Nelson Pass B-1 preamp kit

Nick77 · « **Reply #420 on:** 28 Jul 2010, 02:38 pm »

I have found that the 4-1k resistors have quite an effect with the B1. Im surprized it isnt mentioned a whole lot, seems to be a bigger issue on the dcb1 thread. Im sure it is somewhat system dependant but good parts in this location should be considered.

I have tried several different resistors so far and awaiting some naked Vishays now.

Takman carbon film- great bass and dynamics, warm and smooth but lack transparency
Prp metal film- smooth and transparent but lacks dynamics
Riken carbon film- great resistor with good transparency, smooth, awesome bass and dynamics. I think i could live with all 4 Rikens but some say use in moderation.
Naked Vishay(TX2575)- report back

I am going to try the Vishays as the input resistor and have the Rikens on the output right now, hoping that will be a good balance with awesome transparency. I will also note these results are based upon 330r.

roymail · « **Reply #421 on:** 28 Jul 2010, 06:12 pm »

Quote from: walkern on 27 Jul 2010, 03:57 pm

I think if I had it to do over again I'd be tempted to go with the 9V rechargeable battery set up mentioned earlier.
Neil

The B1 sips very little current. Nelson Pass said, "The preamp typically draws fewer than 0.02 Amps, so current is not much of an issue."

It's little wonder why the two 9V rechargeable setup would work great with the B1. And, it wouldn't cost much to implement.

wushuliu · « **Reply #422 on:** 28 Jul 2010, 07:43 pm »

Quote from: Nick77 on 28 Jul 2010, 02:38 pm

I have found that the 4-1k resistors have quite an effect with the B1. Im surprized it isnt mentioned a whole lot, seems to be a bigger issue on the dcb1 thread. Im sure it is somewhat system dependant but good parts in this location should be considered.

I have tried several different resistors so far and awaiting some naked Vishays now.

Takman carbon film- great bass and dynamics, warm and smooth but lack transparency
Prp metal film- smooth and transparent but lacks dynamics
Riken carbon film- great resistor with good transparency, smooth, awesome bass and dynamics. I think i could live with all 4 Rikens but some say use in moderation.
Naked Vishay(TX2575)- report back

I am going to try the Vishays as the input resistor and have the Rikens on the output right now, hoping that will be a good balance with awesome transparency. I will also note these results are based upon 330r.

Thanks for the report!

Very interested in hearing about the Vishays...

exojam · « **Reply #423 on:** 1 Aug 2010, 10:38 pm »

Well I just got the case and RCA’s ordered up. Now I am just waiting for everything to arrive and then I can start the process of assembly.

James

Nick77 · « **Reply #424 on:** 2 Aug 2010, 11:50 pm »

Looksey what i got today! I am going to hold off on comment till i give'em and few hrs breakin but i will say they seem to live up to all the hype.

bigaudioscotto · « **Reply #425 on:** 3 Aug 2010, 08:58 pm »

Hey guys
Just thought I would post a couple shots of finished B1.

Scott

Nick77 · « **Reply #426 on:** 3 Aug 2010, 09:40 pm »

Guys i have to say switching from prp resistors in the signal path to premium resistors was no small subtle change, but i would say more like 20% jump in performance. I have dynamics thru the roof and the bass is now outstanding. The Riken add a small dose of warmth to the sound but still transparent and the Vishays are dead nuetral and very quiet with outstanding transparency. Cant reccomend premium resistors enough, my B1 is now a great audiophile piece of equipment.

Scott is currently trying the Rikens on my reccomendation, maybe he will give some input.
Scott great looking B1 by the way.

Rikens $4ea Angela.com
Vishay tx2575 $9.40ea Texas Componants

Edit: replaced riken with vishay, riken were a tad warm for my system. 4 vishays are very clean and nuetral.

bigaudioscotto · « **Reply #427 on:** 3 Aug 2010, 10:10 pm »

Guys
Keith is correct,the 4 1k signal resistors are very critical
in the B1,
everything is system dependent,try various resistors until you find the
right flavor.

exojam · « **Reply #428 on:** 4 Aug 2010, 01:46 pm »

Here is my progress so far. Just resistors, jfets and some caps. I wanted to wait on getting the enclosure before running any of the wires for everything else. The picture is not the best so I apologize about that.

