Hi All,
I have a Unison Research Unico hybrid integrated amp. It has a radiowave remote control for volume up and down, but is not functioning. I'm wondering if anyone here can help me diagnose the problem (and hopefully fix it)? I can use a soldering iron, but know almost nothing about eletronics. (I did just build the Pete Millet "Starving Student" tube hybrid headphone amp, point-to-point.)
I suppose the first step is: How do I find out whether it's the remote or the receiver in the amp that's not working?
fishline
I have a Unison Research Unico hybrid integrated amp. It has a radiowave remote control for volume up and down, but is not functioning. I'm wondering if anyone here can help me diagnose the problem (and hopefully fix it)? I can use a soldering iron, but know almost nothing about eletronics. (I did just build the Pete Millet "Starving Student" tube hybrid headphone amp, point-to-point.)
I suppose the first step is: How do I find out whether it's the remote or the receiver in the amp that's not working?
fishline
What do mean "radio wave" ? Do you mean infra red ?? 99.99% of remotes are infra red, a few very old ones (TV) used ultrasonic sound.
To test infra red point it at a web cam or video camera and press the button, and it should show a stead brilliant flash from the front of the remote. Our eyes can't see it, most digital imaging devices can.
To test infra red point it at a web cam or video camera and press the button, and it should show a stead brilliant flash from the front of the remote. Our eyes can't see it, most digital imaging devices can.
It's an RF remote, not IR. That's what I meant by "radio wave". I'll try to take pictures of the remote PCB board and post that.
fishline
If I'm not mistaken, Bose uses RF remote in some of their product. You need not point the remote in certain direction for it to work, and it can even work from a nearby room.
The one for the Unison Unico only controls volume +/- (two buttons only). You can see it in the 3rd picture on this page from the 6moon review:
6moons.com - audio reviews: Unison Research Unico
fishline
The one for the Unison Unico only controls volume +/- (two buttons only). You can see it in the 3rd picture on this page from the 6moon review:
6moons.com - audio reviews: Unison Research Unico
fishline
Interesting, never heard of one using RF before.
As to testing though
Well if it were me I would begin with the easy stuff, don't laugh, new batteries, clean the contacts, then get technical. Can you measure the battery voltage with it just sat there and also when the buttons are pressed. Does the voltage dip indicating it's drawing current ? Or connect a milliameter in series with the batteries and check more precisely that way.
What else... friendly dealer ? that had something it would work on. Probably not.
Scope the wireless receiver, see if any kind of data can be recovered... what frequencies does it use as a carrier ? Does it interfere in any way with a radio etc on different bands ?
As to testing though
Well if it were me I would begin with the easy stuff, don't laugh, new batteries, clean the contacts, then get technical. Can you measure the battery voltage with it just sat there and also when the buttons are pressed. Does the voltage dip indicating it's drawing current ? Or connect a milliameter in series with the batteries and check more precisely that way.
What else... friendly dealer ? that had something it would work on. Probably not.
Scope the wireless receiver, see if any kind of data can be recovered... what frequencies does it use as a carrier ? Does it interfere in any way with a radio etc on different bands ?
I did test the battery (12v) and it read 11.8v on my DMM. Did not try reading the DMM while pressing buttons though. Will give that a try tonight.
How do I test the receiver side?
I bought the amp off Audiogon a while ago, and it came that way. I was not able to find any useful info or spec on the remote unit, only a blurb in the manual that says the receiver can be re-sync with a new remote. I may try contacting Unison Research directly to see if they can provide any info, but this amp is not in their current catalog...
How do I test the receiver side?
I bought the amp off Audiogon a while ago, and it came that way. I was not able to find any useful info or spec on the remote unit, only a blurb in the manual that says the receiver can be re-sync with a new remote. I may try contacting Unison Research directly to see if they can provide any info, but this amp is not in their current catalog...
The only easy way to test the receiver will be to scope it I imagine... I would need it in front of me to be able to even begin to try and identify what's what.
For example does it transmit something like Philips RC5 code ( as an example ) on a carrier or FM modulated carrier etc or is it more basic say transmitting just different carrier frequencies for up/down with no actual data as such... just don't know. Or it may use something like car key transmitter technology in the 300 to 500mhz range,
Remote keyless system - Wikipedia, the free encyclopedia
You mention "pairing" of transmitter and receiver... you could do with finding out more on that one.
For example does it transmit something like Philips RC5 code ( as an example ) on a carrier or FM modulated carrier etc or is it more basic say transmitting just different carrier frequencies for up/down with no actual data as such... just don't know. Or it may use something like car key transmitter technology in the 300 to 500mhz range,
Remote keyless system - Wikipedia, the free encyclopedia
You mention "pairing" of transmitter and receiver... you could do with finding out more on that one.
Here are pictures of the front and back of the remote PCB:
I measured the voltage at the battery contacts again. It reads 11.9v. If I press either button, it goes down to around 11.1v.
I can open the amp and try to find the receiver module, if I know what to do with it.
fishline
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
I measured the voltage at the battery contacts again. It reads 11.9v. If I press either button, it goes down to around 11.1v.
I can open the amp and try to find the receiver module, if I know what to do with it.
fishline
Seeing the voltage dip is a good sign it's transmitting.
I'm guessing those 3 red tact switches are for other models and functions. The rear of PCB looks to have a bit of wire soldered to it... is that original ?
I think you have to find out how to "pair" the transmitter and receiver if that's something that needs doing. It's just possible there is nothing wrong with either.
I'm guessing those 3 red tact switches are for other models and functions. The rear of PCB looks to have a bit of wire soldered to it... is that original ?
I think you have to find out how to "pair" the transmitter and receiver if that's something that needs doing. It's just possible there is nothing wrong with either.
OK. Here are pictures of what's inside the amp.
The pot:
The little board next to it. Not sure if this is the RF receiver board:
Slightly different angle:
The user's manual says that if the remote has to be replaced, it can be synchronized by pressing the reset/synchronize button on the receiver board. However, I couldn't really tell where is the reset button on the receiver board (not even sure which is the receiver board). Help!
fishline
The pot:
An externally hosted image should be here but it was not working when we last tested it.
The little board next to it. Not sure if this is the RF receiver board:
An externally hosted image should be here but it was not working when we last tested it.
Slightly different angle:
An externally hosted image should be here but it was not working when we last tested it.
The user's manual says that if the remote has to be replaced, it can be synchronized by pressing the reset/synchronize button on the receiver board. However, I couldn't really tell where is the reset button on the receiver board (not even sure which is the receiver board). Help!
fishline
Hard to make out. The back to connections on the pot look like they will go to the motor, and it looks like they could go to that board... which indicates it could be the motor driver/logic etc... but whether it's the radio receiver to I can't say. Can't see any switch on it.
Is there not another unusual PCB anywhere. I'm guessing it would be near a surface that is not metal.
Is there not another unusual PCB anywhere. I'm guessing it would be near a surface that is not metal.
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