Is the value of c101 and 202 critical ? I have in hand 2 axon 11uf that I want to use in my build.
i have not stayed at a Holiday Inn in a while, but they should be fine. If you use smaller values, i believe you will limit the low end response.
Hi,
C101 & C201 form a high pass output filter with the impedances that follow them. They also block DC passing to the next stage.
10uF or 11uF feeding 221k//22k will have F-1dB~1.5Hz.
If there is a further DC block at the power amp input and it is also 10uF the F-1dB will rise to ~3Hz and if power amp uses 1uF F-1dB will rise to ~17Hz
The lowest quality of the DC blocking caps should be temporarily shorted out when you have a second DC block in the other bit of equipment.
C101 & C201 form a high pass output filter with the impedances that follow them. They also block DC passing to the next stage.
10uF or 11uF feeding 221k//22k will have F-1dB~1.5Hz.
If there is a further DC block at the power amp input and it is also 10uF the F-1dB will rise to ~3Hz and if power amp uses 1uF F-1dB will rise to ~17Hz
The lowest quality of the DC blocking caps should be temporarily shorted out when you have a second DC block in the other bit of equipment.
Finally acquired all the stuff to build the B1 - the chassis is on its way.
Went with Vishay CMF50 resistors, Jantzen Z 10uF caps, Vishay MKP 1uF caps, Alps pot, and neutrik NYS367 RCAs.
I finally settled on THIS hifi2000 chassis from audiophonics.fr.
For power I acquired some Dell sockets from ebay and I will use one of the many 19V Dell adapters I have kicking around.
I also went with NKK LED tipped switches - hopefully they end up as I envision.
Pics to follow as I progress...
Went with Vishay CMF50 resistors, Jantzen Z 10uF caps, Vishay MKP 1uF caps, Alps pot, and neutrik NYS367 RCAs.
I finally settled on THIS hifi2000 chassis from audiophonics.fr.
For power I acquired some Dell sockets from ebay and I will use one of the many 19V Dell adapters I have kicking around.
I also went with NKK LED tipped switches - hopefully they end up as I envision.
Pics to follow as I progress...
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Joined 2002
I'll probably stuff the board and wire enough to give a quick listen this weekend...I'm anxious to hear how it sounds with the F5
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Joined 2002
I'm in the middle of boxing up my stuff, so when i get to my new place ill finnish the board stuffing, and test mine out too 🙂
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Joined 2002
Looks good, Id use some shielded wire tho, if the volume pot is going to be close those wires should be fine tho!
I am using one from Peter Daniel, who has a GB for th F5 and it psu.
it's actually half a F5 psu, only the positive part. The parts are oversized and maybe to big for the B1 but I had them laying around. Will post some pic's later today and offcourse later on when I have the enclosure.
if you really need that accuracy then 1k8//13k comes to 1k58
R// = 1.8 * 1.58 / (1.8 - 1.58) =12k93, call it 13k
Just finished my B1 the other night….wow…what an amazing little piece of work! The music seems more lively and detailed (as opposed to my passive pre or even my GG clone); also the background seems a little “deeper” or more “black”. Really, whatever the case may be, I like this unit a lot.
I have to give a lot of thanks to Mr. Pass for giving this design to the DIY community – it hits both the price and performance markers in my book…I think that I paid less than 100 bucks for the board, Jfets and other auxiliary stuff I needed to complete this thing (I had resistors and most caps on hand). Also a big thanks goes out to the DIY community in general…lots of help and inspiration on this and many other projects.
I have a few pictures posted on my Google photos site…
Picasa Web Albums - Wayne - Pass Labs B1
Now, as soon as I get a little more free time I will build a proper chassis and make a few mods to the power supply and maybe add a couple of additional inputs and use this as my preamp on a full time basis.
Wayne
I have to give a lot of thanks to Mr. Pass for giving this design to the DIY community – it hits both the price and performance markers in my book…I think that I paid less than 100 bucks for the board, Jfets and other auxiliary stuff I needed to complete this thing (I had resistors and most caps on hand). Also a big thanks goes out to the DIY community in general…lots of help and inspiration on this and many other projects.
I have a few pictures posted on my Google photos site…
Picasa Web Albums - Wayne - Pass Labs B1
Now, as soon as I get a little more free time I will build a proper chassis and make a few mods to the power supply and maybe add a couple of additional inputs and use this as my preamp on a full time basis.
Wayne
My B1 Buffer Preamp
Circuit running at 18v supply.
B1 board is from Sjostrom Audio, thanks Per-Anders.
Voltage Regulator board is from Delta Audio, thanks Rasmussen.
B1 Buffer Preamp is being used with the following:
Playstation One CD Player with output measured at 0.305 VAC rms.
Elliot Sound Products P101 Amplifier 40V rails with gain measured at 26db.
Proarc 2.5 clone speakers.
System is used in my living room, normal easy listening level is with volume knob at 1/4. Knob at 1/2 is loud.
I'm very pleased with buffer thank you Nelson.
Circuit running at 18v supply.
B1 board is from Sjostrom Audio, thanks Per-Anders.
Voltage Regulator board is from Delta Audio, thanks Rasmussen.
B1 Buffer Preamp is being used with the following:
Playstation One CD Player with output measured at 0.305 VAC rms.
Elliot Sound Products P101 Amplifier 40V rails with gain measured at 26db.
Proarc 2.5 clone speakers.
System is used in my living room, normal easy listening level is with volume knob at 1/4. Knob at 1/2 is loud.
I'm very pleased with buffer thank you Nelson.
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Joined 2002
Where did you buy the Regulator board ? Looks nice, nice clean simple layout 🙂
Might hear a difference if you change that pot to a nicer one ?
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