B'ASS Current Amplifier

[esimms86]

I've changed my mind. Not #1 but #2 instead. Gives me more options in the event that I someday get an amp with balanced inputs. Also send and bill me for another standard length Clairixa cable(I only have one and my Intona is disappointed in me). Thanks.

(Ass)uming that B' ASS stands for Bad Ass...

Esau

[esimms86]

You do realize that this plunges the NOS1/1a "head first" into the audiophile headphone aficionado arena. That is no small move. XXHE PC>NOS1a>B'ASS>headphone is a less expensive platform than many already owned by some "headphonistas," particularly as it obviates the need for a separate (expensive) headphone amp. I can easily imagine people debating which high end headphones pair best with their Phasure DAC setup.

Esau

[Rmalits]

Peter, please put me on the list for B'ASS #2.
As I am probably one of your most recently added customers, who will hopefully listen to the sound of XXHE and NOS1a next week for the first time in his life, I can imagine the improvement of SQ you described.
Regards, Richard

[fmanheck]

Hi Peter
This sounds really exciting. Put me in for B'ASS number 3. I have the Blaxius cables but I can't find anyone here to modify and guarantee the circuit board so I'm sticking with RCA and XLR. I use both outputs for main speakers and Subs. Thanks

[fmanheck]

Peter my mistake. I meant version number 2 with RCA & XLR

[acg]

Oh, and I forgot to ask...is this buffer a dual mono configuration or do the two channels share the power supply?

Anthony,

It is shared. But this is only because I planned it like that.
From origine it all does not matter, as this springs from the 8ch design and the whole configuration is as flexible as can be (read : the number of channels serviced by a PSU really does not matter, as long as it can take it).

Please keep in mind that I am not into "audio idiocy" and that a PSU which can supply 7A or whatever it exactly is, is not going to be bothered by two channels requireing 0.000x whatever Watts.

Btw, the plus and minus can be regarded double mono (especially if I'd use separate trafo's instead of two secundaries from one ... but I don't).

Peter

Hi Peter,

My concern, whether founded or not, is more to do with the current for the left channel being sourced from the same power supply as the current for the right channel, and they being effectively "joined".  Whether that power supply can keep up or not is really beside the point (my point anyway), but the pre-amps and buffers that I have heard that I have liked have been dual mono designs from input to output...which may be a coincidence...but that is what I have liked.

Regards,

Anthony

[acg]

Don't worry about the vinyl.  I am more concerned with other analogue inputs such as an FM tuner et cetera.  It would be nice to (still) not have a preamplifier but to be able to use your active buffer for more than one input.  So if I was listening to some music through my DAC and then wanted to tune into a live FM concert it could be done without changing cables and all that associated messing about.

I could sort out a remote volume control whether that be a high end passive attenuator or something with the Muse chip and then I would have the flexibility I need in that department.

Reading between the lines above it seems as though you don't think more than one input could work optimally for SQ...is this true?

Anthony, not explicitly. You guys just come up with more than I planned for this.

Sorry Peter...I hope you understand that I am just asking for what will suit my situation...and that this seems to be the time to do it.  If I can get the basis for a two input - one output B'Ass with or without volume control I can modify it to suit my purposes...but a single input B'Ass does not work for me because I want to listen to FM as well as my NOS1.

Example about the volume : If you ask me I say "undoable". I mean, if it is not allowed to be detrimental to SQ, forget it.
However, the NOS2 design solved that, with weeks of design. Think voltage references and the output responding to that because of the design itself (which explicitly took that into account). This does not do that.
And on a side note and FYI : applying any volume in the differential domain is a challenge in itself, because there should be no deviation between the two differential channels at all (while L/R is easliy allowed to deviate 0.5dB (I say !)). So with differential any volume control is almost a no-go, unless we step back 10 years (of say Phasure) and don't know much about anything BUT that our sound is not the best of the world. Understand ?

I think I understand your position.  I also think that I can get a good sounding passive or active volume control sorted for myself if you are not willing to do it, so that is not an end game.  But two inputs for the B'ass would be so, so convenient in my situation...

This is also how I claim to have learned so much from the NOS2 project, never mind no NOS2 is there. I can tell right now within seconds all the things which will *not* work. But behind such seconds is weeks of thinking ...

All what is "switch" will be too high-Ohmic and therefore no good in the input. One thing I am not so very much experienced with : we are already at a reasonable (line) level. So it is not in advance of a DAC where nothing is allowed regarding switches and such. Anyway, what I would allow for almost sure is just two inputs in parallel. Maybe this is harmful, maybe it is already world-wide known that this is not allowed, but without examining it, I say it may be OK.

Two input would be fantastic...two BNC and I could change the output of the FM Tuner to BNC also.

You know, I am afraid that we are "designing" ourselves more than really necessary, and that any 700 euro device as of now, becomes 1200 euros. Maybe that's OK, but ...

1200 euros works just fine for me.  A used version of the active buffer I am searching for (they seem very rare used) will go for more than that, and it does just the same thing as your B'Ass box...current...but with multiple inputs and a fantastic passive attenuator.

But anyway I now realize that I also have a digitally controlled volume ready on a PCB (f*ck, what did I not do the past 4 years ?!?). It is only that I never really worked with it (so I have the PCB and that is all -it also requires uC programming). But I recall that this too was actually a bit too difficult and it requires some sort of calibration (the differential problem, described above).

