Single stage amplifier - diyAudio
Go Back   Home > Forums > Amplifiers > Pass Labs

Pass Labs This forum is dedicated to Pass Labs discussion.

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 11th April 2006, 11:44 AM   #1
Skorpio is offline Skorpio  Denmark
diyAudio Member
 
Join Date: Mar 2004
Location: Denmark
Default Single stage amplifier

I am building a amplifier:

Unity gain 15W class A symetrical triple emitter follower output stage.

For voltage gain my first thoughts were a tube circuit, but now I have thought at the possiblity for at mos-fet og j-fet driver/gain stage.

This would be something like a zen with output buffer and according to Nelson Pass' definitions a single stage amplifier

Is a bride of zen able of a +/-15-20V voltage sving without too much distorsion? Or should I look for at scaled down zen? Perhaps the new zen-9?

EDIT: There will be ac-coupling between driver and buffer stage and no NFB!
  Reply With Quote
Old 11th April 2006, 07:06 PM   #2
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
It is arguable that a triple darlington is three stages, each
amplifying the current and driving the next stage. If the
technical community wants to call a darlington a single-stage,
then I have lots more single-stage amplifiers than I thought.

  Reply With Quote
Old 11th April 2006, 07:54 PM   #3
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
But just think, you could have a half-stage amplifier.
__________________
The buck stops Here
  Reply With Quote
Old 11th April 2006, 10:14 PM   #4
mos57 is offline mos57  Italy
diyAudio Member
 
mos57's Avatar
 
Join Date: Apr 2006
Location: Catanzaro - Italy
From Some years i have realized a single stage power amplifier that can deliver 50 watt/8 ohm or more. This stage have voltage gain so allows to drive it with with a cd player also (however low impedance is necessary). It acceipt balanced and unbalanced inputs and can switch from single ended to push-pull operation.
Also it permit class A or A/B operation of course. No capacitors in signal wire, no FB. I have tried to buy SIT transistors (especially the Tokin TKS45F323/322/320, TKS15R52, TKS17R52, 2SK180 for the best performance, but as we know it is very difficult. Now, thanks this forum i am in listing to buy the Lovoltech JFet and then to try with its. (my scheme is patent pending). I search a collaboration to engineering this product also for commercial use.
There is one?

Francesco
  Reply With Quote
Old 11th April 2006, 11:35 PM   #5
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
I think you could make a middle-class income from such a thing.

  Reply With Quote
Old 13th April 2006, 12:36 PM   #6
mos57 is offline mos57  Italy
diyAudio Member
 
mos57's Avatar
 
Join Date: Apr 2006
Location: Catanzaro - Italy
Default single stage amplifier

Hi Mr. Pass.
At this time i have built 3 different power version of this amplifier:
8 W, 30 W, 50 W.
I have compared it with tubes amplifiers as:
leak TL 10 Point one (upgraded version)
Audio Tekne IT 2
DY-2 stages S-E amp (first stage 6463, output AD1 plus input (30k:50k) and interstage (30k:30k) transformes. Out tranny (all are made by Bartolucci) is 5k:16. First stage bias grid is obtained from battery. HV power from CLC filter and tube rectifier (Telefunken 1064 mesh). All filaments are in DC. Next days i will replace the 6463 with 6H30.
I also have compared my amp with solid states as:
Audio labor 8000
Classe Audio DR3 VHC (50 W class A)
Accuphase A50 V (50 W class A)
Spectral (i dont remember the model, perhaps DM 100)
Phatos Twin Tower
others.

I will canned evaluate the weak point of my amp and then improved it.

Now my last version sounds refined as near as the AD1 amp, tell me the friends, but it have other advantages such more dinamic, better bass etc

Do you think that i must insist on this project and offer a commercial version of this amp?
Can i make? (i dont have many money to spent)
Tell me an advice.

Best regards from Francesco.
  Reply With Quote
Old 13th April 2006, 06:20 PM   #7
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
I can't advise you as to whether this is what you want to do
with your life.
  Reply With Quote
Old 13th April 2006, 06:39 PM   #8
PMA is offline PMA  Europe
Design engineer, consultant
diyAudio Member
 
PMA's Avatar
 
Join Date: Apr 2002
Location: Prague
Quote:
Originally posted by Nelson Pass
If the
technical community wants to call a darlington a single-stage,
then I have lots more single-stage amplifiers than I thought.

Does it make any difference how it is called?
  Reply With Quote
Old 13th April 2006, 06:49 PM   #9
Bricolo is offline Bricolo  France
diyAudio Member
 
Bricolo's Avatar
 
Join Date: Nov 2002
Location: Grenoble, FR
Quote:
Originally posted by Nelson Pass
It is arguable that a triple darlington is three stages, each
amplifying the current and driving the next stage. If the
technical community wants to call a darlington a single-stage,
then I have lots more single-stage amplifiers than I thought.


some people don't even consider that a follower is an amplifying stage (voltage or current follower, so a cascode (folded or not) would be a 1 stage)

so, this amp would be a zero-stage amplifier
__________________
Just remember: in theory there's no difference between theory and practice. But in practice it usually is quite a bit difference... Bob Pease
  Reply With Quote
Old 13th April 2006, 09:47 PM   #10
mos57 is offline mos57  Italy
diyAudio Member
 
mos57's Avatar
 
Join Date: Apr 2006
Location: Catanzaro - Italy
some people don't even consider that a follower is an amplifying stage (voltage or current follower, so a cascode (folded or not) would be a 1 stage)


Many people consider the cascode a single stage (so the SRPP and the MU-follower) because the devices are in series and the current is the same.
However a triple followers must be consider as 3 stages.

Francesco.
  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
RMI-FC100, a single stage audio power amplifier roender Solid State 1277 30th October 2014 07:54 PM
single stage common-drain amplifier Music_Sg Solid State 4 4th July 2006 06:45 PM
Anyone play with the Zen Single-Stage Single-Ended Class A? Rino odorico Pass Labs 13 29th August 2002 10:01 AM


New To Site? Need Help?

All times are GMT. The time now is 03:36 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