B1 Buffer Preamp

@manus.hattingh Sorry man, I missed your post when asked for advice regarding the B1 earlier this month... Have you taken a decision yet? If your amp had enough gain, then it will work with the B1. For the price, I'd give it a try. Regarding the caps, I tried several ones, and the best results are Mundorf MCap Zn (not available anymore), which are small-signal MKP's with heavy Zinc foil to avoid microphony effects. Second best (almost no difference, really) are WIMA MKP, they are just very neutral as well. Even on direct comparison (I have 2 B1's) it is barely noticable. If I had to rebuild one, I'd go for the WIMA's (They cost 30x less than the Mundorf's).

Here's my build with the Mundorf caps. The B1 is the board on the left (In the center are the 2 Pearl II phono preamp boards). I use a ladder-type stepped attenuator as volume control, all cables are shielded and the shield goes to chassis earth. And the transformers are shielded by empty bean cans. Works like a charm! One transformer is for the B1 and 1 for the phono boards. The small board on the bottom right corner is a voltage regulator board for the B1. Nothing fancy, but it does the job perfectly.

B1.jpeg

Cheers, Denis
 
Last edited:
Hello!
I too built my B1 up after the pcb collected dust for many years and I really love it.

In combination with my ProtoDAC personally haven‘t had a better sounding combination so far.

One question though:
When I turn my 25k pot all the way it is as loud as I can take it. But, I’m using a stepped switch with resistors and the first half is basically useless and then the steps are quite big….

Is there anything I can do other than change to a normal pot?
The other thing I thought about was is to exchange the resistors in the stepper switch which is currently logarithmic
 
Looks like you've got 50 Austrian Bucks in a $300 parts unit. I'd live with it. I replaced a very good PEC KK series pot in my 76 line stage with a Goldpoint and was elated but that's 6 times as much.

The 100K, $50 Audio Note pot I had on hand for my B1 is, as we used to say when tuning to "A", good enough for Jazz.

Rikiheck, the wood is solid cherry. Looking forward to seeing your exotic veneer.
 
By Thanksgiving, the Pass B1 will have a matching Tubelab Simple Push-Pull amplifier and I'll have, with the Audioengine B1 receiver, a full Apple Music system. The cherry case and aluminum top plate are ready for the iron and I began stuffing the board last night.

spp1.jpg

spp2.jpg


The SQ isn't quite up to the excellence of my all vinyl gear (experimenting with the Pas B1 and a $50 T-amp stolen from the TV setup) but darn fine and enables listening on demand to whatever strikes my fancy like new infatuation Brandy Clark.
 
Last edited:
  • Like
Reactions: 1 users
Got holidays side-tracked and haven't finished the Tubelab push pull but came across an ad for this Emotiva A2M for $279 and bit.

Haven't had a solid state amp since a Muse 100 oh so many years ago. It won't replace anything in my main system but exceeds my expectations for a background music streaming setup with both these B1s, Audioengine and Pass.

Streamer.jpg
.
 
Thanks @audiosteve! Btw the supply is single in the FW device. I think, the GND is "floating".
Yup. The design can use a virtual ground or a true bipolar supply. I use this myself in my office stereo with some added gain and a linear biploar power supply. The sound is incredibly good! I am building a larger version right now for the main rig in the living room.