First One - mosFET amplifier module

[Lazy Cat]

Hopefully first batch in March, since outputs will arrive successively. 🙂

 

[danny_66]

Very good speakers you have Danny.

I calculated you will get some +8 dB extra SPL with First One and around 112 dB SPL max, which is very satisfactory for home listening. 😉

Now I just have to provide them. 🙂

Thanks, my neighbours will be happy 😉

 

[Lazy Cat]

First One GB list update

Hi guys

So far 82 First One modules ordered as confirmed on the list bellow. 🙂

For any new order placed, please quote the list in a new post and add your forum name at the bottom. 😉

Thanks.

luca 4
danny_66 2
woofertester 4
rainerco 2
pinnocchio 4
giannettino 2
jokari69 2
mksung 2
ZZoran 2
Edgar 2
Eric06 2
kimon 2
maxidcx 2
e-bok 6
bobo le chat 2
metallicus69 6
scoutOne 4
Iduarte1973 2 (full kit)
quan 2
Greg Stewart 2
colesey 2
analogsa 4
Brianco 2
Theodosis O. 2
chunek 2
Darb 4
CaféNoir 4
Nikitas 2 (full kit)
meanman1964 2
supernet 2

 

[BigE]

Hi,

Is a chassis is being offered? If so, what cost?

Thanks!

 

[Lazy Cat]

Two in preparation, two price levels. Info about chassis will be updated in post #1 as soon as I have them here with complete calculation. So watch on the thread occasionally. 😉

 

[BigE]

Thanks! I am very interested in this project. It seems a very good way to get balanced!

 

[jeremysk]

2 modules please.

luca 4
danny_66 2
woofertester 4
rainerco 2
pinnocchio 4
giannettino 2
jokari69 2
mksung 2
ZZoran 2
Edgar 2
Eric06 2
kimon 2
maxidcx 2
e-bok 6
bobo le chat 2
metallicus69 6
scoutOne 4
Iduarte1973 2 (full kit)
quan 2
Greg Stewart 2
colesey 2
analogsa 4
Brianco 2
Theodosis O. 2
chunek 2
Darb 4
CaféNoir 4
Nikitas 2 (full kit)
meanman1964 2
supernet 2
jeremysk 2

 

[Dane]

luca 4
danny_66 2
woofertester 4
rainerco 2
pinnocchio 4
giannettino 2
jokari69 2
mksung 2
ZZoran 2
Edgar 2
Eric06 2
kimon 2
maxidcx 2
e-bok 6
bobo le chat 2
metallicus69 6
scoutOne 4
Iduarte1973 2 (full kit)
quan 2
Greg Stewart 2
colesey 2
analogsa 4
Brianco 2
Theodosis O. 2
chunek 2
Darb 4
CaféNoir 4
Nikitas 2 (full kit)
meanman1964 2
supernet 2
jeremysk 2
Dane 2

 

[Darb]

I am also interested in the full kit (Chassis, power supply)...

 

[mikvous]

luca 4
danny_66 2
woofertester 4
rainerco 2
pinnocchio 4
giannettino 2
jokari69 2
mksung 2
ZZoran 2
Edgar 2
Eric06 2
kimon 2
maxidcx 2
e-bok 6
bobo le chat 2
metallicus69 6
scoutOne 4
Iduarte1973 2 (full kit)
quan 2
Greg Stewart 2
colesey 2
analogsa 4
Brianco 2
Theodosis O. 2
chunek 2
Darb 4
CaféNoir 4
Nikitas 2 (full kit)
meanman1964 2
supernet 2
jeremysk 2
Dane 2
mikvous 2

 

[lduarte1973]

i will probably ask for another 2 channels full kit later on , but i have to try it against my amps first

 

[PreSapian]

luca 4
danny_66 2
woofertester 4
rainerco 2
pinnocchio 4
giannettino 2
jokari69 2
mksung 2
ZZoran 2
Edgar 2
Eric06 2
kimon 2
maxidcx 2
e-bok 6
bobo le chat 2
metallicus69 6
scoutOne 4
Iduarte1973 2 (full kit)
quan 2
Greg Stewart 2
colesey 2
analogsa 4
Brianco 2
Theodosis O. 2
chunek 2
Darb 4
CaféNoir 4
Nikitas 2 (full kit)
meanman1964 2
supernet 2
jeremysk 2
Dane 2
mikvous 2
presapian 2

😀

 

[lduarte1973]

stupid question , where are the fets in this module ?

 

[BYRTT]

stupid question , where are the fets in this module ?

Post 1, second picture look under PCB.

