Sure buddy. Call me and we can take this forward.
Pass B1
- Thread starter sachu888
- Start date
Sure buddy. Call me and we can take this forward.
Om,
The power supply board used in Pass B1 also has +15-0- -15V supply. I was thinking of using that for SSP.
Thanks
The power supply board used in Pass B1 also has +15-0- -15V supply. I was thinking of using that for SSP.
Thanks
sachu888
Well-Known Member
Yes you can use that most opamps are rated +/-3 V to +/-18 VDC, so anything between +/-9 to +/-15 would be fine.
Regards,
Sachin
Just searched a little bit more. It seems people are using the LSA as a preamp itself. As long as it meets the following conditions: (these are from the first post by the designer in this thread - Lightspeed Attenuator a new passive preamp - diyAudio)
1: Low source impedence (cd player) <200ohms
2: High input impedence (amplifier) > 50k.
if your sources have <200 ohms output impedance, you dont need another buffer before lsa. If your amp has > 50k input impedance, you can connect LSA after the B1. If neither of these are met, then you need another buffer. Om/sachu, could you please confirm this, my little knowledge is a very dangerous thing
.
Unfortunately, for all the sources I have, the manual doesnt state the impedance. Found that essence st has it at 99 ohms as per stereophile. My AVR has it at 47K. still searching for others.
How good a job ssp does as compared to the B1. If I get it and dont need it, maybe i can make another preamp with it for my second system.
1: Low source impedence (cd player) <200ohms
2: High input impedence (amplifier) > 50k.
if your sources have <200 ohms output impedance, you dont need another buffer before lsa. If your amp has > 50k input impedance, you can connect LSA after the B1. If neither of these are met, then you need another buffer. Om/sachu, could you please confirm this, my little knowledge is a very dangerous thing
.Unfortunately, for all the sources I have, the manual doesnt state the impedance. Found that essence st has it at 99 ohms as per stereophile. My AVR has it at 47K. still searching for others.
How good a job ssp does as compared to the B1. If I get it and dont need it, maybe i can make another preamp with it for my second system.
sachu888
Well-Known Member
Yes LSA can be used as a passive preamp and George sells it @ $400
Regards,
Sachin
Regards,
Sachin
Just searched a little bit more. It seems people are using the LSA as a preamp itself. As long as it meets the following conditions: (these are from the first post by the designer in this thread - Lightspeed Attenuator a new passive preamp - diyAudio)
1: Low source impedence (cd player) <200ohms
2: High input impedence (amplifier) > 50k.
if your sources have <200 ohms output impedance, you dont need another buffer before lsa. If your amp has > 50k input impedance, you can connect LSA after the B1. If neither of these are met, then you need another buffer. Om/sachu, could you please confirm this, my little knowledge is a very dangerous thing
Unfortunately, for all the sources I have, the manual doesnt state the impedance. Found that essence st has it at 99 ohms as per stereophile. My AVR has it at 47K. still searching for others.
How good a job ssp does as compared to the B1. If I get it and dont need it, maybe i can make another preamp with it for my second system.
There are many conflicting claims. Whatever I measure using DMM, reflected in modification for sake for moving towards ideal condition. That really helped with case of additional buffer (here low cost solution was SSP) . SSP at input with minimal/no gain and high slew rate chip like AD823 helped a lot to move into all round solution for all sources of different input impedance. Also it maintained transparency in sound. No coloration or tint added. I and many FM listened the difference towards positive direction.
Again SSP could be reused anywhere with alps pot in place of LSA. But LSA is better than Alps Blue (people claim) that is why so much effort to get it correctly in place.
sachu888
Well-Known Member
Simple Active Preamp
I have started a new thread for SSP here http://www.hifivision.com/diy/27074-diy-super-simple-preamp.html
Regards,
Sachin
I have started a new thread for SSP here http://www.hifivision.com/diy/27074-diy-super-simple-preamp.html
Regards,
Sachin
Double Decker PASS B1
This is another version from previous one where I used SSP at the input to accept selected source and drive LSA within PASS B1 where B1 driving output power amp.
By boundry at 2012-05-15
By boundry at 2012-05-15
Recent modifications
Another B1 being planned to replace frontal SSP. Observe the soldering of taller components at the other side by keeping pin numbers same. I excluded power caps in second B1 and tapped Gnd, V+, and V/2 from existing B1.
