Another simple amplifier, this one from North of Europe - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

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
Reply
 
Thread Tools Search this Thread
Old 21st February 2006, 03:20 PM   #1
diyAudio Member
 
destroyer X's Avatar
 
Join Date: Feb 2004
Location: Recife - Brasil Northeast
Default Another simple amplifier, this one from North of Europe

The language i have read, seems that it should be somewhere near Norway.

One word....Jackaard...gave me this idea.

This circuit is interesting to Diy...it may work with 47 volts simetrical.

And will be not difficult to reach 180 Watts at 4 ohms...maybe more than a hundred watts over 8 ohms.

It is simple, beautifully bootstrapped (i like those circuits, Yamaha and Kenwood use them often now a days), do not use hard to find or expensive parts, and it seems that will produce a nice sound.

No!..i did not construct it....but i am thinking about, but first will be the Molerkamp.

Please, post your modifications suggestions, tell us if you already heard this one. how it sounds and those things.

This is all fun!

regards,

Carlos
Attached Images
File Type: jpg interesting.jpg (74.1 KB, 1199 views)
__________________
Convertion of 8 speaker output wire into standard 2 wires; https://www.youtube.com/watch?v=toZjKw3uUMo; Unbeatable!; https://www.youtube.com/watch?v=u4tGBiqMnzQ
  Reply With Quote
Old 21st February 2006, 03:32 PM   #2
lineup is offline lineup  Sweden
diyAudio Member
 
lineup's Avatar
 
Join Date: Dec 2005
Location: the north
Quote:
Tell us if you already heard this one.
not easy to tell anything

we dont know name of amp
we dont know who designed
we dont know any websource

we only know a schematic with some missing data
might be your own drawing, circuit even ....


Carlos
If you want some input
you have to give me a little more to refer to
At least if you want my opinion


regards
lineup
__________________
lineup
  Reply With Quote
Old 21st February 2006, 03:59 PM   #3
diyAudio Member
 
destroyer X's Avatar
 
Join Date: Feb 2004
Location: Recife - Brasil Northeast
Default Oh my dear Line up...i am in the same position as you are, knowing nothing about.

I was in the WEB surffing and trying to have different PC power supply schematics when some new power amplifiers schematics appeared....because i have typed POWER supplyes....and they appear, as they are power.

I know the same as you know...just offering to people that want to try, or know something to make comments, or tell us what they feel observing the schematic.

Those things.

I cannot tell you anything my dear...i am sorry for that.

regards,

Carlos
__________________
Convertion of 8 speaker output wire into standard 2 wires; https://www.youtube.com/watch?v=toZjKw3uUMo; Unbeatable!; https://www.youtube.com/watch?v=u4tGBiqMnzQ
  Reply With Quote
Old 23rd February 2006, 08:51 AM   #4
diyAudio Member
 
Join Date: Jun 2004
Location: HKSAR
I've seen the schematic in several places and that is one of them :

http://www.pablin.com.ar/electron/ci...p260/index.htm

I had always been wondering why it nees no idling currrent adjustment? I think it's related to this also :


http://www.brunt.de/KE/Elektronik/28...erstaerker.htm

Is it really good for the power it claims to provide?
  Reply With Quote
Old 23rd February 2006, 08:53 AM   #5
diyAudio Member
 
destroyer X's Avatar
 
Join Date: Feb 2004
Location: Recife - Brasil Northeast
Default Very good...every information about it is welcome.

The 82 ohms resistor can be substituted by a trimpot (100 ohms) to adjust the bias.

They made this way as will work with 99 percent of the parts used...those three diodes will produce 1.8 volts....0.6 volts each one, and the resistor will increase into 3.6 volts, that will be interesting.


I think that will be more intersting to use 5 diodes and the trimpot, as will be needed 1.8 volts positive and 1.8 volts negative related the output line...biasing all those transistors adequately.


The sittuation in the schematic may underbiased that output units.

Also i think that those darlingtons need 220 picofarads (minimum) from colector to base to avoid oscilations.


