A.Holton AV400 using irfp or Quasi mosfet amplifier ?

[medogrizli]

So I have some kind of schematics AV400 from A.Holton and I dont know is this is good schematics: in the text it stays that you use irfp240 but in the schematics in the same "pdf" file there are 2SK1530 mosfets ?!

So can that schematics be used with irfp and 2SK without any changing in the schematics: 2SK are lateral and irfp240 are vertical mosfets

So if second stage has enough current to drive irfp can the same scehmatics be used with 2SK without any change ?

I would post his schematics here so I dont know is it legal or not?

please if you have good working schematics isnig IRFP-s can you send it here: velikigrizli@gmail.com

Concerned to Auasi amplifier: it uses daul voltage supply : so it can be difficult to buld when using SMPS with feedback

Can Quasi amplifier work ONLY at +/- 70V


About AV400 Holton : What is the purpose of Q19 and Q20 from the schematics:
It wolud be much easier if I wolud post the schematics here...

[quasi]

The Quasi amplifier in the thread "Power Amp Under Development" only uses the 2 main rails, I.e. +/- 70 volt rails. The third rail was dropped during the thread so it will be quite suitable to use with your SMPS.

Cheers
Q

PS. I have not built Holton's AV400 but I'm sure it would sound great. He is well known and respected in Australia for his amplifier designs and one of his designs has been featured in the major local electronics magazine. So you can choose knowing both will be great.

[bigpanda]

Hi medogrizli,

Answers to most of your q. about are in the thread already. You really had to do more homework. Mr. Holton's work is not in the public sector now. Don't post it openly. But the guys who have encountered it knows what you are talking about and would answer you if they want to. You can use irpf instead of the 2sk/j's and that had been answered too less than a week ago but I am not too sure if that's your q. or someone's on this subject.

[TomWaits]

Quasi vs. Holton, obviously the amplifiers are different but both are excellent and they look like they may have a few similarities. As of yet I have not heard Holton's.

I think it is crude to sum it up this way but here goes:

A) Holton can provide you a kit approach and you must purchase the design from him. He can provide you key options to go with your purchase. He is well respected. Holton can provide the board.

B) Quasi offers you his design fully. You get to build at your own risk and skill level. Seems more exciting to me plus no charge is cool. It is fully scalable to your own desire. Q gains high respect also. If you don't want to make the Q board, you can have it manufactured.


However, Quasi’s amp comes with more support if you chose to use the DIY site as you build it. If I was Holton, I would discuss those things only in private emails to protect intellectual property.

I think you should build both and compare them? Aussie vs. Aussie!

Then you will be the expert!

Less talk more building!

Cheers,

Shawn.

[TomWaits]

Update: Q's flag changed. Who knew?

[medogrizli]

Using only N- channel has some "theoretic" advantages

Board is not problem to make

[quasi]

Originally posted by TomWaits
Update: Q's flag changed. Who knew?

I thought I would display it briefly to acknowledge my birth place.

Cheers
(Sentimental) Quasi

[TomWaits]

Originally posted by medogrizli
Using only N- channel has some "theoretic" advantages

Board is not problem to make

Use one power supply and try both? Financially no big difference to try two amplifiers. When you build the case and the power supply twice, well, that's when the money doubles.

Seriously, try both designs and good luck with your decision.

Shawn.

[medogrizli]

Originally posted by TomWaits


Use one power supply and try both? Financially no big difference to try two amplifiers. When you build the case and the power supply twice, well, that's when the money doubles.

Seriously, try both designs and good luck with your decision.

Shawn.

But mosfets are not so cheap and I cant say the difference by ear I am not "audiophile" my ears are not so sharp: for difference you nead measuring equipement:

So if quasi has small distorsion etc. then its ok:

is there any way to use irfp240 in the quas amplifier : I have tons of these

irfp240 is 200V mosfet, max voltage will be ok ,but other characteristic I am not sure what do you think

momentarily I have +/- 50V supply for trying and testing: Can both Holton and Quasy work on that woltage correctly ?

[jacco vermeulen]

Originally posted by quasi
acknowledge my birth place.

Aren't you the bloke on tv who's singing: I'm a Greek in New South Wales ?
(and got arrested for tieing up kids during a birthday party)