The Canadian Guitar Forum banner

1 - 18 of 18 Posts

·
Premium Member
Joined
·
3,177 Posts
Discussion Starter #1 (Edited)



NEW AMP DAY!

I tried ignoring the local craigslist ad for this Sunn Solaris for 2 weeks, but the price was too good and nobody else was taking it. Both of those probably due to the fact that it was advertised as being in unconfirmable functional condition (” Fuse (and fuse casing) is blown, and needs to be replaced. I have both but no soldering iron. So it’s not currently playable but easily fixable with the right gumption “).

So I made an offer conditional on me coming over with my soldering iron fixing that fuse and testing it after that; it ended up working so it is now mine. This is the little brother (2 6550s vs 4) of my 1200s, but the tremelo is MUCH better. Amazing really. There is something weird with the reverb however. We’ll see if I can get to the bottom of that.

The fuse change did not go smoothly tho. Apparently this amp was serviced at a store I have had dealings with before, and amazingly had the exact same issue I am about to describe. Don’t buy/rent amps or have yours serviced at Capsule Music. I don’t trash talk them online lightly, but what they did to the seller, and me years ago, is preposterous and shows a pattern of not giving a shit.

So I showed up and started installing the replacement fuse holder. I was about to put the fuse in and noticed 2 problems: 1) the fuse was 5A not 3A as specified on the amp (DANGEROUS! especially with an amp of unknown functional condition that hasn’t been used in a while) 2) the fuse was not the right size for the fuse holder. Not even close. Any amp tech would know this (amps don’t usually use that style of miniature fuse; hilariously small).

So how to test the amp? I did something bad and not recommended, but only because I needed to know if the amp worked and I was gonna be quick and careful. I put the too small fuse in and then used the solder tabs off the old/broken fuse holder (soldered together to make a thicker single piece) as a conductive spacer to take up the rest of the space and make contact at the other end of the fuse holder. I then removed the rectifier tube (the tubes won’t power up), and flipped the power switch to confirm that the fuse was completing the circuit (pilot light on). Then turned off and put back the rectifier tube. On again. Give it lots of time to heat up. Guitar plugged in, vol at 1, strum a chord and then flip the standby to on - prepared to turn off again quickly in case of anything weird (odd sounds or no sound). But it’s fine; chord ringing out nicely, so I test out all the functions and take her home.

So I mentioned Capsule did the same thing to me above, so after the seller (good dude; one is always hesitant when meeting people for craigslist or kijiji sales) told me that he was given the fuse and holder by Capsule, I told him my story. I once went in there to rent an amp. I needed more power for a gig than my head at the time had. They had a Traynor Super Custom Special on the floor so I got excited and grabbed it. Luckily I didn’t live that far (heavy!). Got home, plugged her in, hit 1 note and pop, fizz, dead. Wot? So I call them up and the amp tech at Capsule says “oh, yeah, I was worried that would happen,” Say what. “I didn’t have the right fuse on hand so I stuck a smaller [in terms of current rating not physical size] in there.”

I was stunned. I told him that I could not believe he would put an amp on the floor until he got the proper fuse. He said he was too busy to go get the right one (as if that somehow makes it OK; as if not putting it out on the sales floor until sorted out wasn’t an option). I reminded him that there was a hardware store across the road from his shop. He ignored that and told me to go get the right fuse and they’d toss me the dollar it cost me when I returned the amp. I could not believe this irresponsible and unapologetic behaviour, but I needed the amp working so that’s what I did. Incidentally, the cheapskate bastards refused to refund me that dollar when I returned the amp.
 

·
Premium Member
Joined
·
3,155 Posts
Wow! I have seen similar incidents in industry. Removing high voltage equipment by simply chopping off the power cord with a grinder. The worst case, I reached to pull a welding plug (no cable) out of the wall of a rental space we were getting. The owner screamed: "DON'T TOUCH THAT!!!" My hand just grazed it enuff to feel 660V of three-phase. !#%@&*@!!. Take nothing for granted. If someone else has worked on it, even your best friend, assume something is wrong and check it all.
 

·
Premium Member
Joined
·
1,351 Posts
Congratulations on the new Sunn.

I have the same model, but without the mid boost switch, and no rectifier tube. The rectifier tube socket is wired in, but it must be a solid state conversion. The reverb unit is missing from mine, but the reverb knob does add noise when you turn it up. I think mine is a 1969 model year.

