Nelson Pass B-1 preamp kit

wushuliu · « **Reply #660 on:** 5 Jan 2012, 06:21 pm »

Quote from: ruphen on 26 Dec 2011, 05:21 pm

Hi,

Sorry for bringing this post back. i wanted to ask what the minimum/maximum voltage everyone is using. Reason i ask, is i have a power supply with a switch but the voltages are 13/30. would this PS work?

thanks in advance,

Ruphen

Not sure what kind of PS that is, but 13v should suffice.

vinylb · « **Reply #661 on:** 5 Feb 2012, 03:43 pm »

Been awhile since anybody posted in this thread. I am about to embark on my B1 journey and will be using the BOM posted on 1st page but I have some questions:

1. is the B1 still the preamp to get in terms of value, sound quality and simple assembly steps or is there another that has taken the crown?
2. Apart from replacing the walwart with a battery solution and also replacing caps, is there anything else that folks are tweaking? I can believe
the battery would make a difference but is the cap replacement noticable?

Thanks to all that have posted their experiences here.

1MOR · « **Reply #662 on:** 4 May 2012, 11:45 pm »

Any one start a new build, finish a build or swapped in new parts on an existing build? Just thought I would check? I finished a diy Pass F5 amp build and have been using the B1 that I built off this thread. I am gathering parts to upgrade the B1 resistors and caps.

The B1 is quite impressive sounding with the F5. Excuse the test setup.

Nick77 · « **Reply #663 on:** 4 May 2012, 11:59 pm »

What caps and resistors are ya gonna try. I just recently upgraded to the DCB1.

1MOR · « **Reply #664 on:** 5 May 2012, 12:56 am »

I have Russian Teflons for the 1 and 10uf caps, 1K Zfoils for input and output resistors, PRPs for the remaining resistors and have Mundorf electrolytics ordered for the power caps. The LED is way too bright so that will be tamed with a 33K resistor. May also do some mods to the case, new front panel to match the F5. Thinking about a 1/4" piece of machined 6061 aluminum to replace the stock panel.

I have enough parts for a hot rod DCB1 Hypnotize build but wanted to take the B1 as far as I could before starting another project..

Nick77 · « **Reply #665 on:** 5 May 2012, 01:01 am »

Sounds like great choices, you will be rewarded.

The B1 with upgraded parts is an excellent buffer, the dcb1 takes it up a few notches.

1MOR · « **Reply #666 on:** 6 May 2012, 04:08 pm »

Anyone else? There seemed to be a great amount of interest when this project was first started?

wushuliu · « **Reply #667 on:** 7 May 2012, 07:13 am »

Quote from: 1MOR on 6 May 2012, 04:08 pm

Anyone else? There seemed to be a great amount of interest when this project was first started?

This thread is over 2yrs old (!), which is a long time in diy years since then there's been the dcb1, dodd tube pre, and the optocoupler-based pre/buffer designs. Glad you are enjoying the B1.

kevinh · « **Reply #668 on:** 8 May 2012, 10:04 pm »

Quote from: 1MOR on 6 May 2012, 04:08 pm

Anyone else? There seemed to be a great amount of interest when this project was first started?

Nelson is still selling the boards with a set of FET's for $40 @ the first watt website/

sachu888 · « **Reply #669 on:** 15 May 2012, 09:01 am »

Hi,
I am using Pass B1 with LDR Volume control.I must say that B1's performance is quite impressive. Most important observation is the quietness of the system even at high volume. Soundstage improved a lot. Instruments became more defined & very very clear.
I have noticed the bass sounded very with B1 using LDR volume control.The Bass-power was reduced drastically.I get a better bass response If I put my LDR volume control at max position and control volume from my Technics integrated amp.I would like to ask other FM using B1 regarding their experience.
My system: TT--> DIY Phono--> B1--> Integrated amp

Regards,
Sachin

voxxonline · « **Reply #670 on:** 3 Jan 2013, 03:26 pm »

Gents, hello

I am specifically registered on this forum due to very hq threads on B1 buffer.
I have my b1 ready, but since I have got salas sslv , I would like to ask for a help, if anybody has built psu specifically for b1 ?
If yes, can one to share how to 's for it , as I dont want to make a mistake

And one more thing- what is a suggested upgrade for b1 components ?

