Nelson Pass B-1 preamp kit

earplay · « **Reply #60 on:** 7 Mar 2010, 06:24 pm »

Thanks for the pics and instructions!

schubert, nice looking build. Mine's going into a cigar box, I suppose. Maybe I should use some grounded copper screen to shield it.

wushuliu, you da man, you da man! I see you intend to keep it coming.

Now, I just need the kit to arrive.

By the way, what is the cost of the kit and parts from Pass diy, Digikey and Mouser? I've seen $80 and $150. Does anyone know?

EDIT: Okay, just did a bit of homework on electrical schematic symbols. They are straightforward enough. Also, looking at the kit's parts list, there is an alphanumeric designator for each part that corresponds to an alphanumeric notation on the pcb. This should be no problem for me, aside from the nerve damage effects on my soldering skills. I'll quit whining now.

wushuliu · « **Reply #61 on:** 7 Mar 2010, 06:43 pm »

My $80 dollar estimate was wrong. $150 would be the total for the BOM I listed including shipping, rca connectors and enclosure I believe. Obviously you can save about $20 going w/ the ebay pcb, and you can save more going w/ a cheaper potentiometer, cheaper enclosure etc.

Nick77 · « **Reply #62 on:** 7 Mar 2010, 07:09 pm »

Wushuliu thanks for all the pics and instruction. So the only item that requires a certain orientation is the j fets? The resistors and caps are omni directional?
Thanks.......

P.S. If you decide to put the unit on tour please count me in.

wushuliu · « **Reply #63 on:** 7 Mar 2010, 07:15 pm »

Quote from: Nick77 on 7 Mar 2010, 07:09 pm

Wushuliu thanks for all the pics and instruction. So the only item that requires a certain orientation is the j fets? The resistors and caps are omni directional?
Thanks.......

P.S. If you decide to put the unit on tour please count me in.

The jfets, diode, led, and Power Supply caps require correct orientation. I will cover the power supply and all other parts that require specific orientation when they arrive.

atroder · « **Reply #64 on:** 7 Mar 2010, 07:53 pm »

Wushuliu - Excellent - above and beyond !

sondale · « **Reply #65 on:** 7 Mar 2010, 08:54 pm »

Wushuliu - you have done the same as I have except that you have shown the circuit along with the components - a very nice idea.

I will forget about posting my photos etc - duplication. I had thought about going through the build of the Lighter Note (Uriah's version of the LSA) but there is a document available from Uriah (see DiyAudio), so instead I will just explain how and why I modified the B1 to include the LSA.

Keep up the excellent work.

Alan

Mariusz · « **Reply #66 on:** 7 Mar 2010, 09:41 pm »

Excellent 1•2•3 step-by-step instructions Wushuliu.
Wish other guys steped up with projects like this.

Thumbs way up

Mariusz

Nick77 · « **Reply #67 on:** 7 Mar 2010, 10:03 pm »

Hal what is the purpose of using 1.5 sonicap intead of the parts list of 1.0?

wushuliu · « **Reply #68 on:** 7 Mar 2010, 10:11 pm »

Quote from: Mariusz on 7 Mar 2010, 09:41 pm

Excellent 1•2•3 step-by-step instructions Wushuliu.
Wish other guys steped up with projects like this.

Thumbs way up

Mariusz

Thanks Marius. Just my way of giving back to the audio community.

HAL · « **Reply #69 on:** 7 Mar 2010, 11:54 pm »

Quote from: Nick77 on 7 Mar 2010, 10:03 pm

Hal what is the purpose of using 1.5 sonicap intead of the parts list of 1.0?

I already had them from another project. They are matched units, and close enough in value to the originals for input coupling caps to work well.

peranders · « **Reply #70 on:** 8 Mar 2010, 09:42 pm »

I had a group buy of these boards (with permission from Mr. pass) but they are all gone, sorry. Red nice pcb's with gold pads.

It's a good design and I'll hope my pcb's will be used.

Sonny · « **Reply #71 on:** 8 Mar 2010, 10:21 pm »

Where can one get the boards to start this project?

sts9fan · « **Reply #72 on:** 8 Mar 2010, 10:23 pm »

Check over at diyaudio for some groupbiysnor I think passdiy may still have em

wushuliu · « **Reply #73 on:** 8 Mar 2010, 10:44 pm »

Quote from: Sonny on 8 Mar 2010, 10:21 pm

Where can one get the boards to start this project?

2 Links are in the first post. If the ebay link does not work, just search 'B1 Buffer'. Buying from
Pass himself is preferable.

Bemopti123 · « **Reply #74 on:** 8 Mar 2010, 11:31 pm »

Quote from: Sonny on 8 Mar 2010, 10:21 pm

Where can one get the boards to start this project?

Need to download an order form from PassDIY, fill, scan and send to their email. NEVER send CC info in this email form. They will reply with a phone number, you call and give them info over the phone.

Even though the Ebay kit is cheaper, as you can already tell, Pass gets 0 anything from it. It is unjust, so I ordered mines through this website. $45 per board shipped with 4 matched Jfets.

The list of items that Wushuliu provided is like trekking across the world, especially with Digitkey which wants to to buy some items at numbers as large as 10X what you need, but hey, we are talking cents worth per items. Not biggie.

I ordered the Digitkey pack. I also ordered some stuff through PartsExpress...but I wonder, the toggle switch is for on and off or was it for source selection?

BTW: Remember to order at least 3 pairs of female chassis mount RCAs, along with a knob for what volume pot you choose. I had to call Canada, prior to their submitting the internet order. Got my volume pot and RCAs from my favorite people, PartsconneXion.

wushuliu · « **Reply #75 on:** 8 Mar 2010, 11:39 pm »

Quote from: Bemopti123 on 8 Mar 2010, 11:31 pm

The list of items that Wushuliu provided is like trekking across the world, especially with Digitkey which wants to to buy some items at numbers as large as 10X what you need, but hey, we are talking cents worth per items. Not biggie.

Thanks for mentioning this bit. I reviewed the BOM and caught the mistake with the 1 ohm resistor. I thought I corrected that already. Otherwise I believe each item is available as a single unit.

earplay · « **Reply #76 on:** 9 Mar 2010, 03:00 am »

To those who know,

My amp has an 100k input impedence. For the B1, the Alps pot I have is a 100k pot. Are these values acceptable of good performance of the B1 with my amp?

wushuliu · « **Reply #77 on:** 9 Mar 2010, 04:37 am »

First official boo-boo. The PS caps I listed in the BOM are too wide for the Nelson Pass PCB. They should be fine for the Ebay PCB, but I have updated the BOM with ones that will fit both.

wushuliu · « **Reply #78 on:** 11 Mar 2010, 03:46 am »

Quote from: earplay on 9 Mar 2010, 03:00 am

To those who know,

My amp has an 100k input impedence. For the B1, the Alps pot I have is a 100k pot. Are these values acceptable of good performance of the B1 with my amp?

I think Nelson's response to the 100k pot question was basically 'give it a shot'.

wushuliu · « **Reply #79 on:** 11 Mar 2010, 03:52 am »

This is continued from the reserved spaces on Page 3, so for those currently following right now you'll want to head back there.

Power jack

Black wire = Negative White = Positive center

Obviously white wire goes to '+' on the pcb to the left.

Waiting for the new PS caps to come in and then this is pretty much done!