NEW/OLD SOLARUS - Question - New to forum too! WOOOO HOOOOO!!!!!

[Enzo]

Well don't just throw parts at it, I suggested that as a solution IN THE CASE THAT the hum is coming from that 22v supply. If the supply is not hummy, adding caps to it will do nothing.

Having said that, I would likely chose something like 100uf 150v for between those resistors. Hell that existing filter in that supply could go up to 100uf instead of 50uf, and I;d be happy. I scope or measure the ripple on a supply like that to find out if it needs help. The cheap way is to get a suitable cap and two clip wires, and clip the extra cap into the circuit. It makes a difference or it doesn't.

Um... DO NOT connect either side of the mains to your chassis. Just because the wiring thinks it is neutral, doesn't mean some outlet won;t be wired backwards (happens all the time), and BAM, you have a burnt socket, a melted plug, and a blown breaker.

Schematics can be inaccurate but even then, MOST of it will be correct. Some of them have a misdrawn connection on the pentode by the phase inverter for example, but the rest of the page is right.

[AjaxLepinski]

Hey Enzo. No worries, I'm not impulsive and I will not be throwing parts at the amp until I sort things out.
I'm just happy to hear suggestions to give me an idea of were to look for the reverb hum issue.
I understand that the schematics can be incorrect and there can be circuit variations, from year-to-year, as the model is manufactured and upgraded.

After removing the 600v .047uF Death Cap and disconnecting the Polarity Switch from the circuit, the red/yellow PT wire, from the Power Transformer no longer has a connect to the neutral power main (before removing the Death Cap, the red/yellow PT wire received neutral juice from the Polarity Switch via the 600v .047uF Death Cap).
It has been suggested, that the red/yellow PT wire is now drawing AC from the chassis because, it is no longer in direct contact with the neutral power main via the Polarity Switch/Death Cap.
To resupply the red/yellow PT wire with the neutral main, I have two options...
1) Run a new wire from the white/red neutral main (where it is soldered to the Power Switch) to the chassis junction where the Blue Cap, red/yellow PT wire meet (and were the Death Cap was also connected before removal)
2) Disconnect the red/white PT wire from it's current position and connect it directly to the white/red neutral main where it is soldered to the Power Switch. BUT, this will cause the lamp, on the Power Switch, to no longer light when the amp is on.

The red wire (marked by blue arrow "Red wire from Hot (Black) Power") comes from the Fuse. A three prong outlet was added with the ground screwed to one PT bolt. This eliminated the need for the Polarity Switch and the Death Cap. To reiterate, before I removed the Death Cap, the red/yellow PT wire had access to the neutral main via the red/white wire going to the polarity switch going to the Death Cap going to the red/yellow wire which is bolted to the chassis. The red/white wire is used to light a bulb on the Power Switch to indicate that the amp is on.

Actually, typing all this out has given me the confidence to go with wiring option #2. The circuitry is now clear to me and I can see that option #2 will work correctly.

[g1]

After removing the 600v .047uF Death Cap and disconnecting the Polarity Switch from the circuit, the red/yellow PT wire, from the Power Transformer no longer has a connect to the neutral power main (before removing the Death Cap, the red/yellow PT wire received neutral juice from the Polarity Switch via the 600v .047uF Death Cap).
It has been suggested, that the red/yellow PT wire is now drawing AC from the chassis because, it is no longer in direct contact with the neutral power main via the Polarity Switch/Death Cap.

NO. The red-yellow of the PT has no need for any connection other than chassis. It was not receiving anything from neutral and should stay connected to chassis only.
The light is a separate issue and should not be confused with the red/yellow of the PT.

[AjaxLepinski]

Hi G1,

Thanks for the input... I am still considering the issue and appreciate your input.

Here is a link to an article that describes the Death Cap issue: https://psg.com/~dlamkins/lamkins-gu...itch-death-cap

I agree... the red/yellow PT wire should remain grounded especially, since that is what the schematic indicates.
The light is indeed a separate issue - I only mentioned the Power Switch indicator light to point out that, removing the red/white wire would cause the light to stop working. The only reason the red/white line is attached to the Power Switch is to power the light and really isn't needed.

