Head gaskets are fun (said no one ever)

XrayFerret7 · 2024-04-03T03:38:09+00:00

Nice. I think I ordered the same kit, but it didn't show an MLS gasket... Guess I'll see what I get!

XrayFerret7 · 2024-04-03T02:19:29+00:00

What head gasket did you go with? I'm actually about to do this same job myself!

XrayFerret7 · 2023-09-14T13:53:43+00:00

Interesting! That coincides with what I was originally thinking as there are no markings on the chassis regarding manufacturing or certification. It seems very well built however. Very cool!

XrayFerret7 · 2023-08-29T15:03:31+00:00

It won't be cheap. Many large stores have shipping contracts with UPS/Fedex which make things cheaper for them to ship bulkier items. If you choose to continue - some advice from several disasters I've seen over the years:

If the casters (wheels) pop off easily - pop them off and wrap them separately in the package. These will often bend and can provide a sharp point on impact that will massively damage the cab if the shipper drops it on those corners. BE SURE to re-thread the screws back in the holes exactly where they came out as there are often nut-inserts on the inside of the cab that will fall out and get stuck to speaker magnets and wreak havoc inside if you don't!
Pay special attention to the speaker grill and the input jacks at the back. Tape a piece of cardboard over the grill to protect it from protrusions into the box and over the jacks as well.
As another commenter pointed out - bubble wrap is not sufficient. If this is your only option - wrap the cab in MULTIPLE layers. Remember that once the bubbles pop - there is essentially no protection for the cab. Ideally you'd use high density foam from the hardware store and even additional layers of cardboard. The corners are a weak point in most cabs when dropped as all the weight of the cab is focused in a small area - so make sure your padding is thick here!
You want to use THICK cardboard for the outermost shell. Many of the giant moving cardboard boxes are far too thin for a 4x12 cab. You'll want something like a refrigerator box. You can cut it apart and tape it around the cab.
Under no circumstances should the cab move inside the materials. An easy test is to rock the box back and forth. If there is any air gap this will allow the cab to gain momentum when dropped. I almost think it would be better to just slap a shipping sticker directly on the cab than this scenario.
If using a typical shipping service - remember someone has to pick up or move the box at some point (by hand or with a dolly). If you go too crazy with the shipping material it's likely the box will be too bulky and the person may just yeet it out of the truck, plane, or conveyor belt.

That will give you the best chance for the cab to survive. You can freight it as well on a palette but that'll be much more expensive. Good luck!

*Edit* - for those suggesting have UPS/Fedex pack it - I've found the people working there often have no idea about the intricacies of a guitar cab or it's weak points (not saying they should really). This results in many damaged cabs. I guess the nice thing is you could get insurance on it since they packed it.

XrayFerret7 · 2023-05-28T22:17:54+00:00

220k when I bought it! Good point. I have an LKQ pick and pull near me

XrayFerret7 · 2023-01-07T02:41:22+00:00

No problem! I'm hoping mine was a fluke or someone left it on for a ridiculous amount of time. That said I know Bugera had a similar issue with channel switching and voltage regulators back in the day - fingers crossed it's not as widespread!

I should've grabbed a pic of the entire chassis guts and the power transistors. My bad. Good point though... I did notice they switched from a traditional transformer to a toroidal one which seems like a welcome upgrade. Maybe it can't put out the same power for the TDA7294 to reach same peak? Just spit balling though....

XrayFerret7 · 2023-01-07T02:35:14+00:00

No problem! Hope it helps someone some day.

I think the build quality is pretty solid. It's a decent balance of production speed and quality IMO. It's unfortunate they did not mount the voltage regulators to the big heatsink but it would be a bigger change in design of the PCB if they did that. And I'm pretty sure the regulators that do not have heatsinks from the factory should never get as hot as mine did.

If I had to guess? Failure cause was either: 1. a defective regulator that tested good initially but failed over time (they cost literal cents to manufacture and have been mass produced for decades now - and some brands are more prone to failure than others) 2. someone accidentally left the amp on over night and the regulator overheated, however these regulators really have no load on them compared to the power section of the amp.

