Hello all,
I haven't been home yet to tinker with the amp yet but I have been doing some searching on the net for a suitable preamp. I came across this preamp design by Carlos Filipe Machado. The design uses a single 2SK170 JFET per channel and is supposedly capable of powering a 10Kohm input inpedence. Does it sound like a good match? It also runs on a single +46V rail which has me tempted to tap off of the power supply of the F3 clone. Any comments?
http://myweb.tiscali.co.uk/nuukspot/decdun/gainclonepre2.html
I haven't been home yet to tinker with the amp yet but I have been doing some searching on the net for a suitable preamp. I came across this preamp design by Carlos Filipe Machado. The design uses a single 2SK170 JFET per channel and is supposedly capable of powering a 10Kohm input inpedence. Does it sound like a good match? It also runs on a single +46V rail which has me tempted to tap off of the power supply of the F3 clone. Any comments?
http://myweb.tiscali.co.uk/nuukspot/decdun/gainclonepre2.html
Hello all. Good news, I decided to switch over to the ZenV9 design as it contained fewer components and was able to get sound out of the completed channel. I have one question though. In the ZenV9 manual it states that the Vds should be set to 2.5V as the third way of selecting R3. Vds is the middle pin of the jfet correct? Is this set at operating temperature or when the amp is first powered up? Thanks.
Hello all. I'm back to tinkering with this DIY F3 again. The amp sounds great. I must thank you all for your input thus far. My concern at this point is that I cannot get a stable Vds voltage on the jfet. The voltage runs all over the place. I know that this device is temperature sensitive. Is this necessarily a problem or is this something that is to be expected? I have considered thermally isolating the jfet by giving them each a dedicated heatsink separate from the mosfets. Would this be a good idea or am I worrying too much?
Thanks in advance.
Thanks in advance.
Hello,
Im starting the amp to build as well, I would say Im a total noob on electronics... I have build a few minor amps and now I try this one to be my personal "high end" amp for single driven fullrange speakers.
I have ordered the parts from:
Tech DIY Company Store
Now I have some realy basic questions:
Does the amp need to be started after soldered? Or does he run on first power up?
Did you put any speaker protections in your amps?
Can you recoment me any transformer for European 240v?
Im starting the amp to build as well, I would say Im a total noob on electronics... I have build a few minor amps and now I try this one to be my personal "high end" amp for single driven fullrange speakers.
I have ordered the parts from:
Tech DIY Company Store
Now I have some realy basic questions:
Does the amp need to be started after soldered? Or does he run on first power up?
Did you put any speaker protections in your amps?
Can you recoment me any transformer for European 240v?
Hello,
......
Does the amp need to be started after soldered? Or does he run on first power up?
......
explain exactly what you mean ?
Hello,
......
......
Did you put any speaker protections in your amps?
........
you don't need SP with F3 - startup is gentle , and it have coupling cap on output , so DC can't reach your speaker .
all you need is some salt between your ears - to prevent overpowering the speaker ...... but that's case with all amps
Hello,
......
.....
Can you recoment me any transformer for European 240v?
I'll pass that one , because I'm not in Europe
... because I'm not in Europe
Exactly, you're always on the top of the (diy audio) World!
(From the other side, sometimes it seems that Europe is on (the dark side of...) the Moon... )
explain exactly what you mean ?
I mean after the PCBs are set up alt the soldering is done the amp is finished, what to do before I first time power up? Can I then just power up, or do I need to apply some procedure?
Looks like not many people built the lovely F3.
The F3 is selective with regard to its audience - not high
power, not trivial to build, not high input impedance,
not direct coupling.
Only lovely sound.
Looks like not many people built the lovely F3.
Of the few who did, anybody's thinking about external psu?
Here is one:
http://www.diyaudio.com/forums/pass-labs/164003-so-my-quad-zv9.html
There is absolute no need to external PS.
The thing is absolutely dead quiet.
Gyuri
In a 6 Moons review it made this statement about F4:
"If you've got a low-power SET and want to hear bass, definition and linearity you never knew you could, go humbucker and tie an F4 to its outputs"
As I'm feeling that the F3 is more for my taste.
could I not at a later date, add as above states, a F4 to a F3 if I wanted more volume to drive a wider range of speakers. ?
"If you've got a low-power SET and want to hear bass, definition and linearity you never knew you could, go humbucker and tie an F4 to its outputs"
As I'm feeling that the F3 is more for my taste.
could I not at a later date, add as above states, a F4 to a F3 if I wanted more volume to drive a wider range of speakers. ?
This is the article I was referring to
6moons audio reviews: FirstWatt F4
and its next page
6moons audio reviews: FirstWatt F4
6moons audio reviews: FirstWatt F4
and its next page
6moons audio reviews: FirstWatt F4
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