By boundry at 2012-08-18
This is how it looks from different angles -
By boundry at 2012-08-18
By boundry at 2012-08-18
From top -
By boundry at 2012-08-18
Changes in sound:
Now some may call it clinical sound, too transparent. This made everything available from 1.2Hz onwards and flat response without any coloration. Low has definitely got more punch and original. HF are clean and overall dark as always. SSP with AD823 was nearby but not that much. Our FM 'sann' used this for one weekend and he wanted me to sell this to him immediately. I did not do so. Enjoying it..
Edited: all source including crappy FM to vinyl LP and Maranz CDP, sound detailed as never before. No gain but no loss in terms of volume level.
This is another version from previous one where I used SSP at the input to accept selected source and drive LSA within PASS B1 where B1 driving output power amp.
By boundry at 2012-05-15
By boundry at 2012-05-15
Recent modifications
Another B1 being planned to replace frontal SSP. Observe the soldering of taller components at the other side by keeping pin numbers same. I excluded power caps in second B1 and tapped Gnd, V+, and V/2 from existing B1.
By boundry at 2012-08-18
This is how it looks from different angles -
By boundry at 2012-08-18
By boundry at 2012-08-18
From top -
By boundry at 2012-08-18
Changes in sound:
Now some may call it clinical sound, too transparent. This made everything available from 1.2Hz onwards and flat response without any coloration. Low has definitely got more punch and original. HF are clean and overall dark as always. SSP with AD823 was nearby but not that much. Our FM 'sann' used this for one weekend and he wanted me to sell this to him immediately. I did not do so. Enjoying it..
Edited: all source including crappy FM to vinyl LP and Maranz CDP, sound detailed as never before. No gain but no loss in terms of volume level.
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B1 + B1 is a killer combination, I initially had a single B1, it was fabulous, but I felt that its low freq extension is less than SSP + B1 Which I had heard before building the B1, then I heard SSP B1 from FM svaze during a weekend and in the next weekend Omishra came up with this wonderful thing called double decker (DD) B1, it sounded amazing to my ears, it had the punch in the low freq which was missing in my single B1, and sounded more detailed across freq range, all these changes without using any opamp is completely satisfying for me.
So, I have heard all the mods to the B1, and to me the DD sounds the best.
yes, I have requested Om to sell his DD to me which he has turned down for now. And I have added his SSP to my B1.
- Happy listening -
- Sann
So, I have heard all the mods to the B1, and to me the DD sounds the best.
yes, I have requested Om to sell his DD to me which he has turned down for now. And I have added his SSP to my B1.
- Happy listening -
- Sann
Om,
Thats a neat idea. I never thought of using B1 itself to isolate the B1+LSA combination instead of SSP. Good to know it is working exceptionally well.
Now, I see you have gone in for bigger coupling caps. Is this because with LSA input impedance of 13K, you want the cap to be higher so that there is no roll off at low frequencies? Can you tell me which capacitor is that and from where you procured it and how much you paid? I will be needing some capacitors for other circuit I am building and hence am interested in knowing.
I dont know if I will be doing second B1 board, may be I will join in if Sachin is ordering the boards and parts for others too.
Thanks
Balaji
Thats a neat idea. I never thought of using B1 itself to isolate the B1+LSA combination instead of SSP. Good to know it is working exceptionally well.
Now, I see you have gone in for bigger coupling caps. Is this because with LSA input impedance of 13K, you want the cap to be higher so that there is no roll off at low frequencies? Can you tell me which capacitor is that and from where you procured it and how much you paid? I will be needing some capacitors for other circuit I am building and hence am interested in knowing.
I dont know if I will be doing second B1 board, may be I will join in if Sachin is ordering the boards and parts for others too.
Thanks
Balaji
1.How will Pass B1 be superior to SSp?
-> here we are comparing apple against oranges. Because SSP is an basic amplifier with unit gain acts as buffer and B1 is pure buffer, no feedback or no gain. Pass B1 is always neutral, 100% transparent. People don't like it's flatness. But shouldnt it like that? It's cleaner as it does not clutter or modify anything from signal. SSP is near to it from range 95% - 98% depend upon which OPAMP you use. I tried bb2134, ad823, lme49720 and lme49990 x2. To know the differences you must have that kind of setup.
