Got mine yesterday afternoon. Thanks again X!
Time for me to build a no holds barred version. Need to order a few more parts.
Turbon - 1 board and 2 sets matched FETs - SHIPPED
Schlomoff - 1 built and tested board and 4 SMT populated boards with matched FETs - SHIPPED (OR, USA Address)
pranavkr - 1 board - SHIPPED
Potatowedge - 2 boards and 1 set of matched FETs - SHIPPED
pcgab - 2 boards - SHIPPED - RECIEVED
bogde - 4 boards - SHIPPED
adn6244 - 2 boards - SHIPPED
tcpoint - 2 boards - SHIPPED
funch - 2 boards and 2 matched sets of FETs - SHIPPED
Wanfai - 1 board and 1 matched sets of FETs - SHIPPED
883bkong - 2 boards - SHIPPED
Kylej1015 - 2 boards - SHIPPED - RECEIVED
Jammer55 - 4 boards - SHIPPED
Tupam - 2 boards - SHIPPED
aud1out - 2 boards - SHIPPED (MI, USA Address)
tommylck - 2 boards & 2 sets of matched FETs - SHIPPED
slaterlovesspam (Head-Fi.org) - 1 PCB and 1 special parts kit - SHIPPED
Time for me to build a no holds barred version. Need to order a few more parts.
Turbon - 1 board and 2 sets matched FETs - SHIPPED
Schlomoff - 1 built and tested board and 4 SMT populated boards with matched FETs - SHIPPED (OR, USA Address)
pranavkr - 1 board - SHIPPED
Potatowedge - 2 boards and 1 set of matched FETs - SHIPPED
pcgab - 2 boards - SHIPPED - RECIEVED
bogde - 4 boards - SHIPPED
adn6244 - 2 boards - SHIPPED
tcpoint - 2 boards - SHIPPED
funch - 2 boards and 2 matched sets of FETs - SHIPPED
Wanfai - 1 board and 1 matched sets of FETs - SHIPPED
883bkong - 2 boards - SHIPPED
Kylej1015 - 2 boards - SHIPPED - RECEIVED
Jammer55 - 4 boards - SHIPPED
Tupam - 2 boards - SHIPPED
aud1out - 2 boards - SHIPPED (MI, USA Address)
tommylck - 2 boards & 2 sets of matched FETs - SHIPPED
slaterlovesspam (Head-Fi.org) - 1 PCB and 1 special parts kit - SHIPPED
I am also very surprised, it takes less than a letter to any country in Europe. Amazing service.
NHB Pocket/Desktop Amp
I couldn't believe the interest the NHB version of the amp got on Head-Fi.org. A member there bought one fully built and he asked for a special version that could be used as a desktop amp as well. After some tiinkering and surgery on the amp, I was able to successfully add a standard 5.5mm coaxial power jack while keeping the pocket size mint tin format exactly the same! Plugging in an external low noise PSU (like the 60uV rms level noise ones they sell for high end DACs with single 15v or 18v and 1amp rating) automatically disconnects the batteries, so preserves them for use when you are on the road. When at home or in the office, plug it in - can also be a nice preamp.
I had to move one of the output bypass Wima's to the SMT side to make room for the power jack. Everything fits together perfectly and the unit works seamlessly between the two modes. I think this is now also the world's first Pocket Class A headphone amp that is also a convertible Desktop headphone amp/preamp.
In case anyone doesn't want to make their own NHB Convertible amp from a GB board, I can sell them prebuilt for a price. Just PM me.
Look how well that coax power jack fits there:
Closeup of the minor surgery:
FFT - hand-tuned harmonic profile to achieve super musicality and and engaging presentation:
Deep deep bass extension, now -0.5dB at 10Hz, top end probably well beyond the measured sampling limit of 96kHz (close to 1 Mhz based on sims):
How does it sound? Perhaps one of my best amps *ever*
I couldn't believe the interest the NHB version of the amp got on Head-Fi.org. A member there bought one fully built and he asked for a special version that could be used as a desktop amp as well. After some tiinkering and surgery on the amp, I was able to successfully add a standard 5.5mm coaxial power jack while keeping the pocket size mint tin format exactly the same! Plugging in an external low noise PSU (like the 60uV rms level noise ones they sell for high end DACs with single 15v or 18v and 1amp rating) automatically disconnects the batteries, so preserves them for use when you are on the road. When at home or in the office, plug it in - can also be a nice preamp.
