musicismath is my bandmate, and it looks like my love of Sunn gear has finally rubbed off on the guy. He picked up a beautiful Sentura I today for a damn good price. He also got a Sunn cab with it as well. It recently had a cap job, and there's brand new JJ tubes inside: 2xKT88's, a tube rectifier, and I *think* the guy said that there's 3x12AX7's in there (which could be bad news, read below). Not sure about the preamp tubes, but will have to check it out tomorrow.
I'll hotlink a couple of pictures, but there's definitely more pics to check out on via the flickr link.
Because it has the Mid-Boost, I'm pretty sure that it's the Sentura I that's listed in the 1969 catalog:
Sentura I 40W 1xD15S 38x24x11.5 7 knobs 4 inputs midboost.
I've never seen this 2x12" cabinet before, but it looks just like the 2x12" Extension Speaker cabinet from the '67 catalog. It has the same grill cloth as the Sentura I.
Sadly, there were no JBL's inside of the cabinet, just 2 Rola Celestion G12-30's (30 watts @ 8 ohms each from the early 80's (?) and have a silver back.) I tried searching around here to see what were originally in the Extension Speaker cabs, but I can't find any information in the catalogs, brochures, museum, or the forum. The cabinet also has 2 inputs on the back, which I have a hard time believing are original:
The original owner had only played the amp for a couple of hours after having it serviced, and it sounds like he never used it that much. Luckily that was the case, as the 2 x 8 ohm speakers in the cab are connected to the 2 outputs separately, which means he was connected to both the 8 ohm and 4 ohm outputs on the Sunn, which drop down to a 4 ohm load when run together. Obviously there was some ohm mismatch action going on, and I know that can be bad. We quickly noticed something was amiss when we turned up the amp to 7 and the speakers started tripping out. We then turned the amp off and looked inside of the cabinet to see what speakers were in there, as I knew there just couldn't be 2 x 4 ohm Sunn speakers in there. [ We now have the speakers hooked up in parallel for a 4 ohm load now, and everything seems peachy ... aside from the speakers sounding a lot like Greenbacks
]
............
And this is where he could use your help loudthud, EdBass, Mel, and anybody else.-- I could be mistaken, but didn't all of the Sentura I's have EL-34s? I know the '67 and '68 models used EL-34's. This amp has 2xKT88's, and am wondering if it's been modded somehow, or if the amp can be safely biased and set for KT88s? I just came across a post by Conrad, and he had this to say about his '69 Sentura I: "I own a Sunn Setura that was built in 1969. It is basically a 100S with some modifications on the front end. One of the nice touches of this amp is the tremendous depth of the vibrato fuction."
http://sunn.ampage.org/sdp/index.php/topic,632.0.htmlIs it possible that there was a Sentura I model that had originally shipped with KT88's?
-- The amp seems to break up pretty early on, just around 3 on the Volume. Is that a certain characteristic of the Sentura I? I've never played a Sunn amp before that broke up that early. It has 3 preamp tubes, and I'm wondering if it's supposed to get a little nasty ... or, maybe the original owner had put 3x12AX7's in there, which the schematics call for a 12AX7, 12AU7, and 7199. I found that information about the preamp tubes in a thread, and not sure if this schematic corroborates that or not:
http://www.richbriere.com/images/Sunn%20Sentura%201%20schematic.gifI can only hope that the 7199 slot has not been modded, and that there's a 7199 seated in there.
