Technics SUV4X runs cool!

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I have never re capped a V4X yet... unlike a lot of amps, there aren't a lot of caps in this amp only 3 in signal path (2 of them on tone board)

There is a 4th cap on phono board.

- I am somewhat a recap skeptic- lost count of how many times I've read on forums how an amp quit working after a so called re cap... but it's no big job to change the few caps in path.
 
Hi, replaced the C501 Lch and C502 Rch- 50V 3.3uF on my SUV4x without issue. Getting good at using the braid for desoldering now thanks SVI2004. I have improved my technique by using a larger and hotter tip which flows the solder easily through the braid and allows the braid to absorb the solder. The tip I was using before was too small.

The amp sounds a bit sharper but it could just be my imagination! I want my little change to be an improvement!

Another thing.

Do you think it is worth reapplying thermal paste to the SVI2004 chip as these amps are 30 + years old now or would it cause more problems than it is worth disturbing things unnecessarily?

Any thoughts....?
 
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Hiya

No point pulling power ic... I never pull chips out unless necessary. The compound from factory is fine and only needs changing on installation of power ic.

I've never recapped a V4X (except the memory gold caps - done a heap)

Main thing is you're getting the good sound

Most of my V4X amps the power ic has never been touched/resoldered... mostly I resolder q501-4 dry joints and the occasional relay
 
Hi all

Not used my SUV4x for a bit and got it out recently. Left channel sometimes drops out completely at lower volumes but comes back on if you turn it up. Often happens if cold but has happened after a few hours of use as well. Tried the usual like checking solder joints on the main board including the relay and also the volume control. Not checked the input selector module yet or balance control or speaker selection. Any advice or pointers would be appreciated. Sounds great when working.

Thanks
 
New problem. At about 33% volume with a heavy bass thump the amp may be clips and goes silent momentarily (not relay) and then resumes. It is too loud for normal listening anyway at this level but just testing it!. There is no distortion prior to the "clipping". Could it be the main power caps?

Thanks
 
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Thats a nice thread. Where do i get a good replacement for an7062? there must be some newly made equivalents, this v4x amps rellay kick ***, got mine for 50eur or so and changed the gold caps already. but now i found that modern supercaps could last longer.

would changing the caps in the signal path or output caps to a greater capacitance improve performance? i was always wondering if one could use motor run caps on amps since they are available in every store and very durable
 
Hi. I purchased my an7062 from little diode on eBay. £20 at the time but now selling for £9. Seemed to work fine. I only changed a small pair of capacitors as described above.

After around five months of not playing with electronics for the summer I have returned to it now the days are darker and shorter. I changed 2 of the caps on another suv4x and initially messed it up and accidentally removed some of the copper track on the board as I pulled out the cap. I fixed it by soldering in a piece of wire from the cap leg to the next soldered component on the track. It is not pretty but works fine. Changing the cap removed a clicking noise the amp was making.
 
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Distortion.

The above mentioned ones all very low distortion amps.
Here's the SU-V60 at 1kHz 3V in to 8 Ohms measured with Victor's oscillator.
Good to be an excellent headphone amp to.
 

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What makes the Technics SU-V4X special compared to other Technics amps, like the the SU-V 460, 560 or the SU-G50, SU-V60 ?

These have something about them.... I have these Integrateds
And the V4X has always been my go to.. they have a stack of punch with huge soundstage... I aren’t the only one to say this... someone on what hifi has heard it too

Says it was a stonking amp, with breathtaking clarity, soundstage and imaging.

SU-500
SU-610
SU-600
SU-700
SU-800
SU-810
SU-G50
SU-G70
SU-G90
SU-V1X
SU-V2
SU-V2X
SU-V3
SU-V4
SU-V4X
SU-V5
SU-V6
SU-V6X
SU-V7
SU-V7X
SU-V8
SU-V8X
SU-V9
SU-V10X
SU-V22
SU-V40
SU-V50
SU-V60
SU-V65A
SU-V77
SU-V85A
SU-V90D
SU-V450
SU-V460
SU-V470
SU-V660
SU-V900
SU-VX500
SU-VX800
SU-VX920
SU-X90
SU-X101
SU-X501
SU-X950
SU-X977
SU-Z2
SU-Z45
SU-Z65
SU-Z400
SU-Z550
SU-Z600
SU-Z780
SU-Z980
 
Well not much to be done... re caps are somewhat moot as there are only 3 per chan in signal path... 2 iirc on tone pcb... class AA amps like the V60 V660/670 have more power but just don’t get that lifelike sound the V4X does.... its kind of a mid spec amp that yielded some magic... a lot of ppl acclaim pioneers A400 for similar reason, but V4X has that something over it.... and my best of them has another strange phenomenon... power ic has a sound that can be heard with no speakers attached....... can be heard in this YouTube clip I did on it - kinda sounds like a needle on a record... YouTube

The magic vanishes from these amps if SVI2004C is fitted.... these lost the Synchro Bias circuitry
 
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