Troublesho otin g G u ide
Channel M issing, Low or H as H um
These issues are EA SY to diagno se a n d loca lize ; all that's requ ire d is a m eth od ical, step -by-step a p p ro ach . M o st
ch a nn e l o u t an d oth e r ch a n n e l sp e cific issues a re du e to prob lem s a t th e au dio sou rce, no t w ith th e pream p. O ften
turntab les an d cartrid ge s be ing use d w ith o u r p ream ps are d eca d es o ld, and have sa t un use d for years. O xida tion o f
co n n e ctio n s (cartrid ge w irin g, head sh e ll plug -in s, p atch co rd plugs) is the m ost com m on cau se o f m issin g o r
in term itten t aud io . T o determ in e w he re the fault lies, p erform a sim ple step-by-step test. Tu rn th e vo lu m e do w n
w hen con nectin g or d isco n ne ctin g cab le s as follow s.
If n o chan ge, retu rn the inp u t cab les to th eir prop er jacks
and then p roceed next to sw ap the left and righ t p lugs at
the p ream p's O UTP U T. If th e prob le m no w sw itche s
sp e a k e rs, th e pream p is m ost like ly a t fa u lt. If n o ch a n ge,
ch e ck th e ou tp ut cable a nd am p/receiver fo r a prob le m .
A ll of ou r p re a m p m od e ls excep t th e TC -450 have eithe r a po w er LED o r sou rce indicator
LED s w hich con firm the p resen ce of p o w er. If n ot lit, m ake sure th at the p o w er sw itch (if so
equ ip pe d ) is on . Som e m odels have th is sw itch in tegrate d w ith th e level con trol w hile on
othe rs it is stan d -alone . Co nfirm th a t the D C po w er p lug is fully in serted in its jack , and that
the D C ja ck is no t spru n g o u t o f its h o le in the p ream p rear p a n el (see illustratio n a t right). If
the jack is d isplace d, yo u can re m ed y this b y insertin g th e D C p lu g an d gently p re ssu ring
sid ew ays o r vertically as n eed e d un til th e jack pop s b ack into p lace. Lastly, try the ad ap to r
in a differen t A C o utlet. M o st verified no p o w er issue s resu lt from ad apto r failure, n o t a
fau lt w ith th e pream p itself. P ow er a d apto rs le ad h ard lives, being exp ose d to lightning and
othe r po w er m ain s irregu la rities; th e u p side to th is is that th e y serve as b u ffers, preven tin g
su rges from re ach ing an d dam agin g the p ream p. R ep lacem en t A C ad ap to rs are a v a ilab le on
ou r w eb site .
R
L
R
L
N o Pow er (LED not lit)
Pow er B ut N o A udio
N o aud io is ra re ly a ph on o prea m p issue. U su ally it's th e resu lt o f m isco nn ection (reve rsing the p ream p inp uts and
ou tp uts), o r co n ne ctio n to a "d ead " inpu t on the receiver o r am plifier. M any h om e theater re ceivers h ave b oth
digita l and an alog inpu ts w ith the sam e lab els (CD , D A T, etc); o n m ost, o nly o ne o r the other can b e u sed . If a C D
player is alre a dy con n ecte d to th e To slink o r P C M C D in p u t, the an alo g C D inp u t w ill usu a lly b e in active an d w ill
pro d uce n o so u n d . If yo u alre a dy h ave a w orking analog so u rce co n ne cted, try tem po ra rily h o oking up yo ur
turntab le and pream p to th at in p u t. A ssum in g th is pro du ces go od sou nd , you can the n m ove o n to figure o ut w hy
othe r in pu ts do n 't fun ction. A th oro u gh re a d in g o f yo ur re ceiv e r's user m anu al w ill usu a lly p rovid e th e solutio n .
Sta rt b y sw ap p in g the left and righ t p lu gs (from the tab le )
go ing into th e pream p inp ut. W h en yo u p lug th e left plug
in to th e right inpu t (an d vice versa ), d oes the p rob lem
sw itch spe a k e rs? If it d oe s, th e cau se is d e fin itive ly n o t
the p ream p; ch eck yo ur cartrid ge , the tab le an d its cable.