Anthony,
good to see you solidly back in the game, your chassis work has
always been top notch 🙂 That looks really sweet.
good to see you solidly back in the game, your chassis work has
always been top notch 🙂 That looks really sweet.
Which is the aim of this circuit ...Babowana said:
I do not understand this diode across R3.
chrismercurio said:
You can easily calculate the required thickness yourself on the next project.
Suppose the bottom plate is a beam which is supported on two opposite sides only.
Mechanics forget-me-not formula for the deflection of a supported beam with a concentrated force/weight in the middle :
Deflection = ( F x L x L x L ) / ( 48 x E x I )
F = force in Newton (=weight of transformer times gravitational force)
L = width of plate ( inbetween the screws/bolts )
E = elasticity modulus of material ( Aluminum is 70.000N/mm2 )
I = moment of inertia = (w x t x t x t)/12
w = non-supported width of plate, t = thickness.
(all dimensions in meters or mm)
A 1KVA Plitron weighs about 15lbs. ( => F ~ 67N)
Deflection of your 16"x 14" bottom plate ;
0.25'' => 0.14mm ( is less than 0.006 inch)
0.125'' => 8 times as much ~ 1.1mm ( a little less than 0.05 inch)
Add a couple of big lytic cans alongside the Plitron transformer and the center deflection of a 0.125'' bottom plate would reach 1.5mm or more.
bobodioulasso said:
The diode is a kind of watchdog. It keeps eyes on the voltages of the mosfet's gate and drain at the same time, and keep the gate voltage to be never greater than the drain voltage by maximum 0.7V. By doing so, it protects the mosfet safe.
I've learned this from Papa . . . Thanks Papa . . .
>🙂<
ttr said:
You may have to play with the resistor values a bit -- I did the opposite -- using a high Idss K170BL (around 11mA) and the lowest Idss J74 I could find (4mA) -- the amplifier worked fine.
Babowana,
post 3450 you said " I made C3-C6 big to have the supply rails as better AC signal ground because the output impedance of the capacity multiplier (mosfet) is not zero."
Should not a BJT darlington be better for this purpose , i mean low impedance?
I guess i understand your aim was more the voltage drop out than the properties of a cap. mult.
The Rod Eliot cap.mult. - originally from John Linsley Hood- would it work properly with the F5? (Say 10000uf at the input and 3300 at the output.) I do not know.
post 3450 you said " I made C3-C6 big to have the supply rails as better AC signal ground because the output impedance of the capacity multiplier (mosfet) is not zero."
Should not a BJT darlington be better for this purpose , i mean low impedance?
I guess i understand your aim was more the voltage drop out than the properties of a cap. mult.
The Rod Eliot cap.mult. - originally from John Linsley Hood- would it work properly with the F5? (Say 10000uf at the input and 3300 at the output.) I do not know.
bobodioulasso said:
It could be better . . .
You know? I'm a pure diyer, having my own principles. One of several priciples is, "Use old parts I have already, instead of buying new!" So, I often see that mine is ended up as a "good enough" instead of "the best".
>>
<<
Hi Babo
Sorry, i did not want to criticise your choices in this PSU. Anyway, with this amount of capacitance, i have no doubt your amp must sound the best possible. I agree it's nice to use the parts one already have. I think you found the best way to drop out these few volts and i like this soft start you introduced for the output cap. Thanks for the diode explanation.
It must be clear that i have no attempt - neither ability - to improve f5. I find this jewel perfect as it is. This is one among the best amplifiers i ever listened to. Crystal clear highs, firm basses, natural medium , absolutely no hum with a simple PSU. (i use only 47000uf per channel)
No, i am just curious about cap. mult. , not especially for F5, but in a general class A amplifiers purpose, as it seems to be a way to spare some money avoiding to buy expensive big low ESR caps while obtaining good results. That’s why i asked advices.
Sorry, i did not want to criticise your choices in this PSU. Anyway, with this amount of capacitance, i have no doubt your amp must sound the best possible. I agree it's nice to use the parts one already have. I think you found the best way to drop out these few volts and i like this soft start you introduced for the output cap. Thanks for the diode explanation.
It must be clear that i have no attempt - neither ability - to improve f5. I find this jewel perfect as it is. This is one among the best amplifiers i ever listened to. Crystal clear highs, firm basses, natural medium , absolutely no hum with a simple PSU. (i use only 47000uf per channel)
No, i am just curious about cap. mult. , not especially for F5, but in a general class A amplifiers purpose, as it seems to be a way to spare some money avoiding to buy expensive big low ESR caps while obtaining good results. That’s why i asked advices.
r5-r8 choice
Can I use the ohmite TA Series thick film alumina resistors for R5-R8 on the F5? Is it better to stick with a more traditional choice like the panasonics?
