Nelson Pass B-1 preamp kit

parodielin · « **Reply #200 on:** 13 Apr 2010, 03:18 am »

I want to buy this volume pot suggested by wushuliu

Ebay DACT-Type Stepped Attenuator - $15 shipped
Even better AND cheaper
You can find values for 20k and higher. These are frickin' great for the money.

http://cgi.ebay.com/DACT-Type-21-Stepped-Attenuator-Volume-20K-for-PreAmp_W0QQitemZ200437532132QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item2eab0205e4#ht_1476wt_1202

Could you suggest a knob that would fit this through Digi-Key? What are the key filters that would ensure the knob will fit the pot? (I can do the search, just need to know the right filters.)

Thanks!

wushuliu · « **Reply #201 on:** 13 Apr 2010, 04:38 am »

Thanks for mentioning this. Since using them I have learned there is one caveat: as they only have 21 steps and are in fact linear I believe, there is a larger volume increase from step to step - it's not a 'smooth' increase in volume. So unless you're familiar w/ these kind of pots, I would recommend getting the Alps pot or similar from the Partsconnexion link. There are knobs for them on ebay. just search 'alps knob'.

parodielin · « **Reply #202 on:** 13 Apr 2010, 03:21 pm »

I am definitely not familiar into this and I was surprised to learn that volume pot could cost $300. Geez.. Learn something new everyday.

Would this Apls work? http://www.partsconnexion.com/product7387.html 100K

How do you tell whether it is linear or not? Would this one work better?

http://www.partsconnexion.com/product7386.html 250K

I don't know what makes the 100K and 250K different.

Quote from: wushuliu on 13 Apr 2010, 04:38 am

Thanks for mentioning this. Since using them I have learned there is one caveat: as they only have 21 steps and are in fact linear I believe, there is a larger volume increase from step to step - it's not a 'smooth' increase in volume. So unless you're familiar w/ these kind of pots, I would recommend getting the Alps pot or similar from the Partsconnexion link. There are knobs for them on ebay. just search 'alps knob'.

wushuliu · « **Reply #203 on:** 13 Apr 2010, 04:01 pm »

Quote from: parodielin on 13 Apr 2010, 03:21 pm

I am definitely not familiar into this and I was surprised to learn that volume pot could cost $300. Geez.. Learn something new everyday.

Would this Apls work? http://www.partsconnexion.com/product7387.html 100K

How do you tell whether it is linear or not? Would this one work better?

http://www.partsconnexion.com/product7386.html 250K

I don't know what makes the 100K and 250K different.

Go for the 50k...

parodielin · « **Reply #204 on:** 13 Apr 2010, 04:11 pm »

Quote from: wushuliu on 13 Apr 2010, 04:01 pm

Go for the 50k...

I think the cost from Partsconnex is expensive adding handling and shipping fee. I'll look for eBay...

wushuliu · « **Reply #205 on:** 13 Apr 2010, 07:27 pm »

Quote from: parodielin on 13 Apr 2010, 04:11 pm

I think the cost from Partsconnex is expensive adding handling and shipping fee. I'll look for eBay...

Yeah, but it's a 'safe' option if you're not experienced w/ using potentiometers. The problem w/ ebay is there are a LOT of fake Alps pots out there (like anything from HK/China probably), and the first link I had actually I think may be fake so I deleted it. If you feel confident in your soldering skills I can give you a link to the VERY cheap ($3?) Panasonic EVJ pots on digikey - they are very good for the money, they just don't have too much wiggle room to solder the wire...

oh dear, AC's very flexible upload size can be a blessing and a curse. sorry!

parodielin · « **Reply #206 on:** 13 Apr 2010, 07:34 pm »

No, I'd not bet my solder skill to be good.

How about this one from PE:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=023-650

The shaft might be too short and I am not sure about its quality. They have 25K too.

Quote from: wushuliu on 13 Apr 2010, 07:27 pm

Yeah, but it's a 'safe' option if you're not experienced w/ using potentiometers. The problem w/ ebay is there are a LOT of fake Alps pots out there (like anything from HK/China probably), and the first link I had actually I think may be fake so I deleted it. If you feel confident in your soldering skills I can give you a link to the VERY cheap ($3?) Panasonic EVJ pots on digikey - they are very good for the money, they just don't have too much wiggle room to solder the wire...

wushuliu · « **Reply #207 on:** 13 Apr 2010, 07:45 pm »

Quote from: parodielin on 13 Apr 2010, 07:34 pm

No, I'd not bet my solder skill to be good.

How about this one from PE:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=023-650

The shaft might be too short and I am not sure about its quality. They have 25K too.

Here you go: Amb is a good site.

http://www.amb.org/shop/

The Alps 50k is listed near the bottom, just scroll down. $16 bucks and I think he
does regular usps.

parodielin · « **Reply #208 on:** 13 Apr 2010, 07:57 pm »

Wow, very impressive on finding this. I know AMB and have one of their DAC. Now off to find a volume knob, probably from AMB if they also have one.

