VSSA Lateral MosFet Amplifier

[Lazy Cat]

What's inside silver boxes?

 

[Esperado]

What's inside silver boxes?

Something i'm specially interested in ?

 

[Lazy Cat]

Well complete BIGBT inside: two power BJTs, mosfet driver, four resistors, five diodes

 

[Esperado]

Well complete BIGBT inside: two power BJTs, mosfet driver, four resistors, five diodes

I thought the mosfet was in serial in the power line

 

[Lazy Cat]

Just classic BIGBT sch inside

Will compare this VSSA BIGBT to VSSA ALF lateral mosfet single and double outputs versions. Nice lab work over the summer hehe

BTW, anybody completed VSSA stereo until now?

 

[miksi]

VSSA completed 10 days a go. Direct coupled to the DAC. Running smoothly. During that time DC on output varies about 2mV. I am awaiting nichicon FGs to try instead of KA.

 

[pinnocchio]

What's inside silver boxes?

LC, did you design that package BIGBT? This is quite compact!

Ciao!
Do

 

[Lazy Cat]

VSSA completed 10 days a go. Direct coupled to the DAC. Running smoothly. During that time DC on output varies about 2mV. I am awaiting nichicon FGs to try instead of KA.

Problems with hum or noise? Probably you don't like the sound as you're intending to change the capacitors. Pictures?

 

[Lazy Cat]

LC, did you design that package BIGBT? This is quite compact!

Ciao!
Do

Yes, I designed it quite some time ago (already presented in SSA thread), purposed just for an amp like this, simple front-end with powerful output. I have four silver box BIGBT-s as needed for a stereo amp.

 

[Lazy Cat]

Lazy Cat I hope they were not matched? Because they are not going to survive this I think... So how many should I order for replacement???

Not exactly matched but both having high hFE ranging from 550-650. Trimmed CCS-s ensure proper DC conditions over wide supply voltage and temperature range, output DC offset fluctuations only a few mV and no power on/off thump present.

 

[miksi]

Problems with hum or noise? Probably you don't like the sound as you're intending to change the capacitors. Pictures?

No hum or buzz, noise only at the 1cm from tweeter, I had to rearrange grounding . Sound is a little bit 2D. I have KeF XQ40. Box is not completed yet - no top and bottom cover.

 

[Idefixes]

BTW, anybody completed VSSA stereo until now?

10uf MKT arrived Today (thanks Umut), may be VSSA could sing next week.

Marc

 

[atupi]

VSSA completed 10 days a go. Direct coupled to the DAC. Running smoothly. During that time DC on output varies about 2mV. I am awaiting nichicon FGs to try instead of KA.

I'm looking forward for your impressions about FG vs KA nichicons.

 

[Idefixes]

This evening 20mn work...

So yet i have to find 2 sheet of wood for proto...

 

[jkuetemann]

Whoo-Hoo! Capacitors arrived today, got some assembly to do!

 

[Idefixes]

Just to complet, the ugly heatsink above is not the final one, it's just for test.

Marc

 

[jkuetemann]

Official LC VSSA almost ready for comparison. My TO-3 PeeCeeBee and the LC kit together.

 

[Nikos]

VSSA T03

New board based to VSSA T03 by Jason kuetemann: CCS-2N5462 at 2,4ma, TLVH431APL /16volt reg at 2Volt on gates -180ma ,2SC3503D-2SA1381E at 12ma all works fine offset total zero.
Very details amplifier.
If someone wants the pcb pdf its available.

 

[presbel]

VSSA

Just fired up my VSSA 0mV on both 12mA VAS bias and 4V on 22ohms. There is hissing sound if you put your ear near the tweeter. It is just beginning to open up. Compared to my PP KT88 my tube amp sound better at first. But after 2 hours of listening the sound almost even with my tube amp. I Am using a temporary power supply with 30V-0-30VAC input. I ordered my SMPS800RE from Connexelectronics.

 

[presbel]

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