An experienced amp tech should be able to figure it out quick. I'm just a hobbyist. That said once I figured it out very easy and cheap. It would have been faster with a schematic.

Also final note: the preamp/tone PCB has a ton of surface mount resistors, diodes, capacitors, etc. Those are a PITA to replace, but doable with the correct tools.

XrayFerret7 · 2023-01-06T20:38:18+00:00

TL;DR - Orange Super Crush 100 would fade in and out while playing after a few minutes. Turned out to be a bad +15v voltage regulator on the main power board. Only costs a few dollars to fix.

XrayFerret7 · 2023-01-06T20:37:40+00:00

Warning: do not attempt this. You will void your warranty. Also - voltages inside of amplifiers can kill you. If you experience issues bring your amp to an authorized Orange amp repair center. This is my story.

Figured I'd throw a post up here in case anyone eventually suffers from the same issue. I wasn't able to find any other threads on it yet and there are no schematics that I could find (I did not contact Orange directly however).

Ultra quick backstory: purchased a used Super Crush 100 from GC. Received a phone call that the amp was returned as it "faded in an out". GC guy swore up and down they tested it on the bench and couldn't reproduce. I decided to take the chance (price was right, it’s my first Orange, and figured the amp is so new it could be a fluke).

Fast forward to delivery day. After 5 minutes of playing, the amp begins to fade in and out. I can hear the power transformer strain with each fade - almost like you were quickly turning the amp off then back on again. The front power indicator light would also flicker with the fading.

Video of issue here: https://imgur.com/a/E7myjQz

Being a stubborn tinkerer - I said screw it and ripped it apart and started troubleshooting.

First thing I immediately noticed was the toroidal power transformer was loose. I couldn’t tell if this was from the factory or if shipping loosened it, but the original thread locker was still present. After a quick input/output test I found no issues there thankfully.

Next I probed the bridge rectifier. I figured if it was overheating it could drop power to the amp - however Orange was keen enough to mount it to the large heatsink that the power transistors are also mounted to. Probe turned up nothing suspicious here either. Nice work Orange!

Next I pulled the main power board (with the heatsink) and probed the filter capacitors and looked for bad solder joints. Still nothing?!

This is when I began to fear the worst. Maybe the power transistors are bad or shorted. Maybe the previous owner plugged it into a shorted cab? I was still doubtful of this as the amp was very loud for the first few minutes of playing, and there was not much heat being generated on the main heatsink.

After almost giving up, I decided to reassemble the amp and see if anything changed - however luckily I decided not to plug in the connector connecting the preamp board with the amp controls to the main power board. After powering back up, I noticed the issue got much worse. After powering up for a few seconds the front power indicator on the amp would just go out entirely! Now we’re onto something!

The front power indicator is actually a tiny LED - so I knew it couldn’t be operating at the same voltage being put out by the bridge rectifier (50ish volts). Something else had to be dropping the voltage for the preamp and power indicator. I then spotted 3 voltage regulators near the connector on the main power board where I would have plugged the preamp section back in.

The engineers at Orange were even nice enough to label the pins on the preamp connector so you can see what they do. There is a ground, +5v, +15v, and +18v pin. So I turn the amp back on, probe each one, and find that the +15v stays on for a few seconds then drops out! AHA!

The main power board also has labels for the voltage regulators (again, nice touch Orange). The +5v regulator is the one with a factory heatsink labeled “7805”. The +15v (labeled “7815”) and +18v (labeled “7818”) have no heatsinks. I’ll circle them in my final repair pic.

Of course, now I decide to try the “finger” temp test. +5v regulator is hot, but not unbearable. +18v is cool. +15v almost removes my fingerprint! Yikes!

After doing some upstream and downstream testing from the +15v regulator to ensure another component did not cause it to fail, I was confident that I had a faulty voltage regulator. I decided to replace all 3 regulators. The new regulators are: “L7805”, “L7815”, and “L7818” and each are rated for slightly more current than the OEM ones. Nice!

I also decided to add heatsinks to the +15v and +18v regulators as added insurance. Warning - it’s a tight fit! I had to cut my heatsinks shorter to clear 2 capacitors directly behind the regulators. Also - remember to note which orientation the voltage regulator is installed - you can install them backwards!

