Searching for an Amp Projekt for +-50V - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Solid State Talk all about solid state amplification.

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
Thread Tools Search this Thread
Old 7th November 2005, 06:24 AM   #1
diyAudio Member
Join Date: Nov 2005
Question Searching for an Amp Projekt for +-50V


I had days searching on the forum-search, I have found a lot but nothing completely satisfying.

I am searching for a simple poweramplifierprojekt that is stable at a voltage of +-48V. Singlesided Pcb-layouts should be availeble.

Power is is limeted with the supply voltage, somthing about 100W into 8ohm should be Ok, more or less is no problem.

So, if someone has designed a small amplifier like this for himself and wants to share it, please feel free to do it!

Thank you very much for your answers ! Though this might be a question which has been discussed many times.

  Reply With Quote
Old 14th December 2005, 03:08 PM   #2
diyAudio Member
Join Date: Nov 2005
Default please help, still searching a amplifier projekt working with +-48V DC


I'm still searching, aftel all I noticed that the red Circuits-desing needs a preamplifier I decided to search again.

Please give me some advice wich projekts, apart from the leach amp are suitable, any power rating, either with or without PCB.

Thanks a lot!

  Reply With Quote
Old 14th December 2005, 03:22 PM   #3
MikeB is offline MikeB  Germany
diyAudio Member
MikeB's Avatar
Join Date: Apr 2004
Location: GŁtersloh
I could only help you with a design suitable with +/- 36v...

  Reply With Quote
Old 14th December 2005, 04:02 PM   #4
lineup is offline lineup  Sweden
diyAudio Member
lineup's Avatar
Join Date: Dec 2005
Location: the north
I wouldnt start with letting power supply decide what amplifier to build.

Here is a nice project,
well documented with schematics, PCB and building description.
I think very few of us would be disappointed with this DIY amplifier project.
When designing this amplifier I put up the following requirements:

Req1: The amplifier must be cheap

Req2: The amplifier must be reliable

Req3: The amplifier must sound fairly good

Req4: The amplifier must be easy to build
Try something simple for a change

  Reply With Quote
Old 14th December 2005, 05:09 PM   #5
jaycee is offline jaycee  United Kingdom
diyAudio Member
Join Date: Apr 2004
Location: Norwich, UK
My 200W/4 class AB MOSFET amp.

If MOSFET is not what you want, it should be quite easy to turn his amp into a BJT output.

Another one:

My first solid state amp

I would probably build that but with MJL4281/4302 output transistors.

You could also use Marcus's M250 amp on 48V rails, you would just get a little less power. Same for amps rated for 55v rails or so, even the Leach should work at 48V.
  Reply With Quote
Old 15th December 2005, 01:33 AM   #6
Account Disabled
Join Date: Aug 2004
Location: Earth
Hi Black Chicken,

If you're putting in the effort to build a power supply, provide heatsinks, and house the lot, why not build something a good measure above the average -

Simple Killer Amp!

Or check out my website -

This has been hailed as the first really new design in decades! It's fully complementary to minimise high order distortions and will get you more power and sheer performance from your given power supply. That's why it's Patent Pending.

  Reply With Quote
Old 15th December 2005, 02:27 PM   #7
diyAudio Member
Join Date: Nov 2005
Default thank you!


This is not my first power amplifier or electronik work at all.

I built a poweramp about two years ago, it worked really well at +-30V, than I started building a enclosure and a Powersupply for the amp that was constructed for +-50V, so I went for +-48V with big caps and good parts. But then The amp started to get instable at 48V one Worked, one not.....I never got this one to work at +-48V.

So now I'm searching a Amp-design to finish the amp and to use the expensive Parts left over by the old design (enclosure, transformer)

The 25W amp looks really good, I do like these designs a lot, thank you very much for the link, maybe I'll build it in the future, just for fun.


Yeah the symasym is a great design too, but I do need something to cope with 50V, though I dont really need the Power giver through the voltage.


Jaycee: nice shematics, wich one Is more reliable in the buil, has one of them been build already succesfully?

Wich of these do you prefer?

I'd like to try the Mosfet-Build with 1 Pair of IRFP240/9240, because I dont need the RMS power all the time (home listenig, not PA use)
Do I need to Change something? Is the amp able to drive these fets?

thank you very much.


Guru: also great designs, but living in Germany I am searching for a free projekt, thank you very much for your advice.

any other suggestions are welcome!

  Reply With Quote
Old 16th December 2005, 12:35 AM   #8
quasi is offline quasi  Australia
diyAudio Member
quasi's Avatar
Join Date: Sep 2004
Location: Adelaide, Australia
If your looking for free then check this thread. You should read all of the thread, especially the last half as this will provide some understanding of the circuitry. Some have been built by members here already (including my self). General feedback so far has been very good.

  Reply With Quote
Old 17th December 2005, 02:50 PM   #9
diyAudio Member
Join Date: Nov 2005
Default hello Quasi

Yes I did already read your thread, but I wasnt sure If the amp woul work at this low Voltage?! Is it still reliable at the lower supplyvoltage?

Another design I found on the Web, is on the attachment, what about it, are there any drawbacks, apart from not having a short circuit Protection?

Thank you very much!
Attached Files
File Type: pdf schematicv2.pdf (21.8 KB, 125 views)
  Reply With Quote
Old 18th December 2005, 05:32 AM   #10
quasi is offline quasi  Australia
diyAudio Member
quasi's Avatar
Join Date: Sep 2004
Location: Adelaide, Australia
I cant see how this design can deliver 100 watts into 8 ohms with the voltage rails it specifies. Even if it could by using higher rails the output transistors specified would blow.

If you use my circuit with 50 volt rails you should;
- change R6 to 12K (this leaves enough voltage for T4)
- change R17 to 27K (less gain)
- change T1 & T2 to BC546 (these are more common and cheaper)
- use one less FET per rail.

You will have an amp module that delivers about 110 watts into 8 ohms and around 190 watts into 4 ohms depending on the quality of your power supply.

There is no short circuit protection offered by my design either (not yet anyway).

  Reply With Quote


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
TL projekt idea Vigo Multi-Way 42 24th September 2013 07:38 PM
searching a ESX Q 275.2 or 175.2 pit bull Car Audio 1 7th December 2008 08:46 PM
Searching... Cortez Forum Problems 1 27th April 2006 12:23 AM
Added new projekt in wiki hanskrj Multi-Way 1 23rd January 2004 06:27 AM
Searching for this guy Guss The Lounge 1 3rd August 2003 11:04 PM

New To Site? Need Help?

All times are GMT. The time now is 04:14 AM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2