Technics SU-7700

Status
Not open for further replies.
Jump to Latest
rhymeswthorange

rhymeswthorange

Member
Joined 2005
#1
I just got a VERY nice, clean Technics SU-7700 on eBay. It sounds quite nice, but has one problem: the right channel is significantly louder than the left. On bass hits, the power meter for the right channel consistantly reaches higher maximums than the left. I have reversed the speakers and played every sort of music I have only to come to the same results.

I have pretty sensitive speakers (fostex fe207e's in a MLTL) and am only driving about 1 - 1.5 watts through them. Much louder is just too much in my little dorm room. Could slight differences in transistor bias, minute unmatchedness of transitors, positioning in my room, or the high sensitivity of my speakers be the culprit?


Thanks!!!
-'orange
 
#3
The cap that goes from the negative feedback to ground through a resistor is opening up. That will reduce the gain - to unity when the cap is completely open or anywhere in between for partial open.


-Chris
 
#10
Hi rhymeswthorange,
Gottum service manual, but no scanner. I'll try to help best I can. For the cost, just replace the caps and see what comes out.

Hi kamskoma,
Don't know about yours, can't seem to find it. Sorry.
-Chris
 
#11
Have any suggestions as of brands to use? The caps in there actually look very similar to modern Xicon packaging... I wonder if they are original? 'Cause the power supply caps look nothing like them besides a common cylindrical shape. Can I use some plain old dirty Xicons, or should I opt for something a litte more refined like Elnas? Does it really matter in this application?
 
#16
Nichon PW series OK? Low impedance... but says well suited for switched power supplies. I think I'm going to replace all the electrolytic caps in my amps using as many panasonic FC series as I can and filling the leftover values up with the Nichion PW's (FC's don't have very small capacitances with low voltages). Mayeb this question is a little absurd, but I really don't want anything damaged or sound worse... it sounds very nice now and putting aside the left channel being weak, this amp is awesome.
 
#17
Hi rhymeswthorange,
They should be fine. Asking about brands of caps is like asking what wine is the best. Dangerous question at the best of times.

Newly manufactured caps are better than those made a while ago. Manufacturing processes are better. Except of course the terrible caps that went into many motherboards and some car decks.

-Chris
 
Status
Not open for further replies.
Top Bottom