Nelson Pass B-1 preamp kit

earplay · « **Reply #100 on:** 12 Mar 2010, 09:22 pm »

I finished the B1 kit from Jim's last night. It might be my eyes, but the color-coding of the resistor values was difficult to distinguish. Anyone else with this problem?

avionic · « **Reply #101 on:** 12 Mar 2010, 09:27 pm »

Quote from: earplay on 12 Mar 2010, 09:22 pm

I finished the B1 kit from Jim's last night. It might be my eyes, but the color-coding of the resistor values was difficult to distinguish. Anyone else with this problem?

Yes. I think that the 6 holes on the jim's board marked S100 and S200 are the switch inputs? Is this correct?

earplay · « **Reply #102 on:** 12 Mar 2010, 09:53 pm »

Quote from: avionic on 12 Mar 2010, 09:27 pm

Yes. I think that the 6 holes on the jim's board marked S100 and S200 are the switch inputs? Is this correct?

Well, if you are asking me, I could only answer in the same way I assembled the kit... by guess and by God.

I haven't powered it up yet, so you certainly would want a better opinion than mine.

Some of the things placements can be deduced from the number of parts, but a few are just my guess. I was going to write "Jim" to tell him that pictures of a completed kit would help, but that wouldn't completely solve the Mystery of the Color-Coding.

wushuliu · « **Reply #103 on:** 12 Mar 2010, 09:58 pm »

Quote from: avionic on 12 Mar 2010, 09:27 pm

Yes. I think that the 6 holes on the jim's board marked S100 and S200 are the switch inputs? Is this correct?

Yes those are the switch inputs.

wushuliu · « **Reply #104 on:** 12 Mar 2010, 10:01 pm »

Quote from: earplay on 12 Mar 2010, 09:53 pm

Well, if you are asking me, I could only answer in the same way I assembled the kit... by guess and by God.

I haven't powered it up yet, so you certainly would want a better opinion than mine.

Some of the things placements can be deduced from the number of parts, but a few are just my guess. I was going to write "Jim" to tell him that pictures of a completed kit would help, but that wouldn't completely solve the Mystery of the Color-Coding.

Part of the reason why I recommend only gettting the pcb from them. Full kits from China/HK usually have poor documentation, dicey quality components, and yeah, tiny resistors with hard to read color coding...

walkern · « **Reply #105 on:** 12 Mar 2010, 10:46 pm »

Quote from: earplay on 12 Mar 2010, 09:53 pm

Well, if you are asking me, I could only answer in the same way I assembled the kit... by guess and by God.

I haven't powered it up yet, so you certainly would want a better opinion than mine.

Some of the things placements can be deduced from the number of parts, but a few are just my guess. I was going to write "Jim" to tell him that pictures of a completed kit would help, but that wouldn't completely solve the Mystery of the Color-Coding.

I asked for a photo of a completed board before I ordered mine, and was told (in a very prompt and polite response) that the board was very clearly marked, and that I would have no trouble identifying exactly where everything should go. Now if ONLY i had memorized those color codes for resistors! Oops. None of the parts are clearly labeled or marked, and I'm sure they MUST have newbies who throw the power supply caps in backwards (not realizing the orientation is marked on the board), or the diode in backwards, etc. And I wonder why he doesn't include a selector switch in with the rest of the parts mix? Oh well... it was a cheap and cheerful way to check out the potential for a B1.

Neil

avionic · « **Reply #106 on:** 13 Mar 2010, 12:02 am »

Thanks guys.
This site has some really good electronics info including resistor calculators and explanations. Just click on the link and scroll through the different topics on the right.
http://www.bcae1.com/

mgalusha · « **Reply #107 on:** 13 Mar 2010, 03:08 am »

Cool thread. I've had one of the B1 boards and FET's for some time now, this makes me want to do something with it.

On a related note, http://www.electronics2000.co.uk has a lot of good info and a very handy and very free electronics calculator.

mike

sondale · « **Reply #108 on:** 13 Mar 2010, 09:56 am »

Although it is an extra cost I think that everyone should have a DMM - Digital Multimeter - this would help to identify easily which resistors are which.

Even when I know what a resistor is meant to be I usually check before putting them into the board.

If you want to do more than just put the B1 together (e.g building your own power supply) or go on to other projects then this is a must-have piece of kit.

If anyone has the chinese kit up and running then I think a photo would help fellow builders.

strobistray · « **Reply #109 on:** 14 Mar 2010, 03:44 pm »

Greetings Everyone

I'm new to this forum and have just recently stumbled upon this thread, a little late unfortunately. I say this because I've already purchased a couple of the Chinese B1 buffer kits and so far it's not been a great experience, you definitely get what you pay for! On the surface the kit looks ok but once you put it together it's obvious there's problems. The top end is tissy and smeared the bass is thin and muted and it just sounds bad.
For starters I think I'll replace the caps and maybe the FETs.

Great thread I'm really enjoying the comments.
Ray

Bemopti123 · « **Reply #110 on:** 14 Mar 2010, 03:57 pm »

I have received a pair of legal Pass DIY boards with the matching FETs. The board of really high quality, clearly labeled. I received some parts of PartsExpress and I am currently waiting for the final items from PartsconneXion and also Digitkey.

I must have dished out around $40 for the board along with FET, $56 for PartsConneXion, ~50 for PartsExpress and another $35 for DigitKey. In no way is this comparable to the $35 price for the Chinese board, but at least I know what I am getting.

