Finally got time to spend continuing my Wayne's BA2018 linestage. I posted a pic before using VRDN to power the boards and worked well.
I added H9KPXG On/Off Soft Start, Muffsy input selector board, and Muse volume control with display. So far so good.
Remote control works for both the Muse volume and the Muffsy I/O selector via Apple Remote and the supplied Muffsy's remote. The only hiccup is that there's a buzz when the display is powered On (Vcc). This is well documented in Meldano's literature for the VC and can be resolved by adding an opto-isolator (ADuM1250AZ). I have it but I forgot to order the socket as it is so small to solder to its pins directly.
All in all, I can listen by disconnecting the display. Time to hunt for a chassis. In the meantime, will listen more and compare the Muse to a DACT attenuator. Very rewarding project.
One quick question for the guys, anybody compared SQ when the BA2018 is powered by say +-15V compared to +-18V? I was using a DC/DC converter before (copied Pfarrell's project) to power the Muse (+-15V) from _+ 18Vdc setting of the VRDN. At present, I set the VRDN to +-15 Vdc and connect the Muse directly to one side of the VRDN. Thanks!
Abe
I added H9KPXG On/Off Soft Start, Muffsy input selector board, and Muse volume control with display. So far so good.
Remote control works for both the Muse volume and the Muffsy I/O selector via Apple Remote and the supplied Muffsy's remote. The only hiccup is that there's a buzz when the display is powered On (Vcc). This is well documented in Meldano's literature for the VC and can be resolved by adding an opto-isolator (ADuM1250AZ). I have it but I forgot to order the socket as it is so small to solder to its pins directly.
All in all, I can listen by disconnecting the display. Time to hunt for a chassis. In the meantime, will listen more and compare the Muse to a DACT attenuator. Very rewarding project.
One quick question for the guys, anybody compared SQ when the BA2018 is powered by say +-15V compared to +-18V? I was using a DC/DC converter before (copied Pfarrell's project) to power the Muse (+-15V) from _+ 18Vdc setting of the VRDN. At present, I set the VRDN to +-15 Vdc and connect the Muse directly to one side of the VRDN. Thanks!
Abe
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Uh Oh......I used the smaller one as 5 and assumed the larger one was the 10.
Boards are not in use yet. Mine looked very similar to each other, with the exception of size. I dont think I recall writing on them. Better check that out before power up I guess.
Blowing up the pic, looks like I picked the right one for once!
Russellc
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It’s picofarads... a few here or there won’t actually make all that much difference. I probably don't need to include both in the kit, but what the heck.
Abe - I’ve built 15v, 18v, and 24v. For a while I thought 18 was the sweet spot, but the more I play around with it the more I don't think there’s an appreciable difference.
Abe - I’ve built 15v, 18v, and 24v. For a while I thought 18 was the sweet spot, but the more I play around with it the more I don't think there’s an appreciable difference.
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My thinking is that the 17K ohm resistor as a jumper is in series with the 10K ohm R17 and would approximate both feedback resistors being 27K ohm and be consistent with Wayne's comment in post # 287. I don’t want to screw this thing up messing around with it because it sounds really great.
Finally got time to spend continuing my Wayne's BA2018 linestage. I posted a pic before using VRDN to power the boards and worked well.
I added H9KPXG On/Off Soft Start, Muffsy input selector board, and Muse volume control with display. So far so good.
Remote control works for both the Muse volume and the Muffsy I/O selector via Apple Remote and the supplied Muffsy's remote. The only hiccup is that there's a buzz when the display is powered On (Vcc). This is well documented in Meldano's literature for the VC and can be resolved by adding an opto-isolator (ADuM1250AZ). I have it but I forgot to order the socket as it is so small to solder to its pins directly.
All in all, I can listen by disconnecting the display. Time to hunt for a chassis. In the meantime, will listen more and compare the Muse to a DACT attenuator. Very rewarding project.
One quick question for the guys, anybody compared SQ when the BA2018 is powered by say +-15V compared to +-18V? I was using a DC/DC converter before (copied Pfarrell's project) to power the Muse (+-15V) from _+ 18Vdc setting of the VRDN. At present, I set the VRDN to +-15 Vdc and connect the Muse directly to one side of the VRDN. Thanks!