The trem reminds me of the Who and the CSI Miami intro music.

I find the Solarus a great amp with lots of headroom, that takes pedals well. It gets loud very quickly and sounds great through a variety of cabs that I have tried it with. The amp is a beast when you use an old school fuzz pedal. It sounds awesome with a simple single speaker cab, or a 212.

It is the next amp that I will be sending in for service for some minor issues.

I am interested in hearing about how things work out.
 

·
Premium Member
Joined
·
16,815 Posts
Congrats!

I have a friend selling a Sceptre for a non-ludicrous price, if anyone else is feeling the SUNN GAS. I meant to make a thread for him :/
 

·
Premium Member
Joined
·
3,177 Posts
Discussion Starter #5 (Edited)
Congratulations on the new Sunn.

I have the same model, but without the mid boost switch, and no rectifier tube. The rectifier tube socket is wired in, but it must be a solid state conversion. The reverb unit is missing from mine, but the reverb knob does add noise when you turn it up. I think mine is a 1969 model year.

The trem reminds me of the Who and the CSI Miami intro music.

I find the Solarus a great amp with lots of headroom, that takes pedals well. It gets loud very quickly and sounds great through a variety of cabs that I have tried it with. The amp is a beast when you use an old school fuzz pedal. It sounds awesome with a simple single speaker cab, or a 212.

It is the next amp that I will be sending in for service for some minor issues.

I am interested in hearing about how things work out.
I love my later 70s Sunn 1200s through my musicman 115rH (almost identical to half of the infamous Sunn 2x15 reflex horns), but lately I've been running it in faux-stereo-flanking-the-drummer mode with that 15 and a tall style 4x12. Just lovely.

The solid state rectifier could be stock; Conrad was a dear and left the sockets in when he switched in case anybody wanted the sag. In my 1200s for example (2 rectifer tubes) only one socket, the one with the plug in diode module, is wired up - the other one is completely clean - never been soldered to.

Congrats!

I have a friend selling a Sceptre for a non-ludicrous price, if anyone else is feeling the SUNN GAS. I meant to make a thread for him :/
That's essentially the same amp (depending on if same era) - the only difference was the cab it came with. .... though after I noticed how amazing the tremelo was on my new Solaris I was trying to figure out why, and it may be that it's because the driver tube (the recovery is solid state and shared with the reverb) is a 6AN8 vs 12AX7 which I think is what is in my 1200s (and the Sceptre) - I'll check when I go to the studio tomorrow. That's a pentode/triode vs dual triode; more gain , which would explain it. I was really (pleasantly) surprised to see that guy in there.
 
  • Like
Reactions: Budda

·
Premium Member
Joined
·
3,177 Posts
Discussion Starter #6


The Studio just got Sunnier. … and yes, I realise idiot me cut off the Sunn PA horn on the left. Crap.

Also, forgot to poke in the back of my 1200s to see what the fx driver tube is. Crap x 2. I did check the schematics online, and all models (1200s, Solaris and Sceptre) use a 6AN8. I wonder if this was a mod in the 80s when hey thought they'd run out of readily available 6AN8s, to convert to 12AX7. The pinouts are very close ; just gotta move the wires on pin 8 and 9. I have found a few allusions to this switchout in some cursory searching online.
 

·
Premium Member
Joined
·
1,351 Posts
I thought the use of a 6AN8 is the reason why the amps are so clean, and give the Sunn amps the kind of voicing that they have.
 

·
Premium Member
Joined
·
3,177 Posts
Discussion Starter #8 (Edited)
No, that would be (in addition to the minimal gain stages in the preamp, huge iron, and massive headroom/high power - they are conservitavely rated) the ultralinear amp mode (not commonly used in guitar amps, more a hifi amp thing). See also the Marshall Major and the Fender Super Twin (not the regular Twin). It requires a special output transformer (some extra taps on the primary side); the oversimplified way to explain it is that it is not class A or AB, but fluctuates between them as is most efficient.

The 6AN8 was used as a fuzz/distortion (The Stinger) by Garnet.; not particularly clean (though it depends how hard you drive it).
 

·
Premium Member
Joined
·
3,177 Posts
Discussion Starter #9
So, when I checked the schems, I was just quickly looking to see if the 6AN8 was in there at all. What I forgot to check was what it was doing. Took another look over the weekend and it appears the pentode is driving the triode which is the phase splitter; not the fx driver - oops. Still curious and gonna check if my 1200s has it or been modified.
 

