Leaderboard

Pair of GRHV Fat PSU boards are up and running! It feels SO much less stressful bringing these up with a variac rather than just a plug&hope approach. All is fine, but voltages are a bit high. +407 and -410 loaded with a 15K 10W resistor for each board. Those test resistors get darn hot after about 5 minutes!! I am using a 350V trafo, so not worried about going above what it can feed, so might just leave that as is. However, the bias test point reads 590 and is still slowly climbing as the diodes heat up. Guessing I should replace one of the 150V diodes or the 130V with something about 10V less? Not sure what values are readily available so will have to look. I have also completed a pair of Carbon boards that @mypasswordis started but decided not to complete (he is going SMD route). I have pre-set the CCSs to 17ma. BTW, the process of using LV (in my case a pair of 9V batteries) to set the CCS was INVALUABLE. I could not set the current for one channel and found the cause: I missed a solder joint! Nice to find mistakes like that without having 800+ volts running through them! I have to wait until my 15/15 LV trafo arrives from Antek before firing up the amps (I am using the on board LV from the GRHV board until I decide if I want to built the GRLV). Those guys at Antek have cancelled my last 2 orders due to lack of stock. Never even let me know this time. I had to call and see why the order was late and they said they never shipped it. Ah, I guess that is why!

Pff, moronity doesn't improve over the years, you're born an undiscerning moron, you die as such.

Got the XLR socket in. Here is the finished amp. The volume pot is cosmetic only - not wired.

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Test Tone @ Home live right now: http://mixlr.com/illuminator/chat

Vivaldi Four Seasons is awesome but there is no way you will not doze off at least once.

The GG psu is actually off ebay or aliexpress, the one that feeds the dac. At least in the one I was sent pics off. Too late now to bother finding the pics but I'll see about doing so tomorrow. The Amanero being from Italy is just precious. It's a cheap USB board from China, seriously...go on ebay. My T2 worked just fine once I completely redid the amplifier board. That is the curse of being the first to do something as you would know...ohhh wait, you haven't done anything, have you? As for my PSU's, I make them tiny, it's what I do. They also have this thing called regulation, you should look into it.

One could argue that mcalister audio is just out to troll people... The sheer level of quality here is just startling. If I could only attain this level someday... ahhh one can dream!!!

It's been a while since I built something just for me but here is something old... So long story short, I was sent some boxes by mistake and the seller said I could just keep them. That also meant I had to find a project to put them. They were tiny 70mm tall boxes with sinks on the sides so an idea was born. It's been roughly 15 years since I built my first KGSS so why not make something to commemorate that..introducing the KGSS Klassik. So this was a pretty difficult birth, cramming the PCB's down to this size while using the same parts I used back in the day...was a challenge to the say the least and well, there is no space in the fucking chassis. So this is a bone stock KGSS like we did back in the day but with a few modern twists. Output resistors, 2SC4686A's instead of the C3675's but that's about it. The PSU is the new SMD version of the old KGSS design. As can be seen, this is a super tight fit and makes something like the KGSSHV mini seem spacious. It does work wonderfully but I need to do something about the Stax socket. So this one comes from the whole host of extension cables I've killed recently and often the threads on those sockets are just toast. So here I glued it in place with some crazy resin glue but it didn't set properly. Other than that, it is a cracking amp and not "that" much bigger than the SRM-252...

$ python -m visa shell Welcome to the VISA shell. Type help or ? to list commands. (visa) list ( 0) GPIB0::16::INSTR ( 1) GPIB0::28::INSTR ( 2) GPIB0::1::INSTR ( 3) ASRL2::INSTR ( 4) ASRL1::INSTR (visa) open 0 GPIB0::16::INSTR has been opened. You can talk to the device using "write", "read" or "query. The default end of message is added to each message (open) query *IDN? Response: KEITHLEY INSTRUMENTS INC.,MODEL 2015,0788786,B09 /A02 (open) close The resource has been closed. (visa) open 2 GPIB0::1::INSTR has been opened. You can talk to the device using "write", "read" or "query. The default end of message is added to each message (open) query *IDN? Response: TEKTRONIX,TDS 3032C,0,CF:91.1CT FV:v4.25 TDS3GV:v1.00 TDS3FFT:v1.00 TDS3TRG:v1.00 (open) close The resource has been closed. (visa) Played around with PyVISA today...

After mwl168 wrote his impressions on the sound, this amp looks very temptating. Ordered 20pcs PCB (SE version, so 4 needed for balanced bridged amp). Plan to use Toshiba BJT as output transistors, as I was unlucky with matching MJE15030 and 15031. Never tried to match MJF though, but I think they are hardly different from MJE.

Thanks guys. Just ordered the silver XLR socket and let's see how that works. I want to keep Nate happy!

The silver XLR would also be a nice option and require significantly less work. To rear mount the socket, given how thick the panel is, you'd have to recess the body of the socket into the panel which is no trivial exercise - unless you're Kerry and have a cnc router in your closet.

Thanks Nate. On the hindsight, I wish I had ordered the XLR socket in the silver color. May still give that a try.

