BPPBP - Bruno Putzey's Purist Balanced Preamp (well a balanced volume control...
That's sad Bill. The production company in fact has quite high initial setup cost (160€, plus 240€ for the stencil [is that the proper English term?] and 90€ for programming), well I'm already taking quite a substantial part of that on me. Since they shall do the production of the modules mini series, I'd wanted to keep that in one hand.
The PCBs are FR4 material, 1.5mm, double sided with solder resist, mounting print one sided, nickel/gold min. 0,05μ Au to IPC Class 2, visual and electric testing.
If we manage to get to 50 PCBs, the price will go down to 17.25€ .
That's sad Bill. The production company in fact has quite high initial setup cost (160€, plus 240€ for the stencil [is that the proper English term?] and 90€ for programming), well I'm already taking quite a substantial part of that on me. Since they shall do the production of the modules mini series, I'd wanted to keep that in one hand.
The PCBs are FR4 material, 1.5mm, double sided with solder resist, mounting print one sided, nickel/gold min. 0,05μ Au to IPC Class 2, visual and electric testing.
If we manage to get to 50 PCBs, the price will go down to 17.25€ .
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Actually a pga2320 is not a digital attenuator - it's a rather traditional resistive ladder attenuator, but in a small package rather than a huge mechanical contraption
It is digitally controlled.
In my DCX2496 mod I used an 8-channel CS3318 (sort of premium PGA23xx) for a 6-channel level control at the xover output.
Works like a charm.
If you are willing to invest some time in the software, as I did, you can have remote level-balance control as well as settable level differences between low, mid high to cater for driver and amp sensitivity differences.
Jan
One can always go super premium and use 2 MUSE 72320 ...available at Mouser and no need for any programming just any pot will do.
..If you look at Pass labs XP30...XS...they both use this chip.
Each chip is stereo , resistor lader, switching is controlled by a pot.
So as opposed to the uC solution in other options, no programming is needed, it is hardwired in chip.
The pot controls the control so to speak.
I would refer you to the UGS preamp ...Muse version elsewhere in this forum.
Yes you are right...i was a bit hasty, confused the need for a rotary encoder with the possibility to use a pot....in this example, the simplest of solutions you use a 10k pot.
Code should be quite simple with this solution.
...of course if you use a rotary encoder you can use the uC to select inputs and display them....heheh
Code should be quite simple with this solution.
...of course if you use a rotary encoder you can use the uC to select inputs and display them....heheh
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BPPBP - Bruno Putzey's Purist Balanced Preamp (well a balanced volume control...
... and again this thread drifts away into discussions that have nothing to do with the topic of this thread, the Bruno Putzey Preamp
Anyway, I look forward to using this single ended design in a balanced impedance connection system, which very well fits my single ended source that I'm currently using. Power amp will be another Bruno Putzey design, the Ncore NC400, which matches that design I think. Good fit, hopefully?
... and again this thread drifts away into discussions that have nothing to do with the topic of this thread, the Bruno Putzey Preamp
Anyway, I look forward to using this single ended design in a balanced impedance connection system, which very well fits my single ended source that I'm currently using. Power amp will be another Bruno Putzey design, the Ncore NC400, which matches that design I think. Good fit, hopefully?
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Blame Jan, He started it
...result of looking at my notes in a rush....i also have the preamp free board built waiting for ...wiring up and a box .
You can use the passive balanced output that B.Putzeys has used on the vol pre-amp to convert your single ended Source to Balanced impedance output.
just add the resistor and capacitor to the return line BEFORE you connect that back into the signal ground.
It's an easy modification, but does need a bit a spare space on the back panel to fit the two 3pole sockets.
Remember that pin1 goes to Chassis at the output socket.
I can see myself using this with a few other bits and pieces to built a complete balanced stereo pre-amp just like I've always dreamt. Add a relay controlled volume control based on Hans' design, add a few more inputs (also one or two unbalanced stereo ones), maybe add a nice ucontroller at the front end driving an LCD screen showing input, volume level, add infrared / remote control volume and input selection, etc.
Something of super high quality, yet Joe Public-friendly
Something of super high quality, yet Joe Public-friendly
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I can see myself using this with a few other bits and pieces to built a complete balanced stereo pre-amp just like I've always dreamt. Add a relay controlled volume control based on Hans' design, add a few more inputs (also one or two unbalanced stereo ones), maybe add a nice ucontroller at the front end driving an LCD screen showing input, volume level, add infrared / remote control volume and input selection, etc.
Something of super high quality, yet Joe Public-friendly
Thats exactly what I'm thinking of and I already resumed work on my own boards.
Only the μC is something I'm absolutely not familiar with, so I will go for relays and switches to control volume und inputs...
Wonderful gents, good luck and success with your builds!! Please do keep us updated here.
Thank you Andrew. Yet I was intending to connect the single ended RCA of my source to the XLR of the BP preamp in a way BP has described in his G-Word article and further detailed in the manual for the Hypex NC400. Figure 3 on page 13 shows this quite well:
Thank you Andrew. Yet I was intending to connect the single ended RCA of my source to the XLR of the BP preamp in a way BP has described in his G-Word article and further detailed in the manual for the Hypex NC400. Figure 3 on page 13 shows this quite well:
Well, take a look at this thread. Some great work there. I've just ordered my first Arduino having never played around with one, but love how you can integrate some nice features with it, keeping it very simple.
That wiring of the screen does not work.
You have connected the Source Signal Return to the Chassis of the Receiver.
Look at Jensen's ap note 003, page3 section 2.4
It shows how to convert the unbalanced output at the Source to balanced at the cost of two resistors and one bi-polar component + a 3pole socket.
It's the same as what Putzeys has included at the output of this pre-amp.
I hot-rodded using 51r, or 100r, and panasonic's 100uF bi-polar of the type suggested. The 100uF can feed Rin down to ~2k0. Whereas Jensen's 220uF hotrod seems to be targetted at 600ohms loading.
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