 

[coolewater]

luca 4
danny_66 2
woofertester 4
rainerco 2
pinnocchio 4
giannettino 2
jokari69 2
mksung 2
ZZoran 2
Edgar 2
Eric06 2
kimon 2
maxidcx 2
e-bok 6
bobo le chat 2
metallicus69 6
scoutOne 4
Iduarte1973 2 (full kit)
quan 2
Greg Stewart 2
colesey 2
analogsa 4
Brianco 2
Theodosis O. 2
chunek 2
Darb 4
CaféNoir 4
Nikitas 2 (full kit)
meanman1964 2
supernet 2
jeremysk 2
Dane 2
mikvous 2
presapian 2
coolewater 2

 

[Lazy Cat]

Thanks! I am very interested in this project. It seems a very good way to get balanced!

Yes very tempting, stereo amp (Left and Right RCA inputs) and at the same time full balanced amp (mono XLR input). In that case I would definitely recommend regulated SMPS with +/-50 Vmax.

 

[Lazy Cat]

First One GB list update

I am also interested in the full kit (Chassis, power supply)...

Here you go.

luca 4
danny_66 2
woofertester 4
rainerco 2
pinnocchio 4
giannettino 2
jokari69 2
mksung 2
ZZoran 2
Edgar 2
Eric06 2
kimon 2
maxidcx 2
e-bok 6
bobo le chat 2
metallicus69 6
scoutOne 4
Iduarte1973 2 (full kit)
quan 2
Greg Stewart 2
colesey 2
analogsa 4
Brianco 2
Theodosis O. 2
chunek 2
Darb 4 (full kit)
CaféNoir 4
Nikitas 2 (full kit)
meanman1964 2
supernet 2
jeremysk 2
Dane 2
mikvous 2
PreSapian 2
coolewater 2

Thanks for the confidence. 🙂

 

[Lazy Cat]

Damping factor

Today a guy from a local audio community called and asked about the damping factor of the First One amp module because it is not specified in post #1. I said that along the THD measurements I noted Zout to be under 10 mOhms, but in reality did not measured it very precisely or specifically on different frequencies.

So today some measurements were performed in order to determine Zout and consequently the damping factor (DF).

Sine signal of 100 Wrms on 20 Hz, 1 kHz and 20 kHz was thrown onto 4,08 Ohm load resistor, measured with FLUKE 289 True RMS Multimeter and here are the results.


1. 20 Hz, 100 Wrms/4,08 Ohm:

unloaded output: 20,205 Vrms (Iout=0)

loaded output: 20,199 Vrms (Iout=4,95 Arms)

voltage drop on Zout: 6 mVrms

Zout(20 Hz)=6 mV/4,95 A=0,00121 Ohm

DF(20 Hz)=Rload/Zout=4,08 Ohm/0,00121 Ohm=3371,9


2. 1 kHz, 100 Wrms/4,08 Ohm:

unloaded output: 20,201 Vrms (Iout=0)

loaded output: 20,199 Vrms (Iout=4,95 Arms)

voltage drop on Zout: 2 mVrms

Zout(1 kHz)=2 mV/4,95 A=0,0004 Ohm

DF(1 kHz)=Rload/Zout=4,08 Ohm/0,0004 Ohm=10200


3. 20 kHz, 100 Wrms/4,08 Ohm:

unloaded output: 20,207 Vrms (Iout=0)

loaded output: 20,199 Vrms (Iout=4,95 Arms)

voltage drop on Zout: 8 mVrms

Zout(20 kHz)=8 mV/4,95 A=0,00162 Ohm

DF(20 kHz)=Rload/Zout=4,08 Ohm/0,00162 Ohm=2518,5


Measurements specifics:

True AC voltmeter probes were connected directly to PCB output terminals, so no load's wires resistance voltage drop in the loop. Any mOhm of the wires and terminals resistance added in the equation will influence significantly to damping factor value.

 

[edionysus]

luca 4
danny_66 2
woofertester 4
rainerco 2
pinnocchio 4
giannettino 2
jokari69 2
mksung 2
ZZoran 2
Edgar 2
Eric06 2
kimon 2
maxidcx 2
e-bok 6
bobo le chat 2
metallicus69 6
scoutOne 4
Iduarte1973 2 (full kit)
quan 2
Greg Stewart 2
colesey 2
analogsa 4
Brianco 2
Theodosis O. 2
chunek 2
Darb 4 (full kit)
CaféNoir 4
Nikitas 2 (full kit)
meanman1964 2
supernet 2
jeremysk 2
Dane 2
mikvous 2
PreSapian 2
coolewater 2
edionysus 2 (full kit)

 

[danny_66]

That's more than plenty of damping factor 🙂