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#701
RushBattle said:
This is very interesting, as I was going to use a BCF following the flip flop boards as well. Can you give any more details?
Click to expand...

I'm just plugging the flip-flop outputs straight into the BCF inputs and will control volume with HQPlayer. Note that BCF isn't like most balanced buffers, from the BCF manual;

"The BCF differs from the classic OpAmp-based differential amplifier and 1:1 isolation transformer in that the BCF's output does not equal 2A, but A. For example, if a balanced pair of input signals that consist of 1kHz at 1Vpk is presented to the BCF, the BCF output will be 1Vpk, not 2Vpk. This can be seen either as a -6dB insertion loss or as preserving unity-gain signal transference, depending on your perspective."​
This isn't a problem for me as my power amps are quite sensitive.

I'm hoping to be in a position to post some more info and pictures of my BCF project shortly.


RushBattle said:
I may have missed it despite my reading this thread twice, what is the output voltage of the flip flop boards? Thanks for doing this work!
Click to expand...

My understanding is that output after the LP filter is in the order of 600mV and my experience with my initial build suggest that is probably in the right ballpark; ouput is definitely lower than my BuffaloIII/Legato. FlipFlop output should be around +/-600mV

If you are planning on using a flipflop board you may want to add yourself to the list as I won't leave it open indefinitely.
 
#702
dwjames said:
Thanks Ray, I think it was a link to the formula for working it out rather than a calculator per se, but if you have a simple method that would be great 🙂

My amps have a 50k input impedance, but I guess if it's simple and you could work it out for 10k 50k and 100k others would likely find that useful.
Thanks,
James
Click to expand...

I'm happy to post some values for a few Low-Pass filter options. What -3dB points?

That said, I'm no expert on the theory behind this stuff so don't ask me about complex filter scenarios: simple passive LP filters I can do.

That brings me to something that one of you filter experts might be able to comment on. Using the TCJ filter calculator to obtain values for simple 1st order passive RC low-pass filters, I have noticed that setting different R(load) values doesn't make any difference to the calculated Rf and Cf values? It does for LR filters.

Ray
 
#703
Hazard500: flip-flop x1
Supra: single-ended x1
Stijn001: flip-flop x1
dwjames: single-ended x1
ichiban: single-ended x1
PJotr25: flip-flop x1
Pegasus21: flip-flop x1
skrstic: flip-flop x1
Snicklefritzz: balanced x 1
flowerpot: flip-flop x 2
Umarcus: balanced x 2
Giulio: flip-flop x 1
Caad: balanced x 2
randytsuch:balanced x 1
deanoUK balanced x 1 SE x 1
Vdi_nenna: single-ended X 2
merlin el mago: single-ended x 2
Nikola Krivorov: single ended Х1
pgour : Flip_Flop x 1 + SE x 1
ligascon: balanced x 1 SE x 1
matejS: single-ended x 1
analog_sa: balanced x 1 SE x 1
lukaluka: flip-flop x 1
xaled: single-ended x 3
Anjump123: Single-ended X 2
asanden: balanced x 1 + SE x 1
whmok: single-ended x 2
JimS: balanced X1, single-ended X2
Guglielmope: balanced X1, single-ended X2
iestynrw: balanced x1
torb: balanced x2
Dimdim: balanced x 1
Leon77 : Balanced x 2, Single-Ended x 2
jborden: Balanced x 2
ravid: single-ended x 2
 
#704
Hazard500: flip-flop x1
Supra: single-ended x1
Stijn001: flip-flop x1
dwjames: single-ended x1
ichiban: single-ended x1
PJotr25: flip-flop x1
Pegasus21: flip-flop x1
skrstic: flip-flop x1
Snicklefritzz: balanced x 1
flowerpot: flip-flop x 2
Umarcus: balanced x 2
Giulio: flip-flop x 1
Caad: balanced x 2
randytsuch:balanced x 1
deanoUK balanced x 1 SE x 1
Vdi_nenna: single-ended X 2
merlin el mago: single-ended x 2
Nikola Krivorov: single ended Х1
pgour : Flip_Flop x 1 + SE x 1
ligascon: balanced x 1 SE x 1
matejS: single-ended x 1
analog_sa: balanced x 1 SE x 1
lukaluka: flip-flop x 1
xaled: single-ended x 3
Anjump123: Single-ended X 2
asanden: balanced x 1 + SE x 1
whmok: single-ended x 2
JimS: balanced X1, single-ended X2
Guglielmope: balanced X1, single-ended X2
iestynrw: balanced x1
torb: balanced x2
Dimdim: balanced x 1
Leon77 : Balanced x 2, Single-Ended x 2
jborden: Balanced x 2
ravid: single-ended x 2
kumori: Balanced x 2
 
