Do you or anyone have these at present. I want to finish this build asap, I need minimum 6. I can either pay you for these or order these for you. Dont want to wait for these to arrive before I finish the build.
Pass B1
- Thread starter sachu888
- Start date
Do you or anyone have these at present. I want to finish this build asap, I need minimum 6. I can either pay you for these or order these for you. Dont want to wait for these to arrive before I finish the build.
svaze
Member
Completed my Pass B1 build late last night :yahoo: Here are some pics
Trying for a brushed metal finish
Fired it up hesitantly to see if it produced smoke or music :lol: Fortunately I could hear only sweet music Not bad for a first time DIYer eh 
Thanks to omishra for his guidance and help throughout the build. Thanks Sachin for initiating this GB.
~Swapnil
Trying for a brushed metal finish
Fired it up hesitantly to see if it produced smoke or music :lol: Fortunately I could hear only sweet music
Not bad for a first time DIYer eh Thanks to omishra for his guidance and help throughout the build. Thanks Sachin for initiating this GB.
~Swapnil
sachu888
Well-Known Member
Hey Swapnil,
Congratulations and welcome to Pass B1 club:cheers:.It doesn't look your first DIY,very professional build.I like brush metal finish on faceplate.
Regards,
Sachin
Congratulations and welcome to Pass B1 club:cheers:.It doesn't look your first DIY,very professional build.I like brush metal finish on faceplate.
Regards,
Sachin
GeorgeO
Well-Known Member
Hi Vikas
Is your B1 being assembled by Philip Isaac? I saw one on Saturday when I went across to Lizzner, looks good. I am getting an amp repaired there-a resistor packed up and needs to be replaced.
Is your B1 being assembled by Philip Isaac? I saw one on Saturday when I went across to Lizzner, looks good. I am getting an amp repaired there-a resistor packed up and needs to be replaced.
yes george, philip is doing my build. when I went last week, I saw your xo being done, big monster inductors
. He's also doing my O2 build.
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bhaskarcan
Well-Known Member
Hi all,
So I'm the latest addition to ever increasing B1 club. With some experiments & some difficulties I finally managed to complete my built today afternoon :clapping:. Ofcourse I'm being the mule, the main credits go to(as usual) Om(+Ramgopal, Om's bro in Hyderbad, the silent one), Sachin & Krishnendu(FM Kroyin). Thank you all. Also my thanks goes to all the FM's who participated & contributed to this excellent thread. Here are some pics(pls ignore the picture quality):
The prototype built, B4 arrival of the trafo, Just to check everything working ok.
I used wooden cabinet.
Back panel. Neutrik connectors for phono & output. Source selector DPDT switch. I've to get 500mA/1A fuse.
Initially I used LSA with SSP. But faced problem with the CNC OPAMPs which were going to protection mode whenever I was changing the selector switch. Then as per Om's advice removed the LSA frm SSP to B1(usual way) & it solved the problem.
Also with 3 OPAMPs & LSA drawing 15volts each frm the power supply, the 2 chip regulators for 15v supply were getting very hot. For this I had to add 2 approx 1 inch Aluminium pieces to them as heatsink.
Finally the listning impression. I'm convinced that this is the best single addition to my audio chain :clapping:. The overall clarity of music improved at least 40%. Even in lower volume the sound is room filling. Excellent sound stage, nice & tight bass. Instruments are more defined. In a single word the musicality improved a lot. And to me that's what matters most. MUSIC HO TO AISA.
Now time to enjoy :licklips:
hyeah:
Bhaskar
So I'm the latest addition to ever increasing B1 club. With some experiments & some difficulties I finally managed to complete my built today afternoon :clapping:. Ofcourse I'm being the mule, the main credits go to(as usual
) Om(+Ramgopal, Om's bro in Hyderbad, the silent one), Sachin & Krishnendu(FM Kroyin). Thank you all. Also my thanks goes to all the FM's who participated & contributed to this excellent thread. Here are some pics(pls ignore the picture quality):
The prototype built, B4 arrival of the trafo, Just to check everything working ok.