Quote from: wushuliu on 13 Apr 2010, 07:45 pm

Here you go: Amb is a good site.

http://www.amb.org/shop/

The Alps 50k is listed near the bottom, just scroll down. $16 bucks and I think he
does regular usps.

walkern · « **Reply #209 on:** 14 Apr 2010, 09:38 pm »

Quote from: parodielin on 13 Apr 2010, 03:18 am

I want to buy this volume pot suggested by wushuliu

Ebay DACT-Type Stepped Attenuator - $15 shipped
Even better AND cheaper
You can find values for 20k and higher. These are frickin' great for the money.

http://cgi.ebay.com/DACT-Type-21-Stepped-Attenuator-Volume-20K-for-PreAmp_W0QQitemZ200437532132QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item2eab0205e4#ht_1476wt_1202

Could you suggest a knob that would fit this through Digi-Key? What are the key filters that would ensure the knob will fit the pot? (I can do the search, just need to know the right filters.)

Thanks!

I browsed through the DIY Audio forum and found a digikey link for a knob that VERY closely matches older Nelson Pass gear knobs. I ordered one, and it fits on the stepped potentiometer that I got via Ebay from Valab... not sure if it would fit the one you are considering.

Here is the digikey link:

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=226-3016-ND

Hope this helps.

Neil

whoaru99 · « **Reply #210 on:** 16 Apr 2010, 12:49 pm »

Anyone tried these Carli caps in the B1 for C101/C201? http://www.madisound.com/manufacturers/carli/index.php

Also, I'm looking at these pots from DigiKey. http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=381N503-ND

Thoughts on either/both?

wushuliu · « **Reply #211 on:** 16 Apr 2010, 04:07 pm »

Quote from: whoaru99 on 16 Apr 2010, 12:49 pm

Anyone tried these Carli caps in the B1 for C101/C201? http://www.madisound.com/manufacturers/carli/index.php

Also, I'm looking at these pots from DigiKey. http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=381N503-ND

Thoughts on either/both?

Those are polyester caps. Perfectly usable, but as a general rule are considered inferior to polypropylene caps. Given the simplicity of the B1 design (and thus the greater influence of cap choice to sound quality), I would not recommend them.

Don't know anything about the Honeywell. The PEC pot recommended in the BOM are well regarded, and were used by Nelson for the retail B1.

wushuliu · « **Reply #212 on:** 16 Apr 2010, 04:19 pm »

Quote from: walkern on 14 Apr 2010, 09:38 pm

I browsed through the DIY Audio forum and found a digikey link for a knob that VERY closely matches older Nelson Pass gear knobs. I ordered one, and it fits on the stepped potentiometer that I got via Ebay from Valab... not sure if it would fit the one you are considering.

Here is the digikey link:

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=226-3016-ND

Hope this helps.

Neil

Very cool! Thanks Neil...

parodielin · « **Reply #213 on:** 20 Apr 2010, 02:33 am »

Quick question on soldering PCB board.

When I solder crossover components, I'll use arligator clips as heat sinks to protect the capacitors. I haven't seen people use this practice when soldering components onto a PCB board. Is that b/c it's easier to heat up at PCB?

The idea should be similar so you heat up the joint and let the joint melt the solder, not the soldering iron, right?

wushuliu · « **Reply #214 on:** 20 Apr 2010, 05:55 am »

Quote from: parodielin on 20 Apr 2010, 02:33 am

Quick question on soldering PCB board.

When I solder crossover components, I'll use arligator clips as heat sinks to protect the capacitors. I haven't seen people use this practice when soldering components onto a PCB board. Is that b/c it's easier to heat up at PCB?

The idea should be similar so you heat up the joint and let the joint melt the solder, not the soldering iron, right?

No, there should be no need for alligator clips at all. Yes, the heated joint melts the solder. Eutectic solder is best like the Cardas I linked in the BOM or Kester 60/40, etc. as they melt very easily. Regardless of what solder, clips should not be necessary for this application.

hth

parodielin · « **Reply #215 on:** 20 Apr 2010, 07:32 pm »

How did you mount the power jack? From the picture, you seem to use glue to fix it and leave a small hole for external plug in. How big the hole it is, like 1/4"?

wushuliu · « **Reply #216 on:** 21 Apr 2010, 03:31 am »

Quote from: parodielin on 20 Apr 2010, 07:32 pm

How did you mount the power jack? From the picture, you seem to use glue to fix it and leave a small hole for external plug in. How big the hole it is, like 1/4"?

Hot glue and 1/4" hole...

parodielin · « **Reply #217 on:** 22 Apr 2010, 12:53 am »

Any suggested place to source interconnect cables? I never though I'd need these but with the preamp, I need one more set.

The wires from Apex Jr are excellent!

wushuliu · « **Reply #218 on:** 22 Apr 2010, 01:18 am »

Quote from: parodielin on 22 Apr 2010, 12:53 am

Any suggested place to source interconnect cables? I never though I'd need these but with the preamp, I need one more set.

The wires from Apex Jr are excellent!

alas, I roll my own interconnects, so I don't really have a recommendation for anything retail.

Mariusz · « **Reply #219 on:** 22 Apr 2010, 01:36 am »

I have one question:

- what would be the single, most influential (sound characteristic wise) part in this circuit ?