Orange Crush 15R

[spud]

Picked up a broken Orange Crush 15R off ebay for cheap.  I asked Orange about schematics and got no reply.  Also on their un-official amp site the guys said that the SS ones made in China are like red-haired step children, they don't really support them - I guess they are viewed as throw away as they are so cheap.  Anyway, haven't been able find any schematic from any source - anyone have any ideas? 

From looking at the guts, it's a TDA030 chip power amp with 3 TL072 chip pre-amp, looks like a some kind of Sym Diode clipping circuit and reverb - so I guess the TL072 are for 3 pre-amp circuits, clean, dist and reverb send/recieve - does that sound reasonable.  It does make a very faint scratchy sound but that's it.  Also, from the look of the board something may have been spilled on/in it.  The outside shows no evidence of that but it was probably cleaned up to sell it.  Owner said it used to work but hadn't been used it in a while and when he pulled it out of his closet, it was like this. 

I suspect it might be a TL072 but need to get some and replace them - I'll add sockets while I'm at it as everything is soldered to the board.  The board itself is pretty spacious and not crowded at all, it's all through hole components and not SMT - so it's human accessible.  The cab is pretty attractive - orange and pretty "beefy".  If I can get it up and running I might sell it but if not I'll gut it and use the cab for my own creation  :tu: 

Well, if anyone has any ideas, send em my way.  Maybe I should try to trace the board out and make my own schematic - might be a useful exercise to learn something...DOH!   

Later,

Jim

[joecool85]

Picked up a broken Orange Crush 15R off ebay for cheap.  I asked Orange about schematics and got no reply.  Also on their un-official amp site the guys said that the SS ones made in China are like red-haired step children, they don't really support them - I guess they are viewed as throw away as they are so cheap.  Anyway, haven't been able find any schematic from any source - anyone have any ideas? 

From looking at the guts, it's a TDA030 chip power amp with 3 TL072 chip pre-amp, looks like a some kind of Sym Diode clipping circuit and reverb - so I guess the TL072 are for 3 pre-amp circuits, clean, dist and reverb send/recieve - does that sound reasonable.  It does make a very faint scratchy sound but that's it.  Also, from the look of the board something may have been spilled on/in it.  The outside shows no evidence of that but it was probably cleaned up to sell it.  Owner said it used to work but hadn't been used it in a while and when he pulled it out of his closet, it was like this. 

I suspect it might be a TL072 but need to get some and replace them - I'll add sockets while I'm at it as everything is soldered to the board.  The board itself is pretty spacious and not crowded at all, it's all through hole components and not SMT - so it's human accessible.  The cab is pretty attractive - orange and pretty "beefy".  If I can get it up and running I might sell it but if not I'll gut it and use the cab for my own creation  :tu: 

Well, if anyone has any ideas, send em my way.  Maybe I should try to trace the board out and make my own schematic - might be a useful exercise to learn something...DOH!   

Later,

Jim

Sounds like a neat project.  If you put up some pics we might be able to help you a bit.  Also, your guesses of TDA2030 and a 3 x TL072 preamp sound on par.

[J M Fahey]

+1 on posted pics.
Don't think it's "a bad TL072" out of the hat, repair technique does not work like that.
You must first of all test amp functionality, make some educated guesses and take some measurements that support or not your theory.
Take a couple sharp well illuminated pics (take it outside, preferably no flash, keep the camera steady); in this case also som from the board underside too, since you talk about spills.
Hope you left negative feedback on the cheaty seller.
I'm guessing it *might* not even have "bad parts" , or very few, the main problem is the spill.
I do not even want to imagine what it was.
I have cleaned a few by pouring very hot water over the board, while brushing with a clean paintbrush, then letting it dry perfectly under the sun for a couple days.
Of course I know that natural resource is not very abundant these days in the good ole' USA, but that's the general idea.
A hair dryer or heat gun may work too, but keep distant so you burn nothing, board should be warm at most.
Don't do this while in the chassis, pull the board by unplugging/unsoldering whatever's needed.
*Take note and make a sketch of every wire you unsolder*, label all them, small paper tape flags work great, do not get even a drop of water inside pots , switches, etc.
Take some pictures too. *Before* dismounting, that is.
Isopropyl alcohol or plain kerosene work great too, but for food type contaminants (beer, coffe, soup, ketchup, ice cream, etc.) hot water first works best.

[spud]

Thanks for the ideas - I'll try to get some pics of it but I've already removed the PCB. It has molex type connectors for each of external items: speaker, power supply, reverb send/rec, etc and all are labeled clearly.  Also, they are the idiot proof kind in that they are keyed - oh, and each is unique - 2 pins, 3 pins, 4 pins, etc - so it's no problem to put it back together - in fact I've done it once already. 

I should say that the idea of washing it with water is counter intuitive to me - in my mind water and electronics don't go together but you're much more experienced that I am so I'll have to go by what you say on that.  I'll see how vigorous I want to get.  I might try some alcohol (since it exporates rather quickly) to clean the tracks side but I'm afraid of getting anything liquid on the components - esp the ICs.  Just my ignorance/in-experience. 

Regardless, first thing is to get the pics up here and I'll get some measurements.  I'll put the board back in and start from there. 

Thanks again for all the help - oh, I know what you mean but I didn't bother with critiquing the seller as it's only cost me $24.- so far and the cab and speaker alone are worth more than that - at least from my point of view.

