BA-3 as preamp or rebuild B1

[KevinHeem]

I'm currently using a B1 between a Pearl 2 and F5. I have increased the gain on the Pearl 2 from stock since my cartrige output is .5 mV. My speakers have a sensitivity 91.5. So with the potentiometers turned all the way up the system can get loud enough for me. I could increase the gain on the F5 if I needed a little more volume.

I would like to upgrade the line stage as my next project. I've been reading about the BA-3 as preamp and thinking that might be the way to go. But then again I could upgrade the B1 with stepped attenuators and new power supply. I know the BA-3 front end would have more gain than I need but it could give me the possibility of building an F4 in the future.

Any Ideas?

Thanks

 

[erin]

I never heard the BA-3. Depends if you are looking for a different sound or not.

The B1 is hard to beat. Its extremely transparent and natural sounding.

I recon build the F4 first then think about your preamp.

 

[ammel68]

No comparison...

Having built both, I think the BA-3 sounds MUCH better than any B1.

 

[Hikari1]

I am using a BA-3 in front of a F5 into Focal 714Vs.

Here's my BA-3 (Post 295)
http://www.diyaudio.com/forums/pass-labs/234641-ba-3-preamp-30.html

I used a passive preamp with and without a tube buffer for a while into the F5. Even used the MC section of my phono stage w/a HOMC cart for more gain (yes, a changed the loading to 47K). Didn't do it for me. I even pumped up the gain resistors on the F5 to 200 ohm. It sounded good but not what I was after.

I cobbled together a Jfet BOZ and bam...immediate gratification. Slam and bass, no downsides I felt.

Put together a BA-3 front end and it was even better. Plus, the P3 pot on the BA-3 really lets you dial in the sound you are looking for. I wouldn't worry about too much gain. With a CD player or 40 gain phono stage and MM cart I still use up 3/4 of the volume knob on occasion. I haven't heard any clipping. To my ears the BA3 is more like 20 gain or so. I felt the Jfet boz had more gain.

I could see the passive/F5 approach working for small scale jazz or some types of music where transparency and delicacy are valued. It worked better with CD than vinyl, which made me mad. But for rock or or classical the F5 plus preamp was better for me. No contest. Especially with vinyl...

 

[6L6]

The ba-3 is so much better sounding than the b1 it's a no brainer.

 

[erin]

I never heard of it until today.
Can you describe where it sounds better?

 

[Hikari1]

B1 is a passive preamp, no gain. Actually negative gain. BA-3, that we are discussing here is actually the front end of the BA-3 series used as a preamp.

Here's Nelson's write up:

http://www.diyaudio.com/forums/diyaudio-com-articles/194809-burning-amplifier-ba-3-a.html

Too me it sounds better with the F5 in every way, the f5 has pretty low gain in the amp.

 

[Hikari1]

Kevin:

If you have 2 10f caps and 2 matched 2k170 you can cobble together a Jfet boz with batteries pretty quick as a test. Actually, you have these items now...they are in your B1. You can use this or any other good preamp to see if you like the sound of your F5 with a preamp. Perhaps you have a friend close by or a shop that demos equipment...

 

[erin]

The thread was also asking about the B1.
Still no one can describe how the BA-3 sounds better?

 

[ammel68]

Still no one can describe how the BA-3 sounds better?

Sure...where the B1 sounds flat and lifeless(I think you describe it as "transparent"), the BA-3 sounds more "alive" in the mids and highs combined with more balls in the lower registers.

After building and hearing the BA-3, I threw my B1 in the trash.
I guess I should have removed those expensive and hard-to-find Toshiba JFETs first, though.🙂

 

[6L6]

After building and hearing the BA-3, I threw my B1 in the trash.

I wasn't quite as dramatic, I merely took my B1 apart and sold the guts and chassis.

 

[ammel68]

6L6, you must have more patience than I do.
Guess I just don't have the time or patience for inferior-sounding circuits.🙂

 

[erin]

Sure...where the B1 sounds flat and lifeless(I think you describe it as "transparent"), the BA-3 sounds more "alive" in the mids and highs combined with more balls in the lower registers.

After building and hearing the BA-3, I threw my B1 in the trash.
I guess I should have removed those expensive and hard-to-find Toshiba JFETs first, though.🙂

What was wrong with yours. 😱 Mine has awesome attack, hardly flat or lifeless. 😕

Thanks for your description.

 

[Hikari1]

It all depends on what amp you are feeding the passive preamp into...i was happy with a passive buffered pre into a tripath amp with about 30dh of gain. Into the 15db F5, not so much. The F5 likes a preamp. I think there was something in the 6 moons review of the f5 about its preamp preference...it was that it liked high gain preamps.

The B1 had its place. But its place is probably not in front of a low gain, low wattage amp while using inefficient speakers with big impedence swings.

 

[erin]

That makes more sense. I was running mine into an Emotiva XPA-2 with 32dB gain.
I never turned the volume pot up more than 3/4

 

[naz]

Now I await the return of the BA-3 pcb back into stock on the diy store...

 

[vdi_nenna]

I use both in my systems. Using heavily upgrade parts in B1 and standard parts in BA3-Pre. I have to say the B1 is hard to beat in the form it's in now. Waiting to see what Jan Didden SuperReg board can do for B1.

They are preamps for different purposes. Sounds to me like you want/need a pre with gain.

B1 is a passive preamp, no gain. Actually negative gain.

Isn't it unity gain +1?

where the B1 sounds flat and lifeless(I think you describe it as "transparent"),

What caps were you using in the input and output in the B1?
Which volume pot were you using?

Guess I just don't have the time or patience for inferior-sounding circuits.

I'm sorry, but you have no idea how wrong a statement that is. I hope you were kidding. :|
You are welcome to come hear my B1 against the BA3-pre any time. 🙂

 

[6L6]

Isn't it unity gain +1?

"Unity gain" (a term that kinda doesn't make any sense, but were stuck with ) would be a gain of zero. Active buffers have some very small losses, so the signal coming out is actually slightly smaller than the input.

 

[vdi_nenna]

I guess it's not +1. it's just 1. Definitely not negative.


Electronics Components: How to Use an Op Amp as a Unity Gain Amplifier - For Dummies

A unity gain amplifier is an electronic amplifier circuit that doesn’t amplify. In other words, it has a gain of 1. The output voltage in a unity gain amplifier is the same as the input voltage.

 

[Dennis Hui]

Interesting discussion. I'm actually in the process of hobbling together a B1,
simply because I already have the board and parts and I've found that I don't
turn my existing preamp above unity gain. (That's the case even with my low
gain amps; I guess I really do listen at quite low levels.)

I have BA-3 boards as well, so I will eventually build them. I think it will
still be educational to complete the B1 and see how it interacts with the
various amps I have to play with.

Cheers,
Dennis