Smiley face Sunn amp head.

[vertigolady]

Hello everyone, I am new to this and am not even sure if I know how to post but I'll try. The reason I'm here is cause I love vintage guitar and amps and am an aspiring collector. I have recently been lucky enough to get my paws on an old smiley face Sunn head. I didn't know much about it when I found it but I knew the logo was different from any I had ever seen and I thought the tolex was a homemade re-do but I read a little on the unofficial web site and figured it must be on of the early garage made amps. In any case, I don't have a cab for it so I used a 2 12 inch vintage fender jensens in a generic 2x12 cab just to hear it and Oh My God this thing sounds amazing. It is very clean and the bass response even with only those two fenders sounded ballsy and thick. Everything on it is original or at least looks that way and I will post pics as soon as I get a chance. I am out of town right now and not in front of it. I wish I was so I could use it but I'll have to wait till I get back. The only issue is it seems to have some noise once it warms up and it gets a little noisier after playing it for a little while. Say 5 minutes. I guess the caps need replacing but I want to enjoy it and hear it before I change anything on it. Can anyone help me by steering me in the right direction for a cap job. What do I need to watch out for? what are the pitfalls? How do I find someone to do it right? I live in a small town and don't have any large reputable service shops nearby.

[EdBass]

Welcome aboard!
The only thing to really watch out for is the current potential that a big filter cap can hold. Unless you know what you're doing you can potentially seriously hurt yourself by poking around inside of your amp. As far as a big shop, well, I don't know that you need a big shop to do what you need done. Any competent electrical repair tech can re-cap an old tube amp, it's actually pretty remedial for a trained tech. Particularly someone who works on old electronics; radios, TV's, etc.
Actually, try to find an old repair person. 
Tell them it's like an old Dynaco, all of the schematics are readily available online, or just have them check in here and I'm sure you can get fixed up pronto.

[vertigolady]

thanks for the lightning fast response. I usually like dealing with older experienced folks. They don't BS you too much and usually know their stuff and share wisdom. is there any way to know/ test if the caps are the problem?

[EdBass]

Usually the amp gets noisy and looses power when the capacitors go south.
The capacitors that are most likely to need replacement are the electrolytic filter caps. Unless they've been changed in last 10-15 years they probably need to be, they have a finite lifespan. They can last a century theoretically, but in actuality they don't. I've had old amps with 40 yr old filter caps that were fine, and I've seen 10 yr old caps start leaking. I look at replacing filter caps as routine maintenence, kinda like changing the oil on your car. They aren't that expensive once per decade or so.
Find that sage, trusted old* repair person and let them go through your amp, it should be a piece of cake. Old Sunns are about as straight forward as it gets in vintage MI amps.






*of course I jest; young people (including a guy that I use that makes very pretty solder joints; maybe even the prettiest solder joints) can be perfectly suitable tube amp techs.

[Soundmasterg]

Maybe Conrad would be into taking a look at the amp for her? He might get a kick out of seeing one of the early ones. Can't get much better than having him look at it.....I can ask if ya want?>

Greg

[loudthud]

Those early amps don't have a ground switch or a Death Cap. You'll get hum and other noises until you get a 3 wire grounded AC cord installed.