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
Quote from: spud on January 12, 2011, 04:11:36 PM
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.
+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.
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
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..
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
*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.
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
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.
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
OK then, fine with me
If you want to get a second opinion you may mail it to juanmanuelfahey (at) gmail (dot) com
Quote from: spud on January 26, 2011, 09:22:34 AM
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.
Hi Spud, thanks for the schematic, it was very interesting.
As I answered in the personal Email:
QuoteI 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.
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-
Here's some pic of the progress...
The "raw circuit traced" I've done
(http://farm7.static.flickr.com/6131/6014211564_4ff02a8b5c_z.jpg)
The grand design:
(http://farm7.static.flickr.com/6142/6013663221_c8ab4ef739_z.jpg)
The chasis
(http://farm7.static.flickr.com/6141/6014211658_30e678eb31_b.jpg)
Top view:
(http://farm7.static.flickr.com/6006/6014211750_a29be02437_z.jpg)
(http://farm7.static.flickr.com/6138/6014212008_810f356f31_z.jpg)
My "Big Butt" along with his new friend the "Crush 15" :D
(http://farm7.static.flickr.com/6136/6013663525_0b7e8bfdcb_z.jpg)
Channel switching:
(http://farm7.static.flickr.com/6027/6013663613_b2f597fcd8_z.jpg)
Dear BluesDog/dogie
To begin with, congratulations on your work.
And I must recognize it's *real* complex .... which can also bring all kinds of problems on its own :'(
Spud asked me not to "spread the Orange schematic all over the Internet" so I am respecting his wishes, posting stricly whatever's needed for servicing your unit, but no power amp, nor power supply, etc.
The incomplete schematic is:
(http://img825.imageshack.us/img825/6690/crush15rincomplete.gif)
The first problem I see is that it is *not* a two channel amp, but a single channel one, with a "distortion pedal" added, which, to boot, is *always* on circuit, always passing signal, even the clean one.
The second (and quite important) problem is that it's not at the beginning of the signal path, as most dirtortion pedals are, which would allow you to replace it with your own "Big Butt", but *after* the clean amp.
Modding it and building a new one from scratch will be about the same, sorry.
Having the schematic, you may try to find a way around this, but personally , seeing that you design and make your own boards (including the individual pot. mini-boards, very neat) I would walk a little further and make a new general-purpose "clean channel" plus switching, so you may build different amps with said clean channel plus any of your distortions.
It would be a very flexible project.
You might include a generic reverb circuit in it (similar to Orange's own) or as a stand-alone board.
With these boards plus your many pedals, you may offer dozens of variations, think about it.
I am intrigued by your chassis.
At first sight I had thought you were modding a JCM900 ... but it has no socket or transformer holes :o
Is that one of those Made-in-Malaysia clones which are offered in kits?
If so, I'm interested, can you provide a link and some info?
Thanks.
PS: I am also intrigued at your 8 output transistors power amp, any comments?
Good luck.
PS2: Switching with relays and with so many flying wires plus intermixing different boards, it takes some time twiddling the layout , grounding and wire dressing until you cut interference down.
You are not doing nothing "bad", but will need to move wires here and there .... and as I said, with that Orange you *always* go through the distortion, so ....
My main problem is that my customer insisted on Low Budget cost... :'(
And it's kinda frustrating me..
If it's my Amp, I will do exactly what you said.
It will be muuuuch more easier to build an all new preamp section.
But the owner also have problem. He already spend a lot of money for the head cabinet amp until he found that the tone and the feature is awfull. When first came, the amp goes like this:
* the Vol of channel A and Ch B interact each other
* the Gain of Ch A and Ch B interact each other
* the REVERB of Ch A and Ch B interact each other
* The connection of the "LineOut", "SEND" & "RETURN" jack is not proper.
So what I do is try to minimize the bad things.
About the PCB tracing & channel wiring; I spend 2 nights doing that.. ;D
About the chasis & the cabinet, they're all made here in Indonesia.
I might find some details about the manufacturer & will email you later.
QuoteMy main problem is that my customer insisted on Low Budget cost... Cry
And it's kinda frustrating me..
You bet.
In his own words, your customer is saying: you can't do it .(I ain't paying)
I'm talking $$$$$ , not knowledge.
Don't get hooked into it; the mistake was made by somebody else, you are not allowed to solve it, sorry.