James

sondale · « **Reply #429 on:** 7 Aug 2010, 10:19 am »

Glad I dropped in on this thread again - as I am about to re-house my LSA / B1 into a case with the NP Pearl Phono I will have to try changing the resistors.

The increase in the level of performance seems to be well worth the effort and cost.

Alan

roymail · « **Reply #430 on:** 7 Aug 2010, 12:37 pm »

Hey Alan, how are things across the pond? Hope you're doing well. Be sure to post your finished project.

Hi Scott, very nice job on the completed B1. Let us know which resistors work best for you. Thanks!

exojam · « **Reply #431 on:** 7 Aug 2010, 11:07 pm »

Well I got some more done today. I made a few mistakes on this project but I do not think anything will impact the performance. I made the hole for the switch a little too big and drilled one hole for an RCA at a bad angle

The RCA is tilting down because on the inside of the cover it is hitting a rib piece. I should be able to somehow file it down so it will be flat but it is also a little off center compared to the other.

Now all I need it to get the power receptacle (back order at this time), solder in the led and get a knob for the volume pot.

The picture just shows the PCB laying ion the housing, I have not secured it at this time, just wanted to take a picture real quick.

James

exojam · « **Reply #432 on:** 10 Aug 2010, 02:15 am »

One more mistake I made was pointed out to me, that would be a mono pot I have installed instead of a stereo one

exojam · « **Reply #433 on:** 10 Aug 2010, 03:28 am »

Quote from: Nick77 on 2 Aug 2010, 11:50 pm

Looksey what i got today! I am going to hold off on comment till i give'em and few hrs breakin but i will say they seem to live up to all the hype.

Nick,

Did those go in R105 and R205? Thanks.

James

Nick77 · « **Reply #434 on:** 10 Aug 2010, 11:43 am »

Quote

Nick,

Did those go in R105 and R205? Thanks.

James

No, the Vishay's are in the input position R102 & R202.

I have Rikens in the output R104 & R204.

It should be noted that Scott tried Rikens in both positions and wasnt favorable results. They seem to only play well in the output, use in moderation seems to apply. Having a good transparent neutral resistor like the TX2575 in the input seems to be key.

Edit: replaced riken with vishay, riken were a tad warm for my system. 4 vishays are very clean and nuetral.

roymail · « **Reply #435 on:** 10 Aug 2010, 11:48 am »

Any noticeable audible difference?

Nick77 · « **Reply #436 on:** 10 Aug 2010, 11:53 am »

Quote from: roymail on 10 Aug 2010, 11:48 am

Any noticeable audible difference?

As i stated earlier the bump in performance over the prp's was quite substantial and in the neighborhood of 20% increase in performance. Mainly dynamics and bass and better resolution.

exojam · « **Reply #437 on:** 10 Aug 2010, 11:56 am »

Quote from: Nick77 on 10 Aug 2010, 11:43 am

No, the Vishay's are in the input position R102 & R202.

I have Rikens in the output R104 & R204.

It should be noted that Scott tried Rikens in both positions and wasnt favorable results. They seem to only play well in the output, use in moderation seems to apply. Having a good transparent neutral resistor like the TX2575 in the input seems to be key.

Nick,

OK so those are just the 1K ohm ones. Thanks for your reply.

James

Nick77 · « **Reply #438 on:** 10 Aug 2010, 11:59 am »

Quote from: exojam on 10 Aug 2010, 11:56 am

Nick,

OK so those are just the 1K ohm ones. Thanks for your reply.

James

Yes the 1k resistors are the ones in the signal path and one should consider premium parts in this position. Again my results are using 330r instead of 1k.

roymail · « **Reply #439 on:** 10 Aug 2010, 12:16 pm »

Quote from: Nick77 on 10 Aug 2010, 11:59 am

Yes the 1k resistors are the ones in the signal path and one should consider premium parts in this position. Again my results are using R330 instead of 1k.

Sorry, what does R330 refer to?