2.What is the cost of kit?
-> Depending on cost of OPAMP it varies by 1000Rs in SSP. And pass B1 cost ~ 4 times more than SSP. First GB B1 cost me some where 3700 while second one gone to 4500.
3.How can we compare to reputed brands.
-> PASS B1 is itself another league, PASS Lab sells it to some $1200 and LSA somewhere $300. Not to forget you add one low noise PS also. That too comes at a price. If SSP gets near by 97% then you can guess the performance. I can't comment against any brand but this won wherever it compared. Also these buffers can not be compared in barebone condition until you make a equally featured preamp from this. Features I am talking about - input selector, volume control and tone controls ( IMO this tone control, loudness control defeats purpose of transparent preamp). Also packaging and artwork adds cost. Working remains point of compare then this is winner. but DIY work and brands never come together.
-> here we are comparing apple against oranges. Because SSP is an basic amplifier with unit gain acts as buffer and B1 is pure buffer, no feedback or no gain. Pass B1 is always neutral, 100% transparent. People don't like it's flatness. But shouldnt it like that? It's cleaner as it does not clutter or modify anything from signal. SSP is near to it from range 95% - 98% depend upon which OPAMP you use. I tried bb2134, ad823, lme49720 and lme49990 x2. To know the differences you must have that kind of setup.
2.What is the cost of kit?
-> Depending on cost of OPAMP it varies by 1000Rs in SSP. And pass B1 cost ~ 4 times more than SSP. First GB B1 cost me some where 3700 while second one gone to 4500.
3.How can we compare to reputed brands.
-> PASS B1 is itself another league, PASS Lab sells it to some $1200 and LSA somewhere $300. Not to forget you add one low noise PS also. That too comes at a price. If SSP gets near by 97% then you can guess the performance. I can't comment against any brand but this won wherever it compared. Also these buffers can not be compared in barebone condition until you make a equally featured preamp from this. Features I am talking about - input selector, volume control and tone controls ( IMO this tone control, loudness control defeats purpose of transparent preamp). Also packaging and artwork adds cost. Working remains point of compare then this is winner. but DIY work and brands never come together.
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Thanks, the caps are Jantzen 400v cross caps, our FM procured extra from partsconnexion and thus cost me minus shipping cost ~$20 or so. Btw value of caps on SSP output and B1 does not make difference, i remember 1.2 and 3hz or like that. Difference comes from addition of a buffer itself, may be SSP or B1.
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sachu888
Well-Known Member
Hi all,
I have received few requests for another GB of Pass B1.If few more people are interested than I can start another run of Pass B1.Please post your interest here.
Regards,
Sachin
I have received few requests for another GB of Pass B1.If few more people are interested than I can start another run of Pass B1.Please post your interest here.
Regards,
Sachin
grubyhalo
New Member
How about offering the DC coupled version of the B1?
sachu888
Well-Known Member
Last time,I asked Salas over DIY audio regarding Gerber files.He replied that it is available with DIY audio store and he can't provide Gerbers for that reason.I have found that Pass B1 has great tweaking Potential if someone found it too clinical(read transparent or plain).It can be upgraded with different output caps like PIO etc or Nude Vishays resisters.Everyone liked Pass B1 here,few members even opted for multiple kits.I have received few requests for B1,so I posted here.Another good option is Simple Active Preamp,which can be tweaked with Opamps according to individual taste.
Regards,
Sachin
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grubyhalo
New Member
Ah, I see. Thank you for the reply.
I know Ive just joined but I have been on the lookout for a B1 GB for some time so if you go ahead please add me in
At the moment im running a home built passive pre and from what ive been reading the B1 appeals I like the nelson pass take on things
Thanks
At the moment im running a home built passive pre and from what ive been reading the B1 appeals I like the nelson pass take on things
Thanks
sachu888
Well-Known Member
Hi Mac,
I think B1 components would be cheaper at your country.This will not make any sense to import it from here.I can provide you PCBs if you need.I will also send you a BOM to your mail address.
Regards,
Sachin
sachu888
Well-Known Member
Yes I know but their shipping is more compared to Us sites.We bought them at same price for our Gb.
Regards,
Sachin
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