DIY Sony VFET pt 1

[MEPER]

Yes, I will try.
The biggest challenge is to find a placement of speakers and listening position where room gain of all basnotes are equal.....

 

[Soundhappy]

Build Vfet SE with friend Xavier :^)

Thanks to Mr. Pass was great honour to finish and complete this new amplifier,
special thanks to Jim aka 6L6 for build guide , Jason & Variac & DiyAudio Team and Gianluca & Modushop.

We enjoy a lot and are conscious about a lots of work involved.

After my lottery kit win I talk with an old friend who was interested by build this amplifier with my technical assistance.
We organized " Vfet amp camp" included Papa who have done components soldering work,
mounting TO-3 transistors, Vgs match, bias veryfications and positive vibes included

Thanks to Xavier was for us a joy on the hobby bench , is now first time class A Pass
audio experience in new family home Best regards from France

 

[thompsontechs]

Lovely work SH!

JT

 

[qwertyl]

Thanks to Mr. Pass was great honour to finish and complete this new amplifier,
special thanks to Jim aka 6L6 for build guide , Jason & Variac & DiyAudio Team and Gianluca & Modushop.

We enjoy a lot and are conscious about a lots of work involved.

After my lottery kit win I talk with an old friend who was interested by build this amplifier with my technical assistance.
We organized " Vfet amp camp" included Papa who have done components soldering work,
mounting TO-3 transistors, Vgs match, bias veryfications and positive vibes included

Thanks to Xavier was for us a joy on the hobby bench , is now first time class A Pass
audio experience in new family home Best regards from France

It looks brilliant!
Where did you get these wire wrappers from?

 

[Soundhappy]

@ Thompsontechs

Thanks for kind words I appreciated

@ Quertyl

Was long time in the past I get this in my drawers..
the product I don't know precise link reference but this one look similar with output diameter = 3mm.
Anyway ask the seller 3mm 70.5FT (21.5M) Spiral Cable Wire Wrap Tube Computer Manage Cord clear | eBay
One more thing : I my build solid core copper wire is SYT AWG20 thicker than kit ones,
can be bend 4~5 times without break and isolant material don't melt easyly with higher iron temperatures.
Make this style wiring = work with patience Good luck

 

[MEPER]

For fine tuning my setup of speakers in my listening room I found this Stereo test CD on Tidal. There are probably many but I found it very good to find the best compromise of speaker placement vs. listening position.
https://www.amazon.com/Stereo-Check-Loudspeaker-Test/dp/B08H4PR4XN

Now I am soon ready to try out the VFET amp and I have the M2X amps as sound reference.....

 

[Monk55]

Great tip!! Thanks!!

 

[MEPER]

I managed to find a "hot spot" for speaker placement and listening position using the "CD". The test tones from 40 to 20 kHz and also the sweep from 20 to 20 kHz is very useful to hear if there are any dips or extensive room gain of specific frequencies.
Other useful tracks also for check of stereo imaging.
This can really give a change in sound.....much more than trying another amp.

 

[Nelson Pass]

Have you tried moving the amp around?

 

[PierreQuiRoule]

MEPER - Agreed. One of the ways I use to adjust speakers placement is to connect my computer to my stereo and place the mic at my listening position. Then play REW pink noise and display the REW real time spectrum graph on a large computer screen that I can watch from where the speakers are located. Then I move the speakers around to flatten the 40-400 Hz portion of the spectrum. I do this one speaker at a time. Flattening a room mode by X dB this way results (as it should) in a very audible improvement. Often a speaker needs to move only a little (say a foot) to fix a problem.

Pierre

PS Sorry if this is off topic...

 

[MEPER]

I don't think it is "very off topic" as speaker placement need to be "perfect" before any amp review takes place.

In my case....after re-organize of my listening room I need a stable reference with my M2X amps before any assessment of the VFET amp.

@Nelson:
I did not move around with amps that much. The M2X blocks are heavy!
The VFET amp much nicer to move around.....
But where to place it.....it will look stupid on top of the M2X amps....so probably at the floor between the speakers......to begin with!

I have to decide as standalone or in a bi-amp configuration with M2X. Probably best to start the VFET assessment as standalone amp!

 

[MEPER]

I could place the M2X amps behind the speakers.....back to back then I only need 30 cm (1 feet) of speaker cable......or so.....

 

[MEPER]

This album is also available on Tidal:
[Album review] Siri's Svale Band "Black bird" - A Music Review on TNT-Audio [English]

The recording has a high quality. The music is a bit special but you can get used to it....and it very good to evaluate sound performance of a system. I will use "Svale Band" to compare M2X vs. VFET. It is a recording where the singers voice is very "up front" and a very dynamic acoustic double bass.....

 

[thompsontechs]

When is round 2 again?

 

[Nelson Pass]

Just assembled the n ch version for final testing. If no issues then production qty boards in 10 days or so.

 

[Mark Johnson]

Congratulations Nelson!

This scrap of info gives diyAudio fans an opportunity to observe, live and in person, the time required between "OK it does seem to work" and "buyer lottery in 2 hours".

 

[gary s]

Thanks for the update Nelson and your immense generosity - which seems forever boundless.

 

[exojam]

Just assembled the n ch version for final testing. If no issues then production qty boards in 10 days or so.

It is a very nice thing that you and the folks around you have done.

James

 

[Analogico]

Thank you Nelson. You are relentless!

 

[Analogico]

Soundhappy,

It looks like you used an alternative Circular Connector on the back panel of your VFet SE amplifier. I think this connector could be a good option for my Salas UltraFSP RIAA build. Can you share its Mouser/DigiKey part number?

Thanks.