no difference and certainly not a "noticeable difference". I wonder if any difference is even measurable?
Other than its size, would the 2sk880 be a drop in part to replace the 2sk170 in the B1 buffer or would other parts need to be changed? Its specs seem to be within Pass's listed specs.
i've kinda given up on searching through this megathread for a specific info that i once glanced on many months ago. i believe it was zenmod who made the comment- something about adding a decoupling cap somewhere to inject some 2h into the mix?
please help. i want to make my b1 sound warmer without lowering the voltage.
please help. i want to make my b1 sound warmer without lowering the voltage.
Advice on adding Self Tone Controls to Pass B1
Hi,
Sorry not to be a purist but given the range of material that we play I have come to the conclusion that some tone "tweaking" is needed.
I already have a Pass B1 buffer feeding my Aleph power amp. I am planning to simply insert the Self tone control board between these two.
This may sound naive but so far I cannot see any problems.. except perhaps that the P1 is now superfluous.
Can anyone advise / comment on this plan .. but avoid arguing about tone controls please?
Thanks for the help
George
Hi,
Sorry not to be a purist but given the range of material that we play I have come to the conclusion that some tone "tweaking" is needed.
I already have a Pass B1 buffer feeding my Aleph power amp. I am planning to simply insert the Self tone control board between these two.
This may sound naive but so far I cannot see any problems.. except perhaps that the P1 is now superfluous.
Can anyone advise / comment on this plan .. but avoid arguing about tone controls please?
Thanks for the help
George
And there I specifically asked anyone who might respond not to get into the tone control argument. I really tried to keep this a technical question but once you get near fundamentalists, of any sort, reasonable debate goes out of the window.
Please, technically, will there be a matching problem between the B1 and the Self pre-amp.. and do I still need the B1 in any case?
Please, technically, will there be a matching problem between the B1 and the Self pre-amp.. and do I still need the B1 in any case?
Hi,
the link at Elektor is Preamplifier 2012 (1) - ELEKTOR.com | Electronics: Microcontrollers Embedded Audio Digital Analogue Test Measurement to see a good description of the PCB, components and performance.
I also feel that the B1 could still be useful .. and I hate to have to remove it. But ......
the link at Elektor is Preamplifier 2012 (1) - ELEKTOR.com | Electronics: Microcontrollers Embedded Audio Digital Analogue Test Measurement to see a good description of the PCB, components and performance.
I also feel that the B1 could still be useful .. and I hate to have to remove it. But ......
10 credits to download the PDF, I also see it has lots of opamps.....
All I can say is try it to see if you like it. And yes, the B1 does look like it will be superfluous.
But personally, I would live with the B1 for a little while, you will get use to the 'tone' fairly quickly.
All I can say is try it to see if you like it. And yes, the B1 does look like it will be superfluous.
But personally, I would live with the B1 for a little while, you will get use to the 'tone' fairly quickly.
Hi,
Thanks for that advice.. and I feel that I have got used to the B1 "tone" already. The problem is more that I play a lot of rather old recordings as well as new and the sound balance (and interest) varies enormously.
Also, I still find it interesting that no one seems to worry about compensating for the reduced and uneven sensitivity of the ear when listening at low volume levels. The only speaker that I know which makes low-level sounds appear to be simply further away is the Quad electrostatic. My conventional speakers (JBL 4343 and Yamaha NS1000M) just make it low-level sounds thin and sort of "reedy" rather than farther off..
Thanks for that advice.. and I feel that I have got used to the B1 "tone" already. The problem is more that I play a lot of rather old recordings as well as new and the sound balance (and interest) varies enormously.
Also, I still find it interesting that no one seems to worry about compensating for the reduced and uneven sensitivity of the ear when listening at low volume levels. The only speaker that I know which makes low-level sounds appear to be simply further away is the Quad electrostatic. My conventional speakers (JBL 4343 and Yamaha NS1000M) just make it low-level sounds thin and sort of "reedy" rather than farther off..
Front End Upgrade
The front end is just a DAC playing into the B1. The DAC is fed from a NAS device using FLAC format.
So far I have detected very little difference between the original CD versions and the ripped versions that I am playing now, however I am working on a DAC upgrade.
My real gripe is that music ... particularly older material.. often does not have a great balance and needs a little help to compete with some newer material. This is a matter of taste, not a claim that it is closer to the original in anyway. In many cases there was no original as the final sound resulted in a multi-channel mixdown, subject to the taste of the mixing engineer. I suppose you could argue (but I won't) that I am deviating from his chosen taste?
The front end is just a DAC playing into the B1. The DAC is fed from a NAS device using FLAC format.
So far I have detected very little difference between the original CD versions and the ripped versions that I am playing now, however I am working on a DAC upgrade.
