I have a vintage 15wpc Marantz 1030 amp with a hiss on one channel. The right channel preamp component (transistor) needs to be replaced. I paid for a professional diagnosis but when the tech guy quoted $150 to replace the transistor, this little amp unfortunately isn't worth it. So I thought perhaps I might try to fix it myself.

Is it difficult to replace a transistor?

Any tips or suggestions?

If you live in Connecticut, would you be my guide? I've never done anything like this before, so be gentle :>

Search the Forum for "recapping" or "recap"or "transistor replacement". There is a lot of information here about desoldering and board work. Replacing a transistor isn't difficult at all, especially a small transistor that doesn't have a heatsink. Do you have an iron?

I've got an old Weller dual heat 100/140w that works well. Or I can buy a new iron @ RatShack.

It is not difficult at all, If memory serves me right all six of the pre amp transistors are the same. One thing to consider is the type of transisor that is in there may appear to be backward compared to the replacement. Just make sure to check the pinout. I used NTE85's but you can find a better Toshiba replacement for less money.

Would it make sense to replace all six pre-amp transistors? I would think it might be a good preventative idea. Plus I have no idea which transistor is bad. I'll trust your advice.

Thanks Roggom for the Toshiba tip.

Tomorrow I'll take a look at the 1030 and see if I can locate the six pre-amp transistors. I might have a schematic for the 1030, the only challenge is that I've never read a schematic, so I'm not sure what I'm looking for.

I just want to say "thanks" for helping a novice. I have no idea what I'm doing, however I always wanted to learn about this stuff, but never knew where to get started.

Well you really do not "have" to shotgun it by replacing all of them. I did because I was using a different transistor than the original so i wanted everything to be similar. The NTE85 are only 1.29 at mouser. What is the part number on the transistors? I only have the schematic and not the parts book.

I've got an old Weller dual heat 100/140w that works well. Or I can buy a new iron @ RatShack.
That Weller would pretty much destroy the circuit board on the Marantz but would be ideal for a "boat anchor".
Go out and buy a small soldering pencil, solder and a solder sucker. You can likely get them from the same place you ultimately get the transistor from. Next go to the local dump and bring home some discarded OLD electronics and practice on a circuit board from that first. Make sure you get something old as the newer electronics don't have "through hole" components like the Marantz but rather "surface mount devices" (SMD) which are whole other kettle of fish to solder.
Be gentle and patient, but you should be able to heat the old solder and suck it off in about 2 seconds per connection and then resolder in about 1-2 seconds per joint.
JimB

Good subs that work are 2sc945 or better! ksc1845 from Mouser.
1845 is low noise and great in pre's I've used it for. Plus they are only like .06 ea.

Thank Jim. I'll get a small soldering pencil, solder and a solder sucker. Not sure I'll find an old junk piece to practice on right now, perhaps this spring I'll hunt around at garage sales. Now if I can just identify the right transistor(s) to replace. Will I need any meters, or just remove old transistors and old solder, and re-solder new transistors?

Well, if they're 6 cents per (more or less) perhaps you should replace them all in that section. And replace some caps too. I mean as long as you're in there. But practice on some junque boards first. If you can't score one maybe someone in your area can give you one. Or go to a local repair joint and scour their trash. DUmpster diving, an audio tradition since, well since forever.
JimB

Good advice Jim.

If you live in Hartford/New Haven area and have a junk VINTAGE circuit board that you can donate so I can practice soldering and desoldering, please let me know.

Thanks! -- another Jim