The BA-3 as preamp build guide

[Soundhappy]

Originally Posted by Dennis Hui

For the Korg Nutube.... So
for those interested, that may be an easy way to give this part a try.

Dennis

Easy way a try something else for sure.
Btw I do collect step by step hi quality parts for original B1Triode version

[ColinA123]

How hot does R13 get? (330r 3w)
My heatsinks are quite big and I could do with mounting these resistors under the boards.
Then stand the boards off the case about 20mm.

[reelone]

found the problem to my build! fake fets from Ebay!

[Zen Mod]

surprised ?

[drpro]

This is one person's thoughts on the AKSA-Lender, the Nelson BA-3 and the Yaniger ImPasse preamps. The amps being used are a pair of bridged Pass designed F4. The F4 amps need a preamp with a larger output voltage than most preamps can deliver. The three listed above are capable of the necessary output.

My first DIY build began in 2014 was the BA-3 followed by one F4. I liked that combination so well I build another F4. The ImPasse was something I wanted to try and finally late last year purchased the boards and input transformers from Jack. Then Hugh delivers his AKSA-Lender preamp to the community and I wanted to try it also with the F4 amps.
Please keep in mind these are my thoughts using this three preamps and your listening experiences will vary, due to variances in the builds, your listening space and choice of speakers.

My BA-3 build uses a single toroidal transformer into a Salas shunt regulator. The BA-3 has genuine Toshiba transistors and I am using 10uf Mundorf SIO caps on the outputs with Goldpoint pot and selector. Using the P3 adjustment, the second harmonic has a negative phase. The AKSA-Lender was built from the BOM listing from that thread. I chose R9 for a more dominate second harmonic. Finally the ImPasse was also built using the BOM from that thread. I did do some tube rolling, started with Electro Harmonix and really didn't like the sound. Finally ended with some NOS RCA and Amperex tubes.

I am using a Pink Floyd song from their 1973 album "Dark Side of the Moon". That song is " The Great Gig in the Sky". The instruments are a piano, Hammond organ, pedal steel guitar, bass, and drums. The main vocals are supplied in an almost orgasmic way by Clare Torry. Her wailing reveals much about the preamps. Also I listened to the live version of Dave Brubeck's "Take Five" from the album "Concord on a Summer Night".

BA-3 preamp
A nice wide sound stage, with the pedal steel guitar coming more from the right side. Good depth with the vocal and drums coming from the rear. Cymbals are crisp. In the second set of vocals distinct sounding. The piano sounds very smooth and rounded. There is a nice sonic balance with the bass.

AKSA-Lender preamp
Also a wide sound stage. The pedal steel is not as defined as the BA-3. Cymbals have a nice sizzle. The Hammond organ is distinct and the vocals are more forward sounding. Drums are also very defined.

ImPasse preamp
Another wide sound stage. The piano and pedal steel are well defined. Vocal appears from upper left with the bass more defined. Cymbal also with nice sizzle sound. In the second set of vocals there is a nice balance with the piano. For me the vocals were not as clearly defined as the two solid stage preamps.

Finally the question would be which is best/sounds better, etc. For me there is a personal enjoyment when listening with each preamp at different times with different music. Ok, my order of preference would be the BA-3, AKSA-Lender, and ImPasse. I believe both solid state preamps have a slight edge over the tube preamp. Finally if you want to look at cost and versatility then the AKSA-Lender has both of the others beat for price and convenience. In my opinion it offers the most bang for the money.

So final thoughts, any of these preamps would be great with the Pass F4 amps. My wife and I for the past twenty years have been involved with retired racing greyhound adoption. In that adoption world, there is a catch phrase that is applicable to the DIY audio world. It is "they are like potato chips, it's hard to stop with only one". True for the greyhounds and so true for the DIY audio world. All I can say is build and enjoy.
Thanks
David

[novanta00]

Please where can I find a BoM for the BA3 as preamp ?
In the Store BoM is blank.
Thanks

[Dudeisms]

If One were so inclined, and wanted to get crazy and fancy with C3, and say that individual didn't care so much about cost (within some sort of reason, barely). What would be your suggestions for a fancy pants 10 uf capacitors.

Asking for a friend (Not really)

[hirscwi]

Originally Posted by novanta00

Please where can I find a BoM for the BA3 as preamp ?
In the Store BoM is blank.
Thanks

Attached is a BoM for the BA3 that I used. It includes the parts on the board and those in addition (i.e. not on the BCP). The components for the board are applicable to all but the others are specific to my build. Hope it helps.

[Hikari1]

Originally Posted by Dudeisms

If One were so inclined, and wanted to get crazy and fancy with C3, and say that individual didn't care so much about cost (within some sort of reason, barely). What would be your suggestions for a fancy pants 10 uf capacitors.

Asking for a friend (Not really)

Pass uses what appears to be clarity cap esa in xp pre. Should be good enough.