Jim

[J M Fahey]

Water is dangerous if still there when connected, but cleaning and drying properly is no problem.
Components themselves are not damaged by a few minutes of water; pots, switches and connectors yes, because they can rust.
The idea is to remove *the residue* on the board, which will corrode or short parts; that's what's dangerous, not clean water.
ICs, transistors, diodes, resistors and capacitors are sealed and waterproof..

[spud]

Oh, I see - well I'll have to remove all the pots as they are soldered directly to the PCB across the front.  There are about 7 of them.  And the switches, about 3 or 4.

Thanks - I'll try to get the pics this weekend as I'll have some free time.

Later,

Jim

[J M Fahey]

*Maybe* you micht avoid unsoldering them if you carefully wash the board with a thin stream of boiling water from a kettle, so it touches the dirty parts of the board (inclined 45 degrees) but not the pots.
Scrub the board with a toothbrush and repeat washing a couple of times to remove the residue.
Even if you get a drop or two of water touching a pot leg, but *not inside it*, you have no prioblem.
Switches lie flatter and closer to the board, so they need removal.
Or just remove all and give it a good scrub; you can add a drop of dishwasher detergent but then wash well with clean water.
Shake it as to remove "mechanically" as much water as possible, then let it dry on a warm, dry place.
Outside in the Sun is best, but I think there's not much of it over there these days.
Good luck.

[spud]

Thanks for all the great suggestions -

I did end up getting schematic from Orange so they are OK in my book.  Just that it's not very clear.  It was a gif of a scan of what appears to be multiple generations of Xeroxes.  Most stuff I can make out but some of the caps and resistor values are pretty un-clear so I'll have to guess. 

Another observation - from what I'm seeing the power amp chip may have been replaced.  The soldering job on it is different than the rest of the amp - which is very uniform and precise and shiny.  The chip looks sloppy and has a lot of flux residue.  Also the heat sink gunk is pretty messy - I'm thinking the chip has been changed out.  Heat issues?  Well, this lead me to looking at the heat sink - how the heat sink is oriented.  When out of the chassis it seems like the heat sink would be effective as the fins have air flow - looking down from the top they look like an E with the chip on the left, flat surface (here >E).  But with it IN the chassis, it gets rotated 90d so the flat surface (where the chip attaches) is now at the top and the fins are all pointing down now.  I'm thinking it could have overheated - probably was run a full volume for a period of time.  Could the chip be damaged? 

I'm think, new chip and either mod heatsink or get another one or even add a fan - maybe 120v?

Before I do anything, I'm going to get it back together and power it up and take some readings to see if I'm getting proper power and go from there.

Thanks -

Jim

[J M Fahey]

Post what they sent you.
Even if with unreadable part values, we can "fill the holes" somewhat, there are not that many ways to make a 15W practice amp.

[spud]

Well, the guy asked that I not post it around on the internet and I said I would honor that request as I'm trying to keep in good graces so I can get his help if I run into issues.  I could maybe email it -

Jim

[J M Fahey]

OK then, fine with me
If you want to get a second opinion you may mail it to juanmanuelfahey (at) gmail (dot) com

[joecool85]

Well, the guy asked that I not post it around on the internet and I said I would honor that request as I'm trying to keep in good graces so I can get his help if I run into issues.  I could maybe email it -

Jim

Emailing should be totally acceptable.  They just don't want to see it all over the internet - which I understand.

Good luck.

[J M Fahey]

Hi Spud, thanks for the schematic, it was very interesting.
As I answered in the personal Email:

I really don't see what they want to hide or protect.
It's just the most plain vanilla practice amp you can find, like a zillion others, nothing special here.

I think you have already mounted it, so let's go step by step.
1) unplug your speaker and touch its terminals to positive and negative of a battery (9V or 1.5V). Does it click?
2) re-plug it into the amp, turn it on/off a couple times, do we hear a pop or click or similar on the speaker?
3) Black multimeter probe to ground, measure DC voltage on all 5 pins of the power chip (TDA2030).
What do you measure on each?.
You *should* have respectively:
Pin 1 , 2 , 3 , 4 , 5 : 0V , 0V , -20V , 0V , +20V. or thereabouts.
Besides, with Master volume on "5", you should hear some buzz on the speaker when touching pin 1.
Good luck.

[blues dog]

Hai there.

My name is Dogie, from Indonesia.

I have a customer asking for me to mod his Orange Crush-15R
The clean channel is removed with my "bluesbreaker pedal" clone
And the power amp section is removed and replaced with all new 100w power.

So it goes on like this:
INPUT to
Ch A: Big Butt ( revoltmusic.multiply.com/photos/album/19#photo=37 )
Ch B: Orange Crush 15R (lead channel)

it goes to EQ of Orange Crush 15R
reverb -> split REVERB controlls for each channel
-> MASTER volume (the MASTER pots is bypassed) ->
SEND
RETURN
POWER AMP

The layout (and the knobs feature) will be similar to JCM900 style.
The circuit is already moved to the larger chasis.

Somehow, it works, but not properly..
In the bluesbreaker channel I still got the leakage from the "original OD" channel.

The Reverb also won't come out properly.
If I shake the tank, I can hear the shaking sound. But not In the tone when I played with.

I really got lost..  I traced the PCB in desperation...
A schematic will help a lot.

So maybe you can sent me the schematic.

Awaiting for your reply.


best regards
-dogie-

[blues dog]

Here's some pic of the progress...

The "raw circuit traced" I've done


The grand design:


The chasis


Top view:




My "Big Butt" along with his new friend the "Crush 15" 


Channel switching: