Leaderboard

Here's my short review - last week I bought a second one. I'm using with the LCD-X (20 ohm) and LCD-3 (110 ohms), with different settings. This is built for IEMs up with various gain and IEM-match adjustments. Basically you try to target 12 o'clock with whatever phones you use. Do I think as a transportable rig it matches the Hugo 2 (on loan)? Not quite, the Hugo has a more relaxed, balanced sound, but at this price of $399 versus $3000, if it gets close I'm happy. I'm happy.

I'm unemployed this time around, so the donation is smaller than I'd like, but it was enough to get you up over halfway there! In!

Brent, every donation is appreciated large or otherwise and really appreciate you digging deep given current circumstances. Thanks for the push over the half-way mark. I’m confident that we’ll make it to the goal line.

https://www.adorama.com/se506911k.html?sdtid=16869128&emailprice=t&sterm=2eM3mlzRDxyPT7EyAhTydzFMUkF3JB3QExTVx80&utm_source=rflaid62905&utm_medium=affiliate Ooops. Accidentally found a link that has that amp PLUS Senn HD800S for 1499$. I hate when that happens.

Ukrainian drone destroys Russian supersonic bomber.

A warming curry on a very unseasonal day for the bay area.

More ingredients, more curry

I am beyond behind nowadays and don't even know what this is. I suddenly want one though.

And Russian propagandists are already literally painting it as terrorist attack. Apparently attacking military targets is now "terrorism"

Moved to HD white tiles tonight. Much cheaper than slate and pretty damn nice when finished. Need to build a jig to make sure I can center images.

Miss you Matt, hope you're still calling Brent a dumfuck from the beyond.

I decided to order some of these, 4oz copper, panelized/scored. Gilmore Purple People Eater, because purple is the most uber color the PCBs will be available if anyone wants a set

All doggie beer coasters, all day.

Hope you're happy with it Mikey (at least until the Micro iDSD Signature Finale Encore 2 comes out). Maybe time to pick up an ugly Italian-Korean-Turkish-Pennsylvanian leather case?

We miss you!

Since the T2 needs a complex power supply I am also including a T2 power supply testing guide. There are multiple options for the T2 power supply but the one I built is: The gerbers can be found here: <insert link> The guide is intended for both pre-power on verification of an amp build, verification of voltages on power on and general troubleshooting. All tests are performed using a Brymen BM869s and peak DCA75. Using a different multimeter may effect the results slightly but you should still get similar behaviours and ball-park figures. All tests are performed with the psu not connected to an amp and no mains transformer connected. unfortunately many of the transistors are packed tightly together so it is not easy or really possible to get test probes onto all the legs of all the transistors from the top and so the verification guide will be separated into two halves: testing from the top and testing from the bottom. Since all the high voltage power supplies are basically identical except for differing values for some resistors ad the pre regulator zeners I will cover one psu rai and the diode tests and dca75 tests should be the same for the other high voltage rails. (The 500V and above rails also have two caps in series with bleed resistors in parallel for the input smoothing and output smoothing to reduce the financial cost of the caps and increase the cap options) The low voltage rails are trivial - diode bridge, bulk cap, monolithic off the shelf regulator and smoothing cap and so will not be covered. NOTE the 3w resistor which direct connects to the 10 volt reference will get hot (depending upon the supply rail) it can reach 80C+, If you look at my schematics above I suggest increasing the value of the resistor to reduce the current and decrease the temperature. Also raise it from the pcb as much as possible to keep it away from the nearby 0.1uF capacitor. NOTE if you use 0.1% precision resistors for the output voltage set resistors then they must be rated at above 250V for the 560V rail or (in my experience if you use 250V rated working voltage resistors their resistance will drift higher and higher with time and the 560V rail will eventually hit the zener string voltage of 600V and this will cause an uncorrectable dc offset in your T2 amp). Transistor and diode location Top The two ksc5026 (T3 and T2) form a long tail pair with T3 input being the 10V reference and T2 input being the the voltage across R5 (and half of P1) in the voltage set string. To improve the performance of the differential amp T6 and T4 form a current mirror. R12 is the common resistor for the long tail. The output of the long tail comes from the collector of T3 and goes to T7. Probe Tests from above Diode test of the zener pre regulator D5 and D4 measuring across each separately, you will get about 0.6V drop, probes reversed the multimeter will register a steadily increasing voltage until it shows open. This is true of each zener in the string. Diode test D2 you will get about 0.6v drop in one direction and an instant open in the other Diode test D1 you will get about 0.52v drop in one direction and an instant open in the other Diode test D3 you will get about 0.54v drop in one direction and an instant open in the other Note it is possible for a transistor to fail in such a way it has very little gain but still has a diode drop and so diode checking transistors is not a foolproof measure of a transistors health. But 0V drop when not expected indicates a short etc. Diode and dca75 tests of the 10m90s NOTE the 10m90s has a live tab and absolutely must be insulated from the heatsink it is mounted to. Like the 10m90s in the t2 amp boards the 10m90s measures the same when the polarity of the probes has been reversed. Just like the T2 amp the peak dca75 can't identify this component in circuit and variously shows it as a low voltage zener ~ 1.6V or an led. Diode and dca75 tests of the fqp8n80s The peak dca75 can't identify this component in circuit and variously misidentifies it as two diodes or a diode and led. Diode checks from underside Transistor and diode location Bottom Diode test T1 2N3904 NPN transistor. forms the active part of the current limit circuit. It monitors the current through R15 and when the voltage drop across the resistor gets too high T1 starts to cut off the pass mosfet FQPF8M80C. If you get correct voltage output with no load but any load massively decreases the output down to about 75V suspect T1 has gone short circuit. Diode and DCA 75 test T2 and T3 KSC5026 NPN transistor. These form the long tail pair differential amp which compares the voltage reference against a portion of the output voltage controlled by the trimmer P1 and the series resistor ladder R3, R4 R5. There should be very close to 10V across R5 if not one possibility is R3 and R4 have too higher a resistance value, possibility from using resistors with a too low working voltage - especially in the -560V rail which puts more than 250V across each of R3 and R4 in the series ladder. NOTE T2 is connected to a both ends of a cap and so this cap will slowly charge resulting in the diode test reading showing an increasing voltage drop until the multimeter finally displays open when the cap has charged to the same voltage as the meter outputs and so no current flows at all fooling the meter into thinking there is an open circuit. This does not occur with T3 The dca75 reliably and correctly identifies T2 as a NPN silicon transistor hfe 19 and T3 as a NPN silicon transistor hfe 2. Diode and DCA75 test T4, T6 T7. Ksa156 PNP transistor. T4 and T6 form the current mirror for the long pair differential amp. NOTE T4 has base and collector shorted together and so measures similarly to a single diode. The DCA correctly and reliably identifies T7 as a PNP transistor hfe 135 The DCA obviously identifies T4 as a diode junction if you don't connect the 3rd lead, otherwise it just reports a short between two of the leads - which is correct. The DCA correctly and reliably identifies T6 as a PNP transistor hfe 2 <<<work in progress>>>