#705
Hazard500: flip-flop x1
Supra: single-ended x1
Stijn001: flip-flop x1
dwjames: single-ended x1
ichiban: single-ended x1
PJotr25: flip-flop x1
Pegasus21: flip-flop x1
skrstic: flip-flop x1
Snicklefritzz: balanced x 1
flowerpot: flip-flop x 2
Umarcus: balanced x 2
Giulio: flip-flop x 1
Caad: balanced x 2
randytsuch:balanced x 1
deanoUK balanced x 1 SE x 1
Vdi_nenna: single-ended X 2
merlin el mago: single-ended x 2
Nikola Krivorov: single ended Х1
pgour : Flip_Flop x 1 + SE x 1
ligascon: balanced x 1 SE x 1
matejS: single-ended x 1
analog_sa: balanced x 1 SE x 1
lukaluka: flip-flop x 1
xaled: single-ended x 3
Anjump123: Single-ended X 2
asanden: balanced x 1 + SE x 1
whmok: single-ended x 2
JimS: balanced X1, single-ended X2
Guglielmope: balanced X1, single-ended X2
iestynrw: balanced x1
torb: balanced x2
Dimdim: balanced x 1
Leon77 : Balanced x 2, Single-Ended x 2
jborden: Balanced x 2
ravid: single-ended x 2
kumori: Balanced x 2
RushBattle: Balanced x 1
 
#706
Hazard500: flip-flop x1
Supra: single-ended x1
Stijn001: flip-flop x1
dwjames: single-ended x1
ichiban: single-ended x1
PJotr25: flip-flop x1
Pegasus21: flip-flop x1
skrstic: flip-flop x1
Snicklefritzz: balanced x 1
flowerpot: flip-flop x 2
Umarcus: balanced x 2
Giulio: flip-flop x 1
Caad: balanced x 2
randytsuch:balanced x 1
deanoUK balanced x 1 SE x 1
Vdi_nenna: single-ended X 2
merlin el mago: single-ended x 2
Nikola Krivorov: single ended Х1
pgour : Flip_Flop x 1 + SE x 1
ligascon: balanced x 1 SE x 1
matejS: single-ended x 1
analog_sa: balanced x 1 SE x 1
lukaluka: flip-flop x 1
xaled: single-ended x 3
Anjump123: Single-ended X 2
asanden: balanced x 1 + SE x 1
whmok: single-ended x 2
JimS: balanced X1, single-ended X2
Guglielmope: balanced X1, single-ended X2
iestynrw: balanced x1
torb: balanced x2
Dimdim: balanced x 1
Leon77 : Balanced x 2, Single-Ended x 2
jborden: Balanced x 2
ravid: single-ended x 2
kumori: Balanced x 2
RushBattle: Balanced x 1
francolargo: flip-flop x 1 😉
 
Last edited:
#707
Hazard500: flip-flop x1
Supra: single-ended x1
Stijn001: flip-flop x1
dwjames: single-ended x1
ichiban: single-ended x1, flip-flopx1
PJotr25: flip-flop x1
Pegasus21: flip-flop x1
skrstic: flip-flop x1
Snicklefritzz: balanced x 1
flowerpot: flip-flop x 2
Umarcus: balanced x 2
Giulio: flip-flop x 1
Caad: balanced x 2
randytsuch:balanced x 1
deanoUK balanced x 1 SE x 1
Vdi_nenna: single-ended X 2
merlin el mago: single-ended x 2
Nikola Krivorov: single ended Х1
pgour : Flip_Flop x 1 + SE x 1
ligascon: balanced x 1 SE x 1
matejS: single-ended x 1
analog_sa: balanced x 1 SE x 1
lukaluka: flip-flop x 1
xaled: single-ended x 3
Anjump123: Single-ended X 2
asanden: balanced x 1 + SE x 1
whmok: single-ended x 2
JimS: balanced X1, single-ended X2
Guglielmope: balanced X1, single-ended X2
iestynrw: balanced x1
torb: balanced x2
Dimdim: balanced x 1
Leon77 : Balanced x 2, Single-Ended x 2
jborden: Balanced x 2
ravid: single-ended x 2
kumori: Balanced x 2
RushBattle: Balanced x 1
francolargo: flip-flop x 1
 
