Jump to content

Leaderboard


Popular Content

Showing content with the highest reputation since 01/11/2019 in all areas

  1. 19 points
    Finally got around to finalize my Megatron, fitted into one chassis with GRHV.
  2. 15 points
    Family trip to Hamilton. Better late than never!
  3. 15 points
    Adopted this little girl today. She is a 6 year old female. Very sweet but very shy. She was found as a stray but now she’ll have a great home.
  4. 14 points
    I'm sitting in the jury assembly room watching a video to teach me about the US justice system and jury trials. Interesting stuff.
  5. 13 points
    Closed on my new home late yesterday and moved today. Too tired to celebrate tonight but picked these up so I am ready. 4 months living in limbo. I am home now.
  6. 12 points
  7. 11 points
    When Nate comes to town, he must be given a proper welcome. Mikey handling the damascus steel Colin's example was the most picturesque, b/c, I mean... This a better view? DoxDoxDox waiting for her slice Waiting to be served
  8. 11 points
    There has been some renewed interest in the DSHA3F (which is our Focal optimized amplifier) of late. In order to keep the manufacturing process as smooth as possible, I am accepting orders for this amplifier for a small batch run for the next 2 weeks or so. I expect these amplifiers to be delivered around late March (with any orders after this batch not being ready until June or so.) Price is $2800, and orders require a 50% nonrefundable down payment.
  9. 10 points
    When I heard these were being released I just had to get a set to see if they matched the supreme crap that the original was. Now after some delays I picked the set up from the postoffice. This first post will focus mostly on the amp, the headphones will be taken apart at a later date. I have been listening to them for a few hours now so some quick impressions are in order though. Same build quality as we've come to expect from Hifiman...i.e. absolute fucking trash. First off, the phones stink badly. These are 1500$ on their own so much like the Shangri-La JR... everything is nasty synthetic crap. Same cable as the Shangri-La and Jr. use which is completely unsuitable for this role. Comfort is ok, I have the headband at max extension and the headpad is a bit uncomfortable due to that. It's odd though as they are feather light. As for the sound, well first thing you'll notice is the utter lack of usable deep bass output. I think there might be a port hiding somewhere in there as they don't squeal as they should. Tonally they are ok though, a bit thin, non offensive and the soundstage is decent. Similar league as the L300 but the bass issue has to be fixed for them to be directly compared. This is off my usual setup (Denafrips Terminator, Carbon CC) and not the included amp. Nothing from China is turned on here without being taken apart... Now for the amp, this is probably the worst chassis design ever and pretty much an utter pain to get into. Now to do so, you have to take off the front and remove the two screws which hold this PCB: Then remove the nut which holds the attenuator (more on that later) and finally remove the screws for the back panel: Undo everything there as well and the power switch and input wires are on connectors. I just cut the IEC off though as the input wires for the switch are nowhere close to safe and so is the earthing in this thing. Just look at how thin that stuff is. Also, why the hell didn't they use push on connectors for the IEC? It would make it much simpler... Once all that stuff is off you can pull out the pcb's and disconnect the transformer: Doing that I saw this gem... the bare wires from the transformer are ziptied to the input lead. Yup...no need to separate that... You can also see the earthing tag there. At this point I'm not sure where the earth is actually connected to the chassis. Two wires connect with a screw to the top PCB at the back, one from the IEC and one from the transformer shield. Granted this goes through some standoffs and to the chassis eventually but that is now how earthing should be done. On the other side of the board there is an earth wire that goes directly to the pot, which is mounted on the chassis but that is also not proper earthing. This is all very China "we don't give a fuck about safety". Now here is the top board as it comes out of the chassis: Clearly the PSU and easy to read the output voltages on the bottom. Fixed regulators for the low voltage stuff (proper JRC parts so that's nice) and simple HV supply. Now anybody familiar with old Stax amps will notice what the amp actually is at this point. Funny to see the mix of crap caps, the input caps for the LV supplies are Lelon (crap) but the output are Nichicon. Same goes for the HV side, input are "JH" (never heard of it) but the output are Nippon Chemicon. Just odd but I'll go more in depth on the PSU when I rip out all the crap caps. Here is the back of the PSU: Now the amplifier, with just three voltage rails, +/-15V and +660V there is just one possible topology here. Resistor current source feeding a single output device. So here we go: Yup this is utter shit and a clone of what Stax did with the SRA-10/12S back in 1972. It gets worse though... Say hello to the mosfet output devices and well...their typical output capacitance of 65pf. That's half the capacitance of the phones and you have two of these per driver. Yup...pure quality here. The 2SC4686A we used in the KGSSHV have a Cob of about 2.4pf and the goal here is to keep it as low as possible otherwise it will mess up the sound signature of the amp. Think Cavalli Liquid Lightning here... Here is the input section and the we need to discuss that a bit. So this amp has a balanced input but it isn't balanced. The volume control is one of those cheapo 21 step steppers you can find on ebay for 15$ and just two decks. There are also just two wires coming from the input board per channel, Rin and ground... Funny too is that the instructions manual specifically states that the volume control is a 21 step relay based attenuator. Yeah...that is a fucking lie. So the amp is resistor loaded mosfet with output capacitance matching the load and isn't actually balanced. The output caps are at least larger what what Stax used back in the day so that is something... Now we need to discuss this board: This is on front panel and for some reason the outputs have relays on them and 1K output resistors. While better than nothing, something in the 5K range would be a better choice. Now comes the point some were waiting for, can this thing be used with Stax sets? At this point I'd say no, there are just 2M ballast resistors on that board for each output (no idea why they used two) so this amp can damage Stax. Ohhh and one funny thing before I go do something productive...they hand matched the output load resistors... Finally just a dump of the extra pics I took if anybody wants to look through them.