Right now, I'm considering running a wire from the Power Switch's red/white wire, keeping the 600v .047uF cap and grounding the cap to it's original position at the bolt with the blue cap and the red/yellow PT wire. That would keep the original circuit in tact (sans Polarity Switch). Still thinking about this so, I think I'll do some more research on the Death Cap thingy.

[g1]

Consider that later models such as Fender had a 3 way ground switch with a center-off position.
The cap is not required for any reason other than removing some nuisance hum which may or may not be present.
In cases where it is desired, there are modern caps designed specifically for this purpose (class Y for line to chassis).
If you don't have a hum problem that the cap is correcting, I would ditch it. If you really want it, use a Class Y.

[AjaxLepinski]

Glad I found my way to the M-E Forum - I'm getting an awesome education!

Class Y caps are for filtering AC noise... thanks for the heads-up g1 !
This is my first restoration project and it's making me wish I started learning about amp repair 40 years ago.

[Jazz P Bass]

Just so you are aware:

X capacitors go across the line (Hot & Neutral)

Y capacitors go from mains to chassis.

Back to Basics: What are Y-Capacitors? | Vicor PowerBlog

[AjaxLepinski]

Thanks Jazz P Bass - that link was very helpful. So much to learn... it's cool and mind boggling at the same time.

Finally had some time to play with the soldering iron yesterday.
I have to say, it was very exciting; trying different wiring options and seeing what was going to happen... Would it work? Would it blow up? Would you read a story in tomorrow's news papers about some crazy Long Island guitarist who was hospitalized?

I tried three different wiring options:

1) Unhooked the red/yellow PT wire from the chassis ground point and soldered it to the Power Switch post with the white/red wire.
Results: Nothing blew up but, it was a no go. The amp lost volume and the guitar sputtered and farted.

2) Soldered the red/yellow PT wire back to the chassis ground point and ran a new wire from there to the Power Switch post with the white/red wire.
This was RiffRaff's suggestion.
Results: This worked and it sounded the same as the amp sounded with the Death Cap and Polarity Switch in the circuit.
But, it still had the same reverb hum and there was some buzz/hum when the guitar volume was on.
If I turned the guitar volume off, the amp was totally quiet, even with the amp volume on 10.
The guitar buzz/hum gets completely drowned out when playing but, it does get louder as I turn up the amp volume.
As the Tremelo did it's thing, it turned the guitar buzz/hum on and off with each trem pulse.

At this point, I was wondering if the amp really had less reverb hum and guitar buzz/hum with the Death Cap in? So, what the heck....

3) I put the Death Cap back in and hooked up the Polarity Switch.
Results: Everything sounded exactly as described with #2.
I guess the amp sounded noisy in the music store (when I was first checking it out). But, I had it cranked and that would have covered up the noise.

Conclusion: The Death Cap can come out with the wiring as described in #2. The guitar buzz/hum and the reverb hum is coming from somewhere else.
I've owned other amps that produced the exact same noises and I just lived with it / ignored it.
My two, glorious, RG80's have the same noise issues. However, the Hi-Tone is as quiet as a church mouse.


This evening, I took the amp (with the Death Cap and Polarity Switch hooked up) to band practice.
MAJOR WOODIE!!!
It gets super saturated and super squishy on 10 and awesome for leads. On 6 or 7, it karangs and takes power chords just fine.
Man, I never played an amp that gets as squishy at this one. The squishyness is defiantly cool and has it's uses and it can be cut back using the guitar volume knob.
Only drawback; at 40 or 60 watts (not sure which), it's just loud enough with a drummer and bass. My old Sunn Sentura II was louder but, it didn't get as saturated so, I'm still loving the Solarus for it's own abilities. (now I'm gassing for a Sentura II haha!!!)
The noise wasn't noticiable while playing and I use my tuner as a kill switch so, it worked out fine.
I hit it with the China Fuzz (Univox Super Fuzz clone) and the amp took it like a champ - it was killer. I'm very happy with my purchase!