That solution sounds excellent, if you can pull it off.

Hey, I am not against anything. But I had one purpose with it and this was just better sound from the NOS1(a). I think we now must be careful not to make it unnecessary expensive for some. But I listen ...

Much appreciated Peter.  Perhaps two versions:  one as you propose just for single analogue input systems;  a second unit for multiple analogue inputs, perhaps with remote volume control.

PS:

But anyway I now realize that I also have a digitally controlled volume ready on a PCB

... which was for the DSD board I also have and never even bought one resistor for. So tempt me and that is in the same box too. Especially because that is voltage output and requires a buffer.
Anything else ?

I can't think of anything else.

[PeterSt]

Hi Anthony,

Let's start with you telling me what this fantastic attenuator is. Next I will get one myself and build it in and try it. Some result will come from that, but you are going to buy that version anyway. If you're okay with this to begin with, we may proceed with this :

Still assumed that two parallel inputs are not detrimental to anything (but maybe let's cause only one source to be active with the notice that the NOS1(a) being active without sound will be odd but won't create more noise than this other source (?)) in the one input could be the high grade attenuator while in the other input there's nothing.
For you this means that you can attenuate your FM signal, while for others it means they can try to use it for their NOS1(a) or whatever DAC they use. If no difference is perceived then these people obviously will use that input, and if they think it is for the worse, they just don't use that input but the other one - the direct one.

I know, this all does not sound very decent up to "illegal" but if it works out, it is better than a switch in the signal path.

Might you know such a best attenuator that comes with a remote, don't hesitate to mention it.
All I know is that in the final stage of the development of the NOS1 I spend IIRC 8 months to create an attenuator which did not kill the sound (to so called "dead bird") and that I gave up on that in the end and started producing the (say) current NOS1. And hey, this included obtaining a 1200 euro attenuator for SE only (balanced was 1800 IIRC). I still have that ...

So unless things changed, our chances are zero. WHICH does not mean that it is not allowed to attenuate this other source. Actually it is a GREAT idea.

Uhm ... ehh ... The next step would be to make an input selector in that indirect path. But now things may get out of hand because some source will require the D/A converter and some do not. And there's only one source going to the D/A converter ... the PC.

To be clear : I am not proceeding on that digital attenuator I talked about and certainly not the DSD board. It is all too much trouble (with completely unknown results). But what I described above I really like.
Yes ...

??

Peter

PS: Don't complain that the case will get larger.

[acg]

Peter,

I will send you an email with the attenuators that I am contemplating.  There are three that I would try at this stage...depending on how they would be used.

Cheers,

Anthony

PS:  Thanks for even humouring me with this stuff...it is very much appreciated!

PS: Don't complain that the case will get larger.

hahaha...no I will not complain.

[Mamba315]

@acg Curious about your list of 3 attenuators also.  I also use attenuators, with the DVD/Bluray player, and also with the Mac Mini --> NOS1a.  I've seen considerable praise for autoformer and LDR based designs, but haven't tried them myself.

[PeterSt]

I've seen considerable praise for autoformer and LDR based designs, but haven't tried them myself.

And hey, this included obtaining a 1200 euro attenuator for SE only (balanced was 1800 IIRC). I still have that ...

So that.
But notice that this wasn't the DIY stuff. So it was (or still is ?) readily built, including a nice display and remote.
And please notice that back at the time (2010 I guess) I did not even know really much about the importance of differential (balanced) needing to be 100% the same, while this light stuff - now I think of it - won't be "the same" at all. I recall that it even requires some means of calibration and that the leds will deviate from that over time.

Btw, there's nothing much special in LDR means. Not if you compare it with today's possibilities (ok, as I know them and which are merely about design (not really about newly available parts)).

Peter

[PeterSt]

PS:

I could also say : yeah, great !! And you know what ? I have a spare set of that. You can get it for 500 only. New in box ! Including remote and nice display and all !!

But I won't.

[PeterSt]

http://www.tentlabs.com/Products/page31/page31.html

I have that on sale too !
Let's make a nice deal : 175 only.

So forget about these too. They are the worse ... (but look so nice). And do notice that this is not about the brand, so to speak. But about the million switches in the signal path (all relais).
Not theory only ... sounds super bad and after that measures the worse.

[PeterSt]

And on the positive side :

The other day I was handed a 60K pre-amplifier. Let's not talk about what I was asked to do with it, but I started measuring it.


So if we look at this then a pre-amp kind of device really may have a good chance, because this measures superbly. And when that stops to be so, it will be a no-go. It would make no sense to me, no matter how much sense it seems to make to you.

Regards,
Peter

[PeterSt]

I've seen considerable praise for autoformer

https://www.hawthorneaudio.us/forums/viewtopic.php?f=1&t=3129

Maybe someone wants to buy this one from me ?
A 100 only !!! And that is because shelf space also is $.

IOW ... this is all way waaay beyond what we are doing today. It is noisy as hell, shows no dynamics at all, rolls off like I don't know what, is unlinear as can be and belongs in a museum.

So forget all transformer based attennuators.

Anthony, I hope one of your ideas is left; I only mention these to be ahead of things instead of nagging afterwards.
And (Matt) never ever hunt hear-says. First investigate the leage you're in and in what leage that "shouting" is. It can be really fine, but always needs thorough investigation.

Regards,
Peter