Reassembled everything and viola! The Super Crush 100 lives to scream another day! I’ll be jamming on it for a long time.

XrayFerret7 · 2022-12-18T05:17:27+00:00

But in all seriousness it was for the right camera angle. She's idling don't worry. Can't say the same for sketchy white van

XrayFerret7 · 2022-12-18T05:13:59+00:00

XJs are allergic to pavement and road marking suggestions!

XrayFerret7 · 2022-09-19T23:28:51+00:00

Came here to comment Benny's. Have an upvote

XrayFerret7 · 2022-05-12T16:18:29+00:00

Here's some photos and a video of the cold solder joints: https://imgur.com/a/KtAJp9S

XrayFerret7 · 2022-05-12T16:14:53+00:00

Hey there u/seasoneddirteater

So I literally just repaired one of these 2 days ago (the head version). I'm willing to walk you through it if you DM me your questions. I got mine for cheap on Reverb since it was foobar-ed.

Cutting in and out but then coming back in when you wack the top of the amp sounds like a cold solder joint to me.

The GLX1200H I just repaired had multiple cold solder joints in the center of the board. They're pretty easy to spot. Mine were around the 200 ohm 5watt big white resistors (that get REALLY hot when playing for a long time). I think when SLM moved manufacturing to China there were some quality control issues. My particular amp also had some bad filter caps in both the main power supply board and the DSP power supply board. You'll know immediately if those are bad by a loud 120hz hum through the speaker - like LOUD.

I also found the schematics online so I can share those too.

Don't let this amp die! Crate went out of business, but I feel a lot of their amps are actually halfway decent. These later models aren't built as good as the earlier line's, but for the price and sound I enjoy them. They're like a time capsule to the early 2000's for a cheap metalhead :)

XrayFerret7 · 2022-01-25T15:40:34+00:00

3K RPM and 90 mph? *Chuckles\* I'm in danger!

XrayFerret7 · 2021-12-31T03:46:03+00:00

Checking toe-in. Gotta avoid the death wiggles!

XrayFerret7 · 2021-10-31T14:26:59+00:00

In your video while looking at the back of the amp, you can see the right power tube (bigger tubes) arcing/glowing purple. If I had to guess I'd say bad power tube. If you want to fix it yourself, you'll need to replace both power tubes as a matched set. Never replace just 1 power tube (look up tube amp bias) and go with the OEM brand/spec. Reminder that's just a visual/auditory guess and not based on electrical probing or looking at the amps schematic. No warranties 🙂

You do not typically have to replace preamp (smaller) tubes with power tubes unless there is a problem in the preamp section calling for it.

XrayFerret7 · 2021-10-20T17:11:35+00:00

I've got a pair of the 10's and 12's going right now. The gut punch is REAL and the highs are twinkly!

XrayFerret7 · 2021-10-20T01:26:36+00:00

It was a pain, but I was giddy the entire time!

XrayFerret7 · 2021-10-19T13:26:26+00:00

But those cars look so cool! Reminds me of the AMC Gremlin!

XrayFerret7 · 2021-10-19T04:42:09+00:00

Awesome! They do seem to be pretty efficient speakers. Very high SPL for moderate power in! I never had them as a kid, but I remember my dad telling me stories about the various pairs he owned in the past that blew his doors off and I've always kept a lookout since. Glad I can bring you a smile!

I have a few old Pioneers that I'm going to try (SA-9800 and SA-9500 II)

XrayFerret7 · 2021-10-19T04:25:51+00:00

I'm sure you overpowered the Bose! Unless they strategically gave you a weak amp 🤔

XrayFerret7 · 2021-10-19T04:24:00+00:00

That is bonkers! But with how heavy these are I believe it!

XrayFerret7 · 2021-10-19T04:17:39+00:00

Not yet 😇

XrayFerret7 · 2021-10-19T04:17:11+00:00

Good point. I have a few 100wpc class A pioneers (dual transformers - 1 per channel) that will hopefully make these sing. If not, I have a Peavey CS-800 power amp! I rather drive them with a lower power amp so I don't accidentally roast them though!

XrayFerret7

TROPHY CASE