This will be a long drawn out post. Just a fair warning for those with better ways to spend 15 minutes or so. I hadn't posted about this here, but the last couple of months have been extremely difficult for my Mother. As it happens her husband stopped making the payments on the motor home (unbenounced to her) that they lived in. To make matters worse, it was close to being paid off. She had 3 days notice of repossession (they're both in their 80's). Couldn't find a way to stop that from here. But I was able to find a used 40' bumper pull trailer in great shape, very close to her. She was able to make that purchase, and the trailer was supposed to be delivered in 3 days time. So just a short hotel stay. That turned out to actually take over 3 weeks and a $2000 hotel stay. She's on a very fixed income. Then, after locking up her old motor home and actually cutting the water and electric hook ups, the bank decided that the motor home wasn't worth repossessing. The giant slide-out had rusted frozen after nearly 20 years in the South Texas beach weather. Also with my Mother and her husband both being legally blind, they had no idea that they were living in a roach infested, mold infested, horrible environment. They had a pretty bad roof leak. My Mom has COPD, and could barely walk from one end of the 32' motorhome, to the other. So, this frozen up motor home that wouldn't start, and was going to cost almost $4000 to be removed from the RV park they live in, the bank decided to abandon at the RV park, leaving my Mother on the hook for removal. Mind you, the bank held the title, left the motorhome locked and unusable (no hook ups). After talking to several businesses, my Mother discovered that no one would even consider moving it without a title. Long story longer, the bank wasn't able to get away with their despicable activities. I fully understand that the mortgage was behind some eight thousand dollars ( however, even though he had missed 8 payments, he had made 6 payments after that. Payments that the bank had accepted). And again, they were literally a few payments away from being payed off, minus the 8 back payments. She did end up having to make rent on two lots for one month, once the new trailer was finally delivered, and the old motor home was still in the old lot space. So, to catch up... They found a company to haul away the motor home with a giant wrecker. This company charged the bank (the legal owner) space rent, while they started refurbishing the motor home. The bank settled with them for lot rent and removal fees. The bank also settled with the RV park for lot space rent (2 months) which the park gave to my Mother. The RV sales company that turned a 3 day delivery into 3 weeks has agreed to reimburse my Mother for 80% of the hotel bill, and the hook ups that they were supposed to do and didn't, which my Mom had to pay someone else to do. Also the payment on the trailer was knocked down $130 a month. They told her that to qualify for the loan, she'd need an extended warranty. Turns out that was bullshit. And she had only financed $7000, and paid cash for the other $11,000. People really like to fuck over Senior citizens! Today I got the news that my Mother qualified for Medicaid. This also qualified her for a helper to come in 14 hrs. a week to clean, do laundry and all the shopping. My Mother and her husband can't drive anymore. He's almost fully blind, and she's loosing her sight pretty quickly ( both have macular degeneration). The Dr. has told her that her COPD is vastly improved (no mold or roach poop for a few months now). And finally, South Texas has no real transit help for Seniors or handicapped individuals. The bus they paid for to get to Dr. appointments is now also covered by Medicaid. That and they qualified for Meals on Wheels (more of a logistics challenge than a financial one). So, what was a complete pain in the ass, and absolutely despicable behavior by the bank (at least in my opinion), has now turned into a bit of a rainbow after a bad storm. I can't thank my Cousin enough, who spent hour after hour moving, boxing, cleaning and redelivering all of the roach infested clothing and belongings. Also pairing down a ton of crap that they just didn't need. Happy ending!

All that’s left is hanging the son of a bitch and seeing if it brings the wall down on top of me.

its easier to do the board, then let the software turn it back into a schematic update: should be final schematic. that is a 3 pole (18db) low pass filter at 18khz. part of schematic now. nfca3.PDF

Did you fall in love with it? Today I took delivery of my new car.

So when I got my case I got pretty upset with the looks of the power switch: So I search around the house for what could be used to improve this and found and unused aluminum kitchen drawer handle. Nice looks, hollow and easy to cut. A couple of minutes later:

Or theatres, or restaurants.