At Last, my own 200s!! now what...

[Smoothwound]

Well I finally have my dream girl, but know I don't know what to do with her.  When I showed up to test it out, she was plugged into a variac. I'm wondering if its safe to plug it in or of I should take it straight to get it serviced? It still has the original ungrounded plug. Please have a look at the pics, if you would, and lend your advice to what the next steps should be. What to clean and what to leave (rust) and what I got here.  Thanks and can't wait to get this baby shakin again. My plans are for studio and rehearsal time only, although I would gig with her if the space was right.  Thanks again all,

https://www.flickr.com/photos/113361253@N05/with/11745885435/

[EdBass]

Nice! Did the last owner tell you why it was plugged into a Variac? I would think that if they brought the old girl slowly up to 115-120 they likely knew what they were doing, and could probably tell you whether it was safe to "plug 'n play".

[Smoothwound]

They said they used it because it hadn't been played for some time, and that it was safe to play. The tubes are covered in dust and there's lots of rust, do you think that's ok?

[EdBass]

I enjoy the smell of dust grilling on a hot output tube, smells like an old tube amp should IMO! Right up there with the new car smell in my book...
I wouldn't worry about some chassis rust either, the key word being "I". I'd fire that bugger up if it were mine, but it isn't mine so you need to make THAT call.

How come you didn't fire her up before you handed over the dough?

[Smoothwound]

I did fire it up, worked great except for some cracklin around 3 or 4 on the volume. Real loud too. I brought it into guitronics this today. He's going to look it over and I'll let you know what the estimate is and what Hal says.

[EdBass]

Taking it to the shop to get checked out is never a bad idea IMO, but I would have played with it a bit first. ; )
However, be sure to get those tubes back from the tech regardless of how they test. Somebody will buy them even if they are toasted.
Particularly the KT88's, even though being labeled Mullard (Mullard didn't make KT88's) probably indicates a later replacement, they are still "Holy Grail" GEC KT88's and people go googoo over them.

I've got some GEC KT88's that are silk screened "Sunn".

[Watson]

Do you know if that something SUNN did during a particular period of time?  Were there other tube types also marked as "SUNN"?

[sunn-tanned]

The ones I have run across had either GE6550 or TungSol's

[EdBass]

The ones I have run across had either GE6550 or TungSol's

The one's I've run across were all KT88's and in '68 or older amps, which of course makes sense as Sunn stopped using KT88's in early '69. All of the Tung Sol's I've seen were labelled Tung Sol, and I've only had one original GE 6550 tube amp and those were also wearing GE screens.

I always thought the Sunn branded output tubes were just a one-time experiment used with British KT88’s, but I don’t know that to be true. Post a pic of those Sunn 6550’s, that would be fun to look at!

[Smoothwound]

I expect when I hear back from Guitonics, they will recommend replacement tubes or at the least back-ups.  Where do I begin looking for some and how do I educate myself on these things? I read that only 3 counties make them now, are these new ones much different than vintage. Should I anticipate spend some time on ebay or do you guys recommend someone?

Thanks for All the support....
ED, wish I could have played it, but there was no output, just the calm hum from the inside.

[66tele]

Smoothwound,
Let us know what your amp tech recommends. I would advise you to replace the 2-prong AC cord with a grounded 3-prong and have the ground switch & cap disabled. If the amp has not been re-capped in the last 10 years or so, have all of the electrolytic capacitors replaced (filter, cathode and bias caps). Be aware that these amps were designed for 115 - 117 volts AC power (wall outlet). Today's wall voltage can be 125 volts AC or higher. This makes a big difference in the rectified voltage delivered by the power transformer to the rectifier and filter capacitors......instead of 500 volts DC you can get 560 volts DC delivered to the primary filter capacitor. This can easily blow a new replacement multi-section filter cap (similar to the ones Sunn used) as the reproduction versions are only rated for 525 - 550 volts DC. Your amp tech will likely know this. Triode Electronics sells a cap board designed for Sunn (and Dynaco) amps that will handle the new voltage. Or your tech can wire discrete capacitors (using the totem pole configuration like Fender used) to obtain sufficient voltage rating. You've found a nice early Sunn! Restore it and enjoy!

66tele

[EdBass]

I expect when I hear back from Guitonics, they will recommend replacement tubes or at the least back-ups.  Where do I begin looking for some and how do I educate myself on these things? I read that only 3 counties make them now, are these new ones much different than vintage. Should I anticipate spend some time on ebay or do you guys recommend someone?

Thanks for All the support....
ED, wish I could have played it, but there was no output, just the calm hum from the inside.

The pursuit of "the" tube for any particular application can trigger OCD even in the most level headed types. There are myriad threads on this forum alone that would bear that out, but the general consensus is that tubes from "the good ol' days" are overall superior to the eastern European/Asian tubes available nowadays.
Moot point for the most part with KT88's, a matched pair of vintage GECs can easily bring more than an entire nice 200S rig will bring.
Price to value I don't think you can go wrong with a pair of JJ's (try www.eurotubes.com) , but myself and others here have tried just about everything that will plug into those sockets and opinions are as diverse as the individual posters themselves.

This forum is unquestionably the most information laden vintage Sunn specific resource on the 'net; search KT88 and 6550 and settle in for a few hours...

The rectifier filter cap thing has been hashed out here ad infinitum as well, also good search material.
I've personally got fully functional gigging Sunns with the SDS replacement board from Triad, the German 550+VDC Authenticap, and even a magical '68 200S with original everything including the original 30/20/20/20 can capacitor.

Do a little digging and you will get more information than you know what to do with!

[Smoothwound]

Well I've been pouring over this site trying to find out about rectifier filter cap and which tubes are better and new boards etc etc, and some of it is actually making a little sense but most is overwhelmingly new and therefore out of my league at the moment.

If one did want to go for the "good old day" tubes, are there better places to support than others?

The whole power question of old wall current vs. new, and how to decide what to put in your amp is almost impossible for someone who hasn't even had the chance to play it yet, wondering what maintenance and/or mods come closest to the original sound.

Also would love a nod towards some of the better discussions and threads to read and reread.

Still waiting to hear from Guitronics, staring at a cover 215 cab everyday wondering when I get to fire her up. grrrrrrrr!

[EdBass]

There is certainly a lot of info to pour over, I would ask your tech what they suggest and then post those ideas here.
That may be a good way for all of us to learn something!