HP (Hewlett-Packard) Stereo 9-Pin PCB manuale d’uso

AUDIO DESIGN Copyright 2006-2008© All Rights Reserved GlassWare Aikido Stereo 9-Pin PCB USER GUIDE Introduction Overview Schematics Recommended Configurations Tube Lists Assembly Instructions 05/29/2008 Revision C[...]

GlassWare Audio Design Warning! This PCB is for use with a high - voltage power supply; thus, a real shock hazard exists. Once the power supply is attached, be cautious at all times. In fact, always assume that capacitors will have retained their charge even after the power supply is disconnected or shut down. If you are not an experienced electric[...]

GlassWare Audio Design 2 The A ikido ampli f i er de li vers th e so ni c goods. It offers lo w d i stortion, lo w output imp eda nce, a great PS RR f igure, and feedback - free ampl i f i cat ion . T h e sec ret to it s superb p erformance — in sp it e not using global feedback — li es in it s int er nal symm e try, whic h balan ces imp erfect[...]

Remember, tubes are not yardst icks that n eve r change , be in g more l ik e car t ir es — th ey we ar out. Just as a t ir e ’s we ight and diam eter decrease over t im e, so too the tub e ’s co ndu cta nce. So the fresh 6DJ8 i s not the same as that same 6DJ8 after 2,000 hours of use. But as long as the t wo triodes age in th e sa me way ?[...]

GlassWare Audio Design 4 Heater Issues The board assumes that a DC 12 V power supply will be used for the heaters, so that 6.3 V h eater tubes (like the 6 FQ7 a nd 6DJ8) or 12.6 V tub es ( lik e the 12AU7 or 12A X 7) ca n b e used. Bot h typ es ca n b e used exc lu s ively, or simultaneously; for exa mpl e 6 GC7 for th e input tub e a nd a 12BH7 fo[...]

GlassWare Audio Design 5 DC Heater PS 300k 2W 100k 1/2W B+ B+ 4 300k 2W 100k 1/2W B+ 0.1µF 250V 0.1µF 250V AC 100 100 A lt er nati ve ly, you might exper im ent with floating the heater po we r supply, by “ground in g” the heater power supply v ia only a 0.1µ F f ilm or ce rami c capac itor. The capac it or w ill charge up through th e leaka[...]

GlassWare Audio Design 6 Jump er J7 co nn ects the PCB’s ground to the chassis through the top centermost mountin g hol e. If yo u wish to float the chassis or capacitor couple the chassis to ground, th en either leave jumper J7 out or replace it with a small - valued capacitor (0.01 to 0. 1µ F ). Warning: if rubb er O - ring s are used w ith PC[...]

GlassWare Audio Design 7 Configuring the PCB as a Line Amplifier The A ikido topology mak es a perfect lin e amplifier, as it offers lo w distortion, lo w output imp eda nce, and excellent power - supply noi se reject ion — all w ithout a global feedback loop. The key points are not to use cap ac itor C 3 . For guidance on part va lu es, look at [...]

GlassWare Audio Design 8 High tran sco ndu ctance output tubes are best for dr iving headphones, for example, the 6DJ8, 6H30, 12BH7, and ECC99. A coupling capacitor of at least 33µ F i s requ ir ed when driving 300 - ohm h eadpho n es; 330 µ F for 32 - ohm h eadphones. Use a hi gh - quality, sma ll - val ued bypass capac itor in C2’ s pos ition[...]

GlassWare Audio Design 9 Assembly Before so ld er in g, be sure to clea n both s id es of the PCB with 90% isopropyl alcohol, w ipin g a way a ll f in gerprints. F ir st, so ld er the shortest parts (usually the resistors) in pla ce, then the next tallest parts, and then th e next tallest... Make su re that both th e so ld er and th e part leads ar[...]

GlassWare Audio Design R4 R2 in out R8 R11 9 9 8 7 6 3 2 1 R3 R9 R1 C11 R5 R6 R12 R13 R7 C2 C12 in 9 9 B+ C1 R14 R14 R13 C1 C2 out out out 3 2 1 6 7 8 1 3 2 2 1 3 6 7 8 R1 R3 C11 R2 R5 R7 R11 R8 R4 R6 R12 R15 C6 R16 C5 R9 R10 R10 V1 V2 V4 V3 9-Pin Aikido Schematic (Rev. C) C12 J7 6 7 8 C3 C3 J8 J8[...]

GlassWare Audio Design 11 Top Side PCB Mechanical Layout 6 4 9 1 2 8 3 7 5 V1 5 7 3 8 2 1 9 4 6 V2 6 4 9 1 2 8 3 7 5 V3 5 7 3 8 2 1 9 4 6 V4 OVERALL PC BOARD DIMENSIONS: 4.00" x 10.0" 8 MOUNTING HOLE LOCATIONS 2.00" 2.75" 2.75" 2.00" .25" .25" .25" .50" 1.00" 2.00" .125R, 4 PLCS 4 VACUUM T[...]

GlassWare Audio Design 12 The table above lists many tr iod es s uitable for the 9 - pin - based A ikido amplifi er PCB. The table lists the same tube under different B + voltages and w ith diff erent cathode res i stor values. T wo ga in s are l i sted: the f ir st i s the gain the tube realizes in the input position in th e A ikido; the second is[...]