I'm new to this scene, but pretty into it so far. A friend of mine gave me an old Bryke Home Amp he had sitting around -- not working. I've been in the process of ripping it apart and cleaning up the insides to, hopefully, get it working.
What's weird is that I cannot find any info on this amp anywhere on the internet. I'm pretty sure it's a solid state amp, but am new to all this, so I am not 100% sure (sorry if I am in the wrong spot). Here are some before and after pictures. It's still under construction as I still have to fabricate some speaker enclosures for a pair of Rainbow Speakers I plan on hooking up.
Here are the pictures
Any info on the amp at all is greatly appreciated.
Thank you.
What's weird is that I cannot find any info on this amp anywhere on the internet. I'm pretty sure it's a solid state amp, but am new to all this, so I am not 100% sure (sorry if I am in the wrong spot). Here are some before and after pictures. It's still under construction as I still have to fabricate some speaker enclosures for a pair of Rainbow Speakers I plan on hooking up.
Here are the pictures
Any info on the amp at all is greatly appreciated.
Thank you.
Being new. . .please be carefull around those 16000uF caps. . . they
don't care what they discharge through. . . including you. Measure
the DC voltage across them. . .discharge with a suitable resistor and
leave it attached while working on the unit--caps have a tendency to
bounce back.
I would disconnect all amplifier circuits and fully test the power
supply. . .caps still good. . .ground good. . . discharge rate. . . load
test. . . measure the transformer. . . I assume that is what you did
in the pictures. . .
As for the amp section. . . maybe someone on the DIY audio has one. .
that would be good. . . otherwise it will take someone with considerable
knowledge to troubleshoot the amp circuit without a schematic.
Depending on the voltages. . . you might be able to turn it into a nice
chip amp. . .there are dual rectifiers and supply caps. . .more than
enough for a chip amp. Strange that the bridge rectifiers are only
being used half of the time.
don't care what they discharge through. . . including you. Measure
the DC voltage across them. . .discharge with a suitable resistor and
leave it attached while working on the unit--caps have a tendency to
bounce back.
I would disconnect all amplifier circuits and fully test the power
supply. . .caps still good. . .ground good. . . discharge rate. . . load
test. . . measure the transformer. . . I assume that is what you did
in the pictures. . .
As for the amp section. . . maybe someone on the DIY audio has one. .
that would be good. . . otherwise it will take someone with considerable
knowledge to troubleshoot the amp circuit without a schematic.
Depending on the voltages. . . you might be able to turn it into a nice
chip amp. . .there are dual rectifiers and supply caps. . .more than
enough for a chip amp. Strange that the bridge rectifiers are only
being used half of the time.
thanks for the quick response.. i work in the automotive industry and know all about not wanting to get shocked by DC.
The caps seem to have very low power. as for the circuit board there was one wire disconnected on it...
it was the ground from the caps on the right side, which i was able to trace back to the right spot because the caps on the left side go to the same spot on the board, just on the other half (mirror of the right).
I do not know how to test loads, the transformer, etc? i feel like an idiot for not knowing these things, but how do i test your suggestions?
does the amp seem like a good one?
The caps seem to have very low power. as for the circuit board there was one wire disconnected on it...
it was the ground from the caps on the right side, which i was able to trace back to the right spot because the caps on the left side go to the same spot on the board, just on the other half (mirror of the right).
I do not know how to test loads, the transformer, etc? i feel like an idiot for not knowing these things, but how do i test your suggestions?
does the amp seem like a good one?
Hi oddetc,
This is either a kit or production amp. I have seen them build like this.
Your output mosfets are static sensitive. Do not touch the leads anymore than you really need to. An open gate maycause the output stage to fail.
From what I have read, you need the help of a good audio technician. So, in what way does this amp not work?
-Chris
This is either a kit or production amp. I have seen them build like this.
Your output mosfets are static sensitive. Do not touch the leads anymore than you really need to. An open gate maycause the output stage to fail.
From what I have read, you need the help of a good audio technician. So, in what way does this amp not work?
-Chris
jaycee said:
Will it work with these speakers then?? Good Quality?
Also, any idea as to the value of the amplifier?
Thank you again for all the help.
An externally hosted image should be here but it was not working when we last tested it.
anatech said:
All I know is that a friend of mine had it and it worked for a while then stopped -- he said it ran 30 minutes unplugged from the wall because of the caps! I assume it's a project amp because the wiring looked amateurish.
It did have several wires that were disconnected, but I traced them all to their original locations and soldered them back (I have a Power Probe Butane SK, so no worries with a bad soldering job).
Would anyone like some better pictures of the back of the circuit board or anything?
Thanks.
Hrm.. it's not a VMOS amp then (vertical mosfet)
I dont agree Unclejed... 48V rails would get you a shade under 100W into 8 ohms - but a single pair of transistors per channel would die under that kind of stress.
Really, we need to know what voltages we're dealing with here. You could wire up just the transformer to the mains, and measure the AC voltage of the secondaries. The transformer looks like it has two sets of secondary windings - with the yellow and green wires being connected together to form a "centre tap".
