Hi all
I purchased a Technics SUV4X and it tunrs out to be a German market model (220v) but seems to run ok in the UK 230/240v roughly. It has a slightly different circuit board (4 copper coils near speaker terminals) and no voltage selector. Unlike my UK market model it runs cool unless you turn up the volume a lot. Why would this be? Replaced SVI2004 perhaps? A small IC chip with a heat sink does get hot and so does the speaker relay which I replaced.
Please note I am very much an amatuer but am willing to have a go and learn.
Best Wishes
SSI
I purchased a Technics SUV4X and it tunrs out to be a German market model (220v) but seems to run ok in the UK 230/240v roughly. It has a slightly different circuit board (4 copper coils near speaker terminals) and no voltage selector. Unlike my UK market model it runs cool unless you turn up the volume a lot. Why would this be? Replaced SVI2004 perhaps? A small IC chip with a heat sink does get hot and so does the speaker relay which I replaced.
Please note I am very much an amatuer but am willing to have a go and learn.
Best Wishes
SSI
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Hi
Thanks for replying. How do I measure the rail voltage with a multimeter and what voltage am I looking for? The amp has a switch at the back to switch between higher and lower ohm speakers. I have it on 8 - 16 ohms as my B&602's are rated at 8 ohms.
In terms of sound quality the unit sounds great and has worked for hours without issue (only had it a couple of weeks), after replacing the relay.
Do you foresee any serious issues with continuing to run the amp?
Best Wishes
Thanks for replying. How do I measure the rail voltage with a multimeter and what voltage am I looking for? The amp has a switch at the back to switch between higher and lower ohm speakers. I have it on 8 - 16 ohms as my B&602's are rated at 8 ohms.
In terms of sound quality the unit sounds great and has worked for hours without issue (only had it a couple of weeks), after replacing the relay.
Do you foresee any serious issues with continuing to run the amp?
Best Wishes
With the very greatest of respect, it could be very easy for you to cause damage. One slip of a meter lead, a wrong range when measuring......
I would suggest you try and locate a full service manual for both variants and initially compare the circuit details. The manuals should show the supply voltages the amplifier runs on and it should also be possible to determine the current the output stage draws (I'm assume its manually adjustable although it may not be). That would be a good guide to the expected heat generation that will be produced.
Also, the relay 'getting hot' doesn't sound normal. If you replaced that part then be sure that the replacement is of similar voltage rating and also of similar coil resistance.
Shouldn't be any issue...
Send a pic of the inside... I can spot a replaced power ic all the way here from Australia
The EGA model got extra chokes on input and outputs... must have had some reg....
Also hold amp sideways a bit power supply down (this will ensure that the coolant liquid will be behind power ic)
Then make sure it's level as these amps do not like having no fluid behind ic
Send a pic of the inside... I can spot a replaced power ic all the way here from Australia
The EGA model got extra chokes on input and outputs... must have had some reg....
Also hold amp sideways a bit power supply down (this will ensure that the coolant liquid will be behind power ic)
Then make sure it's level as these amps do not like having no fluid behind ic
Hi, will post a picture after the weekend svi2004a. Also picking up a faulty suv4x at the weekend with a flashing safety operation light. I have the replacement transistors that you have suggested in previous posts. I would appreciate it if you could give me a fault finding checklist if you have time. I love the sound of these amps. Best wishes ssi
Hi SVI2004A
Here are two pictures of the suv4x chip. Hope you can ID that it is genuine! Let me know if you need further evidence.
Incidentally picked up a Technics SUV505 with intermittent safety operation - recovered if you wiggled the board a bit. There was a sparky sounds as well! Turned out to be one of the pins on the input selector. Reflowed the solder and all appears to be well over the past hour.
Best Wishes ssi
Here are two pictures of the suv4x chip. Hope you can ID that it is genuine! Let me know if you need further evidence.
Incidentally picked up a Technics SUV505 with intermittent safety operation - recovered if you wiggled the board a bit. There was a sparky sounds as well! Turned out to be one of the pins on the input selector. Reflowed the solder and all appears to be well over the past hour.
Best Wishes ssi
Attachments
I'd check for dry joints on Q501-4 or replace them...
DC offset is within AN7062 - check after dealing with pre drive
I had one V4X I had to replace the AN7062 as I had 112mv iirc on one channel. !! Beware of eBay fakes !! A known good one still has the 3 point triangle triskellion logo.. the fakes have a hard to read p/n and M in a square...
DC offset is within AN7062 - check after dealing with pre drive
I had one V4X I had to replace the AN7062 as I had 112mv iirc on one channel. !! Beware of eBay fakes !! A known good one still has the 3 point triangle triskellion logo.. the fakes have a hard to read p/n and M in a square...
Hi. Need some help. Changed Q501 to Q504 but made a bit of a mess with the desoldering so had to create some repalcement copper tracks with some solder for Q501/2 - you live and learn. Also changed speaker terminals but left channel keeps dropping and dc going up and down. Checked all soldering but cannot work it out. Safety operation all OK. No drop in left channel sound through headphones. Sometimes work OK but if you turn it off and on again sound becomes varuable on left channel. Recovers to some degree if you turn up the volume so something is not getting through. Help!
Thanks
Thanks
Hi all.
Replaced the bulbs but as I am an amatuer errors galore on the way but a happy ending. Cut the wire too short on one of the "New Class A" bulbs so had to solder an extension on. But then when I was refitting the ribbon cable from the "lights" board to the main circuit board my wife came in and started asking me about something and I fitted it the wrong way round. I switched the amp on and the realy started clicking on and off so I switched it off instantly and corrected it but the safety operation red led had gone. Fortunately I had some red leds and fitted it but the wrong way round (no way of telling as far as I could see). On desoldering the led the copper track came up so I had to fit some wire to reconnect the led the correct way round.
All seems to be working fine now except the new led is a bit bright and some of the circuit boards look an utter soldering mess but it lives and I am learning! The amp only cost me £20 so not doing too badly.
Replaced the bulbs but as I am an amatuer errors galore on the way but a happy ending. Cut the wire too short on one of the "New Class A" bulbs so had to solder an extension on. But then when I was refitting the ribbon cable from the "lights" board to the main circuit board my wife came in and started asking me about something and I fitted it the wrong way round. I switched the amp on and the realy started clicking on and off so I switched it off instantly and corrected it but the safety operation red led had gone. Fortunately I had some red leds and fitted it but the wrong way round (no way of telling as far as I could see). On desoldering the led the copper track came up so I had to fit some wire to reconnect the led the correct way round.
All seems to be working fine now except the new led is a bit bright and some of the circuit boards look an utter soldering mess but it lives and I am learning! The amp only cost me £20 so not doing too badly.
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Yes, I know it was a bit stupid as I had noted the white stripe on the ribbon cable to make sure I put it back on the correct way round! Still it lives for now.
Anyway learned about LED's:
"On the physical LED, the longer lead (or leg) of the LED is the anode. The cathode is marked on the rim of the LED body with a flat area shown in the diagram.
Another way to tell which lead is the anode and which is the cathode is to look at the two plates at the end of the leads inside the body of the LED. The bigger plate will be the cathode." From https://startingelectronics.org/beginners/components/LED/
Anyway learned about LED's:
"On the physical LED, the longer lead (or leg) of the LED is the anode. The cathode is marked on the rim of the LED body with a flat area shown in the diagram.
Another way to tell which lead is the anode and which is the cathode is to look at the two plates at the end of the leads inside the body of the LED. The bigger plate will be the cathode." From https://startingelectronics.org/beginners/components/LED/
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