Pass Labs X350 manual

P age 1 Pass Laboratories Owner's Manual X1000 / X600 / X350[...]

P age 2 Now For Something Completely Diff erent: The X Seri es are th e bigg est and most pow erful ampl ifiers w e have cr eated, but they are no t unique for that r eason. We hav e chosen t he biggest a nd mos t power ful as the pro per templ e for a new concept in high per forma nce audio ampli fication. Called Su persymm etry™, the ci rcuit t[...]

P age 3 Setup First off, let’ s be cl ear abou t one thing . These amplifi ers are v ery heav y. In the c ase o f an X1000, w e strongly sugg est that you g et four, n ot two, peo ple to h elp you l ift it. Yeah, m aybe two people c ould do it, b ut if you g et hurt, don’ t say y ou weren’ t war ned. X600 an d X35 0 models ar e not m uch ligh[...]

P age 4 the front panel stand- by but ton to go to stand- by mod e, with the meter light o ff and the meter parked to t he le ft. OK, so the a mplifier i s sitting there in stand-by mode w ith just t he sing le blue l ed lit. N o speaker con nected y et. You can go ah ead and co nnect the s ource now. The ampli fier requi res a fully balanc ed sour[...]

P age 5 of our a mplifiers i s almost non-ex istent. This is smal l comfort t o the few, but t ake it easy and give us a cal l if y ou hav e probl ems. Now that th e chann els are up and runni ng, w e can tak e a moment to not e a few things. The meter l ights are bl ue, subtl e lig hting i n daylig ht, a little more dr amatic a t night. The meter [...]

P age 6 9 volts to 1 5 volts. This swi tching is independen t of th e front p anel but ton, so i f the ampli fier is placed in operating mode by the button, the relay will not turn it o ff, only on. So much for essenti al in for matio n. Speaker Interface The X Seri es is opti miz ed for loa ds nominal ly r ated at 4 ohms and above. You can r un th[...]

P age 7 and the en ergy reserv e held in the c apacitors will do its job. As a practical matter, it will not make a lo t of di fference. Jus t don’t c all us u p and c omplain tha t you onl y measur ed 1900 watts in y our living room. I f you do, w e’ll want to k now w hat speakers can take it. Interconnects and Speaker Cable s W e hav e a gene[...]

P age 8 Fun Hardware Facts The X100 0 has two pow er transformers, r ated at 1500 w atts each, con tinuous duty at 85 degrees centig rade. Under actu al conditions in the a mplifier, they will do about 2000 w atts continuously each, and at le ast hal f again mor e than tha t for s hort durati ons. The X 6 00 and X350 hav e one o f these trans forme[...]

P age 9 boards i n the ampli f ier ar e doubl e sided, w ith plated throug h holes and d ouble thickn ess of copper. So how long will this hard ware last? It is my experience tha t, barring abuse or the odd failure of a componen t, the first things to go w ill be the pow er supply capacitors, and fro m experience, they w ill last 15 t o 20 years. F[...]

P age 10 Supersy mmetr y: What it is, Where it came fro m, Ho w it works, Why bother ( theory and philos ophy you can ski p ) Supersym metry is the name g iven to a new type of a mplifyi ng circui t, whic h operates quite different ly than t he desig ns pres ently app earing in liter ature and the mar ketpl ace. I have been designing new amplifiers[...]

P age 11 nature of the device. So I will state here and no w that I c onsider “n o feedback” to be where feedback does not extend further than a singl e gain device or stage, s o that circui ts hav ing “local feedback” are still consi dered “no feedback”. Any body disag reeing with this sh ould send me a diagram of a “true no feedback[...]

P age 12 sink in it. N ow I str ive to be li ke Pic asso, who c ould draw a woman with a si ngle penci l stroke and create a master piece. Supersym metry is not a singl e pencil stroke, but I am making progress. Its orig in goes back to the late 1970’s w hen I was ex amining the v irtues and faults of so-cal led “error correcting amplifier s”[...]

P age 13 feedback w ith a Sup ersymmetr ic conn ection an other 20 dB or so. This is easily accomplishe d with onl y one g ain stage ins tead of the mul tiple stag es required by conventi onal desig n, and so it results i n only one “pole” of hig h freque ncy character istic, and is unc onditi onally stable without com pensation. In fact, i f y[...]

P age 14 People inev itably w ill ask how thi s relates to bridg ed ampli f iers in g eneral , and th e balanc ed amplifier o fferings of oth er companies . It is similar o nly in that both termin als of the ou tput to the speak er are “l ive” ; neither of them is ground ed. You c ould in fact “br idge” tw o X1000’s together t o giv e you[...]

P age 15 On this cur ve (B) we can clear ly see tha t intrinsic sy mmetry due to t he matchi ng of th e two halves r educes th e distorti on by a factor o f 10. Super symmetr y (D ) creates a more per fect match, a nd results i n an ad dition al reduc tion by a factor o f 10. How ever there is esse ntially no differenc e in the distortio n figures [...]

P age 16 X1000 CUR VES[...]

P age 17 X600 CUR VES[...]

P age 18 X350 CUR VES[...]

P age 19 X1000 SPECIFICA TIONS All figur es obtai ned after 1 hour w a rmup, with reg ulated 12 0 VAC pow er line. See m anual notes ab out AC p ower l ine reg ulation. Gain 30 dB Freq. Response -0 dB at DC , -3 dB at 60 kHz Power Outpu t 1000 w atts maxi mum @ 1% THD, 1 kHz, 8 o hms Distorti on refer to accompany ing di stortion c urve Maxi mum Ou[...]

P age 20 X600 SPECIFICA TIONS All figur es obtai ned after 1 hour w a rmup, with reg ulated 12 0 VAC pow er line. See m anual notes ab out AC p ower l ine reg ulation. Gain 30 dB Freq. Response -0 dB at D C, -3 dB at 100 kHz Power Output 600 watts maxi mum @ 1% THD, 1 kH z, 8 ohm s Distorti on refer to accompany ing di stortion c urve Maxi mum Outp[...]

P age 21 X350 SPECIFICA TIONS All figur es obtai ned after 1 hour w a rmup, with reg ulated 12 0 VAC pow er line. See m anual notes ab out AC p ower l ine reg ulation. Gain 26 dB Freq. Response -0 dB at D C, -4 dB at 100 kHz Power Output 350 watts maxi mum @ 1% THD, 1 kH z, 8 ohm s Distorti on refer to accompany ing di stortion c urve Maxi mum Outp[...]