Abe
Try this mods:
Muses Volume
A separate psu for the LED display can completely eliminate the noise.
The wake up delay can cause other problems, but worth to try.
Hi all! Just finished up the first linestage board (blue version). Unfortunately I made a mistake, surely. I can not adjust offset on the boards, DC offset stays at minus 3.5v.
Led's do light up after reversing anode/cathode. R11 and r12 I populated with 27r due to not having 15r. R11 and R12 seem to have 0.3v across them only.
I am using large output transistors and omitting R23 and C4. Powered by 15vdc +/-. It happens on both sides so I seem to make the mistake consistently. Any suggestions? Could the too high r11 and r12 be the cause for this?
Led's do light up after reversing anode/cathode. R11 and r12 I populated with 27r due to not having 15r. R11 and R12 seem to have 0.3v across them only.
I am using large output transistors and omitting R23 and C4. Powered by 15vdc +/-. It happens on both sides so I seem to make the mistake consistently. Any suggestions? Could the too high r11 and r12 be the cause for this?
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Sounds great upon initial startup! Need some more listening to find out if I prefer this over the Korg B1. I have been enjoying the Korg very much so it is a tough and somewhat different contender.
One question on the working of this circuit: Does it convert balanced input to single ended output? I tried putting in a balanced signal with 2.7 DC on both + and - expecting it would null out dc leaving only ac on the output, apparently I assumed wrong?!
One question on the working of this circuit: Does it convert balanced input to single ended output? I tried putting in a balanced signal with 2.7 DC on both + and - expecting it would null out dc leaving only ac on the output, apparently I assumed wrong?!
It is done.
It sounds excellent, even using what many people consider a 'lowly' Alps pot and Lorlin input selector. The two 15VA transformers in the front corners are apparently far enough from signal wiring because I don't hear a hum even with the volume up. I used the larger output devices even though I didn't include a headphone socket. I liked having the option to mount some aluminum bar to sink heat from the final devices. It is a dual mono setup using the excellent VRDN PSUs.
The chassis is a 2U Slimline from Modushop. I designed the faceplate in CAD and they CNC'd and re-anodized it. Input selection is on the left, volume on the right. There are orange LEDs on either side of the power switch, each powered by one of the VRDN PSUs. The knobs are anodized solid aluminum. I designed/3D printed some modular grommet/wire guides that clip onto the edge of the interior bottom plate to keep wires away from any sharp edges. The power from the IEC inlet to the front switch runs between the base plate and bottom cover panel.
I am planning to sell this and the F5 (for at most what I paid for the components/chassis/CNC work). They were fantastic projects to have during lockdown here in Valencia (Spain). But they are really overkill for my setup, and I've found the F5 (25w class A) tends to make our small apartment in Valencia uncomfortably warm. I plan to rebuild/restore a Sansui AU-717 next.
Some pics of my BA2018:
And the matching F5:
Many more photos here.
It sounds excellent, even using what many people consider a 'lowly' Alps pot and Lorlin input selector. The two 15VA transformers in the front corners are apparently far enough from signal wiring because I don't hear a hum even with the volume up. I used the larger output devices even though I didn't include a headphone socket. I liked having the option to mount some aluminum bar to sink heat from the final devices. It is a dual mono setup using the excellent VRDN PSUs.
The chassis is a 2U Slimline from Modushop. I designed the faceplate in CAD and they CNC'd and re-anodized it. Input selection is on the left, volume on the right. There are orange LEDs on either side of the power switch, each powered by one of the VRDN PSUs. The knobs are anodized solid aluminum. I designed/3D printed some modular grommet/wire guides that clip onto the edge of the interior bottom plate to keep wires away from any sharp edges. The power from the IEC inlet to the front switch runs between the base plate and bottom cover panel.
I am planning to sell this and the F5 (for at most what I paid for the components/chassis/CNC work). They were fantastic projects to have during lockdown here in Valencia (Spain). But they are really overkill for my setup, and I've found the F5 (25w class A) tends to make our small apartment in Valencia uncomfortably warm. I plan to rebuild/restore a Sansui AU-717 next.
Some pics of my BA2018:
And the matching F5:
Many more photos here.
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