Friday, 16. October 2009, 11:12:36
diy, audio, hi-fi
I ordered a PCB for a First Watt B1 buffer preamp this week. I was planning on making this one using perfboard but the opportunity to order a high quality and relatively inexpensive PCB was something I couldn't let pass. I still was thinking about how to implement the large electrolytic caps. Now that's all being sorted by the PCB. I ordered the PCB from a fellow diyAudio.com forum member from Sweden and it should arrive early november.
This morning I cobbled together a JFET testing "rig". The JFETs for this project need to be matched for optimum performance. This means ordering more than the four JFETs I need, test each JFET on the rig and then pick two matched pairs.
I'm planning on making a few small changes to the schematic Nelson Pass has released for the diyAudio community. The big caps are gonna be 10000µF instead of 15000µF due to availability, 10000µF is still plenty of capacitance. This means R1 has to be increased from 1 Ohm to 1.5 Ohms to maintain the RC filter (R1, C1) time constant. The volume pot is gonna be a 50 KOhm since that's what comes nearest to the 47KOhm input impedance my CD player currently sees.
Sunday, 6. September 2009, 21:33:05
diy
Friday, 4. September 2009, 17:01:20
aleph, diy, audio, hi-fi
The mini Aleph is slowly progressing at the moment. This week I bought some Prefer AV-24 cable to connect the RCA inputs to the amplifier boards. Today I bought some 2.5mm2 red & black-coloured cable to connect the amplifier boards to the PSU. Still left to buy is a 2x 15V / 225VA toroidal transformer. Still to do: drill and tap holes in the heatsink for the output MOSFETs.
Monday, 31. August 2009, 17:06:03
audio, diy, hi-fi
A heavy parcel from Italy arrived today... Containing: two heatsinks, a rear panel, a top panel, a perforated base and a 10mm aluminium front panel. Not bad, in only a week from Bologna, Italy to my door. The case comes complete with four brackets to put it all together, a bag of screws, nuts & bolts and four basic feet. The quality of the case appears to be excellent. It meets my expecations. Excellent service from www.moduship.biz, highly recommended!
per il facile avvitamento delle viti autofilettanti si consiglia di usare olio o grassi o sapone
What does it mean? I can only understand half of it... Babelfish to the rescue!
for the easy tailspin of the self-tapping lives it is advised to use oil or fat people or soap
Fat people!? Let's stick to grease instead.
Saturday, 22. August 2009, 22:03:30
diy, audio, hi-fi
I just ordered a really nice 2U case for my mini Aleph. It has a 10mm thick aluminium front panel and two large heatsinks (0.55 °C/W each) that should help dissipate the heat from the output mosfets. I also ordered the perforated bottom for it. It should provide some additional airflow inside the case as well as making attaching the PCBs and other stuff a lot easier.
Saturday, 1. August 2009, 11:39:13
diy, dutch
Vandaag ben ik begonnen met m'n zelfgemaakte limoncello. Limoncello is een Italiaanse citroenlikeur. Na lang zoeken eindelijk biologische citroenen gevonden. Waarom biologisch? Nou, voor de likeur heb je alleen de schil nodig. Gewone citroenen bij de supermarkt zijn bespoten en "in de was gezet". Volgens de Keuringsdienst van Waarde gaat er shellac op citroenen. Iemand heeft ooit bedacht citroenen in de was te zetten zodat ze er mooier uitzien. Zo mooi als die glimmende citroenen bij de supermarkt in het schap liggen, zo lelijk zijn ze als ze nog aan de boom hangen. Voor de smaak (erg zuur!) maakt het niets uit. Wat je voor limoncello nodig hebt van de citroen zijn de etherische oliën die ín de schil zitten. Vandaar de wens om biologische citroenen te gebruiken.
R/
5 à 6 onbehandelde, liefst Italiaanse, citroenen
500 ml ethylalcohol 90% à 95%
300 à 400 gram suiker
600 ml water
Citroenen schoonmaken en droog deppen. Met dunschiller de citroenen schillen. Alleen het geel van de schil, niet het wit. Laat de schillen 7 à 10 dagen trekken in de alcohol in een afgesloten fles. Zet de fles op een koele donkere plek. Schud de fles iedere dag. Los suiker op in 600 ml water. Zeef de schillen uit de alcohol en voeg de suikerstroop toe. De limoncello wordt ondoorzichtig geel. Laat de limoncello minimaal 2 weken rijpen in afgesloten fles. IJskoud serveren.
Hoe kom je aan de ethylalcohol? Informeer eens bij een apotheek die nog zelf bereidingen doet.
Saturday, 4. July 2009, 11:14:26
diy, audio, hi-fi, nelson pass
I picked up my F5 parts at the post office yesterday. Yesterday evening I started stuffing the boards and soldering everything. The quality of the PCBs is excellent, a really good job Peter Daniel did in making the layout. Minor niggle, the PCBs are made with tiny resistors in mind. My 0.6W resistors are too large to be lying flat on the PCB, they have to stand upright.
I ordered 0.47 Ohm resistors for the source pins of the output MOSFETs but received 0.50 Ohm instead. I'll just have to account for their slightly higher resistance when adjusting the bias current. No problem though.
The PCBs are now almost done, they're still lacking the thermistors and output MOSFETs. The MOSFETS will have to wait until they're mounted on the heatsinks. The thermistors will have to be bought still. More pics in the
F5 photo album.
I also picked up a copy of the new Chris Ryan novel
Firefight. Something to read coming summer holiday.
Showing posts 1 -
7 of 31.
WIDGETIZE