Carlos
__________________
Convertion of 8 speaker output wire into standard 2 wires; https://www.youtube.com/watch?v=toZjKw3uUMo; Unbeatable!; https://www.youtube.com/watch?v=u4tGBiqMnzQ
  Reply With Quote
Old 23rd February 2006, 09:39 AM   #6
diyAudio Member
 
Join Date: Aug 2003
Location: Prague,Czech Republic
Carlos, you have rare talent, still find again and again " stone age " connections... Whatabout sometimes to visit patent office and look there, how is modern amp... I recomment to you, that you will be very surprized...
  Reply With Quote
Old 23rd February 2006, 10:03 AM   #7
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Hi Carlos,
you manage to post yet more rubbish.

Who ever heard of Re=47r, then the 100pF Miller comp capacitor
and the negative rail with the 100r voltage dropper with 47nF. What are we to think?
__________________
regards Andrew T.
  Reply With Quote
Old 23rd February 2006, 11:36 AM   #8
Eva is offline Eva  Spain
diyAudio Member
 
Eva's Avatar
 
Join Date: Oct 2003
Location: Near the sea
Send a message via MSN to Eva
Hey, this is actually a VAS bootstrapped in both ends. It improves transistor linearity altough not as much as cascoding, while still providing rail to rail output. However, while the VAS strongly benefits from that, the linearity of the input LTP is reduced unless it's cascoded.

Involved components are 270ohm 1W resistor, 47uF 40V capacitor, 100 ohm resistor, and 47nF capacitor. The latter is required to prevent oscillation due to positive miller feedback at RF, and I know because I have tried it and I ran into the same pitfalls.

Output resistors are .47 ohm but the "." appears to be lost due to low-quality image conversion.
  Reply With Quote
Old 23rd February 2006, 11:45 AM   #9
diyAudio Member
 
Ultima Thule's Avatar
 
Join Date: Jan 2004
Location: Koskenkorva Land
Carlos,

only you have shown up those schematics here on diya with light-blue background, isn't it so that you are trying to construct an amplifier and just want fool to us with the originator because you want others opinion without make a fool of your self?
Or else where did you find it, please give us the adress to the greate source of yours!

The circuit have one bootstrapp for driver and output stage, the other botsrapp on the low side is counteracting both LTP and VAS BD139, is this good???

And those miller cap on both side to rail is not good for PSRR!
If they are added to prevent oscillation it would be better to add base stoppers to output transistors first.

Cheers Michael
__________________
"If transistors are blueberries and FETs are strawberries, then tubes must be.. pears"
Michael 29th January 2010
  Reply With Quote
Old 23rd February 2006, 12:37 PM   #10
teemuk is offline teemuk  Finland
diyAudio Member
 
Join Date: Nov 2004
Location: Suomi, Finland
Quote:
Originally posted by Upupa Epops
Carlos, you have rare talent, still find again and again " stone age " connections... Whatabout sometimes to visit patent office and look there, how is modern amp... I recomment to you, that you will be very surprized...
I think a little bit of "back to the stone age - attitude" is always quite healthy. For example, modern circuits do perform better but they tend to be very complex. Complexity causes issues that might actually start to degrade performance. Constant current sources and other "modern" stuff are nice but the increased performance that they bring isn't really THAT huge. In my opinion, the circuit that Carlos posted is after a bit of tweaking a very good performer in some applications where too much modernism just isn't worth it.

Finally, here's some food for thought: I ran a ltspice simulation of bootstrapped quasi complementary stage and a ccs symmetric complementary stage. Sort of a "stone age" vs. "modern" test, though not 100% reliable... Attached is the FFT graph of both amps when they clip mildly. Green graph is the bootstrapped circuit.

Teemu K
Attached Images
File Type: gif quasi-vs-modern.gif (15.7 KB, 529 views)
  Reply With Quote

Reply


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
Best source for amplifier enclosures in Europe/Asia? Danish Parts 2 30th January 2009 05:16 PM
FS on eBay: NuForce IA 7 V2 Integrated Amplifier (Europe) cartman Swap Meet 1 11th February 2008 10:11 AM
Europe and North America serengetiplains Everything Else 17 16th August 2004 12:08 AM


New To Site? Need Help?

All times are GMT. The time now is 01:20 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2