I'll try to make some clips this weekend to post.

Thanks again for all the feedback and help!!!

[g1]

Class Y caps are for filtering AC noise

Class X and Y are also the only caps safety approved for use in those positions mentioned by Jazz in post #22.

[AjaxLepinski]

Thanks again for your help, G1. I think I will copy and print all the info and links into my notebook. Yeah, man! I wish I started studying amp repair a long time ago. Still, I'm enjoying the experience.
I'm going to clean all the jacks: input, reverb and speaker this weekend. After that, if I still get any hum, I'll start checking each cap one at a time with my capacitance meter.
I can live with the hum but, it will be fun trying to track it down.

Here is a pic of my gear (top to bottom) Hotone Purple Wind 5 watt Plexi amp, Sunn Solarus, Hi-Tone DR103-DG.

[AjaxLepinski]

Hi Brian,
I offer the following additional information about your rear panel jacks.

I have seen both pop-rivets and screws used by Sunn to attach the connector mounting flanges to the chassis.
The following photo shows the likely original configuration of your Solarus rear panel. I think your amp originally used the screws.
[ATTACH=CONFIG]39643[/ATTACH]

As loudthud pointed out in post #6, the original dual footswitch jack was phenolic.
There appears to be an exact replacement part available at Phono Jack-Dual Panel Mount (Item: PHOJK-CH2-4) - Radio Daze LLC
[ATTACH=CONFIG]39644[/ATTACH]
The mystery jack that you originally asked about is a non-stock add on. Too bad someone drilled the extra hole in the chassis.

Cheers,
Tom

Hey Tom,

My new RCA jacks arrived today form radiodaze.com. Only cost fifty cents plus shipping .Thanks again for your help!

Brian

[Tom Phillips]

Hey Tom,
My new RCA jacks arrived today form radiodaze.com. Only cost fifty cents plus shipping .Thanks again for your help!
Brian

Cool. I was surprised at the low price too. There are people selling similar parts asking $5 to $10 ea or more. Some of those are salvaged parts rather than NOS. Now all you need are some vintage correct slot head screws with a nice patina that matches your chassis.

[AjaxLepinski]

Cool. I was surprised at the low price too. There are people selling similar parts asking $5 to $10 ea or more. Some of those are salvaged parts rather than NOS. Now all you need are some vintage correct slot head screws with a nice patina that matches your chassis.

I'll be needing slot head screws -and- two, original 0-10 knobs for the front. Somewhere along the line, someone put two, Fender 1-10 knobs on the front.
Thanks again for the heads-up about Radio Daze!

[AjaxLepinski]

HEAR MY SUNN SOLAUS!!!!! CLIP CLIP CLIP CLIP CLIP!!!!!!!!!!!!!

If anyone is interested in hearing what the Solarus sounds like, I just made this clip today: https://soundcloud.com/ajax-lepinski...-ajax-lepinski

[AjaxLepinski]

Alrighty then....

So, I decided to leave the so called, "Death Cap" in place. My reasoning is:
1) The tone doesn't change, at all, with or without the cap.
2) Since the amp is now properly grounded (with a three prong outlet), I am protected.
3) If the cap fails, the circuit will be no more dangerous than, if the cap were removed.
4) With the cap in place, it's available to remove ripple.

What do you guys think? Leave it in?



This weekend, I'll be installing the replacement footswitch RCA jacks (thanks again Tom!) and also figuring out why the reverb stopped working....
I took the amp to band practice and hit a lot of pot holes along the way. Not only were the verb springs rattling but, there was also a "cow bell sound" coming from the tank.
Glad I'm still having fun learning amp repair or, I'd be pissed off!


On another note... I need two knobs so, I contacted the forum member who had ordered a batch of Sunn knobs from the original manufacturer a few years ago.
George placed his order in 2008 and the manufacturer was able to pull up his old order to get the part number and details.
Only issue is, they are asking $1400 for a minimum of 500 knobs! If I can't haggle them down, I'll suppose I'll have to get used to the look of 1-10 Fender Witch Hats!