There are earths everywhere! Any way you have a schematic? Divining the connections by looking at pics it's very hard.
I wasn't clear on whether you bypassed the switch.
the ACP+ could be another amazing front end card for the VFET amp
do you have tried it bypassing the stock front end card ?
I now got the VFET up and running as stand alone amp. The two M2X are powered off.
As expected the VFET needs a bit more "juice" from the preamp. 9 o'clock with M2X then 11 o'clock is needed for VFET which could be a good thing.
The temperature is about 50 C at the hottest place at heatsinks. Front panel is about 43 C.
There is a difference in sound compared to M2X. VFET more relaxed and less "harsh". Deep tones sound more "rounded" and there is a feeling that it reaches deeper. Same experience as when I connect my 300B amp.
Amp is easy to listen to.
A music example where I observed the biggest difference was this recording:
Rinaldo Alessandrini Releases Third Bach Harpsichord Recital On Naive
It exist on Tidal. So maybe try it out......
1st time I played it on M2X I was nearly fallen down the chair as I was expecting a Grand Piano but this one is Harpsichord!
It has some "nasty" overtones and these are much more pronounced when using M2X. On VFET much more "ear friendly". What is the most "correct" sound I don't know as I have never experienced these instruments live (at least not a "concert grade" instrument).
Imaging etc. is on par with M2X. Voices very nice and also a bit more "polished" as compared to M2X.
I may move the M2X's away for a while and place the VFET on top of the rack.
It can play plenty loud for my use!
As expected the VFET needs a bit more "juice" from the preamp. 9 o'clock with M2X then 11 o'clock is needed for VFET which could be a good thing.
The temperature is about 50 C at the hottest place at heatsinks. Front panel is about 43 C.
There is a difference in sound compared to M2X. VFET more relaxed and less "harsh". Deep tones sound more "rounded" and there is a feeling that it reaches deeper. Same experience as when I connect my 300B amp.
Amp is easy to listen to.
A music example where I observed the biggest difference was this recording:
Rinaldo Alessandrini Releases Third Bach Harpsichord Recital On Naive
It exist on Tidal. So maybe try it out......
1st time I played it on M2X I was nearly fallen down the chair as I was expecting a Grand Piano but this one is Harpsichord!
It has some "nasty" overtones and these are much more pronounced when using M2X. On VFET much more "ear friendly". What is the most "correct" sound I don't know as I have never experienced these instruments live (at least not a "concert grade" instrument).
Imaging etc. is on par with M2X. Voices very nice and also a bit more "polished" as compared to M2X.
I may move the M2X's away for a while and place the VFET on top of the rack.
It can play plenty loud for my use!
Attachments
I can add that the "turn-off pop sound" is very very light. I switch everything off at a central place (a PS-Audio power plant) so switched off at the 230 VAC side. The "turn-off pop sound" was louder using M2X and I think the reason is that M2X has linear PSU with a large cap-bank so M2X is still "alive" when preamp "dies" so what I hear is the "pop" of the preamp but with VFET......VFET "dies" faster than preamp so I don't hear preamp "pop".....
Awesome report. Very similar with my experience moving from an F6. It feels as if goes deeper, and very relaxed. Even my wife's first comment as she listened to Nick Cave was "wow, less harsh. I like it". What are your speakers? Looks big
And thanks for sharing an album link. I love Bach and the harpsicord. I can strongly recommend to go and hear one live. It is a brilliant and warm instrument.
The same here
Light thump, very short time.No thump switch turn-on = silence in the speakers
Hey dudes - I just received my amp. Stoked. This will be my third VFET kit build, and all of them are different.
A question on case size & heat dissipation - I didnt get the case released with the kit. Im looking at getting either a 2U or 3U high case. I used a 2U high case on the "other" Sony Pass VFET push-pull amp - but of course, this amp is running in Class A (but with half as many output VFETS...).
Will a 2U or 3U high case be OK in terms of heat dissipation? I expect each case Im considering to be approx 300MM deep - and with both sides fully heatsinked (heatsunk...?)
thanks!
A question on case size & heat dissipation - I didnt get the case released with the kit. Im looking at getting either a 2U or 3U high case. I used a 2U high case on the "other" Sony Pass VFET push-pull amp - but of course, this amp is running in Class A (but with half as many output VFETS...).
Will a 2U or 3U high case be OK in terms of heat dissipation? I expect each case Im considering to be approx 300MM deep - and with both sides fully heatsinked (heatsunk...?)
thanks!
The heatsinks used in the VFET chassis are the same size (and mounting hole pattern) as the Modushop 4U, 300mm deep chassis. These are the sinks you will want to mount the output stage plus the input stage cards.
