In my B1, using a quality switch-mode 18V wall-wart was no problem. Just don't skimp on the B1 RC filter. You could easily bump up the R part as well, the current draw is quite small and it won't drop a lot of voltage there.
As AndrewT says, the DCB1 has a really nice PSU. It should, considering most of it is the PSU, hehe.
As AndrewT says, the DCB1 has a really nice PSU. It should, considering most of it is the PSU, hehe.
The B1 on vero-brd. was far simpler than this ESP P37A discrete component class A preamp from Rod Elliot again on vero-brd. More active components in this one. If you like the B1 the P37A should also please.
I built this for an Malaysian friend who I have built a lot of amps etc. for. There is no PS here. I ran it on four 9V batteries to run it in. Very natural uncoloured sound.
http://sound.westhost.com/project37a.htm
I built this for an Malaysian friend who I have built a lot of amps etc. for. There is no PS here. I ran it on four 9V batteries to run it in. Very natural uncoloured sound.
http://sound.westhost.com/project37a.htm
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A little more progress. The PS is now on the brd. The only other part I added was a 0.1uf poly across the B+. Where Pass suggests 2 X 15,000uf filter caps I used 2 X 10,000uf 'cause that's all I had.
For those who hadn't noticed I had the CCS FETs backwards. I lost two hours pulling one JFET for another.
For those who hadn't noticed I had the CCS FETs backwards. I lost two hours pulling one JFET for another.
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Hello guys! I would like to build a Nelson Pass's B1 buffer. I have try to order one with the matched transistor but I can not get the order from Passdiy.
Do you have or know how I can just order one of this boards and matched transistors.
and also will I need to keep the input caps in my amp after I use this B1?
Thanks guys!
Just call them and place your order by phone.
russellc
The build was pretty easy. The good thing about it being not too difficult is the ease at which parts can be substituted for others. Cap & resistor swaps are common with B1 builds.
In my build, not put in an enclosure as yet, I use a mix of Obbligato Premium 1uf & Russian 10uf K73-16 Caps (Output) & Naked Vishay 330r resistors where they will have the most effect on the sound quality.
The B1 is great to work with & even better to listen to.
In my build, not put in an enclosure as yet, I use a mix of Obbligato Premium 1uf & Russian 10uf K73-16 Caps (Output) & Naked Vishay 330r resistors where they will have the most effect on the sound quality.
The B1 is great to work with & even better to listen to.
BTW, kudos for the Obbligatos - I use the film-in-oil ones and they're so good I probably wouldn't use another brand unless size restricts me. I can imagine the premium foil ones aren't any worse either 
Also - not "smile" designs, but "simple" designs (re: last post). Although the B1 makes me smile
Also - not "smile" designs, but "simple" designs (re: last post). Although the B1 makes me smile
I have had a brief listen on my main system with my 6AS7 SET power amp. Bass is light with mids/treble absolutely fab. Sound stage and imaging stunning. I will trial the B1 on a high-end DIY discrete 200W transistors amp soon. Gain is a bit low for my SET.
Playing a gold pressing, re-mastered Frank Sinatra CD which is the best I have heard this CD. More to come.
Case is Hammond. Gold RCAs with selectable inputs. 4oz solid brass black chrome knob on Alps blue velvet. Inside all the hook-up wire is cotton coated, tinned solid copper wire. Hard to work with.
PS in a Toshiba 19V 3.5A SMPS.
Playing a gold pressing, re-mastered Frank Sinatra CD which is the best I have heard this CD. More to come.
Case is Hammond. Gold RCAs with selectable inputs. 4oz solid brass black chrome knob on Alps blue velvet. Inside all the hook-up wire is cotton coated, tinned solid copper wire. Hard to work with.
PS in a Toshiba 19V 3.5A SMPS.
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There are some resistors to swap from original schematic to improve bass. I don't have time to look right now but I think there are 4x 1k resistors that I swapped for 100R. The difference in the low end is huge. It will be fairly early in the thread...
Best,
Chris
I left the preamp on over night and bass has lifted. More to come.
Done some tests; -3db points 5hz -> 780Khz. Peak voltage (p2p) into 10K = 13V, into 1K = 8V p2p.
"Cotton coated wire for an SMPS supplied board "
I'll assume you like both??
There has been much talk about changing the 4x1k resistors you are talking about with Naked Vishay 330r's. Improvements have been noted.