My real gripe is that music ... particularly older material.. often does not have a great balance and needs a little help to compete with some newer material. This is a matter of taste, not a claim that it is closer to the original in anyway. In many cases there was no original as the final sound resulted in a multi-channel mixdown, subject to the taste of the mixing engineer. I suppose you could argue (but I won't) that I am deviating from his chosen taste?
Dave at Cinemag might be helpful. They build transformers you would stick in the signal. These transformers will also act as a buffer. Not only that but they have awesome CMRR. There are some supposed drawbacks but they might actually be what you are looking for. They can be manufactured to intentionally change the nature of the sound. Making it warmer is one of the things they can do by using a mix of metals in the core. Anyway, its just a suggestion to get a bit of a warmer feel while having the buffering advantage and benefiting from the great CMRR without the introduction of more opamps.
A B1 at the output might still be great because if you put the pot right after the transformer you will again be needing a low output impedance which the B1 will give you.
A B1 at the output might still be great because if you put the pot right after the transformer you will again be needing a low output impedance which the B1 will give you.
Hi, would this BiAmp setup work:
tube phono preamp -> B1 -> PLLXO -> Tube power amps ?
I want the B1 there to provide a master volume control. It would probably improve the PLLXO performance too? I am trying to avoid active XO. Thanks! Henry
tube phono preamp -> B1 -> PLLXO -> Tube power amps ?
I want the B1 there to provide a master volume control. It would probably improve the PLLXO performance too? I am trying to avoid active XO. Thanks! Henry
If the tube phono pre-amp has a lower output impedance then the B1 can be located some distance (of cable) away from it.
If the tube phono pre-amp has a medium or higher output impedance then the B1 should be located at the output of the Tube phono and let the B1 drive the cable to the PLLXO.
What loads does the PLLXO expect on it's input and output?
If the tube phono pre-amp has a medium or higher output impedance then the B1 should be located at the output of the Tube phono and let the B1 drive the cable to the PLLXO.
What loads does the PLLXO expect on it's input and output?
Another B1 Lives..
Another B1 Buffer stage using the 2SK170B
No pot on this one, just a fixed ~10M input impedance and large 100uF Silmic output caps to drive a LF amp from 20 - 200Hz in parallel with my main amplifier.
PS is schottky bridge - a couple common mode 10R resistors, 28kuF - 130R - then 15kuF - 10k - 15uF as per the schematic, drawing an extra 38mA through a 470 bleeder on the first cap to lower the voltage a bit to those 25V rated 15kuF caps. Sets up with 18V C1, and 9V C2. Ground lift on front panel, unit will be energised with switched active from LF amp.
Enclosure and transformer were part of a regulated battery charger supply, part of an alarm system left in the ceiling space of a de commissioned factory 🙂
Really quiet, and dynamic sound running full range. Really impressed, should suit its intended purpose nicely.
Thanks for making the design available, and thanks to Andrew for answering the questions needed to bring this to fruition.
Shane
Another B1 Buffer stage using the 2SK170B
No pot on this one, just a fixed ~10M input impedance and large 100uF Silmic output caps to drive a LF amp from 20 - 200Hz in parallel with my main amplifier.
PS is schottky bridge - a couple common mode 10R resistors, 28kuF - 130R - then 15kuF - 10k - 15uF as per the schematic, drawing an extra 38mA through a 470 bleeder on the first cap to lower the voltage a bit to those 25V rated 15kuF caps. Sets up with 18V C1, and 9V C2. Ground lift on front panel, unit will be energised with switched active from LF amp.
Enclosure and transformer were part of a regulated battery charger supply, part of an alarm system left in the ceiling space of a de commissioned factory 🙂
Really quiet, and dynamic sound running full range. Really impressed, should suit its intended purpose nicely.
Thanks for making the design available, and thanks to Andrew for answering the questions needed to bring this to fruition.
Shane
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I was going to put the B1 and PLLXO in the same box (no cable needed). The phonopreamp (groovewatt) output impedance is around 250ohm. The high poweramp impedance is 30K and the low is 100K. On B1 page it says that the input impedance is the 25K pot (couldn't I just put a 50K in there if I wanted higher impedance?). I seem to remember Nelson saying the output of the B1 is about 100ohms. So it should all work, right? (In case your wondering, I really haven't got a clue).
I thought the PLLXO is designed for the impedance of the poweramps only - and just needs enough power from the preamp (and some from the B1?). I used the excel spread sheet on this site to design it:
TLS.org | Passive Line-Level Crossover
(calculation attached as a pdf)
Thanks!!!
The output impedance of the pre-amp should be suitably low, you will have no issues with B1/ Matter of fast B1 circuitry is a very good choice for making a buffered PLLXO that becomes independent of amp input R.
dave