I used wooden cabinet.
Back panel. Neutrik connectors for phono & output. Source selector DPDT switch. I've to get 500mA/1A fuse.
Initially I used LSA with SSP. But faced problem with the CNC OPAMPs which were going to protection mode whenever I was changing the selector switch. Then as per Om's advice removed the LSA frm SSP to B1(usual way) & it solved the problem.
Also with 3 OPAMPs & LSA drawing 15volts each frm the power supply, the 2 chip regulators for 15v supply were getting very hot. For this I had to add 2 approx 1 inch Aluminium pieces to them as heatsink.
Finally the listning impression. I'm convinced that this is the best single addition to my audio chain :clapping:. The overall clarity of music improved at least 40%. Even in lower volume the sound is room filling. Excellent sound stage, nice & tight bass. Instruments are more defined. In a single word the musicality improved a lot. And to me that's what matters most. MUSIC HO TO AISA.
Now time to enjoy :licklips:
hyeah:Bhaskar
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sachu888
Well-Known Member
Great Sir,your cab looks excellent :clapping:
Regards,
Sachin
Regards,
Sachin
Completed my Pass B1 build late last night
Trying for a brushed metal finish
Hi Swapnil,
Congrats on the build, it looks professionally made.
Even I've ordered Magma's cabinet and remember him mentioning that the entire cabinet is anodized and the face plate is brushed aluminum.
Your faceplate sure looks different. Could you explain what exactly have you done.
Rgds
Rajesh
Hey Bhaskar, congrats on the build. The Wooden faceplate looks great.
BTW, what is SSP?
How did you affix the Aluminum pieces? Could you post a close up pic?
sachu888
Well-Known Member
Hi Captain,
its Super simple Preamp(SSP) or Simple active preamp,DIY Simple Active Preamp - AudioKarma.org Home Audio Stereo Discussion Forums since Pass B1 is a unity gain buffer adding a active preamp with gain helps in sq.Omishra,Swapnil and Bhaskar have done this with good results.It has a very few components and can be built under INR 1000
Do we need another GB here
Regards,
Sachin
Sachu888,
I remember you saying that the bass was little low with B1. Was it resolved? Did you add SSP to resolve it?
I read some threads on other forums and they seem to be suggesting that the LDR resistance is low and hence adding a SSP helps in making the resistance higher (apart from adding gain) and hence improved bass response. Did you add SSP to resolve or did something else?
The trade off seems to be between bass response without SSP vs changes due to additional components of SSP in the signal path.
Thanks
I remember you saying that the bass was little low with B1. Was it resolved? Did you add SSP to resolve it?
I read some threads on other forums and they seem to be suggesting that the LDR resistance is low and hence adding a SSP helps in making the resistance higher (apart from adding gain) and hence improved bass response. Did you add SSP to resolve or did something else?
The trade off seems to be between bass response without SSP vs changes due to additional components of SSP in the signal path.
Thanks
Hi Captain,
its Super simple Preamp(SSP) or Simple active preamp,DIY Simple Active Preamp - AudioKarma.org Home Audio Stereo Discussion Forums since Pass B1 is a unity gain buffer adding a active preamp with gain helps in sq.Omishra,Swapnil and Bhaskar have done this with good results.It has a very few components and can be built under INR 1000
Do we need another GB here
Regards,
Sachin
sachu888
Well-Known Member
Hi,
Yes adding a SSP before B1 solved Bass issue in Bhaskar's case.I will soon add SSP and I think it should solve this problem.SSP is also important for people who don't have a volume control on power amps(F5).SSP will not change sound as we put B1 after that.Pass B1 will remain same(transparent and natural)
Regards,
Sachin
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@baswamin, captRajesh:
While connecting ldr volume control in only B1, source see impedance of 13K. For some sources this is too low compared to standard 47k. Ideally infinite is limit and Nelson Pass suggest 25k. This 13K limit frequency response and current drawn for source. Please note not all sources but few like my Maranz CDP.
