Vocal preamplifier

AnthonyA

Member
2017-08-28 9:38 am
Happy new year all

I got a loan for diy aleph L, almost as good as original one was said. Almost.. .. It's so good for vocal and simple acoustics... I don't think anybody could tell them apart from tune preamplifier in blind test. In fact I think aleph L fared better then most tubes

So what's the ultimate here for tuby lovey dovey vocal acoustic preamplifier?
 
I would agree regarding the sound of the Korg B1 circuit. However, somewhat heroic measures need to be taken to isolate the Korg P1 VFD tube from acoustic and mechanical vibration. Mine sounds great, but it is housed inside the case of a Naim NAC 62 (unventillated cast aluminum) with extra foam support underneath the Korg B1 PCB.
 

AnthonyA

Member
2017-08-28 9:38 am
I have ba3 similar preamp, Fab's usspa. It's somewhat different. It's great for all kinds of music, it's a great balance. Does everything very well yet it's tube like. But not exactly.

But for vocal or simple music.. Alpeh L, single ended ss/tubes just simply better but lose out in other areas... I'll try to avoid tubes since I already have few of them. I want a solid state which outperform tubes in terms of detail, hopefully up the ante on vocal richness

H2 generator.. I'll take a look at it

How bout luminaria?
 

adason

Member
Paid Member
2004-11-10 8:31 pm
Maryland
I built a BA3 preamp for a good friend who is a golden ear speaker designer.
He loves the BA3 preamp. I auditioned his system with the BA3 playing vocal jazz and the system with the BA3 pre was stunningly good.

I find ba3fa to be clean, precise, almost analytical. Not much distortion, not sure if that is what thread starter has in mind. Definitely not tuby lovey dovey.

I do not have korg b1, but i built h2 harmonic generator, and it definitely adds a lot of sweetness depending on trimer settings. I am thinking about putting a pot on the front of the box for easy adjustment. Should be fun.
When i inserted h2 between cd player and headphone amp, i liked to adjust the settings based on the complexity of the music and the recording. When you use tube headamp with lots of its own second harmonic, and you listen to something like enya or loreena mckennitt with too many echoes and reverbant recording, you may even get way overboard with sweetness. Its good to have choice for complex orchestral music, or complex well recorded rock like peter gabriel or sting...

I would start with h2, its easy to built, all parts available.
 
to AnthonyA

Have you tried to adjust pot3 in your BA-3 preamp? (not the bias pots 1 and 2)



I like the BA-3 Pre, KORG NUTUBE Pre, Aleph P1.7.
In my opinion it always depends on the chain.
But at the moment the KORG NUTUBE Pre is the most versatile preamp
for me (from those three mentioned above).
I think the advice of Adason with the H2-generator is really good.
Easy to build, low cost - worth a try.
Greets
Dirk
 
to AnthonyA

Hello Anthony,


to adjust POT 3 on the BA-3 Preamp changes the value between 2nd and 3rd
harmonic distortion. So this is a possibility to adjust the 'sonic character' of the BA-3 Pre in little dosage.

I would describe the overall sonic character of the BA-3 Pre
more on the 'analytic' side. But not harsh or overanalytic or cold!
I like the BA-3 Preamp a lot! And I use mine very often! So please don't misinterpret my words.


If you use the H2-generator of Mr. Pass you play with the voltage over your active device (in this case the J112 / J113 JFet) as well the current running through it. This changes the phase of negative 2nd harmonic distortion in comparison to the outputsignal (or positive 2nd harmonic distortion if you change the polarity of your loudspeakers at the poweramp or in front of the H2 generator). If you feed the H2-generator with an sinuswave signal and you watch your outputsignal and its 2nd harmonic distortion - it is like moving the two sinus curves on the X-axis against each other (this is something different then if you adjust POT 3 in the BA-3 Pre)

Mr. Pass was matching the JFets for this special purpose in the H2-generator in each kit he was giving away!
I think you could do something similar with a JFetBOZ if you make the voltage over the JFet adjustable. I did this in my JFet BOZ. But you will not have the correct values in your JFets to achieve the same result as in the H2 - generator.
And you would have to adjust the drain- and the sourceresistance around your JFet to get into the right 'area'.
I hope I could explain it how I understood it. And I hope that I am not completely wrong. The genius who designed this is Nelson Pass!;)


Greets
Dirk