Technics SUV4X runs cool!

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
This is a comparo of tha A vs C version... (both ICs are working, opened to display difference)
 

Attachments

  • B03D346D-E084-40B3-BE21-432BD9B91331.jpeg
    B03D346D-E084-40B3-BE21-432BD9B91331.jpeg
    136.6 KB · Views: 175
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.

Amplifiers don't have those, speakers have them, amps they have more or less power and distortion.:)
 
Synchro Bias is a circuit Technics developed so power transistors do not turn off...
There are a few threads on new class A and synchro bias on here and the net...

In this series the circuitry in the green box is the Synchro Bias circuit (not in C variant)
Physically located between output transistors in the SVI
 

Attachments

  • BF2B691D-8353-4D1C-ACC7-5CEA251C7EA1.jpeg
    BF2B691D-8353-4D1C-ACC7-5CEA251C7EA1.jpeg
    44.6 KB · Views: 157
Last edited:
If i take the ceramic cover off and cool the chip with a fan will there be any bad side effects? (i just want it to run very cool to last longer, it will be running a lot) this schematic looks simple, but what are the transistors used? maybe this can be replicated on a pcb? why does your amp make sound? is it the caps? have they turned into piezos?
 
No need to pull ic to pieces.... the cover helps clamp it to the heatsink...
All the heat is absorbed by heatsink on rear of ic. Without its cover will not help it

For optimum result, have nothing on top of amp.. and make sure amp is LEVEL so fluid in copper tube is even across ic side and radiator side.

Aren’t exactly sure what specifically what inside the ic was making the sound... but I’m not worried... sound on speakers is awesome
 
Problem with Technics SU-V4X

Hi, I'm having a problem with this amp:
Left channel is working fine, but no sound from right channel, I can hear very quiet sound at max volume.

DC Offset Sx/Dx: 2mV/3mV
R523/R524 : 1.5mv/2.5mV
C Q501/Q502: 1.79V/1.79V
 
Last edited:
Check ground line through to input selector

The V4X has an interesting ground strap setup. The ground that J6 has for input is floating
(Unplugging J6 will cause amp to drift to DC on both channels)

From what I remember grounding of J6 starts at input select board.

Just check across input/ext in/out volume and tone pcb.

Maybe you have an input selector ic out... will have to trace signal
 
Good luck with that... I have never needed subwoofers with mine... though I’m using technics SB-6 and SB-X500 and SB-X700 on my V4X amps.

You’re goin to need a low pass filter circuit to be fed from tone pcb output.

I’d simply hook up more capable spkrs...
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.