I had to move one of the output bypass Wima's to the SMT side to make room for the power jack. Everything fits together perfectly and the unit works seamlessly between the two modes. I think this is now also the world's first Pocket Class A headphone amp that is also a convertible Desktop headphone amp/preamp.
In case anyone doesn't want to make their own NHB Convertible amp from a GB board, I can sell them prebuilt for a price. Just PM me.
Look how well that coax power jack fits there:
Closeup of the minor surgery:
FFT - hand-tuned harmonic profile to achieve super musicality and and engaging presentation:
Deep deep bass extension, now -0.5dB at 10Hz, top end probably well beyond the measured sampling limit of 96kHz (close to 1 Mhz based on sims):
How does it sound? Perhaps one of my best amps *ever*
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Damn X! Awesome to see you trying new versions, iterative improvements on this awesome little amp.
I just finished an hour of head to head listening with my SMSL amp vs the pocket class a. I'm starting to hear a bit more detail, definitely more dynamics.
Enjoying the hell out of this amp. I'm ordering more parts to super match the mosfets, as well as some bigger caps to make a desktop version of the pocket amp. I'm also going to work on finishing the mlackey dual board design from early on in the thread, I've already got a good bit of that one wrapped up, just need more jfets to get the matches I want.
I need to catch up on the thread and try some of the other tweaks I see mentioned.
I just finished an hour of head to head listening with my SMSL amp vs the pocket class a. I'm starting to hear a bit more detail, definitely more dynamics.
Enjoying the hell out of this amp. I'm ordering more parts to super match the mosfets, as well as some bigger caps to make a desktop version of the pocket amp. I'm also going to work on finishing the mlackey dual board design from early on in the thread, I've already got a good bit of that one wrapped up, just need more jfets to get the matches I want.
I need to catch up on the thread and try some of the other tweaks I see mentioned.
I was just thinking the same thing. I want to get some Elna Silmic 10uF for the inputs as well.
Interesting how Elna claims that use of silk paper (protein based) vs cellulose based paper is softer (doesn't rustle) so gives smoother music. Do we buy that?
Aluminum electrolytic capacitors for audio applications - Features of the SILMIC series | ELNA
They cost nothing compared to Wima film caps. $0.39 for 4.7uF 50v. I will order a bunch next order from Mouser.
http://www.mouser.com/Search/m_Prod...GAEpiMZZMtZ1n0r9vR22Vaq1AHMe%2bCMi3QTzt4GdpE=
Interesting how Elna claims that use of silk paper (protein based) vs cellulose based paper is softer (doesn't rustle) so gives smoother music. Do we buy that?
Aluminum electrolytic capacitors for audio applications - Features of the SILMIC series | ELNA
They cost nothing compared to Wima film caps. $0.39 for 4.7uF 50v. I will order a bunch next order from Mouser.
http://www.mouser.com/Search/m_Prod...GAEpiMZZMtZ1n0r9vR22Vaq1AHMe%2bCMi3QTzt4GdpE=
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Not sure about how truthful the marketing nonsense is, but many people here like their sound. I always use them when I place a capacitor in the signal path, if only for peace of mind, but cannot complain about the sound quality. The only thing I've noticed is that they do take an hour or two to "break in" or "settle down." Every time I power on an amp for the first time which has a Silmic in the signal path, the bass is rather forward. Not boomy, just more present than it should be. After an hour or two, though, they calm down and the presentation is balanced. It is an interesting phenomenon.
For those who may need to order SMT resistors from Digikey, here is a suggested shopping cart. I would personally order 100 qnty of all resistors as they are 77cent per 100.
Invalid Request
Additional values of R4 should be obtained to "tune" bias. So have 33R, 47R, 51R, 56R, 68R on hand and adjust to get 50ma to 55mA bias across the R7 array. From building a bunch now, I think 47R should be default value for R4, 33R seems to run a little cold (sub 50mA).
Invalid Request
Additional values of R4 should be obtained to "tune" bias. So have 33R, 47R, 51R, 56R, 68R on hand and adjust to get 50ma to 55mA bias across the R7 array. From building a bunch now, I think 47R should be default value for R4, 33R seems to run a little cold (sub 50mA).
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