It's not my arithmetic, nor maths, that needs checking. They can easily be out by huge amounts.Well, I have a 300W 8R load and a scope. I think I will do my own testing. We will see how good your math is. Like I said, Greg says to not drive the SKA with more than +-50V so I guess we will never know on that one.
It's the power vs voltage model that needs checking.
Maybe we will get to see whether your measurements are as accurate/inaccurate as my model predictions.
It's not my arithmetic, nor maths, that needs checking. They can easily be out by huge amounts.
It's the power vs voltage model that needs checking.
Maybe we will get to see whether your measurements are as accurate/inaccurate as my model predictions.
Ya think?
i want use tube amp before. they have very low THD .
i want crate an tube peramp for apex amps
thank you.
On second thought, I forgot about AndrewT. He is much more qualified to tell you which Apex amp to build. I will bow out of this.
Not me, there are so many coming out so fast that I can't tell which are real and which are proposals, which are tested and which are quessimated.
OK I looked back through some of my Apex amps and I think the SR150 would fit the bill for you. Very stable and 150W into 8 ohm. You will need close to +-50VDC PSU to get the 150W/8R.
thank you but i need an amp with more than 130 watt power and under 4 OHM speaker load
Under 4 ohm is tough on any amp. To be clear, do you need 130W with an under 4 ohm load or 130W from 8 ohm?
We should wait for Mile to suggest something. He knows which of his amps will fit your needs.
We should wait for Mile to suggest something. He knows which of his amps will fit your needs.
On second thought, I forgot about AndrewT. He is much more qualified to tell you which Apex amp to build. I will bow out of this.
be patient
all of us is friend here.
thanks for your helping and all of people for this useful posts.
why mr mile do not answer my request ???
why mr mile do not answer my request ???
I'm sure he will when he comes back.
I'm sure he will when he comes back.
ok dear friend
thank you very much
be patient
all of us is friend here.
thanks for your helping and all of people for this useful posts.
why mr mile do not answer my request ???
A40
Hi Mile,
I thought of the A40 but wasn't sure about the under 4 ohm needs. Now if Hadighorbani can clarify just how much power and at what ohm speaker load, I can hook it up and do some measurements.
I thought of the A40 but wasn't sure about the under 4 ohm needs. Now if Hadighorbani can clarify just how much power and at what ohm speaker load, I can hook it up and do some measurements.
Hi Mile,
I thought of the A40 but wasn't sure about the under 4 ohm needs. Now if Hadighorbani can clarify just how much power and at what ohm speaker load, I can hook it up and do some measurements.
Use +/-65V rails for 8R load, +/-50V for 4R and +/-35V for 2R.
Use +/-65V rails for 8R load, +/-50V for 4R and +/-35V for 2R.
That has been my quandary. According to AndrewT you need +- 60V to get 150W/8R. But I thought +-60VDC was too much for the under 4R load that the OP asked for. I guess with that now with your recommendations he can decide what he needs.
Use +/-65V rails for 8R load, +/-50V for 4R and +/-35V for 2R.
thank you mr mile
These just came in the mail. Great layout by Prasi on AX11 Bimo mod.
Thanks Prasi!
This will be my first Apex BJT output amp.
Thanks Prasi!
This will be my first Apex BJT output amp.

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I suspect you are going to find the same thing Apex said when asked which amp is his favorite. Answer.....The latest one. 😉
I suspect you are going to find the same thing Apex said when asked which amp is his favorite. Answer.....The latest one. 😉
Isn't his favorite something like the BX3330? 🙂 the more transistors the better.
Well in one reply he classified them as VFA and CFA and he did give an opinion but I also remember him answering the latest. That is kind of how it goes with DIY. The newest one is always a favorite until the next one. If you ever get around to building a good A/B setup you will be amazed how similar they all are.
Greeyings mr.xrk i built in fh9 6channel for 5.1 home theatre .give me transformer details rail.ampere.capacitor
Thank you.
Thank you.
Greeyings mr.xrk i built in fh9 6channel for 5.1 home theatre .give me transformer details rail.ampere.capacitor
Thank you.
35v rails for FH9 and 53v rails for FH9HV. HV uses ksa3503 and ksc1381.
For 35v rails:
300va 25va transformer per 2 channels. Each channel with 4700uF X qnty 4 in CRC with R=3.33ohm 10w.
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