Elegant work, but if I may, that chassis begs for the XLR socket to be mounted behind the front panel to maintain the otherwise clean aesthetic. I'd also recommend removing the locking tab, I never had much use for them, unless it's catastrophic to unplug something while the amp is on.

In 12-13 hours it's spent 20% of battery slightly using WhatsApp, updating a couple of Apps and being Wifi and 4G connected, no bluetooth. I'd say it's better than 11.1.1, but not 10.x good.

Not really but bias and the risk of damage is always linked to the drive voltages. So if you push the bias too high, you have to lower the drive voltages.

Damb Chop?

I do a lot of wireless streaming from my iPad (through Tidal) to an Apple Airport Express (only Optical Output).

A favorite misspelled catchphrase of astrostar, burned into my retinas from back when I paid attention to the Stax thread on HF. As I recall, he extolled the virtues of tube DACs, and sported an Audio Note build. This might be him, trolling here with a sock puppet account.

That sucks about Antek. Arrow did the same thing to me. Actually they didn't even cancel the item until I asked why I didn't receive it, which I checked only because they had already been spotty/uncommunicative in the past. And if you have ever ordered from Arrow before, you know it is no easy task to keep track as they split your order up into a million shipments. The Antek transformers themselves seem quite reliable in my experience. As to bias, I would rather err on the side of lower than higher.

Man I hate casework. I cut this one just a little two close.

For $2000 bookshelves (including stand) I know what I would choose. Ascend Sierra 2 w/ RAAL ribbon. It will use up the budget otherwise wasted on surround speakers, sub, and center channel. You'll need to negotiate for those speakers at a later date, but in the meantime you'll pee your pants at every orchestral soundtrack.

can confirm this works like a charm. conference calls for work with my earbuds plugged in and the phone on the charging pad. very happy with the 8+ so far. and a battery that actually acts like a battery.

I have been a little slow in getting the new table up and running, but I bought this AMG V12 Viella off Audiogon last month. Now playing:

Meanwhile ... via: https://www.theregister.co.uk/2017/11/17/us_navy_sky_rude_drawing/ http://www.spokesman.com/stories/2017/nov/16/military-says-zero-tolerance-for-pilot-who-traced-/

Best wishes, Jacob. I spent yesterday mostly sleeping after a 30 hour travel "day".

Buddy from Detroit came in to town and needed to stretch out his expense account. I knew a guy who could help. Chorizo deviled eggs, whiskey cocktails, Cuban tacos (pork belly, pork shoulder, red dragon cheese), fried chicken (spicy and regular), braised pork cheeks with polenta cakes, beer braised chicken tacos, apple tart with toasted pecans, bourbon caramel, and a local ice cream, Nutella cheesecake with toasted almonds and whipped cream, 2-3 Redbreast 12, 3 Macallan 12, George Dickel hand-selected bottle. Probably some more stuff I missed, but wound the night down with some darts and more Macallan 12. That was a fun 7.5 hours. Sent from my ONEPLUS A3000 using Tapatalk

Ehhh who hit you with the stupid stick? I've lost count of how many tube amps I've designed so I'm well aware what tubes can and indeed can't do. Nothing to do with my amps either, some of my customers have Lampi dac's which is why I know they are such utter shit. Now, since you know so much about tubes...are tubes less noisy than transistors? Are they better at amplifying low level signal than transistors? Are they superior in terms of distortion and other artifacts that deviate from the original signal? Nope, fuck no and hell no respectively. What you fail to grasp is how tubes are used and where they work the best. That sure as shit isn't a tube output stage of a DAC which is ironically fed by a current output dac. Also since you bring up the T2, I'm well aware of it and I'm even revising the circuit boards now to hopefully increase its performance so let's dwell on it for a bit. Is the T2 the best amp there is for electrostatics...nope, it isn't. Would it be better if you replaced the front end tubes with fets and the output tubes with SiCfets? Yup...by quite a bit actually. That has nothing to do with "tube magic" or other such BS claims based on not having the slightest grasp of what is going on. The fet's are simply better devices, made to much stricter quality standards. What tubes do well is simple circuits, even silly simple sometimes and they are forgiving of "designers" who don't know what they are doing. It's hard to blow up a tube...though some people have tried their best to do so. Ohhh and they were excellent for HV output duty but the SiC fets are clearly better. As for these super qualities which are now just coming to light...is there anything to back up those claims or just your own BS? I take it the GG is still using a Soekris dac fed by an off the shelf PSU from ebay and another ebay special USB input. Well shit...I have all those parts...hell even two Soekris boards so I should throw something together and charge somebody 40K$ for it. I have some DHT's too so let's make it super exclusive and throw a tube output stage that does fuckall but looks super cool...ohh and fuckups the sound for good measure.

Close to finish casing my balanced CFP amp. Waiting for a 4-pin XLR socket. This one runs on 26VDC rails and 220mA bias current. I am posting an unfinished amp because I want to report that I tried OPA551 for the servo OP and it appears to work fine at less than half the cost of OPA445 but only good to 30VDC. something to consider for those that may be in the process of sourcing parts for their builds. The bias current proves tricky to dial in. It drifts downwards as the amp warms up and seem to continue to go lower even after a hour of operation. The range of drifting is significant too. I am observing 70mA and possibly higher.

Malcolm Young.