You would need to find out which wires belong with which winding.. eg blue/yellow, green/red. To do this, use a continuity meter or ohm meter. If you get continuity between blue and yellow, then these are one pair of windings. It might be blue and green - hence needing to check.
When you find that out, connect the transformer to the mains (be careful!) and measure the secondary voltages. It might be an idea to terminate the wires with some "terminal strip". If you have already crimped spades to the wires, then just make sure the wires dont touch (stick them down to something with some tape, for example)
As for whether the amp is worth saving... hmm... that depends on why it has blown in the first place. I've a gut feeling this amp SHOULD have VMOSFET outputs, and someone has incorrectly used BJT transistors. It would work, but the driver stage would soon blow as the base current demands couldnt be met by the small TO-92 devices on the pcb.
If you want to keep the chassis and build a fresh amp... theres a few nice kits that you could put in there. What kits are suitable would depend on the voltage output of the transformer.
I dont agree Unclejed... 48V rails would get you a shade under 100W into 8 ohms - but a single pair of transistors per channel would die under that kind of stress.
Really, we need to know what voltages we're dealing with here. You could wire up just the transformer to the mains, and measure the AC voltage of the secondaries. The transformer looks like it has two sets of secondary windings - with the yellow and green wires being connected together to form a "centre tap".
You would need to find out which wires belong with which winding.. eg blue/yellow, green/red. To do this, use a continuity meter or ohm meter. If you get continuity between blue and yellow, then these are one pair of windings. It might be blue and green - hence needing to check.
When you find that out, connect the transformer to the mains (be careful!) and measure the secondary voltages. It might be an idea to terminate the wires with some "terminal strip". If you have already crimped spades to the wires, then just make sure the wires dont touch (stick them down to something with some tape, for example)
As for whether the amp is worth saving... hmm... that depends on why it has blown in the first place. I've a gut feeling this amp SHOULD have VMOSFET outputs, and someone has incorrectly used BJT transistors. It would work, but the driver stage would soon blow as the base current demands couldnt be met by the small TO-92 devices on the pcb.
If you want to keep the chassis and build a fresh amp... theres a few nice kits that you could put in there. What kits are suitable would depend on the voltage output of the transformer.
Oh... as a newbie, I would recommend you check out Rod Elliot's article page, there is a lot that you will find useful there 
http://sound.westhost.com/articles.htm
http://sound.westhost.com/articles.htm
jaycee said:Oh... as a newbie, I would recommend you check out Rod Elliot's article page, there is a lot that you will find useful there
http://sound.westhost.com/articles.htm
Very interesting website! I have some reading to do. I'll try to get the wiring checked out later today, but what do you mean by connect the mains?
By "the mains" i mean wall power. It is known as "Mains power" here in the UK
Basically, wire up the primary side of the transformer - the wires that connect to the line cord via switch/fuse in the case. Then power it on with just the transformer secondaries (the blue/yellow/green/red wires) left unconnected (or connected to a piece of terminal strip to prevent accidental shorting). Then measure the secondary voltages using an AC voltmeter.
Obviously, be careful with how you wire up the primary side!
Basically, wire up the primary side of the transformer - the wires that connect to the line cord via switch/fuse in the case. Then power it on with just the transformer secondaries (the blue/yellow/green/red wires) left unconnected (or connected to a piece of terminal strip to prevent accidental shorting). Then measure the secondary voltages using an AC voltmeter.
Obviously, be careful with how you wire up the primary side!
Hi jaycee,
Hi oddetc,
This amp is worth repairing if not for the study value alone. It's worth depends up on the sound quality and not the power. TO-92 driver transistors would not be enough. Look for TO-220 case parts. It's possible this poor thing has been hacked and also possible it has the wrong outputs. Nothing would surprise me these days.
After having a good look at the pictures, I do believe it was a kit build. TO-92 transistors would survive as drivers for a while unless pushed. If they are properly TO-92's, then mosfets are a must.
-Chris
Completely agree on all counts. Those are bipolars (good ones).
Hi oddetc,
This amp is worth repairing if not for the study value alone. It's worth depends up on the sound quality and not the power. TO-92 driver transistors would not be enough. Look for TO-220 case parts. It's possible this poor thing has been hacked and also possible it has the wrong outputs. Nothing would surprise me these days.
After having a good look at the pictures, I do believe it was a kit build. TO-92 transistors would survive as drivers for a while unless pushed. If they are properly TO-92's, then mosfets are a must.
-Chris
I will assume that you meant 30 seconds and not 30 minutes. Even at 30 seconds I find that very hard to believe.
After looking at your amp it would appear to me that it is a hodge podge of parts put together in a shoddy fashon. I would salvage the filter caps, outputs, and transformer and head to the nearest dumpster with the rest of it. The heatsinks are no where big enough to be of any value.
Start over fresh and build something worthy of your time and trouble. I would suggest purchasing some leach boards and start building there.
Just my .02
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