  10. 10 points
    Squeezed this amp into a small Modushop case. Tight fit for the caps, but it works. Doesn't get particularly warm. An interesting alternative for planars.
  11. 9 points
    Reuben burger. Burger Antics.
  12. 9 points
    She's about as self-made as her dad's vagina.
  13. 9 points
    Amplifier built on Gary’s (congo5) boards. I really like this one . Cheap and easy to build - and it sounds really good.
  14. 9 points
    Well I was finally fed up with the shit cable so out came the tools... One funny thing, I just read through the manual and it specifically states that these have a gold plated plug...which they don't have in reality. Why state something which ever owner will easily spot as a lie? Similar earpads to the Shangri-La Jr. The protective mesh is just a black PCB and the other side even has some production markings on the silkscreen. First reveal and yup...these are 100% pcb. Just stacked up in the baffle and no glue at all. Now comes a pile of pics: It's an interesting design but from a build quality point of view, this is miles away from what Stax are doing. One other thing, the headphones are wired up backwards, + output is wired to the back stator. The back grills just drop out and are not fastened in any way. Time for a new cable. The wide PC-OCC Stax cable is a tight fit but it does work. All done.
  15. 8 points
    A few points regarding the boards Michael have had made on my gerbers. They are basically the same as my kitchen made boards I made five months ago. The small tube footprint has no hole for the center pin. So far I’ve cut away the center pin on the small tube socket after checking the pin holders to be not to tight nor to loose. One time I got tube sockets where the tubes fell out when turning upside down. So either you have to cut pin or drill a hole. Be aware that upper tube has a trace between the grids that might be to close to center pin. Right board 270K resistor has a 0805 pad (intention was 1206). It’s possible to solder a 1206 resistor on the 0805 pad. If +220V you get about 130 V cross the resistor so Vishay CRCW0805 is OK here. But with +250 V you get close to CRCW0805’s limit of 150 V. Some of component values on silk screen are poorly place and almost unreadable. The blame is entirely on me, I’m very sorry. There are four octagons on bottom side. One at each big tube socket center hole and one each side of small tubes filaments connections. Here I have standoffs. A few comments on updated layouts. Small tube footprint with center hole. 270K resistor pad corrected - now 1206. Silk screen remade. Pleas notify me if there is any left that needs additional attention. Now “value” of connections on both sides (except heaters). No terminal blocks on my boards. Top right. Updated 2019-02-27. Bottom right. Updated 2019-02-27. Top left . Updated 2019-02-27. Bottom left. Updated 2019-02-27. I call above version .2. My kitchen made and Michaels are version .1. Regarding this amplifier - there is nothing I've invented. I just have picked up different things and tried to put them together. As: Opto servo (the only offset servo you need) by Kevin. 01N100D/TL1021 current source by Kerry. Schematic of Stax T2 provided by Kevin, Et. al. Schematic of Stax T8000 provided by Kevin and Birgir. Etc. etc. Thanks for all knowledge, information and inspiration from you DIYers and Head-Case members. Please look for errors or other issues.
  16. 8 points
    just arrived! going to be comparing the S3000 Pro and Airpulse A100 against my current S2000 Pro for the computer system
  17. 8 points
    a new favorite emerges...DACs are just better when they're wireless
  18. 8 points
    Burger at Fifty Fifty Brewing: half pound beef with jalapeños and honey cream cheese. Sweet, spicy, delicious, to use the Mikey three word tasting notes style.
  19. 8 points
    Meanwhile, in Soviet Russia...
  20. 8 points
    Well I killed my dirt bike this morning so out goes the UTV. Been a lot rain in the mountains on my side of the valley. I'll pull the power washer out after hitting the trails again tomorrow. Was really wishing I spent the few dollars to refill my tear-offs.
  21. 7 points
    Hello, while i wait for some parts for restoring my sra12s i made some new earpads for my sigmas. I also made the internal dampening. Following the advice of Spritzer i used the most dense material i could find. By pure luck the material and quantities i used seems to be ok. The soundstage seems here, definitely the best of the headphones i own. The bass is present and clear so i am pretty happy of the final result. I decided to substitute the earpads because i don't feel comfortable using earpads that have been used by someone else for 30 years... I decided to not use a spare pair of lambda earpads because of the different shape of the lower back part. I made them in leather following the procedure Stax (or their supplier) probably used. I used an embroidery machine to sew the ear oval on the reverse side of fabrics, then i reversed the fabrics. With the fabrics now on the right side i added some low heigh memory foam cutted a couple of mm smaller than the finished earpad. Now i used the embroidery machine to close the earpads. Cutted the excess leather and here they are. They are a bit bigger than the original ones and are less stuffed, nothing dramatical but i will remade them the next time i have time to use the embroidery machine. The same method can be used to make them with a sewing machine for the oval and an overlock machine using 3 threads and a short lenght stitch.
  22. 7 points
    So this was 3-4 hours ago, and it went this hard up until about half an hour ago. Xavier is wearing the traditional winter garb of our people.
  23. 7 points
    I swapped to the 009S a few months ago. It’s not better - just different flavour which happens to suit my tastes better. Maybe slightly fuller sound overall and less toppy with my new amp:
  24. 7 points
    Meet Mittens and Silver. They already follow me around and jump up next to me. A good sign, I think! Mittens is 8 and Silver is about 18 months. They were living happily together at the SPCA, so I couldn’t break them up
  25. 7 points
    Had to travel to Norfolk for work this week so got to visit one of my favorite restaurants - The Grilled Cheese Bistro. The special was the Super Reuben, which was impossible to turn down.
×