA-3 is just a natural follower to the BA-1 and BA-2
well, if buzz is replacing the BA-3 frontend with the 6V6, and driving the BA-3 output stage only, then its totally different matter from what I had in mind
6v6 was driving BA3 FE/BA2 output stage with two pairs vs 3. The output stage was biased slightly higher at 1.5A per fet.😀
The F5 has about15dB of gain an dso does the BA3. The 30dB number is for balanced from what most builders habe found.
The F5 and BA3 are VERY similar, with two major differences. One is the feedback, or lack thereof, and the second is the buffer output. As silly as it may sound, the BA3 as built above has a very different sonic signature than the cascoded F5T(with two output pairs) it was compaired with. If you like the F5 sound with 6v6, and you think the 6v6 may be a permanent part of you rsystem, i can only recommend you build a BA3. It sound adifferent in a good way IMHO.
PS, i hab econsidered how to drive BA output stage with 6v6. Only possibilty i see is either adding follower of samw nature to 6v6 or playing with bias schema of ba2 output stage. All this will begin bein gfleshed ou tin about a ,onth o rtwo after matching. Salas, terribly sorry to clutter your threa dwith my opinions, just trying to communicate whay an excellent sounding pre this is. Also nice to hear yo rthoughts about comparison to 26 pre, as i was considering building one. I think i will super tweak this one first.
You have to ask yourself a question. Would Nelson have released the BA3 amp and the others, if they sounded the same. Being a sort of teacher by nature, i believe there is a reason for most of what he does. Just like i know to watch if Salas releases something. He has heard enogh stuff, that if lets it go to the greedy boyz, it must be worth hearing😉
The F5 has about15dB of gain an dso does the BA3. The 30dB number is for balanced from what most builders habe found.
The F5 and BA3 are VERY similar, with two major differences. One is the feedback, or lack thereof, and the second is the buffer output. As silly as it may sound, the BA3 as built above has a very different sonic signature than the cascoded F5T(with two output pairs) it was compaired with. If you like the F5 sound with 6v6, and you think the 6v6 may be a permanent part of you rsystem, i can only recommend you build a BA3. It sound adifferent in a good way IMHO.
PS, i hab econsidered how to drive BA output stage with 6v6. Only possibilty i see is either adding follower of samw nature to 6v6 or playing with bias schema of ba2 output stage. All this will begin bein gfleshed ou tin about a ,onth o rtwo after matching. Salas, terribly sorry to clutter your threa dwith my opinions, just trying to communicate whay an excellent sounding pre this is. Also nice to hear yo rthoughts about comparison to 26 pre, as i was considering building one. I think i will super tweak this one first.
You have to ask yourself a question. Would Nelson have released the BA3 amp and the others, if they sounded the same. Being a sort of teacher by nature, i believe there is a reason for most of what he does. Just like i know to watch if Salas releases something. He has heard enogh stuff, that if lets it go to the greedy boyz, it must be worth hearing😉
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not according to Nelson himself
jfets are the same, yes
but you forget the mosfet drivers
The voltage appearing at the Gate of Q3 is amplified by something less than the ratio of R10 divided by R8, and with the same happening at Q4 and considering the transconductance of the Mosfets, comes out at about 15. Both of them added make a system voltage gain of about 30X, or 30 dB.