I have been interested on other kits that the HK outfitter sells, but after hearing from the problems with his kits, I will think twice before ordering anything from there.

jmc207 · « **Reply #111 on:** 14 Mar 2010, 04:16 pm »

Quote from: mgalusha on 13 Mar 2010, 03:08 am

On a related note, http://www.electronics2000.co.uk has a lot of good info and a very handy and very free electronics calculator.

mike

Great site Mike! Thanks!

sondale · « **Reply #112 on:** 14 Mar 2010, 04:54 pm »

Quote from: strobistray on 14 Mar 2010, 03:44 pm

Greetings Everyone

I'm new to this forum and have just recently stumbled upon this thread, a little late unfortunately. I say this because I've already purchased a couple of the Chinese B1 buffer kits and so far it's not been a great experience, you definitely get what you pay for! On the surface the kit looks ok but once you put it together it's obvious there's problems. The top end is tissy and smeared the bass is thin and muted and it just sounds bad.
For starters I think I'll replace the caps and maybe the FETs.

Great thread I'm really enjoying the comments.
Ray

Ray - could I suggest that if the B1 sounds that bad then changing bits and pieces may not be the best route - what is that saying "You cannot make a silk purse out of a sows ear".

Although it costs more getting the proper board and components I think it is best. I have one last spare B1 board partly populated - resistors / caps / fets - it is the one I was going to show on this thread but wushuliu is doing a great job. Please PM me if you are interested.

Alan

avionic · « **Reply #113 on:** 14 Mar 2010, 05:34 pm »

I to fell for the low price of the chinese b1 kit. Let's just say I am not happy with it at all. On the bright side it was fun soldering all the components onto the board

I will now order a board from pass like I should have done in the first place. Live and learn thats DIY.

strobistray · « **Reply #114 on:** 15 Mar 2010, 03:50 pm »

Thank guys for all the offers of help! Like any newbee I'm afraid I was a little hasty and posted before checking for obvious problems. The B1 likes to see the full 18 V. and doesn't tolerate anything lower without degradation. Once I replaced the power supply things improved dramatically.

Ray

earplay · « **Reply #115 on:** 15 Mar 2010, 07:07 pm »

Neither picture nor detailed instructions would help much with the Chinese B1, nor the ability to identify color codes. The problem is that you cannot reliably read the colors on the resistors.

That said, I am not completely sure of copyright laws, but the Chinese seller may be quite legally reproducing and selling these boards. If so, I'm not sure that the ethical questions about selling such a board have much standing. It's an interesting question and before I throw mud at someone....

Anyhow, there may be other causes of the Chinese board sounding badly that parts quality or am I wrong? I am especially thinking of assembly issues.

sondale · « **Reply #116 on:** 15 Mar 2010, 07:29 pm »

This is one of the B1 clones against the Nelson Pass original; I am not sure if this was legal but I do not remember any problems. I am trying to see if they are available.

wushuliu · « **Reply #117 on:** 15 Mar 2010, 07:44 pm »

Quote from: earplay on 15 Mar 2010, 07:07 pm

Neither picture nor detailed instructions would help much with the Chinese B1, nor the ability to identify color codes. The problem is that you cannot reliably read the colors on the resistors.

That said, I am not completely sure of copyright laws, but the Chinese seller may be quite legally reproducing and selling these boards. If so, I'm not sure that the ethical questions about selling such a board have much standing. It's an interesting question and before I throw mud at someone....

Anyhow, there may be other causes of the Chinese board sounding badly that parts quality or am I wrong? I am especially thinking of assembly issues.

Why don't you post a pic of your build.

I have one of the ebay B1 pcb's. I like that it's more accomodating of different cap sizes. I think any ethical debates about clones vs. direct order should be set aside. I'd like to hear more about people's builds and impressions!

sondale · « **Reply #118 on:** 15 Mar 2010, 09:39 pm »

wushuliu,

I published a few photos of my B1 / LSA build a few days ago specifically to show how I used batteries. I had started building another B1 for this thread but stopped because of your excellent contribution.

As far as sound quality is concerned I think the B1 is excellent, as far as a simple 'pre-amp' is concerned the B1 takes a lot of beating. I have used valve pre-amps and switched to a Promitheus TVC (Transformer Volume Control) Pre-Amp - I found the B1 better (using ALPs pots) and the LSA/B1 even better.

The sound is open, detailed (but not agressively so) with a wide and fairly deep soundstage. Neither the B1 nor the LSA seem to add anything to the signal. A good test is to listen to some music through headphones and then insert the B1 into the signal path with the volume at maximum (the signal should be roughly what is was before) and listen again - you will be surprised at the very small change (if any) that there is.

The B1 without a potentiometer is very useful as a pure buffer - as far as I am aware (but I could be wrong) Nelson Pass designed the B1 for use with the original LightSpeed Attenuator - which may explain why they go together so well.

Sorry to push the LSA but I think once people have built the B1 and are feeling adventurous then it is the next logical step. I will start another thread for this shortly.

I have not seen the Ebay board - do you have a link?

Alan

wushuliu · « **Reply #119 on:** 15 Mar 2010, 09:57 pm »

Quote from: sondale on 15 Mar 2010, 09:39 pm

as far as I am aware (but I could be wrong) Nelson Pass designed the B1 for use with the original LightSpeed Attenuator - which may explain why they go together so well.

Interesting, did not know that. Yes, please do a tutorial on the LSA!

Thanks for sharing your thoughts on the B1.

And I linked to the Jims audio pcb in my first post...