My MOSFET amplifier designed for music. - Page 11 - 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 15th June 2008, 02:55 PM   #101
diyAudio Member
 
Join Date: Mar 2008
Hi mooly,

Sorry for giving you troubles. Just now I checked my file and I found your circuit design as I had printed when I first saw. It was clear printed so don’t need to send me again.

Tomorrow I will buy some parts like resistors, diod and caps.

Let you know update.

Bets regards
mchael
  Reply With Quote
Old 15th June 2008, 02:59 PM   #102
diyAudio Member
 
jacco vermeulen's Avatar
 
Join Date: Oct 2004
Location: At the sea front, Rotterdam or Curaçao
Send a message via Yahoo to jacco vermeulen
Quote:
Originally posted by Mooly
The only advantage of Class A is in eliminating crossover distortion.
Dongggg, wrong again.
__________________
The buck stops Here
  Reply With Quote
Old 15th June 2008, 04:07 PM   #103
Banned
 
Join Date: Apr 2005
Location: Stockholm
Peranders and Jacco,
where do we stand? OK, cannot give relevant figures, but even if I`m wrong, it does not change anything anyway, as it is just not enough.
Technically, Vgsth must be low, Crss must be small, L must be short, short channels are hard to control, you need the tight lateral structure. The Hitachi designs are over 30 years old, in the first place Gm could be higher, practically still the best sounding devices, there is a general agreement on that among audiophiles and I will definitely not discuss that matter.
  Reply With Quote
Old 15th June 2008, 10:07 PM   #104
KLe is offline KLe  Australia
Banned
 
Join Date: Jul 2005
Location: Brisbane
Lumba Ogir, Peranders and Jacco ... could you please keep personnel matters outside of this thread, as this is Mooly's thread.

Jacco we know that you have alot to offer, but
... "Dongggg, wrong again" ... means very little to perons such as myself
... "Dongggg, wrong again and the reason why Mooly was wrong would invite discussion" which would be especially fruitful to persons such as myself and I am sure others.

Lumba Ogir we know that you have alot to offer also, but
... discussion of Mooly's schematic, possible improvements to circuit and components, why certain components have been chosen, etc, would be extremely fruitful to persons such as myself and I am sure others.

Peranders, probably nothing more needs to be said ... hopefully

  Reply With Quote
Old 16th June 2008, 02:07 AM   #105
diyAudio Member
 
jacco vermeulen's Avatar
 
Join Date: Oct 2004
Location: At the sea front, Rotterdam or Curaçao
Send a message via Yahoo to jacco vermeulen
Hi KLe,

right you are, this is Mooly's thread and we should all respect that.
The only and meagre excuse i have to offer is how easy it is to be side-tracked in a thread after a few pages.

Class A has many advantages, thermal stability is one, but the topic has been discussed in many threads before and has no business in this one.
I have zero interest in Class AB MOSFET power amplifiers and should leave the stage floor to the one and only Mr Mooly.
After all, it's just a passionate hobby, for most.
__________________
The buck stops Here
  Reply With Quote
Old 16th June 2008, 05:11 AM   #106
diyAudio Member
 
Join Date: Mar 2008
hi mooly,

good morning. ok, now i will be starting to asemble the parts.

i have question on C5 and R8. C5 stated "10/25" is it ceramic or Elc cap? there is not polarity indication. what is the value? should be follow zner positive. 10uf can't be ceramic it should be elc cap.

another is R8 as you said earlier use small value first, why not use here one vrble 1k so i can adjust as i require right?

best regards,
michael
  Reply With Quote
Old 16th June 2008, 07:33 AM   #107
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
Morning all ,
Good to see you are all staying interested. And thank you to KLe for a little reality check.
And so in the words of Jacco, Mooly will now speak ( or should that be Mr Mooly to you )
KLe asks why certain components have been used-- why has the design ended up the way it has ?
I take my music very seriously indeed, so I will give a few bench marks I have owned or had chance to listen to fully.
1st amp I ever made--- a kit "Harversonic I think it was, a classic if thats the word Lin configuration with AD149 outputs. At the time it sounded very good, as good in many ways as a B&O system of my parents when used with the B&O speakers.