·
Premium Member
Joined
·
3,177 Posts
Discussion Starter #11
That occurred to me, but I had no other use for it, and tossed the blown one, days earlier. Also they had my CC for the rental and if I did that right there at the counter the dude would be a dick and charge me. He wouldn't even call the amp tech to confirm my story cuz it was his hallowed day off.
 

·
Registered
Joined
·
3,567 Posts
that sucks about Capsule, thx for the headsup though

congrats on the amp!! that is nice

glad it worked out for you in the end!!
 

·
Premium Member
Joined
·
1,351 Posts
I reread the post and realize you have 6550 tube in your Solarus.

Mine has EL34 tubes in it and I do enjoy what I get out of the amp. There must be some tonal differences. Have you gotten the amp running the way you want yet?

I never experienced 6550 tubes.
 

·
Premium Member
Joined
·
3,177 Posts
Discussion Starter #14 (Edited)
Yeah, I was surprised cuz I thought these all had EL34s in em, but they are Sovtek 6550WEs so not original; could have been EL34s in there before and converted. To me 6550s (or KT88s) are an integral component of the Sunn sound (I have heard at least one other Solarus owner wich his had 6550s). I have a quad of NOS military Czeslovak KT88s (it had the original GE 6550As when it came to me) and it is glorious. 2 on the preamp gain knob and I get the nicest crunch out f the power tubes (I play bass through it) - more of a nice growly compression than dirt. Bottom for days. Never owned an EL34 amp, but from my limited use of them they are not as balanced; more midrangey. That might not be the case when used in ultralinear mode; not sure.

Haven't used the Solarus much on account of not proper fuse yet, but I couldn't resist tracking the lead guitarist in my band with the tremelo on that thing.
 

·
Premium Member
Joined
·
3,177 Posts
Discussion Starter #15 (Edited)
So I got the proper fuse in there and started fixing her up. Interesting results:

So the problem with the reverb was that the RCA jacks/plugs were all loose and dirty. Cleaned them up with 2 rounds of contact cleaner + workin it. Then I tightened up the mechanical connection by squeezing the leaves of the plug (aka sleeve where the cable shield would normally connect) with a pair of pliers (just a little) cuz they were very loose in the jack. This (the dirty bit) was the exact same cause of reverb issues when I first got my 1200s (it worked but intermittently, and sounded more radio-fi than I thought it should when it did work). So FYI to all buyers of vintage Sunns w fx.

Even more interesting is that, now that the reverb is working ,the tremelo is not as strong as it was before. I think it's still a bit stronger than the 1200s (could just be the brighter cab/speaker), but close. I mean it's still good, just not quite as deep. ... So if you ever want to use the trem on a Sunn to rec a wicked lead or some shit, try disconnecting the reverb tank (and make sure the reverb knob is at 0, because it will then act as just a gain stage.... and I think that would just be the ss recovery amp so not particularly great).

All she needs now is feet (came to me with none at all - I put on good solid ones that actually absorb some cab shock vs vintage correct ones) and replacing the missing back panel. I have already cut out and painted the new back panel; used the one from my 1200s as a template with a flush cut bit in the router. Might not tolex it (I have scraps of black, but not the same texture so would look weird; just painted flat back is probs better, but I'll check to be sure).
 

·
Premium Member
Joined
·
1,351 Posts
The reverb tank is missing on mine. The reverb knob adds some variation in noise as it is rolled up. I cleaned the RCA connections several times and added a jumper. I can't get any increase in gain stage. I tried rolling some known tubes. Perhaps I am doing something wrong.

I am glad thing are working out well with yours.

The trem is awesome on mine.
 

·
Premium Member
Joined
·
3,177 Posts
Discussion Starter #17 (Edited)
Exactly, because no reverb tank (which is lossy in terms of signal; hence the need for a recovery amp). Yours just adding noise vs volume may be due to the fact that without the tank in there, the ground connection is lifted... but if you jumpered them (not the centre pin but the sleeve) that should take care of it. There could also be differences from amp to amp; apparently there was a factory version of the Solaris that had 6550s vs EL34s, so mine may not be a mod.
 

·
Premium Member
Joined
·
3,177 Posts
Discussion Starter #18


Test fitted the new back panel. Turns out the scraps of tolex I have are actually pretty close to the texture/pattern on the rest of the cab so I'ma gonna do that.
 
1 - 18 of 18 Posts
Top