Thank you

vinylb · « **Reply #671 on:** 7 Apr 2013, 02:00 pm »

Well after months of deciding what to do I ended up purchasing the PCB from Pass store and parts based on the BOM from first page. I know this thread has been dormant for a long time but thought I would share my pictures of my preamp.

I followed pretty much all of the BOM but opted for ALPS pot and boutique caps which to me made a huge difference in the sound - better be for that price

I originally had Solens - Janzten caps
were night and day. In fact it was so good that I can easily say that this preamp now comes very close to my ARC SP6C tube preamp. I was concerned about the length of wiring to each of the 6 inputs
but so far have not had any crosstalk. Yes I do need 6 inputs

DAC (SB Touch to external dac), Vinyl, CD player, Tape deck, Reel 2 reel and a spare. also added a HT bypass so my kids could still hear their games via front channel speakers without having to mess with the input and volume. Worked out good.

Thx again to all who have posted over the years.

Nick77 · « **Reply #672 on:** 7 Apr 2013, 02:14 pm »

Nice build, those signal resistors have a surprising effect on resolution also.

vinylb · « **Reply #673 on:** 7 Apr 2013, 02:58 pm »

Thx Nick77. You referring to the 1K resistors? What did you use ? Were you able to compare to original?

Nick77 · « **Reply #674 on:** 7 Apr 2013, 03:09 pm »

Quote from: vinylb on 7 Apr 2013, 02:58 pm

Thx Nick77. You referring to the 1K resistors? What did you use ? Were you able to compare to original?

Most felt lowering the value to 330r was best for sonics, so thats what i used.
Lots of comparison, best to worst.....

Vishay TX2575 Foil very resolute and neutral
Riken Carbon warm and fairly resolute
PRP Metal film good metal film
Takman Carbon, warm but conjested

vinylb · « **Reply #675 on:** 7 Apr 2013, 03:48 pm »

Yeah I read that somewhere too. K, I will now have to get those resistors

Thinking of getting another preamp/build together, maybe I should save it for that build with even better caps

I really would like to try the DCB1 kit but it looks a lot more complex and pcb's are hard to find.

rif · « **Reply #676 on:** 7 Apr 2013, 04:46 pm »

Quote from: vinylb on 7 Apr 2013, 02:00 pm

I was concerned about the length of wiring to each of the 6 inputs
but so far have not had any crosstalk. Yes I do need 6 inputs DAC (SB Touch to external dac), Vinyl, CD player, Tape deck, Reel 2 reel and a spare. also added a HT bypass so my kids could still hear their games via front channel speakers without having to mess with the input and volume. Worked out good.

Thx again to all who have posted over the years.

What did you use for a selector switch? Does it switch the signal and ground or just signal?

vinylb · « **Reply #677 on:** 7 Apr 2013, 07:08 pm »

I used a 2P6T switch, no ground was used. I would have preferred to have switched signal and ground but I could not find anything cheap and easy to wire up with 6 inputs.
So i grounded all inputs to the pcb which in turn was grounded to chassis.

vinylb · « **Reply #678 on:** 9 Apr 2013, 02:13 pm »

Quote from: Nick77 on 7 Apr 2013, 03:09 pm

Most felt lowering the value to 330r was best for sonics, so thats what i used.
Lots of comparison, best to worst.....

Vishay TX2575 Foil very resolute and neutral
Riken Carbon warm and fairly resolute
PRP Metal film good metal film
Takman Carbon, warm but conjested

Nick, I reread your posts earlier on in the thread and about how you replaced all 4 1K with these TX2575....Do you still believe that the DCB1 is better than your B1 with these TX2575?
I been thinking that at some point if I have not already, will be hitting diminishing returns on any more parts I throw at my B1. I think TeaBag over at diyaudio has new stock of DCB1 kits.
Did you buy the kit or did you buy exotic parts?

Thx

Nick77 · « **Reply #679 on:** 9 Apr 2013, 02:19 pm »

Yes the DCB1 is a cut above the B1 even with TX2575 although I also use TX2575 in my DCB1. I purchased boards only and used exotic parts. Mine is the hotrodded version running at about 600mA.