Nick
Can I use the ohmite TA Series thick film alumina resistors for R5-R8 on the F5? Is it better to stick with a more traditional choice like the panasonics?
Nick
f5-tech-diy kit
Hi Ya Boys!
Just starting to populate my Daniels F5 boards with the parts I ordered from Tech-Diy- Both suppliers were great to deal with-had to use pay pal which I don't like but that's probably another rant for another thread.
Question- my Tech-Diy kit comes with 22k1 resistors for R21 & R22 instead of the NP specced 10k- anyone see any issues here?
A comment on the Daniels boards- they are beautiful but very tight- I think he likes the challenge- all the resistors must be vertically mounted and I would only do this, since they are tightly packed in, with lead insulators- ie teflon "leg warmers". If you haven't done this before it means cutting the tubing about an 1/8" longer than the resistor body for a gentle curving return to the board. All well and good but getting in after to measure voltage will be tough. Just a comment.
Am excited to fire up and listen and I will post pictures of both my b1 built into a Hafler DH101 and the F5 built into a Hafler DH200-the recycler twins!
have fun, be safe
rob
Hi Ya Boys!
Just starting to populate my Daniels F5 boards with the parts I ordered from Tech-Diy- Both suppliers were great to deal with-had to use pay pal which I don't like but that's probably another rant for another thread.
Question- my Tech-Diy kit comes with 22k1 resistors for R21 & R22 instead of the NP specced 10k- anyone see any issues here?
A comment on the Daniels boards- they are beautiful but very tight- I think he likes the challenge- all the resistors must be vertically mounted and I would only do this, since they are tightly packed in, with lead insulators- ie teflon "leg warmers". If you haven't done this before it means cutting the tubing about an 1/8" longer than the resistor body for a gentle curving return to the board. All well and good but getting in after to measure voltage will be tough. Just a comment.
Am excited to fire up and listen and I will post pictures of both my b1 built into a Hafler DH101 and the F5 built into a Hafler DH200-the recycler twins!
have fun, be safe
rob
Re: f5-tech-diy kit
I have Cviller's board, but.....
http://www.diyaudio.com/forums/showthread.php?s=&postid=1643840&highlight=#post1643840
Vishay S102, CMF50, Caddock MK132 fit perfectly.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=140306
I have Cviller's board, but.....
rob lenk said:
http://www.diyaudio.com/forums/showthread.php?s=&postid=1643840&highlight=#post1643840
Vishay S102, CMF50, Caddock MK132 fit perfectly.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=140306
f5 questions
dweekie
thanks so much for the references-very helpful
so many posts its hard to keep them all straight- again thanks for the help!(BTW found a mistake in my placement of R!! and R12-thankyou twice!)
again the TECH-DIY dale supplied resistors must be mounted vertically hence my earlier comment-I'll supply a picture
Also when NP suggests setting P1 & P2 at minumum value I'm assuming low ohms( re 100ohms) vs high ohms(5000)- maybe a dumb question but "I gotts the pre-fire-up Jitters".
throw the old dog a bone
rob
dweekie
thanks so much for the references-very helpful
so many posts its hard to keep them all straight- again thanks for the help!(BTW found a mistake in my placement of R!! and R12-thankyou twice!)
again the TECH-DIY dale supplied resistors must be mounted vertically hence my earlier comment-I'll supply a picture
Also when NP suggests setting P1 & P2 at minumum value I'm assuming low ohms( re 100ohms) vs high ohms(5000)- maybe a dumb question but "I gotts the pre-fire-up Jitters".
throw the old dog a bone
rob
Re: f5 questions
PD boards, turn clockwise (opposite normal) all the way to start.
You can borrow my variac if you want.
rob lenk said:
PD boards, turn clockwise (opposite normal) all the way to start.
You can borrow my variac if you want.
F5-tea-bag
Tea-bag
thanks for the PD info-
very generous to offer your variac- thanks again
but I've got one and will use it!
You are in Kennebunk,Yes? Perhaps we can get together for the fire-up? micro brew or vino?
Gotta love this community!
take care
rob
Tea-bag
thanks for the PD info-
very generous to offer your variac- thanks again
but I've got one and will use it!
You are in Kennebunk,Yes? Perhaps we can get together for the fire-up? micro brew or vino?
Gotta love this community!
take care
rob