The VFET chassis is narrower than the standard offering from Modushop. It is a very good looking chassis, but a little tight on the inside. It needs to have the amp assembled on a special sequence to get everything to fit.
The VFET chassis is narrower than the standard offering from Modushop. It is a very good looking chassis, but a little tight on the inside. It needs to have the amp assembled on a special sequence to get everything to fit.
Kit # 059 finally up and running!!
I am very new to the site and was pleasantly surprised to win an opportunity to build one of these Class A kits! I took my time with the build, checked everything twice and about an hour ago, I plugged in the AC cord, and flipped the switch. Voltage rose toward 20 volts and then everything died -- no volts, no blue LED. Turned out that in my haste to get the amp fired up, I neglected to properly seat the AC plug tightly into the power supply. As soon as I started drawing current when I flipped the switch, the connection opened and the amp died. Simple fix and now up and running. Next step is to start stuffing my recently received ACA+ preamp board. Thanks everyone for your helpful posts.
Happy Jack
I am very new to the site and was pleasantly surprised to win an opportunity to build one of these Class A kits! I took my time with the build, checked everything twice and about an hour ago, I plugged in the AC cord, and flipped the switch. Voltage rose toward 20 volts and then everything died -- no volts, no blue LED. Turned out that in my haste to get the amp fired up, I neglected to properly seat the AC plug tightly into the power supply. As soon as I started drawing current when I flipped the switch, the connection opened and the amp died. Simple fix and now up and running. Next step is to start stuffing my recently received ACA+ preamp board. Thanks everyone for your helpful posts.
Happy Jack
Hello friends! Still waiting for my parts kit, trying to prepare as much as possible. I have a window of opportunity to have a small handful of “niceties” brought from the US.
Would you recommend any way of making the input board “switchable” (as in “interchangeable”)? I most likely will never change the output stage. Is there a recommended piece of hardware that would allow this with minimal / no impact on the sound quality? Or is it better to just solder it and never attempt to change it?
Thanks for any recommendations.
Rafa.
Would you recommend any way of making the input board “switchable” (as in “interchangeable”)? I most likely will never change the output stage. Is there a recommended piece of hardware that would allow this with minimal / no impact on the sound quality? Or is it better to just solder it and never attempt to change it?
Thanks for any recommendations.
Rafa.
Yes, those are OBL-15 using the Ciare 15".
CIARE ITALIAN SPEAKERS - PRO AUDIO B2B: NDH 15-4 S SUB-WOOFER
It seems that VFET drives it with no problems.....probably many will say that it is not possible and the 15" needs a 1000W class D amp
Awesome report. Very similar with my experience moving from an F6. It feels as if goes deeper, and very relaxed. Even my wife's first comment as she listened to Nick Cave was "wow, less harsh. I like it". What are your speakers? Looks big
And thanks for sharing an album link. I love Bach and the harpsicord. I can strongly recommend to go and hear one live. It is a brilliant and warm instrument.
Yes, it is strange.....even that you can't measure it goes deeper it is precepted that way. I have heard similar reports to people switching to small SET amps.
This harpsicord recording could be interesting to hear in "hi-res"....will check Tidal. Harpsicord with pedals! .....first time I see one of those....but not at all harpsicord expert
J.S. Bach, Toccata in d minor / en ré mineur, BWV 565 - YouTube
It seems that VFET drives it with no problems.....probably many will say that it is not possible and the 15" needs a 1000W class D amp
#60 is up and running! Just finished today and after adjusting the 20 volts and lettting it cook for an hour its playing music.I'm running it thru a Schiit Magni3 cascaded with a Schiit Magni 2 Uber hooked to my XBR television audio outs.I am using 2 preamps as the Sony max. o/p is .375V RMS.So I read that the Vfet needed about 3V for 10W and the Shiits max gain(each) is about 5.5.However with one set for unity and the other set for g=5.5 there is plenty of volume.I'm running my EPI M50's currently.They're quite inefficient and yet the room is loud with the volume set about 50%.I may just run one Magni.Soundwise its balanced from top to bottom,very clean precise highs and solid bass,kind of "lively" sounding. I will have to listen more to be able to really compare it to my F7'ish that I normally run.As for the build it was fairly easy.I modified the Meanwell panel input jack so I could push it thru from out side.Reason is I didn't like the way it was recessed when mounted from the inside of the panel.I had to use a needle file and open up the panel between the large and smaller screw holes.In addition the screw holes had to be opened slightly with a drill bit because the screw housings are wider one end than the other. Now the jack butts against the panel and is more solid.However doing so changes the assembly sequence slightly as the rear panel and jack/filter board are now a single unit. So my OCD is now taken care of.I will post a couple of pics when I find my camera USB cable.I have to thank everyone involved,a lot of work has gone into this and I am very grateful.