Gimos50 - a robust guitaramp with IRF240/IRFP9240

moschfet · 05:32 PM

Hello people,

this is my first projekt, that I post here. I want to build a very robust guitaramp. In the past I have built some hifi amplifier, so I am not a bloody beginner

The headline says it. I plan to use irfp240/9240 Mosfets for a 50watt Amp. And I like to give my projekts names, so I call it 'Gimos50'.
There are some conditions for Gimos50:

- it should be oversized to have some reserves
- soft clipping
- stable work

With LT-Spice is this schematic caused. Gimos50 has a very low open-loop-gain. There are high lokal currentfeedback in the voltagegain. The negative-feedback-factor is very week. The result is a stable circuit, it don't need great frequency compensation.
The z-diodes in the negative feedback are limit the output voltage. About 25V should be enough for 50watt at 8ohm.
The overcurrent protection limit the output current to 2A per Mosfet. There should be enough reserves for continuous load.

moschfet · 29th January 2011, 08:42 PM

i have made a FFT with LT-Spice. This pictures shows 1kHz, 1watt and 50watt:

This simulation shows the cut-off-behavior:

nigelwright7557 · 29th January 2011, 10:47 PM

You schematic hasnt been uploaded.

moschfet · 29th January 2011, 11:59 PM

strange

I can see it.

This is the url:

http://www.diyaudio.com/forums/galle...62/Gimos50.jpg

nigelwright7557 · 30th January 2011, 12:02 AM

Quote:

Originally Posted by moschfet

strange

I can see it.

This is the url:

http://www.diyaudio.com/forums/galle...62/Gimos50.jpg

I get webpage not found.

Tekko · 30th January 2011, 12:10 AM

I get "link is broken" It worked a few hours ago though.

moschfet · 30th January 2011, 12:22 AM

Ok, I uploaded it on other sever :

Hostarea Gimos50.jpg – Kostenloses Bilder Hosting

An I hope it work...

edit: it can't be true

moschfet · 31st January 2011, 02:08 PM

This is the layout of the first board(100x160mm). I work with kicad, it is open source and I like it.
The space is not filled with components, so I consider to shrink it.

aman khalsa · 31st January 2011, 02:12 PM

nice work bro...i like it.

thank u...

moschfet · 1st February 2011, 01:51 AM

The new layout has not gotten smaller, but better.

The key tracks are shorter.

There are fewer bridges.

The differential amplifier has now a thermal coupling.

To protect the acid I have closed the open areas as much as possible.

29th January 2011, 05:29 PM	#1
moschfet diyAudio Member Join Date: Jul 2008 Location: Hannover	Gimos50 - a robust guitaramp with IRF240/IRFP9240 Hello people, this is my first projekt, that I post here. I want to build a very robust guitaramp. In the past I have built some hifi amplifier, so I am not a bloody beginner The headline says it. I plan to use irfp240/9240 Mosfets for a 50watt Amp. And I like to give my projekts names, so I call it 'Gimos50'. There are some conditions for Gimos50: - it should be oversized to have some reserves - soft clipping - stable work With LT-Spice is this schematic caused. Gimos50 has a very low open-loop-gain. There are high lokal currentfeedback in the voltagegain. The negative-feedback-factor is very week. The result is a stable circuit, it don't need great frequency compensation. The z-diodes in the negative feedback are limit the output voltage. About 25V should be enough for 50watt at 8ohm. The overcurrent protection limit the output current to 2A per Mosfet. There should be enough reserves for continuous load. Last edited by moschfet; 29th January 2011 at 05:32 PM.

29th January 2011, 10:47 PM	#3
nigelwright7557 diyAudio Member Join Date: Apr 2008 Location: Carlisle, England	You schematic hasnt been uploaded. __________________ http://www.murtonpikesystems.co.uk PCBCAD40 pcb design software.

31st January 2011, 02:12 PM	#9
aman khalsa diyAudio Member Join Date: Oct 2010 Location: punjab	nice work bro...i like it. thank u... __________________ http://http://www.facebook.com/profile.php?id=100000413405389

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Radio to guitaramp conversion hum problem	Krille	Tubes / Valves	6	12th August 2010 06:54 PM
new ampli with IRF240	xcicc	Solid State	23	29th May 2009 05:49 AM
Robust Power Supply PCB suited to hi-quality amplifiers	RyanW	Solid State	58	17th April 2008 12:34 PM
Need helps with building guitaramp	hoangduongo	Instruments and Amps	1	22nd February 2008 08:23 PM
mosfet 450w irf240 / irfp9240 amp help	aletheian	Solid State	5	29th August 2005 03:20 AM


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

29th January 2011, 08:42 PM	#2
moschfet diyAudio Member Join Date: Jul 2008 Location: Hannover	i have made a FFT with LT-Spice. This pictures shows 1kHz, 1watt and 50watt: This simulation shows the cut-off-behavior:

29th January 2011, 11:59 PM	#4
moschfet diyAudio Member Join Date: Jul 2008 Location: Hannover	strange I can see it. This is the url: http://www.diyaudio.com/forums/galle...62/Gimos50.jpg

30th January 2011, 12:10 AM	#6
Tekko diyAudio Member Join Date: Jan 2005	I get "link is broken" It worked a few hours ago though.

30th January 2011, 12:22 AM	#7
moschfet diyAudio Member Join Date: Jul 2008 Location: Hannover	Ok, I uploaded it on other sever : Hostarea Gimos50.jpg – Kostenloses Bilder Hosting An I hope it work... edit: it can't be true

31st January 2011, 02:08 PM	#8
moschfet diyAudio Member Join Date: Jul 2008 Location: Hannover	This is the layout of the first board(100x160mm). I work with kicad, it is open source and I like it. The space is not filled with components, so I consider to shrink it.

1st February 2011, 01:51 AM	#10
moschfet diyAudio Member Join Date: Jul 2008 Location: Hannover	The new layout has not gotten smaller, but better. The key tracks are shorter. There are fewer bridges. The differential amplifier has now a thermal coupling. To protect the acid I have closed the open areas as much as possible.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read