To make this acceptable either add 12K inline to input of ldr volume control or add another buffer which hides exposer of LSA to source. Adding 12K make LDR limit lower half of volume level 0-13K from total 25K (12+13)K.
Another solution is to add another buffer at input which poses infinite impedance and never loads any source. Here we added SSP, super simple preamp with gain 1.47(can be made 2 with replacing one resistor). This compensates some loss of gain due to addition of 12k in LSA path. Additionally this poses impedance of 1M ohm to source which any source in world is happy to drive. This SSP lets LSA draw required current without loading source. This SSP is one OPAMP board with minimal components which does not modify signal.
Now I will be trying , input->B1->LSA->B1->output. Let's see!
While connecting ldr volume control in only B1, source see impedance of 13K. For some sources this is too low compared to standard 47k. Ideally infinite is limit and Nelson Pass suggest 25k. This 13K limit frequency response and current drawn for source. Please note not all sources but few like my Maranz CDP.
To make this acceptable either add 12K inline to input of ldr volume control or add another buffer which hides exposer of LSA to source. Adding 12K make LDR limit lower half of volume level 0-13K from total 25K (12+13)K.
Another solution is to add another buffer at input which poses infinite impedance and never loads any source. Here we added SSP, super simple preamp with gain 1.47(can be made 2 with replacing one resistor). This compensates some loss of gain due to addition of 12k in LSA path. Additionally this poses impedance of 1M ohm to source which any source in world is happy to drive. This SSP lets LSA draw required current without loading source. This SSP is one OPAMP board with minimal components which does not modify signal.
Now I will be trying , input->B1->LSA->B1->output. Let's see!
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Hey people, you guys have improved upon your B1 without our knowledge:sad::annoyed:
Of course yes; neki aur pooch poochIt has a very few components and can be built under INR 1000
Do we need another GB here
hyeah:Sorry Captain, but it was still in the experimental phase till more people confirmed the same result. Now you have 3 members telling the same.Hey people, you guys have improved upon your B1 without our knowledge:sad::annoyed:
go for it. Of course yes; neki aur pooch pooch
The costly parts are only 1 X OPAMP (~450), 2 X output caps (~350) and 1 X PCB (as per order) while remaining stuff is not more than 25Rs.
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It is Light Speed Attenuator, a LDR based volume control which used single channel of stereo pot to control LDR (light dependant resistance) which changes with its LED current and volume level.
Me and FM 'quad' designed PCB for this which could replace standard stereo volume control with LDR based. last year we had GB for it.
More details are here DIY Lightspeed Attenuator - Passive LDR Volume Control (optocouplers)
svaze
Member
Hi Captain, I wet sanded the face plate. First with 120 grit, then 320, 600, 1000 and finally with 2000. At this point I got a mirror like finish. To get the bushed finish, I rubbed it using a pad of Scotch Brite. While the sanding can be done using a "to and fro" movement, the Scotch Brite pad should be used in one direction only to achieve a uniform finish.
All this was done to mask the damage done by the drill bit while drilling the holes for the source selector's LED. I had the option to get it painted, but decided to try this out instead. Since the anodizing is now ruined, I'm not sure what effect weather will have on it. Plan to get a clear coat sprayed on the face plate later.
~Swapnil
All this was done to mask the damage done by the drill bit while drilling the holes for the source selector's LED. I had the option to get it painted, but decided to try this out instead. Since the anodizing is now ruined, I'm not sure what effect weather will have on it. Plan to get a clear coat sprayed on the face plate later.
~Swapnil
Hey buddy, I'm a game for it. Do you have the PCBs? Let's start a group buy.Sorry Captain, but it was still in the experimental phase till more people confirmed the same result. Now you have 3 members telling the same.
The costly parts are only 1 X OPAMP (~450), 2 X output caps (~350) and 1 X PCB (as per order) while remaining stuff is not more than 25Rs.
Aluminum will oxidise very fast. Either get it anodised or clear coat sprayed ASAP.
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