#708
another one

Hazard500: flip-flop x1
Supra: single-ended x1
Stijn001: flip-flop x1
dwjames: single-ended x1
ichiban: single-ended x1, flip-flopx1
PJotr25: flip-flop x1
Pegasus21: flip-flop x1
skrstic: flip-flop x1
Snicklefritzz: balanced x 1
flowerpot: flip-flop x 2
Umarcus: balanced x 2
Giulio: flip-flop x 1
Caad: balanced x 2
randytsuch:balanced x 1
deanoUK balanced x 1 SE x 1
Vdi_nenna: single-ended X 2
merlin el mago: single-ended x 2
Nikola Krivorov: single ended Х1
pgour : Flip_Flop x 1 + SE x 1
ligascon: balanced x 1 SE x 1
matejS: single-ended x 1
analog_sa: balanced x 1 SE x 1
lukaluka: flip-flop x 1
xaled: single-ended x 3
Anjump123: Single-ended X 2
asanden: balanced x 1 + SE x 1
whmok: single-ended x 2
JimS: balanced X1, single-ended X2
Guglielmope: balanced X1, single-ended X2
iestynrw: balanced x1
torb: balanced x2
Dimdim: balanced x 1
Leon77 : Balanced x 2, Single-Ended x 2
jborden: Balanced x 2
ravid: single-ended x 2
kumori: Balanced x 2
RushBattle: Balanced x 1
francolargo: flip-flop x 1
Barryblue7: Balanced x 1, Single-Ended x 1
 
#709
A little more progress and I'm pretty much there with installing the revised SE board and building my flip-flop based project. I expect to get a listen to them both this weekend.

On the assumption that all goes well I've put a simple spreadsheet together with all the board requests that have been posted so that I can get the additional boards ordered and work out postage costs. The spreadsheet is attached; can I ask you to check and let me know if I've made a mistake with your request. I'll also need to know home countries for a few requestors so that I can work out the postage costs.

A few build notes and A BOM will be forthcoming.

I'll order the PCBs in batches of ten. Allowing for the few spare boards I already have I am going to draw a line at 37 for each type of board. People can still request boards beyond 37 but I'll not order another batch until there are 10 more on the list. Also, I'm sure a few requestors will change their mind so a few more might become available to latecomers.

Ray
 

Attachments

#711
leon77 said:
An good idea to use the flip-flop balanced output and then filter with this Broskie's circuit below
Balanced-Ouput DACs and Tubes and Aikido
Click to expand...

Perhaps you'll try it and report back?

I have another Broskie board to try, the Aikido MFB. This board has onboard options for active filters and I'll use it configured for a 2nd order active filter, fed from one of my SE boards.

Ray
 
Last edited:
#712
I don't are an expert, but from my knowledge the real problem is the gain, lower for buffer and higher for line stage, also if I want to use the tube with low mu as ecc82. I looking for a right choice, but not is easy. An another aspect that we will to consider that the output from Se or Balanced is lower for impedance, and maybe could to provide a low resolution
 
#714
stijn001 said:
Very generous of you to tak on the adhoc group buy.

Regarding the -3dB filter cut of point. I have no experience with this, like other who will no doubt correct me shortly. But I would start very high, 30-50Khz and make some incrimental steps down, to see what the diferences sound like. Shouldn't be to hard or expensive to do.
Click to expand...

No problem with the gb stijn,

I understand that the SACD standard (equivalent to DSD64) specifies a filter point at 50KHz. For my initial project I set the -3dB point at 40KHz, which seems to work well.

As I'm now running everything at DSD256 the SE and Flip-Flop boards I have just assembled have -3dB points at 80KHz - should further remove filter influences from the audio band.

Ray
 
#715
leon77 said:
I don't are an expert, but from my knowledge the real problem is the gain, lower for buffer and higher for line stage, also if I want to use the tube with low mu as ecc82. I looking for a right choice, but not is easy. An another aspect that we will to consider that the output from Se or Balanced is lower for impedance, and maybe could to provide a low resolution
Click to expand...

For the BCF project I'll be using 6DJ8 tubes.

For the Aikido MFB it'll be 12AX7 tubes at the input, followed by 6DJ8s. Broskie provided me with component values to configure this board with either 0dB or 7dB gain, both with the -3dB filter point at 40KHz.

Ray
 
#720
nautibuoy said:
For the BCF project I'll be using 6DJ8 tubes.

For the Aikido MFB it'll be 12AX7 tubes at the input, followed by 6DJ8s. Broskie provided me with component values to configure this board with either 0dB or 7dB gain, both with the -3dB filter point at 40KHz.

Ray
Click to expand...

Hi Ray

this is great, to have a custom product, could you posting the link for Aikido Mfb? So, do you want to try both solution? but with Aikido Mfb you have to use only single ended or is possible to go with balanced? In the kit on Broskie's site there isn't this product with differencial input

Emilio
 
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