QuoteIf it's my Amp, I will do exactly what you said.
It will be muuuuch more easier to build an all new preamp section.
Yes, it doesn't pay to
design , debug and build *just one*.
If you had a kit it would mean soldering and wiring, but not that much else, but
designing? ... forget it.
Quote
But the owner also have problem. He already spend a lot of money for the head cabinet amp until he found that the tone and the feature is awfull.
He did not spend that much money with you. ;)
QuoteWhen first came, the amp goes like this:
* the Vol of channel A and Ch B interact each other
* the Gain of Ch A and Ch B interact each other
* the REVERB of Ch A and Ch B interact each other
That's *exactly* what the Crush 15R does.
It's a cheap generic beginner's amp, its features are adequate for what it is, but not more.
I bet it's built by a monster factory in mainland China which supplies 30 or 40 other distributors under many trademarks.
I recently learnt that the same company, with the same schematic, supplies many models of famous expensive amps, among them Randall, Egnater, and similar high level ones.
The supplied schematic is the same, only rewriting the small "box" in the drawing which states the model.
Couldn't believe it ! :o :loco :duh
What's the best part?
1) they are all Marshall JCM 900 copies .... with errors :o
2) even better: in some forums musicians discuss to death the sonic advantages of one against the others :o
In your case, I think the best would be to leave the modded amp as-is, and sell the customer one of your Fat Ass (or any other) pedals, external, to use at will.
But don't waste more time on that amp.
:tu:
speechless.. but really thinking hard..
thank you sooo much..
What you've said really really open a new perspective to me.
I'll sent the progress here.
Done!
Just after got the schematic, get into the board, around 90minutes, all is done.. 8)
I've complain about some "fuzz leak" ini my own built clean channel. And no reverb at all.
My biggest interest is in reverb. So I check the reverb section. Getting frustrated, I cut the dry signal. I want to check how the reverb signal work. Then I found out: no signal. Only a tiny fuzzy tone goes out there. But shaking the reverb tank will gives a big rumbling reveb sound.
Looking at the schematic I found out that one single IC work as the driver and receiver of the reverb. I'm curios: is it posible that the first opamp is broken while the second one is not? I just replace the IC (TL072 in schematic, but TL082 onboard) with a new TL072. Done!!! There's an obvious reverb now!
Then I put back the dry signal. Just as I expected. The tiny fuzzy tone is also gone! Now I have a pure clean british channel.
Then I goes to the drive section. The original signal path of Crush 15 (drive channel). The reverb is also there.
The signal path goes like this:
IN
(switch)
- channel A: Big Butt (GAIN, VOL, PRESENCE = TONE)
- channel B: Crush 15 drive channel (GAIN, VOL)
(switch)
back to Crush 15 board: EQ section
SEND jack = End of EQ section
RETURN jack = back to MASTER VOLUME*
to REVERB driver & receiver
(switch)
- channel A REVERB pots
- channel B REVERB pots
(switch)
back to mixing section
goes to power AMP**
*I bypass this pots, since each channel already has one
** In Crush 15 board, the signal path ended going in TDA2030, the TDA 2030 is already cut out when the unit came. But not wired properly. So now, I wired this point to the power amp board.
That's it. I might want to make a video about it.. Still not decide yet.. :)
Tks guys.. Tks JMF. You're the best! ;)
It's too kind of you, you'll make me blush. :-[
The good thing is that you could finish the job as the client wanted, sometimes it's not possible.
Another important factor is that you could justify all the hours of work you had already lost working on it, which nobody can give you back.
As they say: "all is well that ends well"
Congratulations :tu:
Congrats! Another amp saved from the dumpster! 8)
Hi all, can anyone please tell me the value of the resistor in R8?
My amp got her "toasted" and I'm Having difficulties in reading that from the PCB
Thanks in advance...
I have the preamp schematic and parts numbers start from 100 up :o
In general even the same basic design goes through different variations and upgrades, so unless somebody has the exact same schematic and version of yours, "R8" does not mean much.
Please post a closeup picture showing the damaged resistor and the parts surrounding it, from both sides of the PCB, top and bottom, we *might* deduce its function and hence its value.
That said, if you have a burnt resistor, "something" burnt it, so just replacing it won't be enough.
What are the actual symptoms of the failure?