Desktop amps generally have RCA inputs and 1/4in TRS outputs, but we have JST connectors so you can wire your favorite connectors with leads. To have it on the board will force people to drill very exact holes on their panels and will be too restrictive.
One thing we are considering is to make the PCB a perfect fit for the $36 Aliexpress case with all holes precut (except for Xfeed bypass). That would force everyone to get that case but it would be a nice integrated "turn-key" solution.
One thing we are considering is to make the PCB a perfect fit for the $36 Aliexpress case with all holes precut (except for Xfeed bypass). That would force everyone to get that case but it would be a nice integrated "turn-key" solution.
I was thinking along the lines of having it as an option (JST and 3.5mm) like how there were multiple holes for caps on the DCA. But yeah I get your point
We have so many options right now built into board that we may need simplify by removing some features. For example, switchable cross feed is sort of hard to implement with switchable AC coupling. This amp’s raison d’etre is really the fully-DC-coupled topology, so I think we may leave AC coupling as some solder pads for installing a small box film cap and leaving out a wire jumper for DC-coupling. Even adding passive cross-feed upstream of pot requires forcing pot to a specific value (10k) in order to fix the input impedance of amp to ensure stable slope and frequencies of the cross feed filter.
More progress on integrated amp from JPS64. Note how JPS64 maanged to stuff a cap Mx onto the bottom side of the already full PSU board via use of SOTR223 MOSFETs.
Some amazing work there JP, simply beautiful and professional layouts never before seen on DIYA. We really are lucky to have you spinning boards for us.
Some amazing work there JP, simply beautiful and professional layouts never before seen on DIYA. We really are lucky to have you spinning boards for us.
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The amp that resembles Bob's Blender is the DLH, which has a pot that can control relative H2/H3 and absolute THD.
http://www.diyaudio.com/forums/soli...ifier-trilogy-plh-jlh-amps-8.html#post5179107
From here:
To here:
To here:
With a twist of a knob.
http://www.diyaudio.com/forums/soli...ifier-trilogy-plh-jlh-amps-8.html#post5179107
From here:
To here:
To here:
With a twist of a knob.
Nifty. I wasn't referring to the adjustability so much as this amp's low distortion with H2 dominance. Bob sez:
"No distortion sounds better than a little bit of bad distortion, but moderate, well-distributed distortion sounds better, too!"
This amp seems to nail it on both counts. Although I guess with ultra low THD, we will get very little H2 to magically "mask" the higher harmonics, so the overall sound becomes heavily dependent on the sound sig of the source.
"No distortion sounds better than a little bit of bad distortion, but moderate, well-distributed distortion sounds better, too!"
This amp seems to nail it on both counts. Although I guess with ultra low THD, we will get very little H2 to magically "mask" the higher harmonics, so the overall sound becomes heavily dependent on the sound sig of the source.
This can tweaked to user's desires by setting bias current and/or putting asymmetric Source/Drain power resistors, and also by choice of feedback resistor materials, and bias current setting. 400mA is smoking hot (14w per channel) and THD is <1ppm, whereas at 100mA bias current it will be closer to 0.005%THD (all H2). 100mA is plenty for most headphones and only 3W dissipation per channel.
Well, I've got these darn power-hungry Fostex planars. So lowering bias will probably not be a good option for me...as it would increase not only the H2 of the amp's output signal, but also probably significantly increase distortion of these 50 Ohm, 92dB sensitivity drivers.
My LingDAC has a SE Class A buffer, so hopefully I'll have a good distortion profile from the get-go, and this amp will simply "do no harm" 🙂
My LingDAC has a SE Class A buffer, so hopefully I'll have a good distortion profile from the get-go, and this amp will simply "do no harm" 🙂
I am able to run my 86dB 50ohm HE400i’s on 95mA bias and it plays quite loud without distorting. The voltage swing is also important so maybe go for +/-18v at 95mA to 110mA would be a good combo without too much heat.
Working with JPS64 on prototype PSU with hone etched board to test our concept.
System has CMC choke, DC-DC isolated step up with dual +/-24v outputs, followed by Texas Instr LDO VR’s, then a capacitance multiplier for slow ramp up starting, finally a CRCRC to clean it all up.
Here is the etched board ready to be drilled.
This could be a handy dual rail PSU for any application where you want ultra low noise supply wothbup to 310mA and up to +/-20v with simple 8v to 18v input.
System has CMC choke, DC-DC isolated step up with dual +/-24v outputs, followed by Texas Instr LDO VR’s, then a capacitance multiplier for slow ramp up starting, finally a CRCRC to clean it all up.
Here is the etched board ready to be drilled.
This could be a handy dual rail PSU for any application where you want ultra low noise supply wothbup to 310mA and up to +/-20v with simple 8v to 18v input.
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Given the success of the critical new DC-DC dual rail PSU, any new interest in this GB given no need for working with mains voltages needed for this amp?
Cool PSU... Out of curiosity, does it sound any different to you compared with the torroid?
Count me in too! Looking forward to A/B'ing the Whammy, AKSA Lender, and this one!
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