2nd amp was a design in Practical Wireless. The "Europa" by a Mr B.C Toms. A class AB amp single rail with a long tailed input pair with the the feedback one (the one on the right if you know what I mean-- or the inverting input should I say) was bizarrely made up of a darlington pair of BC109C. With an LM381AN preamp this was my first taste of "the transistor sound" we all dislike. The power amp was not so bad sonically, the preamp was dreadful.

3rd amp was a go at building a Radford ZD22 and HD250. This was in my college days and a lecturer had the full manual and allowed me a copy under strict orders it was shown to no-one, highly classified and all that. The preamp was wonderful musically, classic textbook design but all highly optimised. The power amp I never did get to work properly, it was always prone to stability issues-- of course years later I realise that was as much to do with my inexperience in layout etc as a problem with the design. At about this time another college pal built from a kit another Practical Wireless design, the Linton ? was it. My first introduction to lateral FET's. With some correctly built speakers using the KEF B139 this was the best I had heard.

A neighbour had a Quad set up, 405 amp and matching preamp, Gale 401's and Michell Gyrodec I think. I never really rated this, but I could never put my finger on just why.

I carried on building and experimenting-- JLH's 80 watter in Wireless World" was then my best build to date. Very musical !
With the coming of CD I felt I wanted the best possible amp and so went down the commercial route and bought a Pioneer A80. If specifications mean anything then this amp was supreme. It sounded good -- very good in the best sense of the word Hi-Fi but it to lacked a bit of "musicality". Today we would call it revealing, even if you ended up not playing 90 % of your music collection. A Marantz followed, and this was more musical.
There had to be more than this, and the friend with the Quad setup changed to an all Sugden rig, the A21 and CD 21 with ProAc floorstanders. I went along during the "shopping expeditions" and got to hear a lot of top end kit.
I now had a "reference" point, the Sugden Class A was clear and incisive, but musical, and certainly not warm sounding-- I liked it.
At this time I had just finished building Doug Selfs blameless Class B amp on the official PCB's . It was good and I kept this for about 6 years or so but still felt it lacked that musicallity-- that wow factor that compells you to listen and explore the music.

So from all this emerged my present design, I had noticed the JLH designs always made music, but I was uneasy with Class A. The thought of a "storage heater" in the corner did not appeal at all. If I could get the sonics from Class AB then that was really what it was all about. The single ended input stage always sounded better to me than a long tailed pair, maybe because it helps avoid the ever present problem of common mode rejection of the differential pair. Even with OpAmps I use the shunt or inverting configuration for this reason.
Again the friend with the Sugden was getting restless and an "upgrade" was in the pipeline. Again it was to be Sugden, and I was very fortunate to be able to audition their products, including some not yet released directly at the factory and to talk to the designers. A truly wonderful place and the care that goes into each handmade item has to be seen to be believed.
The friend ended up with the latest A21 SE and CD 21SE and I ended up more than satisfied that I had more than the equal of anything I had heard to date.
So that is really how it all came about.
  Reply With Quote
Old 16th June 2008, 08:00 AM   #108
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
Hello Space,
C5 the 10 mfd cap over the 12 volt zener is electrolytic. The positive end goes to ground, the negative end to pin 4 of the I/C. The "strippy" end of the zener goes to ground. Make sure C1 and C3 are fitted as shown polarity wise.
  Reply With Quote
Old 16th June 2008, 08:06 AM   #109
alex mm is offline alex mm  Europe
diyAudio Member
 
alex mm's Avatar
 
Join Date: Mar 2006
Location: ROMANIA ,
Default C5 and R8 component

...Hi ,space

Regarding C5 value its 10 uF/25V elco with positiv terminal to ground . U can find value for R8 in post #41 , so U can go with 470 ohms from minimum , if I'm right . I will start to build this amplifier like another project soon . Regards alex mm .

B.T.W - My last revised PCB its OK?
Sorry for my poor english .
  Reply With Quote
Old 16th June 2008, 08:21 AM   #110
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
Hi Alex,
Knew I had forgotten something replying to Space. Yes R8 is a preset to begin with, initially set on minimum resistance so that the collector of Q3 and Q5 are linked to start with.
  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



New To Site? Need Help?

All times are GMT. The time now is 04:25 PM.


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